Drive Train

Rattling Noise from Driveshaft/Transmission Area

Rattling Noise from Driveshaft/Transmission Area

About a month ago I posted on my developing engine marbles (87 a/t 127k) - this rattling noise like loose nuts and bolts occurred mostly at shutdown but progressed so that it was present often at idle. Some of you mentioned this noise preceded your torque tube replacement. Some others brought up a rivet problem where the rear flex/drive plate connects to the torque converter, and I pretty much decided that was my problem. The noise was definitely coming from the torque converter area, and traveling forward in the torque tube. Not looking too fondly to this big job....

Last weekend I got under the car, removed the exhaust and heat shields, and removed the front flywheel/flexplate cover. There is an access hole at the front bottom of the torque converter for the 6 bolts on the drive/flex plate. These should be torqued to 34 ftlb and all seemed fine but I "snugged" them anyway. (I used a screwdriver to turn the flywheel to move the torque converter bolts into position.)

At the same time I checked all the bolts up front at the flexplate. The 8 bolts in the center of the triangular flexplate were very tight, but I "moved" them (barely) to make sure they were tight. Same with the 6 outlying bolts on the flexplate. I really couldn't tighten them but managed to budge them tighter.

The last thing I checked was the rear torque shaft pinchbolt - there is an access hole in the torque tube. The manual calls for 54-61 ftlb, but I went with Tony's 66 ftlb on my torque wrench (Tony - thumbs up on the website drop boxes!). I started turning, the bolt was pretty tight but it didn't click. I turned again with some muscle... no click. Then came the nerves... is this right? I'm not gonna pop this bolt am I?? Check the wrench torque setting. Turn a little more very slowly. No click. Oh Dear Lord this is a nightmare. Stop, rest, take some calming breaths, pray, give it another small turn. Click. About time!! (This is where you get up and run away before your shark bites you - haha.)

Put everything back together - no noise !! I drove the car to work three days last week, and also ran an errand or two. Now when I turn the key off, the engine just shuts down - no rattle-bag of marbles!!! Whew! Glad I didn't drop the rear-end, the transmission, etc!!!

SO, I suggest you guys check your rear torque shaft pinchbolt (after you check the forward pinchbolt).

BUT I'd really appreciate any thoughts on this - I've got no real clue about the actual cause of the noise. !??

John Pirtle
87 a/t 127k (a quiet car is a happy car, and mine is happier)

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