Transmission Noises

[AMGeneral]

Ok,got a few questions,The trans in my 816 makes 2 distinct noises,the first is best described as a rattle near the input shaft/bell housing aera only at low idle(550 to 600 rpms)with the trans oil at operating temp.It usually accompanied by the engine bogging down while making the noise always occurs in neutral while sitting still. The second occurs between 40 and 50 mph in O/D,also sounds like a rattle or slack in the trans gearing,only occurs in 5 th with hot oil,never cold oil.No other unsual noises,no metal or other contaminants in the oil,shifts fine through all gears,no other noises in any other gears,I'm running GL-1 with Lucas oil stabilizer,mixed 80/20.I have pulled the top cover and made a visual inspection of the trans internals,no visible problems.Any ideas before I resign the 816 to the" NMC "line for repairs?

P.S.I have checked the backlash on the PTO and it's within specs.

 

[Scrounger]

I would pull the inspection cover on the transmission and check the throw out bearing for slop. It could be something as simple as a bearing retainer clip loose. Beside it will give you a chance to give a quarter turn on the grease cups on the inside of the housing that lube the cross shaft.

 

[AMGeneral]

Well,mine has grease fittings on the shaft outside the bell housing,so that's not an issue .And i've already pulled the inspection cover and checked the relase bearing(which i've noticed mine does not have a grease fitting by the way).The noise is definetly not a clip as it is MUCH more pronunced.I've heard other old trucks do this when the input shafts get worn so much that they rattle in the clutch disk splines,but mine seem tight from what I can see.But good ideas to be sure.

 

[FormerNewMVGuy]

I had this noise in a dt466 found out the input shaft bearing was shot

 

[5tonpuller]

sounds like old age and use. could be more OR something easy to fix.
I hear saw dust works well. Sorry Mine makes more rattles when warm too. When you get all that stuff ran thought you and age I guess i would rattle too when warm.
My $0.05 worth.
Matt