failing throw out bearing

[dripley]

I just made a 1000 mile round trip from Alabama to home and back again. Upon arrival last night I noticed a slight squeal with the clutch depressed. Drove the last couple miles to the rv and sure enough I am hearing it while changing gears. When I parked I left the engine running and it appears the bearing is turning constantly. That might explain why it is failing prematurely, only 70k on the bearing. 

 So today I determined that the bearing is definitely turning all the time. I removed the slave and started the engine and no noise, the bearing was not spinning. I replaced the slave about 60k and never compared it to the original.   So I am thinking that maybe the rod is a little long and has been spinning the bearing for a long time.  . I shortened the rod a little better than 1/4" and re installed it. The bearing is still spinning, engine on and clutch released. The clutch feels no different. I still have about 1/2" to 3/4" movement before meeting much resistance. So I am thinking I will shorten the rod another quarter inch and see what happens. I cant help but think if the rod was to long that the bearing would have held up this long constantly spinning. Is there something else in there that could fail and cause the bearing to be engaged all the time?

 I know the tranny has got to come off no matter what to get this fixed. I am just trying to either get it home and do it myself or find some one that wont bend me over the stump and do it right. To get it home I have got to get this bearing to stop spinning. 

[Mopar1973Man]

They are constant load throwout bearings the slave rod will constantly keep pushing back against the throw out fork. So you going to need to replace the throw out bearing like it or not. All you have to is measure the fully extended length of the slave rod and then measure the distance from the bell housing to the fork and see that the slave rod will be pushing quite a bit on the throw out bearing.

[joecool911]

Not used to the concept of constant contact. Ok. I got 300,000 miles out of my F350 on the original clutch and bearing. My initial comment was to say put the truck in neutral at stop lights and foot off the clutch pedal. May still be a viable habit. But my suggestion now is to buy an American made, best quality bearing you can get. Too hard to get to it for replacement with a cheap bearing.

[Mopar1973Man]

Like my slave cylinder if I unbolt it and let it hang out at full extent then it would be like two inches out of the bell housing I would have to shorten mine but then I would have no throw afterwards to disengage the clutch. So the only thing I can say is time to invest in a throw out bearing! I know everyone hates to drop a transmission for this reason but its broke and needs to be fixed.

[joecool911]

Time to look at the clutch and rear main seal too.

[dripley]

I was not a ware of the bearing always spinning, but when I had the slave out yesterday I noticed it is as Mike describes it. I dont think you could cut enough off to stop it from spinning and still use the clutch. The clutch and bearing only have about 70K on them. The bearing and clutch came from Valair and I am pretty disappointed on the short life span of the bearing. Hope the clutch is fairing better. I had the rear main changed at the same time. 

 I changed the OE clutch out at 240K while it was in the shop replacing the ECM. Turned out the old clutch still had some life left in it and the bearing was still fine. 

 I have to agree it is going to suck replacing the bearing but is necessary. It is not much fun dropping that 6 speed in the gravel driveway and paying someone to drop the drive line for $50 bearing sucks even more.

[dripley]

Well I finally made it home after completing the job in Alabama. Here is a photo I was able to take. Thought yall might like it, I darn sure enjoyed taking it.

Anyway I got home and pulled the tranny and all that goes with. With the racket it had been making I was surprised that it had quieted down a lot by the time I got home. Not sure why because this is what I found when I got it out.

Nothing left but the races and the were worn down to nothing. No bearings at all and the only thing I found after dropping the tranny was metal shavings. Not sure why the one from Valair failed.

The new one I have is a National bearing part#  614114. Timken had the same part #, but I see on the box it is made in China. Might try and find another tomorrow, if not I guess I will have to roll the dice.Got to get back on the road by Wednesday. 

[greed]

Rockauto has throwout bearings made by SKF. That is what I used. I don't know if they are any better than others, but, as for price, they should be.

[Mopar1973Man]

Just about everything is made in China anymore. If it was me, I would go to the local NAPA store grab one and get that trans stuffed back in the truck.

[IBMobile]

If the OEM bearing  lasted 240k miles and the aftermarket lasted 70k miles I think I'd put the  OEM back in.

[dripley]

Rockauto has throwout bearings made by SKF. That is what I used. I don't know if they are any better than others, but, as for price, they should be.

I did see that one and it was about double in price. In retrospect the difference is really not that bad if you consider having to replace it again.

 

Just about everything is made in China anymore. If it was me, I would go to the local NAPA store grab one and get that trans stuffed back in the truck.

Very true. I went ahead with the National bearing. 

 

If the OEM bearing  lasted 240k miles and the aftermarket lasted 70k miles I think I'd put the  OEM back in.

I cant disagree with what you say. The numbers add up. 

 

 

I had to rent a car and take a road trip for work. Got back Wednesday and went back to work on it. I did find some of the bearings up in the bell housing. The big thing I noticed was the tube the bearing slides on was dry and rusty, no grease. I went back and checked the bore of the failed baring and it was the same way. No evidence of any grease ever being applied. I guess I am going to have to take the blame since I replaced the tranny about a year after I had the clutch installed, 4 years ago. Not sure how I missed that step, but it was pretty evident I did. I big     on me.I do believe the guy that installed my clutch missed it also. It is greased now. I cant help but think that this is probably why the clutch was jerky on engagement. I believe W & F was right when he said in another thread on the subject it was a sign of another possible problem. Either way it is back together and the clutch does operate smoother. 

 

This is the second time I have removed the 6 speed in my drive way. The first time 3 people helped me. This time I only had 1. My son helped me get the transfer case off, the cross member out, and the tranny off. He was able to come back one afternoon and help me bolt up the tranny(got it on by myself) and get the cross member back on. I did the rest by myself. I am getting to old for this, there is not a muscle on me that ain't worn out. 

