Rear End Whine

[bk10s]

How much rear end "whine" is normal/acceptable for a 200+K mile 2002 Sport Trac? Beginning to notice a whining that is tied to speed. Most prominent when accelerating from 25-40mph, and coasting from 30mph to a stop.

 

[blert]

When was the last time you changed the pumpkin juice?

 

[bk10s]

You are going to be so impressed......Trans Fluid, Front Diff Fluid, Rear Diff Fluid changed 11/2018 at the dealer with 124K miles. I now have 209K. Are you thinking that this whirring is the rear diff telling me it is time for a fluid change??

 

[blert]

Personally, at 80k+ miles, I would say it is past time to do them all. It can't hurt to change to rear pumpkin juice, especially if you live in a moist environment or have driven through any deep water (or snow), it is relatively inexpensive. Be sure to inspect the breather tube, or just replace it to be sure.

It may or may not help the whining but that is the first question someone who knows more than me will ask so I was just getting it out of the way.

 

[bk10s]

Getting worse. I replaced the left side rear wheel bearing about 5 yrs. ago. Maybe wheel bearing on right???

 

[Phil Frady]

In my case, my clutch plates wore out and cause everything else in the carrier to wear out. You can test your LS by jacking one rear wheel, release the parking break, and put a torque wrench on it set at 40lb/ft. If the wheel turns your clutch plates are worn out.

 

[bk10s]

I'm sorry....What is LS? I have a torque wrench. I'm assuming limited-slip? Where do I put the wrench?

 

[Phil Frady]

LS is short for Limited Slip. You use a 3/4 socket on your torque wrench and place it on a lug nut and turn it.

 

[rwbenner]

Mine whines. Like all the time. My first differential had an acceleration whine that started around 225k. So I swapped the rear end for a lower mileage one from boneyard (I don’t know how to rebuild a rearend), and it started whining about a year later. I now have 315k and it whines from 25 to 65 mph, and I’ve given up on it. It’s been whining for 40k or so miles. I assume it is a worn pinion gear since it was only on acceleration. I realize I’m not moving the conversation forward with solutions, but just that I feel your pain!

 

[RR-sport trac]

When my rear end started whining and then got progressively worse wound up having a local rear end shop rebuild it - pricey but now it is all new and runs great - worth it for me as we use this as long trip vehicle so need something as reliable as possible

 

[bk10s]

The rear end noise worsened quickly. Took it to a respected mechanic that helps me with more complex repairs. Well, my rear differential is toast. Not sure exactly what the culprit is yet. Looking into options - Rebuild vs. Used unit from salvage yard. Is there a chance other parts in the drivetrain are damaged?

 

[rwbenner]

I did a boneyard replacement and it also now whines. I figured Trying to find an Uber-low mileage differential was prob unlikely. In hindsight, I should have rebuilt :/

 

[RR-sport trac]

I had the same choice junk yard replace or rebuild - since I can't afford a new ranger or maverick and I really like my sport trac I decided to go with rebuild because all the junk yard options I saw here in Northern California were high mileage - mine was so worn that it had worn the driver's side axle so badly that since it was apart I had them change the axle and all the seals - plus inspect and change fluid in front diff - cost 1600 but s far worth it

My 84 year old dad has a 2001 job1 that he went the junk yard route and just replaced the whole axle and got disc brakes in the process - only problem was hooking up the parking brake cable - not sure if he worked that out yet but he said that stopping power was greatly improved

 

[bk10s]

There is a 4.10 limited slip available locally with 110K for $400.

 

[RR-sport trac]

That is what mine is 4.11 LS - 400 sounds reasonable if they provide some sort of guarantee - sounds like it has quite a few miles left - mine did not start whining until around 240 K

 

[bk10s]

What fluid should I put in this when I get it?

 

[RR-sport trac]

Rebuilder recommended 85 so I am using an 80 - 90 weight from Lucas - seems to be working well - input from others?

 

[blert]

If you get the LS don't forget the small jug of modifier fluid.

 

[bk10s]

I have a choice: Differential or entire axle. What is the more straightforward remove and replace?

 

[blert]

The whole axle might score you disc brakes if you don't already have them. But that adds the extra cost of new rotors, calipers, etc.