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Wouter
04-25-2013, 11:33 AM
As mentioned in my other thread :
http://www.mastercraft.com/teamtalk/showthread.php?t=53645

After changing the ATF fuid of my velvet drive 71c (model 10-17-004) (which had probably never been changed) the transmission started slipping severely. I decided, it was time for a rebuild, so here goes the write-up:

Tools/fluids/parts you’ll need:
- Dexron III ATF oil (preferably mineral)
- WD40 / engine cleaner
- Rebuild kit (includes forward and reverse clutch plates, seals and gaskets) http://bpi.ebasicpower.com/p/ALT23901
- Complete snap ring set or at least front bearing snap ring:
http://bpi.ebasicpower.com/p/ALT23255
- Possibly a new damper plate:
http://bpi.ebasicpower.com/p/ALTDA-106A/
(All these parts are also available elsewhere (i.e. skidim.) I have no affiliation with ebasic.
- An arbor press (mainly to compress the clutch pack)
- Snap ring pliers
- Rubber mallet (came in very handy)
- The usual assortment of torque wrench(es), socket (hex but also at least one 3/8" 12 points socket), etc.
- One big (38mm) 1-1/2” hex socket
- A feeler gauge 0.018" to 0.055" (to set clutch clearance)
- Shop or service manuals:
http://www.mastercraft.com/teamtalk/showthread.php?t=32581
different manual attached to this post. look below transmission tag.

Important things to remember:
This thread does not cover reduction ratios.
Stage the parts in order as you are pulling them out to remember how they go back in.
If you can, take pictures as you go in case you forget how/when a particular part came out.
Make sure to note position of pump housing (this is particular to your engine’s rotation direction.)
Read service manual and thread completely before starting

Wouter
04-25-2013, 11:46 AM
Bellow is a diagram of the velvet drive: I'll use the diagram part numbers for the rest of the thread:

Wouter
04-25-2013, 11:47 AM
remove transmission from boat and note position of pump housing.

Wouter
04-25-2013, 11:50 AM
remove pump housing 104

Wouter
04-25-2013, 11:55 AM
remove pump drive gear 101 (slides off)
remove woordruff key 65 from drive gear assembly 64

Wouter
04-25-2013, 12:00 PM
remove 99 (12 points (10mm) 3/8" socket necessary)

Wouter
04-25-2013, 12:02 PM
forward and reverse adapter (99) comes off
Note sealing ring 96 is sitting on adapter 99

Wouter
04-25-2013, 12:08 PM
remove reverse clutch pressure plate (92) (it's sitting on the adapter in picture), outer clutch plate (91) and reverse clutch assembly (90)
stage in order

Wouter
04-25-2013, 12:13 PM
You can pull the drive gear assembly at this point (just pull out by hand)

Wouter
04-25-2013, 12:18 PM
Remove snap ring 87 (this one is very thight and often gets warped with removal, that's why you might want to order it with the rest of the parts)
and snap ring 88 (use snap ring pliers)

Wouter
04-25-2013, 12:48 PM
read bellow

Wouter
04-25-2013, 12:53 PM
At this point you should be able to slide the drive gear out of the ring gear (I used the black mallet to help it out) (you'll be replacing the insides anyway)

Wouter
04-25-2013, 12:57 PM
Set drive gear aside and let's take look at the ring gear.
Remove snap ring 89
remove bearing 86 (I put in a WD40 bath)

Wouter
04-25-2013, 01:00 PM
the forward clutch cylinder 84 should come out now. You can separate it from the clutch spring 79 (note the direction of the spring 79: lower side of the dish is closest to shaft)

Wouter
04-25-2013, 01:04 PM
You can inspect the clutch plates inside the ring gear now. In my case the insides of the tranny were full of debris.

Wouter
04-25-2013, 01:11 PM
You can now remove snap ring 78, clutch pressure plate 77 and the clutch plates (stage to remember order when new ones go in)

Wouter
04-25-2013, 01:19 PM
Remove the rest of the clutch plates (stage in order)
When you have removed pressure plate 71, check if you have a snap ring that separated it from the ring gear (69) (b/w pressure plate and ring gear.) This snap ring normally sets the clearance of the clutch pack. Some models transmissions have this snap ring, some do not according to the experts on this forum. Mine does not.
When you receive your parts you can give the clutch plates a 24h bath in atf fluid.

