The Stovebolt Site Forums The Shop Area Driveline T5 swap- diaphragm clutch requires shorter TO bearing-taller pivot ball ???

When I installed my T5 transmission with a new diaphragm style clutch, the clutch fork geometry seemed bad to me- the lever would touch the bellhousing when the pedal was depressed. This was after it was properly adjusted. So I installed a washer underneath the pivot bolt to improve the geometry. There aren’t many threads on the pivot ball, so I can’t put any more washers under it. One washer worked, and the lever no longer hits the bell housing at full travel, but the setup still isn’t correct geometry-wise. I think this has contributed to my clutch judder issues.

I have a diaphragm style clutch, so I have to use the shorter throw out bearing with the flat surface (the longer TO bearing has the curved surface). Do I need to go back to a three finger clutch cover to get things right? Are there any other options? Adjustable pivot ball that will work with the stock cast clutch fork? Longer throw out bearing with a flat surface for the diaphragm clutch? If so, where do I find one? I have looked everywhere…..


I have the truck 216 bellhousing with the cast clutch fork and mechanical linkage.

Needing some guidance on this, as I am dead in the water at the moment.


Here is mine: Clutch fork and pivot bolt with washer under it

Or could it be the wrong throw out bearing?

Gord, there are only two different TO bearings, and the other one has a curved surface for three finger clutches…mine is a diaphragm clutch, so I think I’m stuck with the TO bearing that I have…which has the flat surface.

If I use the longer TO bearing, then I will have to change to a three finger style clutch cover (which may be the only choice I have left if there is no adjustable pivot ball that will work with this cast clutch fork.

[Edit] i just discovered the McLeod adjustable GM throw out bearing. Adjusts from 1 3/8 to 1 13/16. It has a flat surface for diaphragm clutches. I have ordered it and this should get me close enough- it can be adjusted to three different lengths… I’ll
report back here once it’s installed.

Hmmm…well a few years ago I explained how I had to make a new linkage rod. There weren’t enough threads to allow for adequate adjustment and nothing worked until I did this. On my computer at home I have an image of what I did but am sitting with grandkids now. The original linkage rod was too short. All works fine now. I had to use the short throughout bearing also…diaphragm clutch.

I am wondering whether all of this is the result of me converting to a 12 volt flywheel?

Were the 6 volt flywheels considerably thicker?? I could not find a viable 6v flywheel- every single one I found was toast, just like mine, so I converted to 12v when I found a really nice 12v flywheel.

Not to my knowledge, Dave. And I was wrong in my memory. Shows you what aging will do to you late at night. I had to make a shorter rod...think it was just shy of 6 inches. There were not enough threads on the other clutch linkage rod, so the original would not work at all. I've lost a couple of images, but here is the OEM rod and you can also see the new one I made (from common 5/16" steel rod). As I recall the new one is a bit shorter than 6 inches and now I have plenty of adjustment threads (as you can see...it is about in the middle). Please consider this rod. Took care of my problem tout de suite.

There are 2 different diaphragm clutches & each uses a different TO brg. The older style has flat dia. fingers that are in about the center of the housing. It uses the long TO brg. The later model dia. clutch has fingers that protrude out of the center of the pressure plate. These are often called "beehive" clutches. It uses the short TO brg.
I never have heard of the Mcleod brg. but it sounds like a good idea & will probably solve your problem. The old style flat finger clutch should not be used with high rpm engines like v-8s. I would not use a 3or4 finger clutch. They are old fashion & not as smooth as the dia. type.

George

Thanks for the pics Jon. As soon as my new throw out bearing arrives, ill be looking at everything. I hadn’t considered a shorter rod- Thanks for the idea.

Here are some pictures of the two different styles of release bearings mentioned in the comments above. The correct release bearing must be matched with the appropriate pressure plate.
I believe there are custom release bearings available. The best people in the business are these guys:
Brake & Clutch Supply
Ask for Richie
407 So 8th St
Waco, Tx 76706
254-752-4307
Fax 254-752-7533

Lugnutz- Today I picked up a new clutch cover plate that was part of a kit that included the disc and throw out bearing. The throw out bearing in the kit is the one on the right in your picture. What is interesting, is that there are apparently two different kinds of “diaphragm” clutch covers. The one that I had installed in my truck required a flat face throw out bearing and the Sachs- type diaphragm clutch cover in my new kit came with a curved face throw out bearing.


Thanks for the referral to the Texas shop. I have actually spoken with them years ago…they were very knowledgeable.

Pics: Two different styles of diaphragm clutch covers

I think I may have discovered why I have a clutch fork geometry problem- the diaphragm clutch that I had installed has fingers that sit much higher than the Sachs type diaphragm clutch cover. The Sachs cover has a shorter finger height and a longer throw out bearing. I think the new cover and the new throw out bearing that came with it will get my fork geometry sorted out.

[EDIT]
Long story short, I remember trying to install the old cover with the longer throw out bearing, and the combination of the two pushed the throw out bearing too far aft. With the new shorter cover, the longer bearing should end up right where it is supposed to be, hopefully. We’ll see in a few days.

Right now, the pilot bearing is not cooperating with my attempts to remove it from the crank- large slide hammer has had no effect. I have not tried the grease method yet, but this thing is so jammed in there that I may end up having to remove it one piece at a time…

The Texas shop in my prior post sent me the clutch kit I’m using. Here’s a pic of the pressure plate (ignore the text on the pic) and mine uses the shorter release bearing that is on the left (flat surface).

Clutch is installed. The lower height diaphragm cover plate with the longer throw out bearing fit very well, so the geometry problem is solved without the use of the McLeod adjustable throw-out bearing.

Transmission is also back together….I had it apart and together 9 times. After the rebuild, shifting wasn’t right, and regardless of shifter position the trans was either in 4th gear or the entire trans was locked up and would not rotate….I was just about to give up when I discovered my error- I had installed a new synchro ring behind the new input shaft and accidentally installed the ring with the larger slots. That one mistake made the trans impossible to shift correctly, and when it did shift it was either locked up tight or one-to -one (4th gear).

Synchro differences…



Everything is good now. I’ll reinstall the trans tomorrow.

Here’s a pic of 2 badly damaged synchro rings with a look at the different notch sizes. Smaller is 1cm.

Wow those rings look awful. The only wear I found in my trans was the input shaft where the seal rides on the shaft… I guess I got lucky at the salvage yard! Your T5 rebuild site was a great help Lugnutz- thank you.