Engine/Transmission (1998.5 - 2002) 5600 failing?

[Ramtough]

Recently returning from a 700 mile trip w/my 10K 5th wheel. Last mile, transmission develops a major whine in 4 & 5th gears. I changed the transmission & transfer case oil for the first time at 78K mi right after this happened. Haven't towed since but I've run ~ 200 miles around town empty. I have a mild whine that probably wouldn't be noticeable to anyone else in 4th &5th gears around 2K RPM. I am also detecting a very mild whine at interstate speeds in 6th.



What should I do? Run it until it gets worse? Wait for it to seize? Hope it's my imagination?



The whole reason for buying the manual in the first case was to avoid a towing related transmission failure. This transmission should not be failing @ this mileage. Other than towing, it has never been in water or otherwise abused. Towing % is around 35% of total mileage.



What would you folks suggest? Thanks in advance.

 

[Gary - K7GLD]

Not too many choices, other than watching for external problems like lube leaks and such. Meanwhile, just drive it and keep an eye on it.



It *is* sorta suspicious that there seemed to be a reduction in whine AFTER the lube change tho' - was the transmission up to level on lube before the change - and what shape was the drained oil in? Did you check the used stuff carefully for metallic particles and such - and residue inside the case? Stuff that comes out of a noisy gearbox CAN give excellent clues as to what's going in inside...

 

[Ramtough]

I think the reduction in noise is related to two factors. First, the load on the transmision and secondly heat. The noise seems to increase as the transmission gets hot. When not towing, I can drive it about 15 miles before I start hearing significant noise.

 

[Gary - K7GLD]

Might want to check to make sure no body parts are coming in contact with the transmission case, and conducting normal gears sounds thru the sheetmetal...

 

[24Vpirate]

Could Be A Rear Diff Bearing Too

 

[Texas Diesel]

I hate to say this but it sounds like a transmission bearing failure. Stuff happens. Go to a good dealership and ask to take the transmission guy for a ride. They see this stuff all the time and should be able to give you an opinion. A good dealership will loan you a mechanic for few minutes.



I was looking at a 3500 6 speed that was whining in 5th/6th. I went by my favorite dealer, Benny Boyd in Lampasas, TX. The mechanic went for a quick ride and advised me to find another truck. I could barely hear the whine but to his skilled ears it was a very bad indicator.



Only an experienced ear will be able to give you a decent opinion.