I have a high pitch whine at 70MPH only, coming from the rear differential. Has anyone tried to rebuild one or replaced theirs?

I need to know how much it cost please, and would it be a good idea to buy a used one?

 

I'm interested to know how you determined that the diff is making the noise ONLY at 70 MPH.
Did you jack it up and spin up to 70 ?
Had a lady bring her coupe (90,000 miles ) by last year for me to have a look at and I would have sworn the diff was toast.
I jacked it up on the rear and spun it up all the way to 70 and there was NO noise.
It was her worn out tires, she got a new set of Hankooks installed and it was quiet as a mouse.

 

When I let off the gas pedal it stops making the whine noise, I am assuming it's the differential. I made an appointment with a local shop that does rear ends for Monday, hopefully they will tell me the truth, that's why I came to you guys first.

I found a few other forums here about this same noise and people replaced their rear differential under warranty, too bad mine is older than 8 years, but has less than 80k miles! Oh well, I really love my car. I just wouldn't want to spent 4-5k on a brand new rear end

 

How did you make out with the transmission shift problem

 

The transmission seems like it's shifting fine now, maybe it was the oil just changed? Took some time to adapt, but is much better now. But now I noticed this noise!

 

There are ways to diagnose the differential just by the noises it makes. I replaced mine @43,000 because it had a light throttle whine above 65mph. I haven't opened up the old diff but am sure it's the pinion bearing. Dependant on ring/pinion wear it is rebuildable with a new bearing and some good knowledge in setting up backlash. Hopefully yours is an easy fix. The differentials are easy to drop out and replace. Don't let the shop dismantle the rear suspension to do it, adds time, requires an alignment and is un-necessary.

 

When you hear a whining sound coming from the differential while under load, and it disappears when you let off the gas, it's usually caused by a worn pinion bearing.

 

Any idea how much a new this could cost? Part + labor?

 

... Have you changed the oil? A lot of Mercedes make this noise and it is considered normal operation... Mercedes used to replace them under warranty but guess what(?) the new diffs. made the same noise. I've driven MB's with the same noise from 7miles - 400k miles. Not saying I haven't seen a blown MB diff but usually it's more of a groaning than a whine... this has been discussed many times before.

 

Back in the day,

this

this

was the answer if you could not afford a new rear end. Once ran a FIAT 124 Spyder with 160,000 miles and a whine for a couple of years that way & sold same-same.

Corvair IRS was really easy to setup with a dial indicator, just screw in or out each side until right.

 

It would be helpful if we knew what year and model Crossfire you have . . .

https://www.crossfireforum.org/forum...tml#post812689

If you end up finding that you have to replace the rear differential, I would suggest getting one from a salvage yard. Lots of them available (search on E-Bay for "Crossfire rear differential") with most priced well under $500.00. Just R&R and put in fresh fluid.

 

i have a 2004 with 70,000 miles

 

2004 used two different differentials for the NA. One had half shafts that bolted to the flanged output shafts. The other more common one has the half shafts that just pop in and out of the diff. Check to see what you have before trying to source a replacement from a salvage yard.