3spd to 4spd clutch differences?

Any known differences between 3spd and 4spd clutches? Swapped the 3sp over to 4spd this weekend but having an enhancement concern. Seems the clutch is engaged and will not disengage with the pedal. Did not touch the clutch or bell housing, correct coded toploader for the 302 and input shaft appeared to be correct. Clutch functioned correctly with the 3spd. What did I miss?

Glad I decided to start it and check it while still on jackstands as it appears I’m not done just yet!

Sounds like the pilot bearing is jammed. It might break lose if you put the parking brake on

No difference.

It sounds like you did the transmission swap without disconnecting the Z bar? If you tilted the engine then you may have bent the Z bar or damaged the throwout bearing clip. Or if you are lucky maybe just pulled the clutch fork out part way.

It has to be something that happened unseen from the install, I did not think there was any difference between the 2 but wanted to double check. Clutch is relatively new with very little miles, but its sat in a garage for many years before I have owned it. However I know it all functioned ok before so it has to be something gone wrong.

Yes everything forward of the transmission itself was untouched. I did support the engine with a jack so no movement there from the z-bar. Zbar has all new bushings and linkage, springs etc. I did check it visually for any anything out of the ordinary once I discovered the issue and it looked ok. Clutch pedal feels normal as well.

I made sure the throw out bearing was sitting on the fork correctly before stabbing the transmission, but entirely possible it got bumped. I will pull the fork rubber off tonight and see if I can see anything out of place with the fork or throwout bearing. If its the pilot bearing no seeing that without pulling everything out.

Gotta love when upgrades go sideways and actually make it worse then it was before, I mean at least it worked before :laughing: Now Im taking up the whole garage and the wife has gotta park outside this week and looks like we have a few 110* days heading our way!

bushing or bearing? It sure looked like a bushing when I took a quick look during the swap

I’ve seen both. I am running a bearing but I think it was a bushing originally.

I think Bill pegged this with the pilot bearing suggestion. I checked the clutch last night and its indeed working. I can see full disengagement and full engagement with the engine off. The shift fork and throwout bearing are in the right place and move freely. Shifter linkage is all adjusted correctly. Z-bar moves freely without binding or twisting and the throw out bearing pulls away from the pressure plate just fine.

I messed with it enough to get the engine warm and actually was able to get it through the gears if I was firm and fast enough with the shift. I wasn’t able to do that after install when engine was cold. I know these take some effort to shift compared to a modern transmission but I still felt it was too much effort and reverse was not happy. Still harder then the 3spd I took out so something is still not right. Its all gears and not just one which leads me to believe the transmission is ok(also visual inspection of trans before install looked good.) Only thing left could be the pilot bearing or bushing causing the input shaft to spin when it shouldn’t. This is backed up by what Im seeing happen, place transmission in a gear with engine off and start engine and I have enough power flow through the transmission to spin the tires with clutch disengaged . I can apply the park brake and it will hold the tires still but can actually hear very slight load on the engine happen but not enough to make it want to want stall. If that bearing is hanging up it could be applying too much load to that input shaft and causing my hard shift concern.

I did grease the input shaft before installation but looks like its got to come back apart to get it fixed. I might try to run it a little more with the park brake engaged to force that input bearing to spin and free up but I would be concerned with it failing entirely. Still not sure if its a bushing or bearing, wish I took a closer look at it now :wall: I would think it would be a bearing based on the history but you never know since that was before my ownership.

If the bearing or bushing is in a little crooked it will bind. If you used bread to remove the old one you really have to dig that stuff out of there. I have learned to check the bearing on in the input shaft before installing it. I got a replacement bushing at AutoZone that was too small to fit. I think it was size to allow the input shaft to be turned.

Im really good about checking part fitment or correctness before installation to avoid doing it twice(which I really hate doing it twice :laughing: ) I assumed all would be well with the swap from one to the other. The 3spd worked well enough so I didnt think I would need to mess with the clutch but thats just my luck it wouldn’t be as easy as I was hoping.

I have a slider hammer with a specific attachment for pilot bearings so shouldn’t need the grease or bread trick to get it out. I do need to find the proper clutch alignment tool for installation however. Mine are either for a truck ZF or toyota mini truck.

Hopefully I get some time this weekend to yank it back out and fix it.

I decided I wanted to see what happened after a heat cycle. Started it up cold after a heat soak then cold soak over 24hrs. Everything seemed to be working as it should even on a cold start and after it warmed up. Decided to get it off the stands for a spin around the block for a roadtest. Hammered through the gears a few times and all seems well! No shifting issues, no weird noises or vibrations. Maybe just maybe I lucked out for once :open_mouth:

If the bushing was crooked there is a lot of force that wants to center it. Hopefully that is what happened.

or its going to all explode on me and Ill be going back in there anyway :laughing: