Flex Plate Bent??? Maybe? (1 Viewer)

[JonnyB96TLC]

Preamble: I'm a new owner of a 96 FZJ80. I've tried finding info on this, but I have not found a satisfactory answer. If you know of a thread, directing me there would be of great help.

Data: 4.5L inline six, AT, all time 4WD

The Problem: When going at Interstate speeds >70mph and IN DRIVE, there is an audible scraping/whirring sound when I'm not on the throttle. Much like a hung up brake pad, but not coming from the brakes. The sound goes away immediately if the throttle is depressed enough to engage the transmission or if the vehicle is in neutral. There is no harsh chatter or vibrations I can feel, just a really annoying noise.

Potential Issues: Normally, I would seek out a diff or wheel bearing, but the relation to it being in gear leads me to believe it is something else. I did just replace the front main seal due to the thing leaking oil badly. When re-torquing the bolt, I used a ratchet handle to jam the flex plate in place.

Could I have bent or misaligned the flex plate slightly? Or is there something else more likely that I'm missing? What is the best way to check?

Could this lead to more problems rapidly? I can't say I'm eager to drop the transmission in the near future. Could it be driven say 5-10k miles like this or will it destroy other parts.

 

[ccslider]

So this noise only presented itself after the seal replacement?

You can pull the plastic cover and manually spin the engine by hand to inspect the flex plate. The recommended way to hold the plate is to use a socket on the bolt head, not wedged into the flex plate.

I would think if the flex plate has an issue then it would always be making a noise. Just because you shift to neutral does not stop the flex plate from spinning.

Usually noise that goes away when the throttle is depressed is driveline. When you depressed the throttle it loads up the driveline and tightens up if that makes sense.


You should try to get this thread moved to 80 tech and you will receive alot more support.

 

[JonnyB96TLC]

That was the first I noticed it, but I'm also very new with this truck. I THINK I've tracked the noise down to the center diff/transfer case.

Went through and greased everything and changed diff fluids. Hopefully that will take care of it. Haven't had a chance to go interstate speeds to test it out.

Added one on 80 series tech. I really appreciate the input!