G56 OFE "pulsating" when pedal is depressed

[hwebster]

Hi Guys!

I recently changed out my stock clutch for a SouthBend unit - G56 OFE. I have been noticing a pulsating feeling when I push the clutch in. My mechanic doesn't think this is a good thing! #@$%!Anyone have any insight into this? Thanks!

 

[seafish]

I could make a guess , and I am sure others will chime in, but the simplest thing to do would be to call SBC in the morning and ask them to diagnose the pulsation. There customer service, and associated tech support, is simply top-notch !!!

One way or another, please DO let us know what you find to be the problem... I will be installing the same clutch sometime in the next several months!!!

 

[hwebster]

Well I called SBC and also went back to the firm that installed the clutch. SBC suggested a bent finger or issues with some bolts, possibly an issue with the fork. We scoped the clutch, every thing looks fine, no obvious issues with the fingers, no broken bolts or even clutch dust.

Bryan at SBC was very helpful - suggests putting some more miles on it to see what happens... Will let you know!

 

[RustyJC]

Take a runout on the face of the flywheel. I had this problem as well as a 1-per-revolution vibration at idle when a local shop installed my OFE in my 2002. The problem was the shop's local machinist had misindexed the flywheel when he refaced it (he hadn't indexed it off the crankshaft mounting flange surface), and the shop found 0. 050" runout on the flywheel face.



With a new flywheel, this shouldn't be a problem, but it's worth eliminating as a potential cause.



Rusty

 

[DPrew]

When I had a con ofe put in my 02' with a NV5600 mine also made a bit of a vibration when the clutch pedal was pushed in. It worried me but it was normal for the con ofe. I never had a problem with it.

 

[CKelley1]

an 06 of mine started doing that and it progressively got worse. we pulled it down and two bolts that hold the pressure plate to the flywheel were broke off and another was lose. they were new bolts with the kit and torqued with a torque wrench. it had about 50,000 on the clutch when it did it. i think it was defective bolts. it caused wear on the fingers and fork. i went back with new fork pressure plate, through out bearing and grade 8 bolts and washers

 

[hwebster]

Update on the SB issue

Well I gave it some time and recently I started getting some serious vibrations and growling for lack of a better descriptor. So I gave up and took it back to the guys who did the install. Attached are some pictures of the clutch -

The obvious question is what the bleep is going on? I don't ride my clutch, even going to neutral at stop lights. I haven't over loaded it, last run was 3,000 miles with a 14ft uhaul!

Any suggestions? I've sent the pics on to Southbend as well. .

Have a great Christmas all!

 

[RVTRKN]

The discoloration looks to me like grease had contaminated the clutch.

 

[hwebster]

Thanks for the input... Will check with the mechanic...

 

[Joseph Donnelly]

The input shaft could be wobbliing from a bad bearing and G56 main case. that will cause transmission lube to get onto the clutch. See my column in Issue 71 when it comes out in February.

 

[hwebster]

Thanks Joe I'll check with the mechanic working on it. . H

 

[hwebster]

Well the shaft bearing is fine on the G56. Southbend has discussed the issue with the shop and will warranty the clutch but believe the issue is related to the installation. My thanks to Pete and everyone at Southbend and Harry at Peak Diesel performance! Will advise on the fix once it is in...

 

[seafish]

OK... . So how DOES one check the input shaft/bearing while installing a clutch...

Do you check for axial play, end play, or roughness or all three things??

Are there tolerances for the play check, or is NO play allowed??

I will beinstalling a SBC Con-Ofe sometime in the next 90 days, and would like to make sure that all goes smoothly, which to me, from what I have read, should DEFINITELY include checking the input shaft/bearings on the G56.

Definitely looking forward to the upcoming article in TDR...
Joe, does the article cover a full clutch installation ??

 

[RVTRKN]

Well the shaft bearing is fine on the G56. Southbend has discussed the issue with the shop and will warranty the clutch but believe the issue is related to the installation. My thanks to Pete and everyone at Southbend and Harry at Peak Diesel performance! Will advise on the fix once it is in...

With customer service like that, I guess I know where to buy my clutch parts, when I change mine out. Did they confirm contamination?

 

[hwebster]

New G56 is Installed and What A difference!

Got the truck back Wednesday after the shop rolled out the old G56 and put the new one in. I had to stop and call the shop to see if they had actually put a clutch in! I almost put my foot thru the floor! Previously I had to stand on it to shift...

So there must of been some issue from the get go. The shifting is smooth and no vibration what so ever...

Again my thanks to SouthBend- far exceeds the DMF unit... :-laf

 

[HBarlow]

Happy endings are always good to read. I've never heard anything but praise for SBC.

 

[RVTRKN]

Are you saying that they installed a new clutch or replaced the trany and clutch, what was the problem?

 

[hwebster]

Nope Just the DMF CLutch assembly, however I had issues with the 1st attempt, and endup replacing the new clutch. Still not clear what the issue was... The G56 comments were related to the possibility that the main bearing might have been an issue. It wasn't... Whew!

 

[RVTRKN]

The G56 is a good transmission, I'd rather own an NV5600, but it is what it is. I think they contaminated your clutch disk, and SB took care of it anyway. Does SB expect to get the clutch back?

 

[hwebster]

I have the clutch at the shop. I need to have a chat with SB on that. Frankly I can't see any contamination being the core issue. Same clutch and my sore knee is getting a little better... No idea why it was so hard to operate... No effort at all!