It may be a bronze bushing/repair sleeve pilot bushing that everyone seems to have good results with, but on this truck it's a Gold Medal failure. Didn't even make it 10,000 miles. Two different engines, two different transmissions, five different clutches, three different styles of pilot bearing/bushing. I'm thinking to just get another clutch because this new one now has a ruined hub. And then sell this POS. Pieces of spring laying in the bell housing and it wouldn't disengage from Montana to my home in S. Arizona. Had to start it in gear and shift without using the clutch to get home. I'm out of ideas.

 

I'm not familiar w/ these transmissions but is the bell housing a separate piece on these? If so, has it been checked for square/plumb?

 

That's very odd. You definitely got a issue somewhere.

 

Bell housing is the front half of the transmission body. Had the exact same problem with previous engine and transmission. And the clutch hub has enough give to be able to accomodate a lot of variance.

 

4R100 swap?

Pay up insurance then add fuego, or park it near the border until stolen?

I'm a problem solver.

 

Dang, Kwik. Are you starting in L every time and minimizing the amount of time the clutch is working? I would think miles would be independent of engagements, and not all engagements are the same.

 

Either Low or 1st gear. Never give throttle until the clutch is fully engaged. Sometimes 2nd if the rig is pointing downhill, but that's a rarity. Again, never give throttle until my foot is off the clutch pedal.
I'm starting to wonder if the stock clutch simply cannot handle pulling a rig that weighs 26k. Looking at the weight ratings for Southbend, they don't endorse weights that I have until you get up into dual disk setups. This time around I had broken hub springs fouling things up and it was a Valeo brand clutch, the same brand that came out of the setup when I pulled the transmission the first time around. Came from the factory like that in a 550, which is supposed to be able to pull 17,000-18,000. My trailer is around 13,000 fully loaded up. So the GVW is pushing 25,000. I don't know if SB clutch is rating for GVW or just the trailer being towed. I'll ask tomorrow when the work week starts.

 

I read your post stating 2 diff engines, 2 diff trans and several diff clutches. Did each clutch come with a new flywheel or is this the same flywheel used on all the above?

 

Are you installing new or reman clutches? I will absolutely not install a reman in a class eight truck. Just recently, around Christmas, we got a poorly machined flywheel for a class 8 truck, brand new mind you, had to remove the transmission two times to resolve the issues. Drive lugs were not perpendicular to the radius of the flywheel. Center plate would not float properly. The only reason I am telling you this is because manufacturing defects seem very prevalent these days. I will add another little tidbit of info also. Never ever install an Illinois clutch, had one of those in another truck that was obviously a manufacturing defect and Illinois would not make it good. Ended up going with a new Eaton. Problem solved! I am not sure what your issue could be unless it is some kind of alignment problem with the input shaft not being concentric with the clutch and flywheel. Have you replaced the slave cylinder assembly either time, not just part of it, but the whole assembly?

 

this time around it’s the second flywheel. Factory flywheel was ruined because I tried a ball bearing for a pilot bearing and it hogged out the part where the pilot bearing goes. Rendering it useless. Bought a new one. Contact surface still looks perfect and every bolt still nice and tight.

 

Last go round was a new flywheel and clutch assembly. Granted, purchased separately, but they were both brand new. I never put reman clutches in myself. Used to operate an auto repair shop for 40 years, bought everything from my supplier and they carried good brands. LUK, Valeo, Sachs, etc. Three different brands of clutch, three different design theories of pilot bearing from factory design, plastic bushing, back to factory design, now this "bulletproof" bronze bushing. All same result. Hogged out pilot bearing.

 

Is it possible heat is cooking the grease out of them?

 

I hate to ask about driving habits....


The only time there's relative motion between the input shaft and pilot bearing is when the clutch is depressed. Do you sit at stoplights with the clutch down/transmission in gear?

Do you downshift at high speeds using the clutch? When downshifting, the input shaft will spin way faster than the flywheel during the downshift process.

 

Usual driving habits are low rpm shift points when empty unless getting on the interstate. Then I'll run it up to 2500 rpm. Otherwise I'm in 5th gear by 40 mph. 4.88 rear axle. I don't need to wind it up at all to get going.
Towing. I will push it to 2800 sometimes 3000 rpm when accelorating. At that engine speed it's better to shift because the engine out put is dropping off and it makes best power below 2800. When pulling a big hill that requires downshift, I'll use the clutch, but the rpm for the downshift usually waits until the engine will be turning 2500 in the lower gear. OD to 4th is quite a jump so I have to wait on that until below 55 mph or so. Again 4.88 rear axle. Only on the steepest mountain passes do I have to drop into 3rd.
Running a Power Hungry Performance chip set on the 25hp tune. Any hotter than that, the EGT will go into the red. When there's a hill that is just steep enough to make the engine go WOT and maybe lose 1 mph, the EGT will push 1250 and the boost will be 21.5. 4" downpipe, 5" straight pipe exhaust with an AFE Big Boost air filter. Everything about the engine is stock, injectors, HPOP, etc.
Clutch engagement. No throttle given until the clutch is fully engaged, then I give enough to get it rolling with full throttle only applied in 3rd gear and up. Again, 4.88 axle. By the time I'm in third gear, the rig might be rolling 25 mph.
I'm at a loss for words on what the solution might be for this. I'm skilled enough to get an old school transmission into non-syncro granny low without crashing the gears together with the truck still rolling. Know better than to treat the truck like a race car and do all I can to avoid driveline shock. One of my goals when driving is to make the shift feel as smooth as possible and grimace when I miss a shift. Again, no throttle given when starting out from a stop until my foot is off the clutch. When towing, I use Low to get rolling, then into 1st gear, 2 gear and so on.

 

I'll add that the gearing on this truck with the 4.88 puts the engine rpm at around 2800-2900 rpm at 75 mph in OD. In direct drive gear (4th) 2500 rpm will net you around 50 mph or a little more.