Wouter
04-25-2013, 01:30 PM
I started with the front of the transmission but you can also start with the propeller side. My transmission case was extremely dirty and filled with debris, particularly between the case and the oil baffle 74, making it clear that everything should come off and get cleaned.
Next I removed the valve spring assembly. Once you have removed the valve cover and gasket, be very careful when you remove snap ring 35. This holds valve spring 37 in place under a bit of pressure. If not careful, 36 will go flying in the air.

Wouter
04-25-2013, 01:39 PM
Next: For main shaft nut (1) you'll need a 1-1/2" (38mm) socket.

Wouter
04-25-2013, 01:40 PM
Pull bearing 5.

Wouter
04-25-2013, 01:45 PM
more to come

Kyle
04-25-2013, 02:05 PM
Nice TAG HEUER Link. I love mine.

BallBushing
04-25-2013, 04:11 PM
Just followed the whole string and you make it look relatively easy. I think the hard part is getting the tranny out of the boat (have a V drive) Lots of parts for a direct drive, some engineering went into that.

ttu
04-25-2013, 04:16 PM
Nice TAG HEUER Link. I love mine.

dang kyle, good eye! i like mine also.

thatsmrmastercraft
04-25-2013, 04:41 PM
more to come

Great thread! :toast:

catamount
04-25-2013, 05:02 PM
I may need this thread in the future, so I just wanted to say thank you!

CantRepeat
04-25-2013, 07:56 PM
Great thread! This site has needed this for a long long time. It will show people that rebuilding these velvets are within the grasp of the normal shade tree.

Once you post up the reassembly this should be cleaned up and added to the FAQ for sure. Once all the photos and such from the reassemble we can all add our 2˘ and links to tech manuals and what not.

Wouter
04-26-2013, 04:54 AM
Remove pinion cage 59.
Put the bearing in WD40 bath.
remove oil baffle 74.
remove old gasket.

Wouter
04-26-2013, 04:57 AM
Next: let's get the oil strainer assembly 55 out. Mine was extremely clogged. In fact I wonder how or if it was till working at all.

Wouter
04-26-2013, 05:05 AM
Your almost done with dis dis-assembly at this point. Your case should now be empty (except for forward and reverse gear trans valve 39 which I removed later (you can remove it now as well if you prefer))and ready for inspection.
Inspect case for more debris. As you can see there was a lot of clutch gunk in mine.
All these parts will have to get cleaned thoroughly before reassembly.

Wouter
04-26-2013, 05:12 AM
Clean all parts.
I started with the oil baffle 74.
then the bearing retainer 4 (remove oil seal 3 (you should have a new identical one in your kit / check before removal))
Note: the ebasic kit contains more parts than you actually need for this particular transmission.

Wouter
04-26-2013, 05:19 AM
clean coupling 2.

Wouter
04-26-2013, 05:19 AM
clean ring gear 69.

Wouter
04-26-2013, 05:21 AM
clean forward clutch cylinder 84.

Wouter
04-26-2013, 05:23 AM
clean clutch pressure plate 71.

Wouter
04-26-2013, 05:24 AM
clean clutch spring 79.

Wouter
04-26-2013, 05:27 AM
clean snap ring 78 if you are reusing the old one (if you got a complete snap ring set you can discard the old one)

Wouter
04-26-2013, 05:29 AM
clean clutch pressure plate 77.

Wouter
04-26-2013, 05:35 AM
clean reverse clutch pressure plate 92. It's best to always keep your parts in the same order they came out but if things got mixed up at some point you have pictures or the manual to remember the right sequence.

Wouter
04-26-2013, 05:37 AM
clean forward and reverse adapter 99.

Wouter
04-26-2013, 05:42 AM
remove sealing ring 105 from pump housing 104 (you should have a new one in your kit (check before removal))

Wouter
04-26-2013, 05:46 AM
Dis-assembly and cleaning should now be complete. All the parts you are reusing should be clean. You can start reassembly now. I cleaned my table before starting. Here are my new clutch plates which have been sitting in ATF fluid for the last 24 hours. Again, there are more plates in the ebasic kit than what you will actually need for this particular rebuild. When in doubt: what came out goes back in.

