Odd 'stock' clutch failure. And South bend clutch 1947-OK-HD notes.

[Tuesdak]

Want to see if I cured the problem or if there is more wrong. I assume clutch pressure plate was hurt during install or dropped in shipping from the finger wear. But we know what assumptions do... This was supposedly a stock replacement by the PO - miles unknown, maybe 50K tops.

Clutch would start to grab lower on the pedal but not hold till near the top. Sometimes would grab hard enough to stall the engine. Would slip in 6th sometimes and did so till it smelled bad couple times.

The flywheel had burn/hard spots bad enough you could catch a fingernail on. Minor cracks in the surface.
Looks like grease from throwout bearing being thrown across surface.

Pressure plate was FUBAR.
Warped as it would rock on the flywheel with the disc out.
Diaphragm fingers to throw out bearing contact area wearing on one side only.
4 hot spots on pressure plate.

Disc questionable.
Plenty of wear left on it.
Hub to center disk loose and wearing leaving a groove. (I do not know if this is normal. Doubt it.)
2 rivets on pressure plate edge talking wear from disc.

South bend clutch 1947-OK-HD notes.
The clutch appears to feel a little heavier than stock as it adds a little bit of notching during shifting. Could also be the pivot ball bushing being new.
Pedal feel with the hydraulic kit is slightly stiffer than stock.
Smooth engagement. I would say as close to an auto smooth as you can get. (Vs. the mess I just replaced anyway.)

 

[Tuesdak]

Disc pics.

 

[Tuesdak]

As I hate threads that describe *your* symptom and NEVER have a solution...

Different good shop found a missing dowel pin. Of course this allows the transmission to move around and the pics above say it all.

 

[GCroyle]

The missing dowel sleeve caused the loose hub observation. Loose/groove. I opened up an NV5600 and found a missing sleeve, trans was replaced and assumed that the sleeve went with the core. Can also accelerate pilot bearing wear and maybe not great for input shaft too.

 

[South Bend Clutch]

Glad to hear the problem was found!!

Peter

 

[mwilson]

The missing dowel sleeve caused the loose hub observation. Loose/groove. I opened up an NV5600 and found a missing sleeve, trans was replaced and assumed that the sleeve went with the core. Can also accelerate pilot bearing wear and maybe not great for input shaft too.

One of the many reasons that I tell customers to keep any core until the job is finished.

I don't know how many times we have gone through the cores looking for the spacer for the starter from an 855 Cummins...because 9 times out of 10 it will stick to the starter when you remove it. The customer never looks the core over, installs the reman starter and then calls ..."That new starter is junk, it's making a noise!!!!"......

 

[RVTRKN]

My guess is that the throw bearing was sticking from time to time which would wear the PP fingers could also cause clutch slipping and then be OK, and that could also get it hot enough to allow grease to melt and fling inside, any evidence on the TB sticking?

 

[inlinesix3million]

Mr Doremire, Please describe the location of the missing dowel pin. When I have my clutch replaced- what to look for? Thank you

 

[inlinesix3million]

Never mind- I read your other thread that describes missing dowel pin allowing transmission to move around... thx again

 

[TBusclas]

Please let me how you like this clutch, my throw out is on it's way out and this is the clutch that South Bend recommended after reviewing with me what I had done to truck, what it is used for and max I would be towing. Even though the throw out is the only thing going on at the minute the truck is approaching 300,00 with as far as I know original clutch and I want to make this a one trip ordeal. Also did you replace the hydraulic with upgrades? Everything should be here by weekend and will put it all in weekend or first of next week. Thanks!

 

[Tuesdak]

So far I like the clutch. No grabbing or chatter. Just a smooth predictable engagement. I did the flywheel with HD pilot bearing, rear crankshaft seal, trans input shaft seal, and new hydraulics. Later added a missing dowel pin and re-replaced the clutch as the missing pin turned the new SBC clutch into a flex plate just like the one above with wandering misalignment of the engine and transmission.

I would consider replacing the pivot bearing on the fork. Also check out Core Shifters for a new shift bushing that goes on the end of the shifter in the trans. It tightened the gates up on mine a lot.