Defective LUK Throwout Bearing

[jaluhn83]

Anyone have issue with a LUK SM clutch having a bad throwout bearing? I pulled the truck down last month to replace a bad ring gear and decided it would be wise to do the clutch at the same time even though the old one only had ~50k on it. New one seems to have a bad throwout - as soon as started it I had a high pitched squeal that went away as soon I stepped on the clutch petal but then showed back up intermittently while driving, usually as a 1-2 second chirp but sometimes 10-15 seconds. Similar to a belt squeal but not quite. No real pattern, though it seemed to happen more often at higher rpm and would chirp fairly consistently when going from load to coast. (ie reversing the load on trans). No evidence of slipping, vibration, etc, just obnoxious noise. Put about 1200 miles on it that way and then it stopped, but now has a fairly quiet metallic rumble and vibration through the clutch petal. I suspect one of the balls or rollers in there had issues somehow, but either way pretty sure it's the throwout. No changes to the trans, engine or clutch hydraulics and no reason to think I messed anything up putting it in.

I did notice that the throwout design was different on this kit than the last 2 I've had. Cant recall exactly how, but definitely a different design. IIRC date on manufacture on this was 2014. 1st one I got was new from LUK around 2005, 2nd was off ebay purchased around 2012-3 but no idea what the actual manufacture date was. I'm wondering if this is some new fancy POS cheaper design they went to?

Really ****** me off since I only replaced it because it's a pain to get in there with the turbo and I wanted to be safe.... and I'm in the middle of moving and going to be TDY for the better part of the next year almost all without any easy shop or spare vehicle and driving across the country and back... so I made sure everything was good and solid only to have to monkey around and now redo half of it for a $30 part I didn't actually need to fix!

 

[riotwarrior]

Well no exp...but did find I did not like the new TO i purchased...stamped steel face vs machined flat face.of old.

Spent crapload time repacking old one with good synthetic Viper Grease...works well no issue yet..crosses fingers.

 

[franklin2]

This guy had the same problem/question a couple of weeks ago.

http://www.oilburners.net/forums/showthread.php?77294-T19-Manual-tranny-throwout-bearing-squeak

 

[MTKirk]

Just a theory, but; I believe many sealed bearings are "de-greased" in storage. They get too hot and because they are stored flat the grease oozes out, this doesn't happen in the vehicle because centrifugal force keeps the grease away from the seal when they are in use (and hot). The solution? remove the seals and add grease (good luck on a throw-out bearing) or order your bearings in late winter/early spring from a company that has quick turnover. Check the date, if it's been in a warehouse over the summer and feels anything but buttery smooth, send it back!

 

[IDIoit]

the throw out bearing for these trucks SUCK!
its not just LUK,
i spent over 700 on a SBC, AFTER 6 MONTHS OF USE, AND 8 MONTHS OF SITTING...
and when i went to put my clutch in, the TOB was waisted.

i blame it on the fact that we get most of our stuff from china.
END IMPORTED "GOODS"

 

[jaluhn83]

Is the LUK bearing the same as the regular 7.3 idi stuff? I know the clutch is special for the SM setup, wouldn't think the TO would be too but curious if anyone knows for sure.

Any suggestions on where to get a better one? May just stick the old clutch back in - at least that one worked. Problem is I'd have to figure out which of the random unlabeled boxes it's buried in....

I sent a '***' email off to Luk yesterday, have to see what comes of that....

 

[south bend clutch]

IdIoit is exactly right. All the throwout bearing manufacturers in the US have either closed or moved out of the country. I tried to get a bearing manufacturer out of Chicago to make us a T/O bearing for our most popular number. We use around 18,000 per year of one number so I offered to pay up front for one year and give them a PO for the next five years at the same quantity. They chuckled and said that I had to pay up front and take 100,000 bearings for them to make the bearing. Calculated out to 1.8 million dollars. Now realize this is for one bearing, one vehicle...we make clutches for ALL vehicles. America needs to wise up!

Peter

 

[riotwarrior]

IdIoit is exactly right. All the throwout bearing manufacturers in the US have either closed or moved out of the country. I tried to get a bearing manufacturer out of Chicago to make us a T/O bearing for our most popular number. We use around 18,000 per year of one number so I offered to pay up front for one year and give them a PO for the next five years at the same quantity. They chuckled and said that I had to pay up front and take 100,000 bearings for them to make the bearing. Calculated out to 1.8 million dollars. Now realize this is for one bearing, one vehicle...we make clutches for ALL vehicles. America needs to wise up!

Peter

Thats almost 50 TO per day...for one specific type...wowzers

 

[jaluhn83]

Finally got back to update this...

Turns out it wasn't the throw out bearing at all, go figure. When I pulled it apart the 'nose' section of the trans that the throwout bearing rides on was broken off from it's mounting flange and just flopping around on the input shaft. Fairly clean fracture at the flange and it looked like the front (clutch) side has been rubbing as well. No idea how or why through. My initial thought was I had put the clutch disc in backwards and it was rubbing on the hub, but after checking it was in correctly. Double checked the measurements and there should have been at least 1/8" clearance between the end of the nose section and the clutch disc hub. By best guess is that I somehow got it caught on the pressure plate putting the trans in and managed to bend it to where it was rubbing on the input shaft. Not sure how that led to it breaking off though...

Thankfully it was easy to unbolt the flange (S47 is bolt on thankfully, S42 is press in and I'd have been screwed) and weld it back up. Seems to be working fine now.