6.5 diesel manual Tranny issues

[rfletes79]

Not sure if this is the right section but looking for some help on a 6.5 I'm working on. It's a factory manual 5 speed 1998, CC dually 4x4. All forward gears work great but as soon as you put it in reverse it feels as though it has a dead clutch. Slips so bad you can actually stop the truck completely in reverse and not stall.

Again, forward gears perfect. And will stall going forward. Reverse slip like crazy almost not able to move.

1998 Chevy, 3500, 6.5 diesel, 5 speed manual, 4x4

 

[LBZ]

Does it smoke the clutch when in reverse and you Rev it up/leave it in reverse?

Sent from my D5803 using Tapatalk

 

[zf>allison]

That's weird, I do think that the later 90s trucks had a dual mass flywheel. Not sure how that being bad could do what your describing though. The 5 speed should be an nv4500, they are more notorious for the 5th gear nut backing off and losing 5th gear. I had a zoom aftermarket clutch that I ripped the center of the clutch disc out and it did all kinds of messed up stuff. Drove it into the shop with the clutch pedal on the floor, that's the only way it would move.

 

[rfletes79]

No clutch smoke at all in reverse or any gear....

 

[02CCSB]

It's an NV4500, reverse has its own fork, cast iron, at the back of the shift tower. The 5th gear fork runs off the side of it. My guess is the reverse fork is toast, not common, but if someone was in there and rebuilt it with the reverse collar on backwards, it wouldn't fully engage and would destroy the fork in short order.

 

[THEFERMANATOR]

Going to sound weird, but try putting the transfer case in 4 low and see what happens. Did a search, and found some reports of the transfer case doing this in reverse only. I know the slider is tapered to go in one direction, so I could see the nylons wearing, and it kicking out in reverse.

 

[rfletes79]

Just seen this today, gonna give it a shot. What might I expect by trying 4 low??

 

[THEFERMANATOR]

Iits just to see if its in the transfer case or not.

 

[rfletes79]

OH ok. Thx.

 

[rfletes79]

Well, it backs up in 4 low.... No prob. Can't even hold it back with the brakes at all.... Now what?? Does this mean transfer case is messed up? Good call ferm, 4 hi and 2wd same little to no reverse (slipping like crazy).

What transfer case does this thing have?

 

[THEFERMANATOR]

Have to crawl underneath and see, but I think it has a borg warner 1350 in the duallys.