Wouter
04-26-2013, 05:48 AM
Start with the ring gear 69.

Wouter
04-26-2013, 06:00 AM
Your transmission might have had a snap ring 70 for clutch pack clearance when dis-assembling. If you staged your parts this would normally be the first part that goes into the ring gear 69. However this snap ring does not go in now. We'll get back to this. My transmission did not have this snap ring. First part to go back into the ring gear is clutch pressure plate 71. It goes in with the flat side up (flat side towards ceiling, reverse of first picture.)

Wouter
04-26-2013, 06:08 AM
Next are your new clutch plates. First bronze than steel alternatively. Mine had:
bronze-steel-bronze-steel-bronze-steel-bronze-steel-bronze (for a total of 9 items.) This may or may not vary from transmission to transmission. I put back in what came out (after making sure the new plates had same thickness as old ones (measured with caliper))

Wouter
04-26-2013, 06:10 AM
Next comes clutch pressure plate 77 (flat face towards last bronze clutch plate)

Wouter
04-26-2013, 06:12 AM
Next is snap ring 78

Wouter
04-26-2013, 06:16 AM
next comes clutch spring 79 and forward clutch cylinder 84. the clutch spring is dished. the lower side of the dished spring should be closest to the shaft.

Wouter
04-26-2013, 06:21 AM
Place spring and forward clutch cylinder in ring gear and place snap ring 89. You will need a press at this point. Pressing down on the forward clutch cylinder will allow to place snap ring 89 in its groove. I don't have a good press, but fortunately the Opel mechanic across the street let me use his.

Wouter
04-26-2013, 06:34 AM
place bearing 86 in place (coat it with silicone grease) with a press or mallet if you don't have a press. Make sure it is nice and horizontal.

Wouter
04-26-2013, 06:35 AM
If during dis-assembly, you had a snap ring 70 (I did not), it is now time to replace it. Turn you clutch pack around and use a press to compress the clutch pack in the opposite direction as before. This should create clearance between ring gear 69 and clutch pressure plate 71. The snap ring 70 goes between these two elements. The snap ring 70 comes in different thicknesses: http://bpi.ebasicpower.com/p/ALT23258/ , http://bpi.ebasicpower.com/p/ALT23258-130/
For a 71c with bronze clutch plates, the clearance should be 0.018" to 0.053" Verify with feeler gauge.
Again, my transmission did not have this snap ring and I didn't replace it.
I inserted the drive gear at this point. You'll need to align the clutch plates to get the drive gear through.

Wouter
04-26-2013, 06:39 AM
place snap ring 87 in groove around drive gear to lock the bearing. This is the snap ring that might have gotten warped during dis-assembly. If your ordered it, replace with the new one. (I hadn't but the snap ring was still ok)

Wouter
04-26-2013, 06:41 AM
place snap ring 88 in place. forgot to take a picture.

Wouter
04-26-2013, 06:42 AM
Your clutch pack and drive gear are now ready. You can now return the oil baffle 74 to its original location in the case.

Wouter
04-26-2013, 06:47 AM
Next I replaced the oil seal 3 and placed it in bearing retainer 4.

Wouter
04-26-2013, 06:52 AM
place bearing 5 in case. the groove in the bearing goes towards the coupling (propeller) side. Your kit should contain an O-ring that goes into this groove. (I don't remember the old one on dis-assembly)

Wouter
04-26-2013, 06:52 AM
place gasket 6 in place.

Wouter
04-26-2013, 06:56 AM
Place bearing retainer 4. Use a torque wrench to place bolts. 27-32 lbs-ft I used ARP on bolts.

Wouter
04-26-2013, 06:59 AM
Pinion cage 59 goes back in. I used the mallet to seat it correctly.(further in than what is shown in picture)

Wouter
04-26-2013, 07:03 AM
Don't forget thrust washer 62 when putting in the clutch pack and drive gear.

Wouter
04-26-2013, 07:09 AM
Place pressure plate springs and greased dowel pins.

