Transmission fluid leak

[Farmer Ted]

Puddle of transmission fluid in the bilge, take off dipstick and there is pressure in the resevoir.


What do I need to do? Reseal the transmission?
Anyone done this? Anyone had this done? If so how much does it cost?
JimN what's book on a job like this. 1:1 not powerslot

Grrrrr

[sfitzgerald351]

Clean off the transmission and you should be able to tell if it's the front or real seal (or something else). I did the front and rear seal in my 1:1 and it took about 20 minutes once the transmission was separated from the motor. Simple matter of pulling off the old seals and putting the new ones on.

We pulled the motor out with a forklift since we needed to do the oil pan gasket, etc... but all you really need to do I'm told is unbolt the shaft coupling from the trans, unbolt the trans mounts and support the bellhousing of the engine on some wood and then unbolt the transmission from the engine. I'm sure someone here has done it and can go into more detail and give you an estimate of time.

[Engine Nut]

Puddle of transmission fluid in the bilge, take off dipstick and there is pressure in the resevoir.


What do I need to do? Reseal the transmission?
Anyone done this? Anyone had this done? If so how much does it cost?
JimN what's book on a job like this. 1:1 not powerslot

Grrrrr

You don't say if you have a ZF/Hurth or a Velvet Drive transmission. It doesn't really matter but you need to know which it is when you get the parts. What you are hearing as pressure when you remove the dipstick is really probably vacuum. The breather vent on the trandsmission is a one-way check valve. It lets air and moisture out of the transmission but not back in. What you are hearing is air being sucked back into the transmission ... kind of like opening a coffee can.

You should be able to determine if the leak is from the front or rear seal by the location of the puddle. In either case, you will have to unbolt the propshaft, loosen the front motor mount trunnions, unbolt the trans mounts and lift the back of the engine to access the transmission.

If it is a rear seal, you will need to remove the nut that holds the output flange and remove the flange from the transmission. The seal is under the flange. A ZF/Hurth requires a special tool to remove the flange nut and a Velvet Drive uses a socket. The nuts will be tight ...88 lb ft for a ZF/Hurth and 220-260 lf ft for a Velvet Drive. You can pry the old seal out and install a new one without too much trouble. When you put it back together, ZF/Hurth says to apply Loctite 245 to the splines. This along with an O-ring prevents trans fluid from leaking past the splines and out the back of the coupler. The coupler nuts have to be torqued as specified above.

If it is the front seal, you have to remove the transmission from the bell housing. The front seal on both the transmissions is in the pump cover. It is probably easier to remove the pump cover and replace the seal. Just make sure that the pump cover goes back on the same way it came off ... note the directional arrows on the cover before you remove it. Also make sure that the pump drive key did not become dislodged or lost when the cover came off.

Once the seal is installed, torque the cover in a criss cross pattern to 13 lb ft for a ZF and 17-22 lb ft for a Velvet Drive. Put some grease on the input shaft spline and reinstall the transmission on the bell housing making sure the splines have engaged properly.

Lower the back of the engine, reattach the motor mounts, align the engine/transmission to the propshaft and tighten all of the fasteners, reattach the shift cable and you should be good to go.

The Indmar part numbers for the seals are as follows:

Input Shaft Seal ZF P/N S905004 Velvet Dr P/N S885033
Output Shaft Seal ZF P/N S905070 Velvet Dr P/N S885035
Output Shaft O-ring ZF P/N S905125 Not used on Velvet Dr.

Your local MasterCraft or Indmar dealer will be able to get the parts for you.

[east tx skier]

Hate to hear it, Farmer. Get that bad boy up and running for June.

[André]

You don't say if you have a ZF/Hurth or a Velvet Drive transmission. It doesn't really matter but you need to know which it is when you get the parts. What you are hearing as pressure when you remove the dipstick is really probably vacuum. The breather vent on the trandsmission is a one-way check valve. It lets air and moisture out of the transmission but not back in. What you are hearing is air being sucked back into the transmission ... kind of like opening a coffee can.

You should be able to determine if the leak is from the front or rear seal by the location of the puddle. In either case, you will have to unbolt the propshaft, loosen the front motor mount trunnions, unbolt the trans mounts and lift the back of the engine to access the transmission.

If it is a rear seal, you will need to remove the nut that holds the output flange and remove the flange from the transmission. The seal is under the flange. A ZF/Hurth requires a special tool to remove the flange nut and a Velvet Drive uses a socket. The nuts will be tight ...88 lb ft for a ZF/Hurth and 220-260 lf ft for a Velvet Drive. You can pry the old seal out and install a new one without too much trouble. When you put it back together, ZF/Hurth says to apply Loctite 245 to the splines. This along with an O-ring prevents trans fluid from leaking past the splines and out the back of the coupler. The coupler nuts have to be torqued as specified above.

If it is the front seal, you have to remove the transmission from the bell housing. The front seal on both the transmissions is in the pump cover. It is probably easier to remove the pump cover and replace the seal. Just make sure that the pump cover goes back on the same way it came off ... note the directional arrows on the cover before you remove it. Also make sure that the pump drive key did not become dislodged or lost when the cover came off.

Once the seal is installed, torque the cover in a criss cross pattern to 13 lb ft for a ZF and 17-22 lb ft for a Velvet Drive. Put some grease on the input shaft spline and reinstall the transmission on the bell housing making sure the splines have engaged properly.

