GT_NFR

I've tried searching and nothing has turned up thats relavent.

About 3 weeks ago I had a flat on my driver side rear tire which warranted the use of my spare. Without reading the Manual I mount the under-inflated spare on the rear and limp it to a gas station 3 miles away. I inflated it to the proper PSI and park it home b/c tires shops were all closed by then.

The next day, I drive (with the spare on the rear) out to a shop 20 miles (long story) away to get my 2 rears replaced.

I found out afterwards that the spare is never to be mounted on the rear so I'm afaid my diff may have taken too much abuse.

Now, after my drive from atlanta and back (3.5 Hr each way), I'm hearing some sort of a noise comming from the rear...its not high pitched so I can't say its a whine. But it come in the loudest at 38 mph and I can only hear it if I'm in neutral or completely off the gas (so my intake doesn't mask it).

Does anyone have any clips of what a diff whine sounds like? I'd drain the diff but I don't have the proper tools where I am now and won't be able to until 3 wks from now.

Does anyone else notice a noise from the diff/wheel/rear when you're coasting in neutral of not on the gas?

I'll get a video of this after work today but it will be hard to pick up. Its not overly loud but I can definitely hear it if there is not too much ambient noise.

Here is the Video

Burt Reynolds

Where did you hear that the spare shouldn't be used on the rear? I've used my spare in the rear... I probably drove about 20 miles too (no whine here)... I know the spare is temp use only but it is reasable that you would need to go maybe even 100 miles on it!

Why even bother with a spare if you can only use it on the front. Sure, I understand we have an LSD and the ratios (right wheel vs. left wheel) will very but I wouldn't imagine it being that bad.

JackS

Diff whine is not uncommon. The manual does say to swap out the front and place it on the rear and use the spare in front. If I were you, I'd change out the diff fluid and stay confident that no damage was done.
There really is nothing else you can do and for all you or I know your differential may last the life of the car. Think positive.

GT_NFR

it says so in the manual. you're suppose to swap the front one to the rear if you blow out a rear and use the spare on the front.

I hope you guys a re right but I could swear I've never noticed this rear end noise before.

chris_barry

The type of damage you would cause to the differential by running different rear tyre diameters would only show itself when the wheels are travelling different speeds (going around corners). When you are travelling in a straight line the left and right sides of the LSD are stationary relative to each other.

If you run different sided rear tyres the tyres run at different speeds and the LSD gets a work out. The S2K LSD is a torsen style so will just heat up the oil. If you had a friction plate diff it would be a different matter as the car would try to drive in circles with different rear wheel sizes.

I would just drain the oil as it may have got hot and to check if its making metal as a precaution.

GT_NFR

I don't have any tools or equipment here to do that. All my tools and jacks are at home 3.5 hrs away....

Perhaps I'll take it to a shop to get the diff fluids drained and inspected.

Jim

GT_NFR

Hey guys, I got the video up. See if you guys think that the noise is unusual.

animeS2K

I hear the hum, but I wouldn't worry about it. Sounds relatively normal to me.
Change the fluid as recommended and go from there. Check for bits of metal in the fluid larger than shavings. If there are larger bits, then investigate.

Also do some tight circles in a parking lot (full lock, both directions) under light load and see if you hear anything unusual. If you do hear some weird sounds, your LSD may be damaged.

GT_NFR

I've done the full lock turns, I haven't heard anything unusual. could it be my tires doing this?