Wouter
04-26-2013, 07:14 AM
Place your new reverse clutch plate assembly 90 and 91. Bronze goes in first, then steel, then bronze again (no picture of last plate).

Wouter
04-26-2013, 07:20 AM
Next comes reverse clutch plate 92. Align plate half moons with dowel pins so that springs correspond with clutch plate holes. The plate should drop and sit almost flush with case.

Wouter
04-26-2013, 07:29 AM
Place gasket 97.
Place sealing ring 96 (I had forgotten this, that's why you still see it next to the blue screwdriver at bottom right of next pictures but you should place it now)

Wouter
04-26-2013, 07:32 AM
place forward and reverse adapter 99. Bolt with torque wrench 27-37 lbs-ft. Again 96 should be in by now.

Wouter
04-26-2013, 07:33 AM
Place woodruff key 65.

Wouter
04-26-2013, 07:35 AM
Place pump drive gear 101

Wouter
04-26-2013, 07:37 AM
place pump gasket 103

Wouter
04-26-2013, 07:41 AM
At this point I realized I forgot to place sealing ring 96 (sitting under the blue screwdriver) So I worked backwards, removed 99 and placed it.

Wouter
04-26-2013, 07:50 AM
Place pump housing 104 and wrench to torque 17-22 lbs-ft. The pump housing has to be placed in the same position as when you dis-assembled (two positions are possible according to your engine's rotation) Make sure you get this right. If you don't remember check pictures if you took some or check manual and place according to your engine's rotation direction.

Wouter
04-26-2013, 07:54 AM
The position in the previous picture is not right for my engine. Finished product should look like this. Compare with first picture before dis-assembly. Make sure this is right.

Wouter
04-26-2013, 07:59 AM
Next comes the oil strainer assembly 55.
Replace in same order as when you dis-assembled.

Wouter
04-26-2013, 08:05 AM
Almost done now. I hadn't completely removed the valve assembly 39 during dis-assembly, so I did this now, cleaned it and returned it to its location in the case.

Wouter
04-26-2013, 08:13 AM
Next I returned spring 36 and its retaining cap. You'll have to press the spring to be able to place snap ring 35.

Wouter
04-26-2013, 08:18 AM
Now let's remove, clean and replace the forward and reverse shift lever. Be careful not to lose the steel ball that sits on popper spring 46. Check the lever moves smoothly from forward to neutral to reverse.

Wouter
04-26-2013, 08:22 AM
On the other side we still need to place the safety neutral switch.
Final bolt for me was the main shaft nut (1-1/2" hex socket)

Wouter
04-26-2013, 08:24 AM
A bit of paint on the parts that were scratched to avoid future corrosion and your done.

Wouter
04-26-2013, 08:26 AM
And here's the finished product.

Wouter
04-26-2013, 08:41 AM
Where I live, I only found one mechanic who could do the job (apparently this transmission is also used on some fishing boats) but he wanted to charge me 1200 € (1560 $) for it (which is price of new) so I decided to give it a go myself.

I had no experience with transmissions and (if it finally works out well when I put it back in my prostar) all together I would say this an average difficulty job. It does require a good press and some unusual (to me) tools like a 1-1/2" socket. The transmission itself is very heavy, making it a PITA to pull from the boat.

Hopefully, I didn't forget or skip anything and am sure the other users will correct me if I did anything wrong.

Hopefully this will be useful to the next person. Personally, I will think twice before changing atf fluid on a transmission that hasn't been serviced in a decade (although I must say I am happy I did it considering the amount of debris that was in there.)

On a last note: there was also a bunch of crap in the water line of the oil cooler so that's also nice to have removed.

Super special thanks to Kyle and Cantrepeat for their knowledgeable insight.

Wouter
04-26-2013, 08:50 AM
And the pressure test figures compliments of Cantrepeat.

Wouter
04-26-2013, 09:05 AM
Next step will be to repair small leaks in muffler with fiberglass and puting muffler and tranny back in the boat. I don't think I will replace the damper plate in the end: it looked good as is on first inspection.

bstewart0529
04-26-2013, 09:38 AM
I can not say thank you enough. this will be helpful in the future for me i am sure. thanks for taking the time this was fantastic.

