Another hydro clutch ?

[79Jimmy]

This is probably a dumb question, but I'm getting ready to swap over to a hydro clutch using all junkyard acquisitions and I was just wondering what if anything keeps the release/throwout bearing from riding against the pressure plate fingers when the clutch is "out" ? It should be up against the tranny on the input shaft bushing when in the "resting" position shouldn't it? I know on my '79 I have a spring which attaches to the fork and forward to the frame to keep the fork and thus the T.O bearing in the rearmost position. Is this accomplished by the nature of the hydraulics?
In the slave cylinder there is a spring which sits under the "shuttle" in the cylinder keeping it extended thus pushing on the fork thus making the T.O bearing ride against the fingers all the time.....At least that's how I'm seeing it. Probably a very simple explanation Perhaps I'm over anylizing and should just put it in, I just like to know how things work and want to do this right the first time.

James

 

[koldsimer]

I wondered the exact same thing when I did my swap and I couldn't find an answer. Mine has worked fine for about 10K miles now with no noises or weird feel. Any clutch gurus out there who can educate us on this?

 

[Burt4x4]

I'm no guru but I set up my T/O bearing so it does not touch the P-plate's fingers when released. I put a spring on the fork to make sure it pulls away from the P-plate about 1/4" or less. I belive this will extend the life of the T/O bearing.
.02c

 

[79Jimmy]

Thanks for the replies guys and the pic Burt! That's prolly what I'll do with mine as well. I was, and still am, just curious as to why the hydro doesn't have a hole in it for a return spring to keep the T.O bearing off the preassure plate fingers. I agree that setup should extend the life of the bearing.

James

 

[Burt4x4]

Ya no clue on the factory GM hydro setup.
I used Advance Adapter's slave mounting bracket to my old cast bellhousing. That slave you see is from a Toyota LandCruzer. I mounted a GM master to my firewall and driled a hole in my clutch pedal for the push rod.
My manual linkage was set up to keep the TO bearing off the fingers too so I figure it must be the prefered way to doit

 

[RootBreaker]

Ya no clue on the factory GM hydro setup.
I used Advance Adapter's slave mounting bracket to my old cast bellhousing. That slave you see is from a Toyota LandCruzer. I mounted a GM master to my firewall and driled a hole in my clutch pedal for the push rod.
My manual linkage was set up to keep the TO bearing off the fingers too so I figure it must be the prefered way to doit

I bought a 1985 fullsize GMC Jimmy for $100 so I had EVERY part I needed. Can take pics if ya like... but the factory setup is awww so sweet......

 

[atho]

I bought a 1985 fullsize GMC Jimmy for $100 so I had EVERY part I needed. Can take pics if ya like... but the factory setup is awww so sweet......

Yeah but factory hydro clutch trucks arent exactly common, and burt used off-the-shelf parts that anyone could. His probably wasn't that expensive either. Or do you just hate the thought of a Toyota part on your truck?

 

[79Beast]

I use a local clutch rebuilder instead of the parts store. He told me when I was doing my swap that you use a different throwout bearing in a hydraulic application.

 

[79Jimmy]

I think he may have been referring to a hydraulic throwout bearing which is a totally different animal. From what I have looked up so far, the T.O bearing on the SM465 never changed when GM went to hydro in '85 FWIW, I could be wrong.......

James

 

[dyeager535]

Napa shows same part number for both hydraulic and mechanical clutches.

15590168 was the GM number, I believe disco'd.

 

[RootBreaker]

Yeah but factory hydro clutch trucks arent exactly common, and burt used off-the-shelf parts that anyone could. His probably wasn't that expensive either. Or do you just hate the thought of a Toyota part on your truck?

yoda part... that would be cool....

i have edlorado parts on my truck.....