Clutch slipping.....sometimes...few and far between (1 Viewer)

[Zack1978]

Hi everyone,
I need some help diagnosing a slipping clutch issue. The clutch in the truck has anywhere between 5,000 to 8,000 miles on it and it was an Asco clutch (actually it was a Centerforce that was was just rebranded).
About a year ago (or perhaps even longer) I was driving and the clutch started to slip badly for a couple of minutes, where you would hit the gas and the rpm' s would rise and the speed would not increase. After a few minutes the slipping stopped, and it never happened again. In fact I almost forgot about it because it was so long ago.
Then today...
I drove the truck for about 20 miles, and it was fine. I parked the truck for 30 minutes then got back in and drove some more. In the first minute the truck was fine , then I pulled out on a main road where I had to accelerate quickly. As soon as I started to accelerate it started to slip again and it noticed started to smell like burning clutch. I let off the gas and drove slower. Within two minutes the truck was normal again with no slipping at all.
Any ideas as to what might be happening?

Thanks,
Zack

 

[dkyuss]

Possible engine/tranny oil leak that doesn't normally hit the clutch.... just sometimes and then it slips for a bit till burnt off? Any oil leaks at the bottom of the bell housing?
Just a guess though.

 

[Output Shaft]

Hey Zack, what year is the cruiser?
Is the slave cylinder adjustable or not?
If the salve is adjustable and too tight, it would prevent the clutch cover from fully clamping.

A clutch disc can go over a quarter million miles without wearing out, so that isn't the problem.

Were all the clutch components replaced/resurfaced when the clutch was recently done?

• New clutch cover
• Resurfaced flywheel
• Cleaned and greased hub

A slipping disc can also be caused by contamination of the friction surfaces.

Does the clutch release smoothly without judder?

 

[Zack1978]

My Cruiser is a 1987. The slave and master are only about a year old. With respect to the clutch parts replaced, yes it had all of the items that OutputShaft mentioned replaced including the flywheel resurfacing. Yes the clutch releases without any judder or anything else. I just drove it again a little while ago and it was totally fine.
With respect to the contamination of the disc, I guess that could be a possibility since the underside of the tranny is "moist". I am taking the 60 to work tomorrow, I will report back later in the day as to how the clutch worked.

 

[Landpimp]

long shot...........but any chance it was not actually the clutch slipping but maybe the fan clutch locking up, then unlocking? it sorta feels like the RPM's go up but the power does not, also gets louder.

 

[Zack1978]

long shot...........but any chance it was not actually the clutch slipping but maybe the fan clutch locking up, then unlocking? it sorta feels like the RPM's go up but the power does not, also gets louder.

Is there an easy way to check the fan clutch? I don't think this was happening because the speed was dropping as well.

The truck was driven a lot today, and not one bit of problems.

 

[Landpimp]

guess not if the speed drops. Sorry, never know.

Is there an easy way to check the fan clutch? I don't think this was happening because the speed was dropping as well.

The truck was driven a lot today, and not one bit of problems.

 

[Zack1978]

guess not if the speed drops. Sorry, never know.

Sorry? No way thank you! I appreciate any and all input! That is what makes the mud community so great.

 

[woytovich]

Do you have the cover on that goes under the flywheel/clutch assembly? I might you have been in a situation where something (water/oil etc) could have gotten up in there just before the slip incidents?

 

[Zack1978]

Do you have the cover on that goes under the flywheel/clutch assembly? I might you have been in a situation where something (water/oil etc) could have gotten up in there just before the slip incidents?

Yes I believe so, when the rain stops I'll go check.

 

[TysonFunk]

Any updates on your situation? I have a similar issue happening with my 84 3B-T H55F. I replaced my clutch last year after I put a turbo on my truck and it started to slip, installed a new clutch from EBI cruisers rated for 15psi of boost. Running 9psi currently. It started to slip last month after about 20,000km. New rear main seal, machined with a 20 thou (?) step flywheel, PP, TO bearing, pilot bearing, clutch disc, transmission was all re sealed and received new bearings. I adjusted my clutch fork/slave cylinder shortly after it started to slip and the problem went away for a few weeks but here it is back with a vengeance. Slips at 1800-2000rpm in 4th and 5th only. Any ideas?

 

[OSS]

Any ideas?

Gotta drop the transmission and replace the clutch disc and clutch cover. Make sure zero grease can get flung off the input shaft to contaminate the disc.
In my experience, once a clutch disc gets contaminated - it’ll never grab the same again.

 

[franklin40]

Gotta drop the transmission and replace the clutch disc and clutch cover. Make sure zero grease can get flung off the input shaft to contaminate the disc.
In my experience, once a clutch disc gets contaminated - it’ll never grab the same again.

so if i’ve got an oil leak that has contaminated my clutch disc even if i drop the tranny and clean it and get the engine sealed up that disc is done? i just noticed a little catching/slipping with letting the clutch out but once fully engaged it grabs fine. i just developed a major oil leak on my last road trip i have yet to identify but know my clutch got a little of the black gold on it.

 

[Spook50]

so if i’ve got an oil leak that has contaminated my clutch disc even if i drop the tranny and clean it and get the engine sealed up that disc is done? i just noticed a little catching/slipping with letting the clutch out but once fully engaged it grabs fine. i just developed a major oil leak on my last road trip i have yet to identify but know my clutch got a little of the black gold on it.

Stumbled on this thread while searching for ideas as to why my clutch seemed to be slipping a bit today. As it is I'll be digging out my FSM tomorrow first to make sure the pedal is adjusted right, but an old trick people use to use to extract oil from brake shoes that've gotten soaked in it is to use a large tip propane torch and dance it over the material on the shoes. You don't want to full on barbecue the thing, but just enough heat to extract the oil from the friction material may be a thought. You could also put it in the oven (over a drip tray!) at about 170° for three or four hours.

Done the torch trick on brake shoes on antique tractors and on those it works a treat. Going to be doing it on a 1947 Ford 8N next spring actually.

To be honest though, when it involves dropping the tranny to get to it, I would ONLY do this if I was absolutely desperate to have my truck running and in no way could afford a new clutch. If you can get your hands on a new clutch, I say just replace it.

 

[franklin40]

i haven’t been able to drive it much this summer to know if it’s still happening. i’ve been trying to figure out why it won’t start. finally got that sorted and will get it back this week from getting a tune up. i also found my oil leak. it’s from the girdle so i wont be able to easily seal it back ip. the engine needs to come out to do that. i’m going to try giving it a good ropey seam of sealant over the joint. there’s no pressure there so maybe i can stem the tide for a while. at least when i was redoing my oil pan a week ago i noticed flywheel area was clean and dry so i do t think it’s a rear main. maybe it was just a little oil that got blown up onto the clutch and then didn’t off. fingers crossed anyway. seems like the inevitable that in the next few years i’ll need to pull the engine and tranny for a refresh to get oil leaks gone