Wouter
04-26-2013, 09:41 AM
With pleasure! This forum has saved me from expensive mechanic bills so many times for things that are, in the end, reasonably easy to do yourself provided you have the right advice...

Wouter
04-26-2013, 10:54 AM
Nice TAG HEUER Link. I love mine.

did you say Bourne?

bsloop
04-26-2013, 11:07 AM
I think that is the most pictures I have ever seen on a write up!
Thanks

46Chief
04-26-2013, 11:50 AM
What was the tool that you had on the propshaft coupler? Presumably to keep it from spinning. The coupler Didn't require any special tools for removal. It looks like my hurth zf45 needs some sort of spanner wrench.

I priced a rebuild and it does seem high for a one day job.

Thanks for the writeup.

Wouter
04-26-2013, 12:02 PM
What was the tool that you had on the propshaft coupler? Presumably to keep it from spinning. The coupler Didn't require any special tools for removal. It looks like my hurth zf45 needs some sort of spanner wrench.

I priced a rebuild and it does seem high for a one day job.

Thanks for the writeup.

It's an oil filter remover, I used to, like you said, keep the shaft from spinning. I had the mechanic from across the street remove and at the end tighten the coupler nut because I don't have a 1-1/2" hex socket + it was presumably a lot easyer with his pneumatic wrench.

Kyle
04-26-2013, 12:15 PM
Great write up and thanks for all of the pictures.


Excellent work. Now all you need to do is put her back in and ski.


Oh and maybe take some install pics of transmission removal. I am sure there are other threads where they are removed but the way you take pics and document, makes it extremely easy for the non mechanic to understand. If you can show how you got the engine to stay level and not flop backwards or how you got the transmission lined back up.


Thank you thank you thank you. I'm sure this thread will be edited and cleaned up from a mod and saved in the FAQ. This will very much help others in the future. It is always nice to help someone.

Wouter
04-26-2013, 02:02 PM
Looks like it's raining this weekend: don't think i'll put the tranny back in if not sure about weather but will try to take pictures when I do.

Wouter
04-28-2013, 04:38 AM
Boat is back in the water and running great. Didn't take pictures of the re- install ( forgot camera at home) but it's very straight forward.

thatsmrmastercraft
04-28-2013, 09:49 AM
Boat is back in the water and running great. Didn't take pictures of the re- install ( forgot camera at home) but it's very straight forward.

Congrats on conquering a task that a lot of people wouldn't tackle, and thanks for the great write-up. :toast:

Kyle
04-28-2013, 01:08 PM
Now get out and ski.

How was the engagement of forward and reverse.

Wouter
04-28-2013, 03:47 PM
A little rough at first but then completely smooth after topping off the atf. Creep in neutral is gone. Thanks again... Ski time finally!

Cloaked
04-28-2013, 07:34 PM
damn


heck of a job in no time at all....

CantRepeat
04-28-2013, 08:56 PM
Great job on the write up and I'm glad it all work out for you!!

/cheers mate! :D

Scottman
05-01-2013, 02:36 AM
This is awesome! Great write up.

f925
05-04-2013, 03:38 PM
94478
Sorry to thread jack, but is this an acceptable ATF for the 71c? I am about to start this project myself. Thanks for the write up! Where in Belgium are you located? I spent several months working in Puurs and living in Antwerp.


Sent from my iPhone using Tapatalk

f925
05-04-2013, 04:05 PM
One more annoying question, is there an alternative to a shop press that I could rig at home? I have bottle jacks i am just trying to think of a way around buying a press for one use.


Sent from my iPhone using Tapatalk

Wouter
05-06-2013, 06:20 AM
Hi, I'm in brussels. Mineral is more recommended than synthtetic, but i think you shoul be ok with that ATF.

For Velvet Drive and Borg Warner 71C and 72C transmissions, use Dexron IIE ATF, Dexron III ATF, or any ATF fluid which meets Detroit Diesel Allison C-4 specifications

Maybe someone else will confirm? The press was a problem for me aswell: i didn't want to purchase one for one time usage... I think you should be ok to use a bottle jack if you have something that can be used as counterweight or to lock it in place with the ring gear. You'll only really need the press for the clutch pack compression.

etduc
05-20-2013, 01:46 PM
Place pressure plate springs and greased dowel pins.

