Turning right - sometimes there's a noise

[Oliver S.]

Hello,

after a 100 mile trip I experience a rhytmical noise when slowly turning right - but not always. First I thought it came from the back then I wasn't sure.
This year the tires have been replaced (now 215/70, formerly 205/75) and the differential was out in order to replace all the seals (I have a Posi and additive was added) - some 300 miles ago.
Actually, I don't think it's the tires.
What could be the cause? How sounds a defect differential and how to make sure?

Regards
Oliver

[Paul J.]

Re: Turning right - sometimes there's a noise

Hello,

after a 100 mile trip I experience a rhytmical noise when slowly turning right - but not always. First I thought it came from the back then I wasn't sure.
This year the tires have been replaced (now 215/70, formerly 205/75) and the differential was out in order to replace all the seals (I have a Posi and additive was added) - some 300 miles ago.
Actually, I don't think it's the tires.
What could be the cause? How sounds a defect differential and how to make sure?

Regards
Oliver

What does the noise sound like? Describe it for us. How many miles are on your tie rod ends, and wheel bearings (front and back)? At what speed does this noise occur (by "slowly turning right" do you mean slowly turning at speed or turning while moving slowly)?

Paul

[Jody B.]

Re: Turning right - sometimes there's a noise

I had something very similar happen while slowly turning and getting out of the driveway. The problem was a worn out speedometer cable housing. once the speedo cable was replaced, the noise was gone.

JB

[Oliver S.]

Re: Turning right - sometimes there's a noise

What I know of the car is this:
Front springs have around ~ 5000 miles (previous owner)
Rear shocks 1800 miles (me)
Tires 300 miles (me)

Slowly turnig right means on a crossing or driving in the garage entry - between 5-10 mph I would guess.
Rhytmical noise: more rubbing/rattling like.
Sound is not high or shrieking.

I've just been back from a parking lot to try to provoke it and to be able to describe it better - but it hasn't occured again. Thus I would definitely rule out the tires.


My concern ist that maybe the pre load wasn't correct when reinstalling the diff by the garage. Could this cause this kind of noise?

Regards
Oliver

[Paul J.]

Re: Turning right - sometimes there's a noise

You just changed your tires to a larger size. There was a recent post where someone with a set of 215's on a 65 had a tire rub when turning into a driveway (or crossing). See if you can find this in the archives, and check to see if you have a tire rub.

Paul

[Oliver S.]

Re: Turning right - sometimes there's a noise

@Paul, as I mentioned I was on a parking area driving circles to the right in various diameters and at various slow speeds. Also, I drove on the same crossing with the same speed and, of course, back in my garage where I noticed the noise initially. Nothing.
Before deciding to go for the 215/70 I checked the forum and actually found nothing regarding rubbing issues.



Oliver

[Keith B.]

Re: Turning right - sometimes there's a noise

I would see if you could reproduce the noise while driving. Once you get to speed you make slight turns back and forth. If it occurs under driving conditions I would think wheel bearing.

[Duke W.]

Re: Turning right - sometimes there's a noise

[quote=Oliver Schoenhaar (33229);563747Before deciding to go for the 215/70 I checked the forum and actually found nothing regarding rubbing issues.
[/quote]

Depending on wheel offset, 215/70s may rub on the frame at full lock. This is not a safety issue as full lock is only applied at parking lot speeds, and it will not hurt the tire.

Evidence is usually paint abrasion on the frame, and it is most likely to occur on the LH side as the tire may rub against the steering gear carriage head bolts.

What you describe could be a little Positraction clutch chatter, which can manifest as a "growning" noise. This can sometimes happen even with fresh fluid and Positraction additive, and doing some circles in a parking lot will often make it go away - at least for awhile.

Unequal tire circumferences (or unequal tire pressures side to side) can also cause the problem. A 215/70R-15 should have a circumference of something near 85" and it's best if the rears are within one-half inch of each other with Positraction axles. Tire circumference can be measured with a tape when the rear is off the ground.

Duke

[Oliver S.]

Re: Turning right - sometimes there's a noise

@Duke: There was no such noise before the diff was out to change the seals. Of course, this could be pure chance.
Since this noise doesn't occure in a 100% reproducable pattern - at the moment - it will be hard for me to convince the shop that there's something wrong.
Here's my idea - after a forum search.

1. I will ask the shop if they filled in 80W-90 - if not, they shall use this with a bottle of additive (or better right two?)
2. If it is 80W-90 - fill in a second bottle of additive (remove respective amount of fluid before).

Regards
Oliver

[Loren L.]

Re: Turning right - sometimes there's a noise

Verify that you have the correct weight + additive and that it is Full.
Go find a large parking lot and do 8 full RH circles, followed by 8 LH circles and 4 figure 8s. The go drive and see if your noise is gone.

[Duke W.]

Re: Turning right - sometimes there's a noise

@Duke: There was no such noise before the diff was out to change the seals. Of course, this could be pure chance.
Since this noise doesn't occure in a 100% reproducable pattern - at the moment - it will be hard for me to convince the shop that there's something wrong.
Here's my idea - after a forum search.

1. I will ask the shop if they filled in 80W-90 - if not, they shall use this with a bottle of additive (or better right two?)
2. If it is 80W-90 - fill in a second bottle of additive (remove respective amount of fluid before).

Regards
Oliver

SAE 80W-90 GL-5 is the modern equivalent of the original Mil-L-2105 spec. I recommend one four ounce bottle of Positraction additive to start, and leave the diff a little underfull. If chatter is noticed, add one-half more bottle (2 0z.) If chatter persists add the remaining half-bottle.

If chatter persists with two bottles of additive, there is probably an internal problem.

Once the proper Positraction additive amount is achieved, fill the diff to the bottom of the plug opening when the diff is HOT.

Change the fluid with the appropriate amount of Positratraction additive every 30-60K miles or if clutch chatter becomes noticeable.

Duke

[Oliver S.]

Re: Turning right - sometimes there's a noise

I'll contact my mechanic tomorrow. Today I've tried what Loren suggested but the noise has occured after driving some 15 miles. Still only when turning right.
Maybe I can be more precise now:
The noise occures at a crossing after standing or rolling very slowly and then turning right together with slightly accelrating. The noise is rhytmical and - in the short period where audible - decreases, increases and decreases.

Oliver

[Ronald L.]

Re: Turning right - sometimes there's a noise

Is it in the front end or rear???

If front the new tire size is highly implicated and you should see scraping on the wheel house - fender skirt area and or frame rail. Especially since you are saying on RH turns only. If not and still in the front wheel bearings or something hitting the brake shields.

[Oliver S.]

Re: Turning right - sometimes there's a noise

Ronald,

it's from the rear and - currently - only when the car has been driven a couple of miles. Driving circles and "8" right after the start doesn't yield the noise - even when turning the steering wheel as far to the right as possible. Thus, I'm almost certain that the tires can be rules out.

Oliver

[Gary R.]

Re: Turning right - sometimes there's a noise

Typically posi chatter or hammer is very pronounced and often heard once the diff is hot and the car starts at a turn or corner. The clutches stick and chatter. The lube to use is the GM additive available from any dealer for about $12. I use Lucas 85-140 gear oil in my diff's but you can use their 90 wt as well.

If you have a rubbing sound then maybe it's tire related.

Another thing to check is endplay in the diff side yokes. Concern here is more with 72-79 but could also be found in the earlier diffs. If the endplay wears to the point the side yoke hits the diff you will hear grinding, metal on metal. Again this is extreme but not totally uncommon- worth taking a look to see how much endplay you have.

Since work was done go back do simple checks to make sure all bolts are tight and nothing is moving around.