Slipping Clutch, under 50k?

[MichaelOverfield]

OK, pics help a bit but are not test results.

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5. Might be interesting to see your observations about the guide tube condition and grease in the old bearing cast iron collar.
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No test results and just pic's to review. I didn't see a smokin gun.

Gary

Concur, nothing was obviously bad, except the DMF. For the guide tube, no abnormal wear, same on the release bearing. All that looked fine too, I can try to snap a few pictures, since I have the old guide tube, it was the stock sheet metal formed part. I replaced with heavy duty cast steel part. There was zero free play on the input shaft, none whatsoever, like would be expected on a new or re-built transmission.

The characteristic shutdown "rattle" that has been there almost since new, it's gone. Seems that was the DMF making that horrible racket.

 

[MichaelOverfield]

Over 1200 towing miles in the new clutch, I really like it, even with the stock tune. I now have an automatic downshift device. Without the DMF, the vibration into the transmission will let you know it's time to go to a lower gear, which makes it obvious why the DMFs often fail, when they are there they are absorbing that energy. South Bend wasn't recommending this clutch with a stock tune, but it seems quite OK, granted I've been using 1st and when slowly backing, use LR. Both good to use with any clutch.

 

[RVTRKN]

Any updates?

 

[MichaelOverfield]

Any updates?

New clutch is working great. Completed about 2700 miles with tow. There is more pedal effort required, and at times a bit more noise at idle. I also note a clutch pedal push or two can quiet that down. Not sure what in the clutch causes that, but it's not a big deal in any case. Now I have an early oil change message and rising oil level due to regens to deal with.

 

[RVTRKN]

New clutch is working great. Completed about 2700 miles with tow. There is more pedal effort required, and at times a bit more noise at idle. I also note a clutch pedal push or two can quiet that down. Not sure what in the clutch causes that, but it's not a big deal in any case. Now I have an early oil change message and rising oil level due to regens to deal with.

My opinion on that noise, is the DD clutch is slightly out of center causing vibrations. BTW, it is a lot worse with a SMF. It doesn't seem to center when the clutch engages. I will pump clutch a couple of times, when warming up the truck, to help center it. I imagine its bad for the input shaft, if left to idle long periods.

 

[MichaelOverfield]

My opinion on that noise, is the DD clutch is slightly out of center causing vibrations. BTW, it is a lot worse with a SMF. It doesn't seem to center when the clutch engages. I will pump clutch a couple of times, when warming up the truck, to help center it. I imagine its bad for the input shaft, if left to idle long periods.

Seems plausible. Given the much beefier piliot bearing it's probably not likely to do much harm. That bearing would have to get loose before the input shaft would see much of a that vibration, I would think. I had ZERO play on the input shaft. I was worried it could have some play given the racket from the DMF.

 

[MichaelOverfield]

My opinion on that noise, is the DD clutch is slightly out of center causing vibrations. BTW, it is a lot worse with a SMF. It doesn't seem to center when the clutch engages. I will pump clutch a couple of times, when warming up the truck, to help center it. I imagine its bad for the input shaft, if left to idle long periods.

Another possibility: it's free play on the splines to the discs. When both engage on one side of that free play there is wiggle room for chatter.. other times the engage slightly out and close up or eliminate that free play, given it has 2 discs.. and then it's quiet. That might explain why it goes away with some clutch cycling..