How many pressure plate springs, did you have? Build sheet mentions 12, I have 11 in my trans.

f925
05-22-2013, 12:45 AM
I think I too had 11. 2 in the lower left and 3 in each of the other corners. Thank you so much for this thread, it got me through the entire build with no problems what so ever!


Sent from my iPhone using Tapatalk

mikeg205
05-22-2013, 12:50 AM
94478
Sorry to thread jack, but is this an acceptable ATF for the 71c? I am about to start this project myself. Thanks for the write up! Where in Belgium are you located? I spent several months working in Puurs and living in Antwerp.


Sent from my iPhone using Tapatalk

I use this ATF in my '95 -- I plan on switching to full synthetic on next change after a bit more research. Found some info on Synth being to slippery but it was anecdotal, but found synth to have better shear and high temp strength.. so if you overheat you may get some precious extra moments of protection - maybe just enough to shut her down...

No reason you can't switch IMO and from what I am ready on none manufacture sights as well as manufacture sites as long as you meet Dexron III requirements at a minimum...but I have not switched to full synth yet...

etduc
05-22-2013, 10:06 AM
I think I too had 11. 2 in the lower left and 3 in each of the other corners. Thank you so much for this thread, it got me through the entire build with no problems what so ever!


Sent from my iPhone using Tapatalk

Thanks, just making sure, I didn't loose one.

sam196370
05-23-2013, 05:03 PM
So I am in the process of rebuilding my 71c and getting some of these smaller snap rings off is a pita - I bought the "heavy duty" snap ring pliers and they aren't helping.....any tricks to get these things off? 87 is the trouble maker.

f925
05-23-2013, 11:08 PM
So I am in the process of rebuilding my 71c and getting some of these smaller snap rings off is a pita - I bought the "heavy duty" snap ring pliers and they aren't helping.....any tricks to get these things off? 87 is the trouble maker.

Yup, they suck. Swear at them and call them names that are so offensive a crude stand up comedian would shy away from. The woodruff key was my nemesis. I have the HD pliers and most every ring slipped of numerous times. For the rings that sit inside and press outward I found small screwdrivers to be better. The snap ring that goes around the main shaft was indeed a huge PITA.

To get 87 off: if you got pliers with multiple tips find the beefiest tips and put them on. You can run a file over the outside edges a few times to make a flat spot on the tips. The round shape of my plier tips made it more likely to pop off. Try starting by getting one side started. I found both ends would not move equally. So squeeze like crazy and try to tilt the ring so one end is sitting on the shaft out of its groove. Now get a shim under it so that end cannot drop back down. At this point it is just a matter of squeezing the pliers hard enough and working the ring around. A second set of hands may be the key here because it is not hard to make progress and loose it trying to work your way around to the other side. I hope this helps!

Sent from my iPhone using Tapatalk

Scot
05-24-2013, 12:20 AM
So I am in the process of rebuilding my 71c and getting some of these smaller snap rings off is a pita - I bought the "heavy duty" snap ring pliers and they aren't helping.....any tricks to get these things off? 87 is the trouble maker.

Did you buy "snap ring" pliers or "lock ring" pliers? I tried working with these things with the former and they didnt do a darn thing. Picked up some "lock ring" pliers from pep boys and life was much better.

sam196370
05-24-2013, 11:44 AM
Got em off with a couple of screwdrivers - I need to remember how much it helps to take a break when stuck on something frustrating like this...

Surprised that the rebuild kit didn't come with the springs, soaking parts and waiting for springs to arrive. Painting outside in the meantime.

Thanks for all the help

cptskier15
06-05-2013, 06:11 AM
My saftey switch on velvet drive from S&S 1981 giving issues, its the 1:1.51 gear, which part can I use to replace. Will ski dim have it. Also I saw briefly you cleaned the oil filter, is that easy to do when it is still in the boat?

Well done on such a well documented rebuild!

TRBenj
06-05-2013, 10:51 AM
I use this ATF in my '95 -- I plan on switching to full synthetic on next change after a bit more research. Found some info on Synth being to slippery but it was anecdotal, but found synth to have better shear and high temp strength.. so if you overheat you may get some precious extra moments of protection - maybe just enough to shut her down...

