That !@%$#$ Knock..., think it's the trailing arm pivot Options

[ss6]

For most of the summer, I would get this random knock when the car was moving, sounded like it was right behind my head, ie around the oil tank, tightened the piss out of everything, but it kept coming back.

OK, last DE of the season, it's 35 degrees on the track (some poor soul totalled his '93 turbo when the sun went down and the traction went with it), and now both sides of the car started making this noise. Best I can figure is it's the trailing arm pivots.

These pivots were completely rebuilt 2 yrs ago by a pro. Do I need to lube them somehow? Do I have them too tight? WTF?!?

[redshift]

Random knock? Is it random and singular, or a frequent event?

It's not related to any condition?

(IMG:style_emoticons/default/smile.gif)

WHAT THE HELL IS HAPPENING!?

heh

M

[Brad Roberts]

I'm betting that the inside control arm mounts are oblong'd. If your "pro" used the hard plastic bushings and he didnt trim them to fit on the outside.... then the control arm shafts where never tight in the car. The nuts on the ends can be tight but the shaft never locks down against the inside ear (which in turn allows it to move around in the ear.)

Pull them down (not off..) you should be able to drop them far enough away to see if the inside ear needs to be welded back up.. then the bushing will need to be trimmed down.


B

[Mueller]

nuts could be loose, or the thru holes on the inner mounting "ears" could be oblong.

1st issue is easy, tighten the nuts
2nd one is more involved, welding and reaming is required

[larryp]

John, just stop whining and drive the car.

[ss6]

Whining? I don't have a turbo...

[maf914]

If you know its from the suspension, forget this post.

But, is your rear window tightly glued in? When mine started to work lose, it would knock and rattle over certain bumps. Took me a long time to figure out where the noise was coming from. I searched everywhere for the source. Pre-internet days. No source for help.

Mike

[Jeffs9146]

I had the same knock and I thought it was a failing CV but it turned out that the heat exchanger was hitting the drive shaft when I was turning on acceleration.

Jeff

[Brad Roberts]

Bad tranny mounts Jeff ?? or engine mounts (which car).


b

[SirAndy]

yepp, bad engine mounts can do that to you too (IMG:style_emoticons/default/sad.gif)

took me a while to convince brad that i was NOT on crack.
there was a very destinctive "knock" from back there somewhere, but only sporadically, wasn't easy to reproduce. thought about a CV coming loose first, but then we decided to check the front engine mounts. both were completely broken off.

but because the rear tranny mounts were still holding up, the engine wasn't always just jumping under sudden load, which would have given us a clue.

Andy

[ss6]

I shoulda provided a bit more info - don't think it's the engine mounts, the knock happens even when I'm pushing the car into the garage with the engine off. Thinking it might be some kind of "stiction" thing, sometimes I can cause it by stepping up on the rear bumper.

Guess I'll have to add a 'yank-it-out and look at it' exercise to the winter project list. I'll post what I find.

[Brad Roberts]

Normally they "creek and moan".. they dont knock.. if you are hearing it while pushing on the bumper... its the bushings. The knocking I was referring to happens when you load the car into a hard right or hard left... you hear a THUMP/KNOCK.


B

[Jeffs9146]

Bad tranny mounts Jeff ?? or engine mounts (which car).

It was the 74 that I sold to James. He figured out that the heat exchanger bracket was loose and he was able to raise up the HE and tighten it enough to get it out of the way! At least thats what I thought he said, maybe he will chime in!

Jeff