Stiff shifting after bushing replacement

Brotok · 02-09-2010, 10:44 PM

I just replaced the ball cup and shift rod bushing in the shifter of my '79 SC and the movement of the lever is now much stiffer. That is, there is noticeably more resistance when moving the lever around, so much so that the 2nd to 3d shift now takes more effort. I used Weltmeister plastic bushing suspension lube, which is very sticky and thick and gets all over the place, on the bushings and suspect that this might be causing the problem. Has anyone experienced this and should I just wait for the bushings loosen up with time?

Thanks for reading.

911pcars · 02-09-2010, 11:11 PM

Quote:

Originally Posted by Brotok

I just replaced the ball cup and shift rod bushing in the shifter of my '79 SC and the movement of the lever is now much stiffer. That is, there is noticeably more resistance when moving the lever around, so much so that the 2nd to 3d shift now takes more effort. I used Weltmeister plastic bushing suspension lube, which is very sticky and thick and gets all over the place, on the bushings and suspect that this might be causing the problem. Has anyone experienced this and should I just wait for the bushings loosen up with time?

Thanks for reading.

Factory plastic bushings?

Remove the shift housing assy. and inspect the bushings. The ball cup bushing should be snug but not tight around the ball end of the lever. The shift rod support bushing should provide enough clearance for the rod to rotate and slide fore and aft and not bind the shift rod. Try removing any excess gorilla snot, reassemble and road test.

If the friction is reduced, remove the heavy grease entirely. I recommend synthetic chassis/wheel bearing grease.

If the frictional drag doesn't change, perhaps the bushing clearance is too tight. Use med. grit sandpaper to increase the busing clearance slightly, then retry it.

Sherwood
SeineSystems.com

Brotok · 02-10-2010, 08:01 AM

Yes, these are factory bushings.

I was hoping not to have to go back in there but it looks like there might not be any choice if this is not normal.

Thanks for the advice.

Pazuzu · 02-10-2010, 08:52 AM

Does your '79 have the locking nut/tension screw on the front of the shift housing? Is there a chance that you made that too tight? When I put my short shift in, with new bushings, I found that I could make the shifter anywhere from flopping around to unmovable with a *tiny* adjustment of that screw.

Brotok · 02-10-2010, 09:37 AM

I do have that screw but I made sure it is properly adjusted. The shifter was "flopping around" (nice description) before I actually put it into the car.

Thanks!

911pcars · 02-10-2010, 12:04 PM

If it's not the shift housing assembly causing the stiffness, it's the shift rod or..... more dire, something inside the gearbox. Check the shift coupler under the rear floor cover and again, the round bushing that supports the front of the shift tube.

Here's a couple of scenarios of "if it can be done, someone's done it":

1. The front shift tube bracket, the one that contains the bushing, is L-shaped. The lip normally sits on top of the tunnel sheet metal. Some owners try to position this under the tunnel metal. This can cause binding.

2. An owner tries to install a pre-owned WM short shifter. He has the longer shift lever (below the pivot point), but not the matching spacer under the housing. This will cause binding, especially when the owner tries to close the resultant housing to tunnel gap with 100 ft.lbs of torque.

Sherwood

Brotok · 07:00 PM

Just fixed the problem. The issue was that I overloaded the cup bushing with grease so the ball would not sit properly and got jammed in there when I slid the bushing it into the housing. Come to think of it, I must have been creating quite a bit of binding force down there. I am hoping that this didn't stretch the plastic....??? I'd hate to not be getting everything out of the repair and am hoping that the bushings are hardy enough to have withstood the punishment.

Also, thanks to Sherwood's post I now realize I have a Weltmeister short shift kit (I have the aluminum spacer), and am disappointed that it is not a factory kit. Would those of you with experience recommend changing away from the Weltmeister unit? I feel another thread coming....

Many thanks for all your help.

911pcars · 02-10-2010, 08:41 PM

Quote:

Originally Posted by Brotok

Just fixed the problem. The issue was that I overloaded the cup bushing with grease so the ball would not sit properly and got jammed in there when I slid the bushing it into the housing. Come to think of it, I must have been creating quite a bit of binding force down there. I am hoping that this didn't stretch the plastic....??? I'd hate to not be getting everything out of the repair and am hoping that the bushings are hardy enough to have withstood the punishment.

Also, thanks to Sherwood's post I now realize I have a Weltmeister short shift kit (I have the aluminum spacer), and am disappointed that it is not a factory kit. Would those of you with experience recommend changing away from the Weltmeister unit? I feel another thread coming....

Many thanks for all your help.

Some find the shifting "notchy". That's because the WM unit shortens the throws by about 34%. The factory short shifter provides about a 23% reduction in throw distance. What you gain in throw reduction, you lose in leverage (shifting effort increases). YMMV.

The shorter throws may also encourage the owner to shift faster. This places more wear on the synchro assemblies. The 915 gearbox prefers slower, more deliberate shifting.

Sherwood

Walt Fricke · 02-11-2010, 04:58 PM

In addition, WM type short shifters also reduce, by an equal percentage, the side to side movement. You might think this is good, but I don't.

I think the factory side to side motion helps you select the gear you want. Reducing that part of the throw means you have to be even more precise there. Precision is not required in the fore and aft direction, as you just push until in gear and things stop. But it is side to side.

The factory short shifter reduces fore and aft throw, but keeps the side to side pivot in the same relative position. Better mousetrap.

However, I drove happily with a WM for some years. My main gripes were that the glue used to hold the new, longer ball end on failed. I had it tack welded in place, but then the shifter broke because the tack weld had burned through the shift lever tube (and I must be ham handed). That was the excuse to purchase the factory unit.