Chip

Well, I just installed a SBC in my rig. I replaced the flywheel with a new one from Cummins. Wow, what a fun job that was ! A pretty painless job. I had all the right tools and took less than 6 hours to replace. I have one question to anybody that has a SBC, I'm getting some chatter when releasing the clutch into 3rd gear. I'm thinking I may have a bad output shaft bearing on the transmission ! Any info would be appreciated.

Chip

marksmith

Was your flywheel flat? If your flywheel has any taper to it that clutch wont last long. (Might be the reason for the chatter) The flywheel needs to be stone ground flat. Taking it to a machine shop and having it lathe cut is not recommended.

Thats all I can think of
Take care
Mark

thumper 549

your shift into 3rd ought to be pretty fast (not room for a lot of slip) so....Iwould check all other things b4 the clutch...if it was going to act this way it would do so in other gears also.

Chip

Thumper549,
Yea, it is a short shift- it only does it when I engage the clutch in 3 rd gear then it goes away. It's not a slip of the clutch but a chatter. Maybe I need to check or replace the output shaft bearing on the aft end of the transfer case where the rear drivshaft goes into the transfer case.
Chip

thumper 549

so it only dose this as your releasing the clutch?? in 3rd??

MCummings

Which South Bend Clutch do you have?

Sounds like you are trying to start off in 3rd gear.

Some chatter is normal,, especially is you launch in a high gear, or have to slip the clutch at low RPM, with a big load.

Merrick

Chip

Yep, only in 3rd gear-- I have the mu 0900 CON O. If I keep the rpm's up around 2k when I change to 3rd, it doesn't seem to be as bad !!

Chip

MCummings

Give it some time, and if it doesn't get better with 500-700 miles, Give Peter at South Bend Clutch a call. These Clutchs act funky when breaking them in. Most people report slipping in the first 1,000 miles. Mine did, but with miles, it kept holding stronger everyday.

Like I said, give it sometime, if it doesn't get better, or if another problem arises,, you will definatly need to look into it.

Merrick

Chip

Thanks for the input Merrick, Oh, I'll be watching everyday, I crawl under quite a bit checking the new rear main seal that I also replaced--- hence the reason for replacing a throughly oil soaked disk. So far, so good, no leaks.
Chip

Chip

Merrick,
I have a question, Would the 100k Cummins warrenty still be good if I'm the 2nd owner of my truck ?

MCummings

5 years, 100K. Whicj ever comes first. Granted the previous owner didn't void the warrenty with injectors or a "hot" box,, or any other performance modification. Yes, it should be.

Chip,, Watch that leak very closely. Oil on the clutch will defiantly make alot of chatter, and will ultimatly lead to a clutch replacement.

Merrick.