Start-off creak

[JHZR2]

Hello,

What would be the cause of a creak coming from the left rear of a RWD vehicle, just as the clutch is being let off from a start?

There is no creak shifting gears, or going into any gear with the car rolling, it is only from a dead start.

The parking brake grabs and then lets go completely. This is evidenced by it stopping the car from rolling on inclines, and the car rolling by itself on very slight inclines.

The car has an LSD.

What are the signs of subframe, diff mount and trans mounts going?

I had my wife accelerate with the parking brake set - nothing seemed to move, clunk, or shift, though the rear of the car did squat down.

Neither of the rear shocks is loose. Nothing seems to move.

Any ideas? Need to drive the vehicle a few hundred miles this week. Drives, rides and handles like always, just the noise.

Thanks!

 

[Colt45ws]

Bearing?

 

[The_Jeff]

What if you back up a hill then toss it in neutral and let it naturally reverse direction?

 

[JHZR2]

Originally Posted By: Onmo'Eegusee
Bearing?


I was wondering about spring plate or clutch on an LSD... There is no indication of a bad bearing otherwise...

 

[JHZR2]

Originally Posted By: eljefino
What if you back up a hill then toss it in neutral and let it naturally reverse direction?


huh? back it up and then let gravity take its toll? Nothing. It would creak when first starting to go in reverse, then would just come to a halt and roll forward. It rolls on its own without issue.

 

[JHZR2]

I seem to induce a similar noise on the same side if I pull the parking brake with the car moving.

However, again, I have no indication that the parking brake is holding the car when it is not engaged. The car, which is light and not particularly aerodynamic (older 3-series), will roll along in neutral on very slight incline/declines. Just a click or two of the PB will make it stop...

 

[Colt45ws]

Might be a bushing or something when the suspension gets the additional load and squats. Have you tried pushing down on it manually?

 

[JHZR2]

Yes, pushing, pulling, shaking, up/down, starting with PB engaged, etc.

Can't get it. Car has to start moving... but sound is coming from outboard, near the wheel (it seems), makes me doubt it is the LSD.

 

[PT1]

Look at all the rubber bushings on the rear suspension. If the car has a stabilizer bar that could be it as well. Also if the driveshaft has a center bearing that could be it as well. Lube all ujoints as well.

 

[CROWNVIC4LIFE]

Originally Posted By: JHZR2
Hello,

What would be the cause of a creak coming from the left rear of a RWD vehicle, just as the clutch is being let off from a start?

There is no creak shifting gears, or going into any gear with the car rolling, it is only from a dead start.

The parking brake grabs and then lets go completely. This is evidenced by it stopping the car from rolling on inclines, and the car rolling by itself on very slight inclines.

The car has an LSD.

What are the signs of subframe, diff mount and trans mounts going?

I had my wife accelerate with the parking brake set - nothing seemed to move, clunk, or shift, though the rear of the car did squat down.

Neither of the rear shocks is loose. Nothing seems to move.

Any ideas? Need to drive the vehicle a few hundred miles this week. Drives, rides and handles like always, just the noise.

Thanks!


What make car is this?...Year?...Mileage?

 

[Steve S]

Originally Posted By: PT1
Look at all the rubber bushings on the rear suspension. If the car has a stabilizer bar that could be it as well. Also if the driveshaft has a center bearing that could be it as well. Lube all ujoints as well.
+1!!!

 

[JHZR2]

He car is a 91 BMW 318i, 120k. Did the ds support bearing when I had the LSD rebuilt - around 100k, when the diff got noisy (water had gotten in in the past).

 

[Papa Bear]

"Re: Start-off creak" ... In this case, it's probably old age.

 

[mechtech2]

Suspension bushing. Start with the sway bar and links.

 

[PT1]

I'm guesssing ujoint or if the driveshaft is telescopic maybe needs some grease. Did you rotate the driveshaft to see how much play is in it? Try it with a strap wrench. Also try slipping the driveshaft forward and backward. If it has a yoke into the back of the trans remove the driveshaft and grease the yoke spline. Inspect all the ujoints while it is off. If it has rear lower control arms look at the bushings. If it has rear coil springs lubricate the tops & bottoms of the springs with some teflon grease or lubriplate. Or get out the silicone spray and have at all the rubber components in the entire driveline including any transmission mounts and or body mounts. I have had lower control arm bushings and body mounts do that. Look inside the car where any struts bolt into the top mounts and be sure the bushings are tight and not worn beyond tolerance.

 

[JHZR2]

Before I got to inspecting much, and due to travel, it got cold and I didnt work on it. But with the cold, the creak also went away. I have not heard it in months of driving!

Well, yesterday was beautiful, today is too... Today the creak came back, now both on starting from a dead stop and also under some breaking.

Bummer.

ill be taking it to my indy shop to have a look soon...

 

[artificialist]

How about the rubber cushion between the coil spring and frame? Those are a common source of noise. You might find that yours has rotted away 100%, and that is why you don't think about it being a problem.