Shudder from rear end?

[sean99]

After backing up and driving forward while turning left I feel a shudder or shake.It feels kind of like the shake of a bad clutch when letting it out.This feels like its coming from the rear end.It has only happened from a stop.And once it happened without backing first but still turning left.
I have had the Explorer for a couple of months and have felt this three times.
99 v6 sohc Ls 4.10. Any ideas?

 

[gijoecam]

Find a local auto parts store that sells friction modifier for the rear end. Your limited slip clutches need it. Simple solution.

-Joe

 

[sean99]

Find a local auto parts store that sells friction modifier for the rear end. Your limited slip clutches need it. Simple solution.

-Joe

I bought the truck used and it came with a receipt from Oilchangers.12/04 Puratech GL5 gear oil with Sta-Lube gear additive. That was 25k miles ago.Do you think I should just change it out or add the modifier to the existing fluid?

 

[gijoecam]

Six of one, half-dozen of the other. If it was mine, personally, I'd change it out to Mobil-1 synthetic or Amsoil (or Royal Purple) and add a fresh bottle of friction modifier to it. For $45-$50, it's cheap insurance.

Or you can just add the FM to it and see if it works. Worst case you're out another $5. Best-case, it works itself into the clutch pack and the shimmy should disappear.

It's a common problem. The FM alone works about half of the time. The fluid change with the proper lube works about 95% of the time. If neither of those do the trick, it's time to rebuild the clutch pack in the rear end.... IIRC, the dealership charges about $300 to do so, but any good driveline shop or transmission shop should be able to do it for less.

-Joe

 

[sean99]

The rear end was rebuilt by dealership 9/04 32k miles ago.
I just noticed on the oil changers receipt that it says rear gear box fluid change.Are they talking about the diff?If so whatever was put in by the dealership since the rebuild is still in there.

 

[gijoecam]

Probably the diff.... it was probably doing exactly what it is doing now.... Try the fluid first and see. It's not going to make it any worse.

-Joe

 

[sean99]

Probably the diff.... it was probably doing exactly what it is doing now.... Try the fluid first and see. It's not going to make it any worse.

-Joe

I'll change out the fluid.
Thanks

 

[Joey P]

Have you changed the fluid and added the modifier? Mine does the same thing and am wondering if it has helped your problem. Thanks.

 

[sean99]

Have you changed the fluid and added the modifier? Mine does the same thing and am wondering if it has helped your problem. Thanks.

I havent changed the fluid yet.I need to put in a new radiator today.I'll try to fit it in this week.