 

I did have a transmission jack this time. This one  http://www.harborfreight.com/automotive-motorcycle/lifts-stands/800-lb-low-lift-transmission-jack-69685.html. i found i guy on craigslist who had one barely used for $80. It worked fairly well except the adjuster to pitch it forward and back was impossible to turn with the knob with the tranny on it. I had to take vise grips and clamp them on and turn it. It operated fine with the transfer case on. The chain for strapping lacked a little to be desired but I used a ratchet strap instead. 

 

I am up and running and life is good again.

[joecool911]

Just about everything is made in China anymore. If it was me, I would go to the local NAPA store grab one and get that trans stuffed back in the truck.

I'd guess that the Timken made in China has higher quality standards than a Napa one.

[dripley]

Lets hope so. Cant help but thinking the lack of grease in the bore and on the tube it slides on put some undo stress on the bearing, especially since it turns all the time.

[IBMobile]

The t/o bearing my have lasted longer with the part being greased. Looks like it never fully released from the pressure plate. Any added stress on a part will shorten it's life span. IE: if a part is designed with a 100k mile life span and an uncalculated force / load is applied a premature failure is inevitable.  

 

By the way how were the fingers on the pressure plate?

[joecool911]

Any access to grease these suckers without dropping the transmission? Is it common these days to have constant contact with the pressure plate? Seems like a design flaw. I've always taken my stick shift into neutral and release the clutch pedal at lights.

Edited June 1, 2014 by joecool911

[IBMobile]

My 40+ years of working on cars have almost all been with Volvo. With that being said all the cars that had clutch cables before 1983 had a spring attached to the through out arm that would hold the bearing off the p-plate when not engaged. 1983 and newer did away with the spring  and the factory spec is 5mm of negative play (slack) between the cable and t/o arm so the bearing is resting on the p-plate.    All the hydraulic actuated clutches I come across In the newer Volvos and other vehicles have 0 play. As for getting in there to lube it, very hard to see in there let alone lube it. 

Edited June 1, 2014 by IBMobile

[joecool911]

So, does running idle at stop lights in neutral and foot off the clutch pedal reduce wear in this situation? Seems like without added pressure it should help some. Spinning with light pressure versus spinning at full pressure make any difference? My 1996 ford F350 went 300k on the original clutch and T/O bearing. Always put it in neutral at stop lights. It had hydraulic clutch.

[Mopar1973Man]

So, does running idle at stop lights in neutral and foot off the clutch pedal reduce wear in this situation?

 

Not really. Because with your foot on or off the pedal the bearing will continue to turn. It comes down to how much grease was added to the bearing when its sold. You'd be surprised how much force just the slave cylinder pushes again the bearing.

[dripley]

Any access to grease these suckers without dropping the transmission? Is it common these days to have constant contact with the pressure plate? Seems like a design flaw. I've always taken my stick shift into neutral and release the clutch pedal at lights.

 

There is about a 5" long by maybe 1/4" slot between the bell housing and the tranny on my 6 speed. I believe it is there to allow any leaking fluid out. Cant imagine getting anything in there to grease it with though.

 

The t/o bearing my have lasted longer with the part being greased. Looks like it never fully released from the pressure plate. Any added stress on a part will shorten it's life span. IE: if a part is designed with a 100k mile life span and an uncalculated force / load is applied a premature failure is inevitable.  

 

By the way how were the fingers on the pressure plate?

 

The slave keeps the bearing in constant  contact with the fingers. When I re installed the slave I had to push it in at least 1 1/2" against the pressure of the slave. The fingers did not appear to be damaged, but were polished a little.

 

The old bearing from the second tranny I installed has grease in the bore.

 

Not really. Because with your foot on or off the pedal the bearing will continue to turn. It comes down to how much grease was added to the bearing when its sold. You'd be surprised how much force just the slave cylinder pushes again the bearing.

 

This bearing did have grease around the exterior of the seal. The bearing turned easily but you could not make it free spin. So I hope there was enough in there. I could not see a way to add any more to it.

 

The slave does put a good amount of pressure on it. I re used the old slave that I cut a 1/4" of the rod and it shifts fine and goes into gear, 1st and reverse, just fine while sitting still. I don't think it makes much difference since the slave loads up as soon as it make contact with the throw out arm.

 

I does seem to me if you add any pressure, like riding with your foot on the pedal or the bearing binding on the tube, it could cause premature failure. At least I am hoping that was my problem.

 

So, does running idle at stop lights in neutral and foot off the clutch pedal reduce wear in this situation? Seems like without added pressure it should help some. Spinning with light pressure versus spinning at full pressure make any difference? My 1996 ford F350 went 300k on the original clutch and T/O bearing. Always put it in neutral at stop lights. It had hydraulic clutch.

 

I do this mainly to avoid wear and tear on my leg. My OE was still fine when I change the OE clutch at 240K. 

[Mopar1973Man]

I does seem to me if you add any pressure, like riding with your foot on the pedal or the bearing binding on the tube, it could cause premature failure. At least I am hoping that was my problem.

 

If the bearing was binding up from sliding on the tube the master cylinder would most likely explode. Don't ask how I know this one.

 

As for riding the pedal I don't think it will change much of the life span of the bearing but it would indeed change the life span of the clutch (slippage). The fact the bearing is constantly turning loaded or not as soon as the grease disappears the bearing will fail pressed or not.

 

Thinking a bit more about this grease disappearing... The only thing I could figure that would do that is excessive heat in the clutch housing making the grease sweat out of the bearing?   (educated guess...)