QuestionI have a 1988 Chevrolet 3/4 ton Chevrolet Suburban that i use almost exclusively for towing about 9 t0 10 thousand pounds of RV trailer.The Suburban has 76000 miles on it.454 engine 3.73 rear end.
I have a bump or thump sound from the rear end at times on accelleration when towing or not towing.Runs fine going down the road and most of the time.I have had the drive shaft and center bearing repaired and balanced.All new U-joints and center bearing.Everyone i ask about it says not to worry it is just play in the rear end gears from wear.What do you say?Would any kind of rear end additive help? Thank You
AnswerI have an additional thought.
The driveshaft has a splined slip yoke. When the brakes are applied, the shaft kinda legnthens in the splines.
Then as you accelerate, the rear end tries to move about 3/4 inch foreward due to the spring flex, etc, but the torque in the driveshaft keeps the splines from sliding easily, and they don't slide...till the torque lessens somewhat, and then it pops in, creating the thunk.
I have seen it happen, usually on a Ford pickup. But pulling it apart if it doesn't have a grease fitting, and liberally lubricating it can lessen the severity of it.
That is, if that happens to be your problem.If it is a limited slip rear end, some slip-lube might help.
Van
