Rubbing/grinding noise...

[FreedS4]

I've done some researching and can't find anything that seems to help with the issue I'm having. When I'm turning at relatively low speeds (when in reverse, first, second, and sometimes third) and when the transmission is engaged, I hear what appears to be a grinding noise coming from the rear of the car. It almost sounds like tires rubbing, but I've already checked that. It doesn't sound like pure metal-on-metal grinding/rubbing, but I can't for the life of me figure out where it's coming from. Any ideas or similar situations? Danke schoen in advance...

[xLibelle]

a limited slip diff will make funny noises at low speed turns.
Is the vehicle new to you? The PO could have installed one. You can tell by checking the metal tag on one of the diff cover bolts.
On the other hand, it could be dead output bearings in the differential.

[dark89e30]

CVs?

[wagonizzle]

My LSD was a bit noisy until I put Redline into it; haven't heard a peep since...

[FreedS4]

a limited slip diff will make funny noises at low speed turns.
Is the vehicle new to you? The PO could have installed one. You can tell by checking the metal tag on one of the diff cover bolts.
On the other hand, it could be dead output bearings in the differential.

The car is new to me. Would the metal tag say LSD on it?

My LSD was a bit noisy until I put Redline into it; haven't heard a peep since...

Was it noisy whether or not the clutch was engaged? The noise for me for goes away if I've got the clutch pedal pressed.

[xLibelle]

when you depress the clutch, the lock in the diff opens up and thus no more differential clutch scrub noises. I've not heard of a LSD make a dramatic grinding noise, though mine was pretty bad at one point and has since gone away... maybe mine is toast.... hmm.

But the tag will have an S after the number. The gear ratio will be printed on it as well. It should be like 4.10 or 3.73, to name a couple possibilities.
If the diff were removed from the car, it could have an S painted on the top of the casing.

do some searching about the topic. there are ways to quiet the noise but otherwise, dont worry about it.

[FreedS4]

when you depress the clutch, the lock in the diff opens up and thus no more differential clutch scrub noises. I've not heard of a LSD make a dramatic grinding noise, though mine was pretty bad at one point and has since gone away... maybe mine is toast.... hmm.

But the tag will have an S after the number. The gear ratio will be printed on it as well. It should be like 4.10 or 3.73, to name a couple possibilities.
If the diff were removed from the car, it could have an S painted on the top of the casing.

do some searching about the topic. there are ways to quiet the noise but otherwise, dont worry about it.

Thanks, I appreciate the help! That makes me fell a little better about the "problem".

[wagonizzle]

Was it noisy whether or not the clutch was engaged? The noise for me for goes away if I've got the clutch pedal pressed.

Do Redline in the trans too. The getrag trannies used in these cars are notorious for input shaft bearing noise, which is present in neutral but goes away when you depress the clutch pedal. I am not even sure if this is what you mean, but it's a good idea nonetheless. Redline is good stuff and made both ends of my car nice and quiet.

[FreedS4]

Do Redline in the trans too. The getrag trannies used in these cars are notorious for input shaft bearing noise, which is present in neutral but goes away when you depress the clutch pedal. I am not even sure if this is what you mean, but it's a good idea nonetheless. Redline is good stuff and made both ends of my car nice and quiet.

I'm going to try putting Redline in it to see if that helps. Also, I looked at the diff and the number on the metal tag said S3,73 3942. What's that mean?

[wagonizzle]

Limited slip 3.73 ratio. Best all around diff for an m20b25 IMO

[xLibelle]

red line isnt likely the fix for the noise. like i said, do a search and you'll find the magic potion.

[FreedS4]

red line isnt likely the fix for the noise. like i said, do a search and you'll find the magic potion.

Are you talking about the friction modifier sold at Ford dealerships? I learned a lot about our diffs whilst looking for that magic potion!

[PiercedE30]

I LOVE the Redline fluids. I have MT90 in the trans and my 4.10. Surprisingly, I don't have the Getrag rattle. I'm not sure if it is was just a well kept tranny, or if the Redline actually had something to do with it. I never got to hear if the tranny did rattle before I put the fluid in due to a blown motor that came with the car.

[FreedS4]

I LOVE the Redline fluids. I have MT90 in the trans and my 4.10. Surprisingly, I don't have the Getrag rattle. I'm not sure if it is was just a well kept tranny, or if the Redline actually had something to do with it. I never got to hear if the tranny did rattle before I put the fluid in due to a blown motor that came with the car.

So I've got more than one vote for Redline fluids...

[FreedS4]

FYI...that friction modifer worked. All noise is gone!