tramsmission clicking

hey guys. Been asking around on this to my mechanic savvy friends and most seem stumped.. Stumbled on this forum figured I would see if anybody has had something similar.

my transmission for the most part acts fine. No slip on speeding up seems 100% fine. Until I slow down to about 5-10mph... I get a slight rumbling sound. Sometimes... Lil once a week its more of a ping like metal on metal. But high pitched. But for the most part of rumbles wit a slight vibration. And only when its about to kick into idle after accelerating. The only other symptom that I can think of that started bout the same to.e is if I am at high speeds... Like 50-60 and let off the accelerator there is a very slight vibration for about a half a second then goes away. Two might not be related but figure more info is better.

don't know much about vehicles... But my mechanic I do trust and have used for a decade plus is now 8 hours away.

something obvious wrong? I will eventually have to take it in... But would like the opinion of people who had a previous experience or just knowledge but not trying to take my money first. Thanks a ton.


dave

 

Grease (or by now, maybe replace) the driveshaft u-joints and/or center bearing.

 

wow thanks for the quick response. You sound very confident.. Is this something I should try to grease and if it comes back replace? Or in your opinion just replace? Also.. Are both symptoms related to the same issue do you think?

 

I assume you've got higher mileage and if the u-joints have never been greased honestly replace them. Now, the center bearing... lay on your back under the truck; see where the driveshafts meet at that "center" bearing? Now push up on a shaft very near the bearing, does it move up and down several inches or is it fairly tight? On an old truck of mine you could swing that sob 10 inches all around in a circle (in other words I got my moneys worth out of it) Good luck!

 

Just an update. I greased all but one (that one was at an angle the cuppler wouldn't stick on it flat) of the U-joints to see if it had any effect, and it did seem to help but both problems still persist. Quite honestly, I had never greased them in the 95k miles I have had the truck and I'm betting when I brought it in for a tune up that's not something they did. They look beat up, so I'm going to replace them myself this weekend. I"m sure the bearings on them are dust by now. It did seem to help some though, so will post back here when I replace them.

The center bearing has almost no movement at all... I expected at least some as it's never been replaced, it might have moved 1/16th of an inch, is there supposed to be SOME movement? As in more than that?

Thanks again for your advice. It is truly appreciated.

 

fololow up for readers. when checking u-joints, lift the rear axle off the ground so the tires are free and no parking brake and tranny in neutral. then spin, check, move the shaft.By taking the load off the wheels and shaft spins free, you will find failed ujoints you will not find with the wheels on the ground. personal experience 101.

 

many u-tube videos on carrier bearing inspection and replacement. watch them once real work is done. A pita without a good 1/2 inch air impact wrench.

 

Just realized I never replied to this. Thanks so much for your information, it was indeed a bad U-joint causing all the symptoms I had posted. Replacing the culprit did fix all issues.