Archived NVG 4500 Shifting problems

[K.L.Schumacher]

The 4500 5 speed in my 96 3500 4x4 has recently been giving me some downshifting issues and also getting into gear from Neutral. Trans has at least 200,000 miles on it. Trans is from a 99 with the 96 shift tower on it. Oil is around 19 months old (Castrol Syntorq/Mopar) First time I experienced downshifting issue was a month ago. Mountain driving, Light load coming into off ramp was unable to downshift.
Coasted to stop, Shut down and restarted in gear and drove away. Seemed fine for rest of day. Resumed travel next day and completed a 900 mile journey. Drove truck where I was staying and had some minor issues up shifting and downshifting. Started trip home. Drove 6 hours and approx 60 MPH for 6 hours, Coming into town went to downshift and had trouble downshifting again. Stopped truck, Put into gear and went and parked for the night.
Soon as I stopped checked trans temp with laser temp and showed 170 deg F approx. Checked oil level next morning and it was slightly overfilled still from last year. My thoughts are Pilot Bushing hanging up. Trans was last out Christmas 2005 when it got a new clutch, Pressure plate etc. If truck is not running I can move shifter in and out of any gear with no issues. Start it up and its hit or miss. Clutch pedal is pressed firmly to floor.

Thoughts . Just want to form an attack plan.

 

[Killer223]

could be hydraulics not working correctly, or yes the pilot bearing is dragging on the input shaft.
i have the same issues with my SB clutch that has only 1500 miles on it.
So check the hydros are working correctly. then i'd likely be the pilot bearing.

 

[K.L.Schumacher]

Thanks. I was leaning towards that area for the problem. Time to start pulling stuff apart.

 

[petersonj]

Time to start pulling stuff apart.

Before you start pulling stuff apart, you may want to do the following when you are having the problem:

Put the transmission in first or second gear. Depress the clutch pedal and start the engine and let engine idle. With your right foot on the brake, start releasing the clutch pedal and note the pedal height when clutch engagement occurs - is it early or is it normal?

If clutch engagement is early it is likely to be a hydraulic problem, although you can't rule out the clutch disc or pressure plate.

If the clutch engagement is normal, then it is likely to be a pilot bearing/bushing problem..

Hopefully it is a hydraulic problem which will save you considerable labor.

- John

 

[K.L.Schumacher]

Don't think that is the issue. Pedal height and engagement is good. I have never abused clutch that's in truck nor do I let others drive it. Pretty much figure its the pilot bushing in crank. Still has to come apart. Talking with mechanic that installed clutch for me. Hoping he will take truck on to fix it. Problem is he has had some cancer issues with his back. Hoping he will have his son do hard part with him overseeing job.

 

[petersonj]

Sounds like you are on track - let us know the final outcome.

- John

 

[K.L.Schumacher]

My truck is still sitting at this time. Mechanic I wanted to do work has bowed out due to his health issues. Working on alternate shop at this time. Just want to know what people would suggest as to style of crank shaft pilot bushing would be best for long term reliability and not ridiculously priced. I do have a factory torrington style in my new parts collection. If I use that one should it be re greased with better grease. Thoughts.

 

[GAmes]

A sealed bearing will give you better performance than a bushing. South Bend Clutch has them, but it might involve a little machine work of the flywheel to enlarge the hole.

 

[K.L.Schumacher]

Update on my shifting issue. Mechanic called me today that trans was out and he found the crankshaft pilot bearing was gone. Trans input just needs a fine sanding to clean and he told me clutch looked like new. I mentioned clutch has been in truck 12 years and that was when pilot bushing was installed. I don't abuse my clutch. New throw out bearing going in while apart. Going to see it apart Thursday and should have Friday. Got stuff to haul with my trailer.

 

[K.L.Schumacher]

Ended up needing a new transmission mount so that was installed. When picking up truck I chatted with both mechanics that double teamed on it and head mechanic thought I said clutch was only 2 years old . Corrected him and said just hit 12 years old. They were both blown away on how good a shape it was. No checking, Heat evidence or wear on pressure plate or flywheel. Guess I know how to drive a clutch properly after 45 years.Truck shifts good now for a high mileage transmission.No problem getting into gear stopped ,Downshifting or up shifting. Now I just have to service front driveshaft and reinstall and next is a new Spicer steering U Joint on drivers side in front axle.

 

[rhoads]

assume they installed a new factory bearing, if you ever pull the transmission again do your self a favor remove flywheel an install south bend clutch pilot bushing. hole needs to be enlarged a bit however it will last forever. I bought 12 and sold 8 to other owners (at cost ) over the years. I installed mine ,when I sold my 96 I had over 500k on the bushing no problem's. One gentleman was in a hurry installed a used flywheel resurfaced/w/bushing from S B C . called me later to give me his old flywheel, re surfaced with the bushing. Only thing he would take for it was the $12 he paid me. Saved his customer.

 

[K.L.Schumacher]

I had a factory bearing and chose to go that route again. 12 years on last one, I think truck will be gone before that's an issue.