Lower the back of the engine, reattach the motor mounts, align the engine/transmission to the propshaft and tighten all of the fasteners, reattach the shift cable and you should be good to go.

The Indmar part numbers for the seals are as follows:

Input Shaft Seal ZF P/N S905004 Velvet Dr P/N S885033
Output Shaft Seal ZF P/N S905070 Velvet Dr P/N S885035
Output Shaft O-ring ZF P/N S905125 Not used on Velvet Dr.

Your local MasterCraft or Indmar dealer will be able to get the parts for you.
Hey, i was going to say that too... :D
I'm sure this post will be reffer to a lot! Very detailled and readable! :toast:

[MarkP]

Hey, i was going to say that too... :D
I'm sure this post will be reffer to a lot! Very detailled and readable! :toast:
Andre,

I’m going to have to go ahead and second that:worthy: !!

[latch]

Have a 98 ProStar 190
Was in the shop yesterday for servicing. Asked the shop to change oil and filter in transmission. Transmission is a ZF Hurth Marine
Model HSW 450D
The shop foreman told me that this transmission does not have a filter. Is this correct?

[east tx skier]

I think that 94 was the last year of the velvet drive, correct?

[G-man]

If the fluid is changed on a regular basis, doesn't overheat or get water in it, I wouldn't change the filter.

[Engine Nut]

The 450D does have a filter. The problem is that it is a pain to get at. It is on the bottom of the transmission just ahead of the propshaft coupler. You have to separate the propshaft from the transmission and lift the engine to get at in most cases. The filter is a washable screen that just needs to be cleaned, not replaced.

Engine Nut

[erkoehler]

Man, you are just a wealth of knowledge! Welcome to the site, you should post more often.

[dchatagnon]

I want to reseal mine also. I dont know how to remove the pump cover?
After removing the 4 bolts, what should I do?
I guess there is a seal to change also for the pump cover...
(see attached picture of my trans)
thanks.

[boatweight]

Wanted to thank 'Engine Nut' for the great post above and the help purchasing the parts needed to replace my rear seal on my ZF/Hurth trans. The project from start to finish took about 3 hours--thanks to a friend with the knowledge and right tools. Job went smoothly; pulled the prop, removed the flange bolts, slid shaft back, heated the special nut, used a punch to remove the nut since we had a new replacement nut, used a pulled to remove the flange, removed the seal, put it all back together. Taking the boat out tonight.

Thanks Larry for the help.

[André]

Well look at this!On the same night that i blow a transmission seal on my 94 Prostar, the thread i need is right there!!!

Will be taking the tranny out tomorrow.Mine is Borg-Warner Velvet drive 1:1
Any other special advice? Do you think i can get those front and back seals(Might as well do both at the same time?) at any industrial bearings and such suppliers?
Need to be back up runnin ASAP....
My big scare is realignement.Not sure how to do it.I know the tolereance on the flange is .003" but if you only raise the rear of the engine,shouldn't things be at the same place ?
Thanks for ANY advices...:)

[Chicago190]

Well look at this!On the same night that i blow a transmission seal on my 94 Prostar, the thread i need is right there!!!

Will be taking the tranny out tomorrow.Mine is Borg-Warner Velvet drive 1:1
Any other special advice? Do you think i can get those front and back seals(Might as well do both at the same time?) at any industrial bearings and such suppliers?
Need to be back up runnin ASAP....
My big scare is realignement.Not sure how to do it.I know the tolereance on the flange is .003" but if you only raise the rear of the engine,shouldn't things be at the same place ?
Thanks for ANY advices...:)

I've attached the procedure for aligning the engine/trans and prop shaft. I wish I knew who did the write-up so I could give them proper credit for their well written instructions, but I saved it a few months ago in case I needed to do it myself.

[André]

Thanks for the tip!
Got my seals kit,about to pull the boat out of water to do the job.
Wish me luck!
Good thing JimN is on i may need him later!!!:)

[André]

Surgery went well!
Only bug was getting an 1.5" socket for the flange nut but quickly found one.
Will test right after that damn rain stop!!!

[downtime]

Gonna attempt this soon on my 95 PS205. Were can I find this "special tool" for the hurth. Also, dealer is over an hour away, any other sources for seals?

[downtime]

Anyone......

[boatweight]

I purchased all the needed parts from Engine Nut (Steve) give him a shout. The special nut was not cheap, around $230+. I heated the nut up just a bit, then used a punch to loosen the nut. Since you are putting a new nut, rubber o-ring, and gasket on it seemed to work for me. Give Steve a call, very knowledable and his pricing was great.

[downtime]

Just sent him an e-mail, thanks. Did you have any alignment issues once completed?

[jraben8]

I have one of those special sockets for the special nut on the Hurth transmission if someone needs one. I'll sell it for 1/2 price and hope that I never need it again...

[B-rad]

Jraben, might be interested in that nut, im getting ready to pull my trans next week. is it a special design nut or just an 1.5 If so i have that.

[B-rad]

Anyone have a number to contact engine nut about parts?

[André]

Jraben, might be interested in that nut, im getting ready to pull my trans next week. is it a special design nut or just an 1.5 If so i have that.

1.5 " was for a Borg-Warner transmission...

[downtime]

I have one of those special sockets for the special nut on the Hurth transmission if someone needs one. I'll sell it for 1/2 price and hope that I never need it again...

PM sent.....