6.9 idi best pilot bearing/bushing?

[OldIron82]

What is the best pilot bearing/bushing to use for a 6.9 idi that will be going against the zf5 trans? I see mixed opinions on this kevlar bushing offered. Also am I correct in saying the 6.9 flywheel MUST be used and NOT the 7.3 correct? Thanks.

 

[Knuckledragger]

If you use the later flywheel, you may have some harmonic problems since the rotating mass is different. Otherwise, it will fit.

 

[MTKirk]

The decision on the pilot bearing was made for me. The old needle bearing pilot bearing had worn a groove in the input shaft (see pic), I doubt a needle bearing could survive on that surface. I was able to push the kevlar deep enough (or was it shallow enough? I can't recall) that it was mostly riding on ****** steel.

Also; In the picture you will notice the scoring on the input shaft collar (where the throw-out bearing rides) I've seen this on most manual transmissions I've worked on . It can become a problem by increasing the force needed to press the clutch pedal (wearing out your leg & clutch linkage). This is where a grease-able throw-out really shines. My pedal (with the grease-able throw-out) requires much less pedal force than previously. With my T-19 I was able to find a factory grease-able bearing. If I couldn't find one I would drill & tap a hole for a nipple (in the collar where the fork rides in a regular bearing) then attach a piece of fuel line to the nipple at the bearing end. Attach the other end of the fuel line to a zerk mounted on the bell-housing.

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[IDIoit]

kevlar....
south bend made that decision for me.
after ******** about it here, everyone said it was the best option

 

[OldIron82]

Grease-able throw out bearing!? Does my zf5 have that? If so I'll be under there tonight with the grease gun! Thank you gentlemen South Bend Kevlar it is.

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[79jasper]

You have to mod/add that.

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[The Warden]

Grease-able throw out bearing!? Does my zf5 have that? If so I'll be under there tonight with the grease gun! Thank you gentlemen South Bend Kevlar it is.

If there's a grease-able throw-out bearing available for the ZF5, it's news to me. I bought a throw-out bearing with a hose and a Zerk fitting meant for a T-19, hoping it would fit the ZF5, and found that the T-19 throw-out bearing's inner diameter is too small and will not fit on the input shaft collar.

The T-19 and ZF5 throw-out bearings; T-19 on the left, ZF5 on the right:

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The T-19 grease-able throw-out bearing; note the nipple for a hose...you're supposed to drill a small hole in the bellhousing, insert a Zerk fitting, then run a hose from the Zerk fitting to that nipple. Great idea; I wish a similar throw-out bearing were available for the ZF5:

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As to the original question, I'm a big fan of the Kevlar pilot bushing. Here's the pilot bearing on the T-19 flywheel that I removed...you can see that it got dry.

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The Kevlar pilot bushing compared to the pilot bearing that came with the ZF5 single-mass flywheel.

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Also, for what it's worth, I bought a South Bend single-mass flywheel clutch kit when I did my T-19 to ZF5 conversion. The flywheel/clutch kit were meant for a 7.3L; I used them on an '84 6.9L. I've been running it for over 10 years and 50,000 miles and have had no trouble whatsoever