No reason you can't switch IMO and from what I am ready on none manufacture sights as well as manufacture sites as long as you meet Dexron III requirements at a minimum...but I have not switched to full synth yet...
Give some of the manufacturers a call and see what they say. PCM will tell you not to use synthetic in their transmissions- too slippery. They tried it and started seeing premature failures (~800 hrs) similar to those seen in motorcycles and dirt bikes (which also use wet clutch set ups). Suggesting to others its ok to use synth because you havent done your research is a bit reckless.

Stick with conventional Dex/Merc or Dex III. Avoid high mileage formulations and synthetic and your tranny will live a long life. If youre overheating your engine badly enough to damage the transmission, youve got other major issues to worry about.

8sammy8
09-25-2013, 06:55 PM
Hello I'm reassembling my tranny and snap ring 78 isnt fitting int the grove. It pulls out very easly. Is this normal?

Wouter
09-27-2013, 05:44 AM
Hi Samy, it's been a while since I did the rebuild but I think snap ring 78 did sit tight in a grove when I rebuilt my transmission (page 5 of the rebuild thread.) In your case: you don't see the grove at all or does the snap ring not provide enough pressure? Did you replace the right number of clutch plates? If you put in more than came out (remember there might be more plates in your rebuild kit than necessary for your particular transmission) they might sit higher than the grove and therefore not allow to put in the snap ring? Am not really sure how critical 78 is since the clutch assembly is really held together by snap ring 89 after using the press. Personally; if the problem is just that snap ring 78 sits in the grove loosely, I would order a new one and replace it to be sure.

8sammy8
09-27-2013, 09:28 AM
Thanks for the reply. I did put the same number of clutch plates back in but even with nothing in there the ring doesn't fit. I had ordered a new one and same problem. I can see the grove, when i put the ring in it easily pushes right back out. When I took everything apart all that stuff just fell out, I was thinking that might have been the reason it was slipping.

Slackwater
10-10-2013, 09:31 AM
I have a 71c that is leaking transmission fluid out of where the no 48 shift lever goes into the transmission. I am assuming this is caused by a defective no 40 o-ring. Does this sound like a correct assumption? If so I'd just like to confirm that I can replace this o-ring without disassembling the rest of the transmission. Making such the spring doesn't go flying into the bilge. I.E. By just removing no. 33 valve cover plate, shift lever, etc. and pulling the no. 39 valve out. Then replacing the o-ring and reassemble. From your thread it appears I can do this in the boat as I have excellent access.

JMann
10-10-2013, 03:14 PM
This is a great thread that has me thinking about buying an old transmission to rebuild for the experience. I found one a couple hours away it's Borg Warner Velvet Drive. 1:1 ratio from a late 80's american skier. Does anyone know if this would fit into my 91 prostar 190?

strad
10-10-2013, 03:37 PM
Is your 91 a Powerslot? If it is, a 1:1 transmission will be shorter than the one in your boat. What does the trans tag say on your transmission?

JMann
10-10-2013, 04:05 PM
No, I have a 1:1 in there now, not a power slot. I'm checking that it came off a ford motor (probably did) if so I assume it will bolt right in if I ever need it. If I get it I will probably rebuild it and sell it or just sit on it until some needs it. Looking for a winter project.

TRBenj
10-11-2013, 01:24 PM
I have a 71c that is leaking transmission fluid out of where the no 48 shift lever goes into the transmission. I am assuming this is caused by a defective no 40 o-ring. Does this sound like a correct assumption? If so I'd just like to confirm that I can replace this o-ring without disassembling the rest of the transmission. Making such the spring doesn't go flying into the bilge. I.E. By just removing no. 33 valve cover plate, shift lever, etc. and pulling the no. 39 valve out. Then replacing the o-ring and reassemble. From your thread it appears I can do this in the boat as I have excellent access.
All of the above is true... the entire shift body can be removed easily, o-ring replaced, etc.

TexasT
08-02-2014, 10:26 PM
I joined just to say thanks for the great write up. I have been looking for a boat and this opens up the idea that I can get one cheap needing trans work. Thanks again!