Engine/Transmission (1994 - 1998) Noisy NV4500 when under load

[khalsey]

I use my 1996 3500 during warm weather times of year for pulling my 15500 lb 5th wheel. I purchased it new and now has 84,000 miles on it. I noticed last year that when boost gets to about 12 lbs or higher in 3rd, 4th, and 5th it makes a noise like a bunch of marbles rolling around in a container. I have changed the lube two times and used the proper Castrol Syntorq. I plan on changing it again in spring before I start driving it again to see what old lube looks like and if new lubes makes any improvement. It's a RWD with 3.54 axle ratio.

 

[NIsaacs]

If it sounds like a pig eating marbles, that is a bad sign I would drain the oil and pull both pto covers and take a good look at everything. On a 4x2 it is easy to pull the rear housing and inspect 5th gear.

Nick

 

[khalsey]

I agree with you that it is time to take a good look at internals with covers off and tail housing off. I had the tail housing off at 38,000 miles to install a bettter 5th gear retainer nut before it it came loose.

 

[HCannon]

Harmonic balancer? They can cause some strange things.

 

[khalsey]

I will take a good look at the harmonic damper before I drive it again. Thanks

 

[GAmes]

I replaced my damper with a Fluidampr and it decreased engine vibrations dramatically, but it didn't make my NV4500s last any longer. Inspection criteria is in the FSM and to do it right the damper will probably need to be removed. The little lines that are supposed to line up are very difficult to see when the damper is installed.