View Full Version : Velvet Drive 77S&S Problem After Rebuild

Apatski S&S 77
07-05-2011, 02:35 AM
Hello, Teamtalk, I need your help!!

I now have more information from my previous post, Velvet Drive Fluid Problems. (Check post for exterior restoration.)

I have an 77 S&S 351 with a 71C, 1to1 Velvet Drive, 2000+ hours. While running about 30 MPH the engine RPM went up and the boat speed slowed. It lost fluid and I found that the front seal was defective. I replaced the front seal and against recommendations I put it back in and hoped that the tranny would be OK. It did not function correctly and would not go into forward at idle speed but would go into forward at increased RPM, reverse worked OK. I ran the boat for about 20 minutes and the tranny got real hot. So I figured it was slipping and that rebuild was the next option. Bought the rebuild kit from Lakewood Trans off Ebay. Dissasembled the tranny and found the following: 1. The reverse clutch was broken at one place but was not worn. Thickness just .003 thinner than the replacement. 2. The new forward plates were actually thicker than the replacements by .005, (cleaned and oiled before measuring). 3. Pump has small wear grooves on inside face of inner gear and slight discoloration on inside face as well. Pump gears inner and outer are smooth and fit tightly together. 4. Reassembly went smoothly for my first rebuild. The only issue was when I was inserting the drive gear assy/forward clutch hub into the forward clutch I had to push down hard using my hands and body weight while rotating and wiggling to get it to seat so snap ring could be applied to drive gear shaft. Other than that I had no great problems in assembly.

After putting the tranny back in I tried the operation on the trailer and it seemed to work properly. Shaft not connected. Had slight rotation, sometimes rotating reverse and sometimes forward, while in neutral but could stop by putting pressure on rear coupling. Connected everything an headed to lake. With boat on trailer I tested and found the following. 1. Reverse gear engages when shift lever on tranny is moved to reverse detent in lever, no problem. 2. PROBLEM When shift lever is moved to forward detent position it does not engage forward gear without raising engine RPM. Tried leaving it in forward with engine at 1500 RPM for 3-4 minutes and then trying, neutral to reverse, OK, neutral to forward, same thing, over and over??? Just like it did before the rebuild.

What do you think, do any of you have a diagnosis for my problem. NO Boat, NO Ski, No Fun!!

Thanks for any information you may have. I am stuck????? Please post anything you know or call if you feel you can help.

Pat Kendall
Tulsa, OK

07-05-2011, 10:35 AM
Once it is finally engaged does it run properly? It may be a shot in the dark but this just worked for me with a similar problem: After I swapped engine and trans it had a delayed engagement in forward- (reverse was fine), but forward, the rpm's would surge and then it would fully engage- around 2,000 rpm's- it felt like you were slamming it into gear violently. This is what I found: These controls are designed so that when you move them, the trans cable will move first and start to shift the trans into gear before the throttle cable moves the throttle linkage. After the trans is in gear fully the throttle cable then continues to move and opens the carb. With the engine off, check to see when the trans shift lever is *fully* engaging the trans forward related to throttle cable / linkage movement. I suspect it may need adjusting to keep the engine from revving up too much before the trans is fully engaged. You might be able to adjust (shorten) the shift cable which will cause it to engage the trans sooner when moving the control in the forward position. If you look at the end of the cable at the trans, there is a small amount of adjustment- like 0.25" of threads or so. Adjust it there and re-test. If this is not enough to fully engage the trans I believe you can take the controls out and adjust the cable on that end as well. I did not have to go that far as the small adjustment at the end of the cable fixed my problem. The same goes for adjusting the cable the other way (lengthening) to engage reverse sooner. You may also be able to adjust the throttle cable in the same fashion- lengthening it would move the throttle linkage later, delaying the rpm rise before the trans was engaged all the way. Hope this helps!

Bruce Carr
07-05-2011, 12:49 PM
Did you replace the pump, as in both the back plate, gear and housing? Even just a little wear on any of the parts can cause the pump to not gain sufficient pressure to hold the clutch pack.

Apatski S&S 77
07-05-2011, 01:47 PM
Thanks 74Stars, It is not cable adjustment. I tried the shifting without the cable hooked up and just moved the shift lever. Reverse ok at idle but not forward.

Thanks Bruce, I did not change the pump. I am planning to check pressures if I can get the plugs out of the test passages they are rusted. I will post the results.

07-05-2011, 04:21 PM
Give Eric a call. Use the link below to get his contact information. I had the same problem after a rebuild. It is a small C-clip that holds a widget in place in the whatumacallit. Eric can explain and help, he has helped others on the site.


Apatski S&S 77
07-06-2011, 05:27 PM
Skipper, Thanks for the info on ERIC he explained the possible issues and gave me light at the end of the tunel.

Will post updates

Thanks Again!!!!

08-30-2015, 10:22 AM
Skipper, Thanks for the info on ERIC he explained the possible issues and gave me light at the end of the tunel.

Will post updates

Thanks Again!!!!

I am have a similar issue with forward not engaging at idle. Is there not an adjustment in the shift lever assembly? I don't want to rebuild and then have the same issue.