Noisy limited slip?

Truckedup · Mar 19, 2018

I have owned for about three months an 09 Ranger Sport 4.0 5 speed 4x4 with the stock limited slip rear axle, R6 code...94,000 miles and it seems to have not been abused..
The posi seems to function normally but at slow speeds making sharp right or left turns there a slight humming noise or low "squealing" noise from the rear axle. It's noticeable when coasting or at neutral throttle, step on the gas a bit and the noise seems to disappear..Other than low speed sharp turns the rear axle is quiet...
I have both a Chevy and Jeep with limited slips and they don't make this noise but like the Ranger they do chatter a bit when turning on loose surfaces...
No know history so maybe I should just change the rear axle oil.... :icon_confused:

Denisefwd93 · Mar 27, 2018

Truckedup said:
I have owned for about three months an 09 Ranger Sport 4.0 5 speed 4x4 with the stock limited slip rear axle, R6 code...94,000 miles and it seems to have not been abused..
The posi seems to function normally but at slow speeds making sharp right or left turns there a slight humming noise or low "squealing" noise from the rear axle. It's noticeable when coasting or at neutral throttle, step on the gas a bit and the noise seems to disappear..Other than low speed sharp turns the rear axle is quiet...
I have both a Chevy and Jeep with limited slips and they don't make this noise but like the Ranger they do chatter a bit when turning on loose surfaces...
No know history so maybe I should just change the rear axle oil....

Looks like your post was missed by the many responders on the site! anyhow welcome to the site!

I feel your pain, my truck is essentially doing the same thing it's rather unsettling.

Craig0320 · Mar 27, 2018

Truckedup said:
I have owned for about three months an 09 Ranger Sport 4.0 5 speed 4x4 with the stock limited slip rear axle, R6 code...94,000 miles and it seems to have not been abused..
The posi seems to function normally but at slow speeds making sharp right or left turns there a slight humming noise or low "squealing" noise from the rear axle. It's noticeable when coasting or at neutral throttle, step on the gas a bit and the noise seems to disappear..Other than low speed sharp turns the rear axle is quiet...
I have both a Chevy and Jeep with limited slips and they don't make this noise but like the Ranger they do chatter a bit when turning on loose surfaces...
No know history so maybe I should just change the rear axle oil....

I have the 8.8 limited slip in my 98 ranger. I changed the gear oil and did not add a friction modifier. Thus when everything was hot I had a vibration/grumble on first take off or sharp turns. Pull the pan and inspect the gears. If there is no scoring and not to much slop in the ring and pinon then you might be able to get by with just a fluid change. Just make sure the oil you put in has friction modifier or just add some. The modifier keeps the clutches from grabbing in our l/s rear end. I used mobil synthetic with friction modifier and it has been super quiet ever since.

adsm08 · Mar 27, 2018

Change your rear end clutches. They are rated for approx 100,000 mile service life. If you have any issues with chatter, noise, grabbing, or lack of traction, etc above 90,000 miles, just change the clutches.

Truckedup · Mar 28, 2018

I changed the oil to Mobil 1 75-140 yesterday before checking back to this thread...The noise is gone,the chatter is gone, the limited slip still seems to work ok....
During the summer I'll check it. I've worked on Chevy posi's, I assume the Ford is similar, pull the axles, remove the differential for clutch replacement ?

Craig0320 · Mar 28, 2018

Truckedup said:
I changed the oil to Mobil 1 75-140 yesterday before checking back to this thread...The noise is gone,the chatter is gone, the limited slip still seems to work ok....
During the summer I'll check it. I've worked on Chevy posi's, I assume the Ford is similar, pull the axles, remove the differential for clutch replacement ?

Good deal. The fluid change solved mine as well.

Denisefwd93 · Mar 28, 2018

Craig0320 said:
Good deal. The fluid change solved mine as well.

Good on ya! I may try the same on my truck, bide some time to work the truck we got last night

Denisefwd93 · Mar 29, 2018

Denisefwd93 said:
Good on ya! I may try the same on my truck, bide some time to work the truck we got last night

What did y'all use? Yukon, Lucas, or purple?

Craig0320 · Mar 29, 2018

I use mobil one gear oil.

Denisefwd93 · Mar 29, 2018

I got the same.. store person wants model make for off the shelf oils even LOL

adsm08 · Mar 29, 2018

Denisefwd93 said:
I got the same.. store person wants model make for off the shelf oils even LOL

You used to do HVAC, right?

Someone walks into your store and asked for a piece of stove pipe do you ask for some info about what they are doing with it, or do you just hand them any random thing? What if they need 8-in double wall to go through a wall and you hand them 6-in single and they smoke out the house right before it burns down?

Same with oil. You can't just say "I need oil for my car" and expect to get the right stuff. Hondas and Toyotas like 0W-20. Most diesels take 15W-40. Neither of those are the 5W-30 the book for your truck calls for.

Denisefwd93 · Mar 29, 2018

I agree, and know better, but only made phone call and asked if they had on the shelf https://www.yukongear.com/productdetails.aspx?ProdID=11585

Could not get an answer

Will · Mar 29, 2018

It's not that sophisticated. If a manufacturer specifies something extremely weird they are either trying to crutch a design flaw or they are the only one making the specific product and trying to screw you. Honda is famous for never telling you what other compatible brands work. The low viscosity stuff is because they could only meet EPA mpg with thin oil. It's not at all like specifying the wrong stove pipe in a house. You could put straight 30 dino into about any mechanical object and it would be fine for years. That includes using it for 2-strokes and mixing it into JP-8 to lube diesel engine injection pumps.

All the specifications are polish. Main thing is to not run without oil.

Truckedup · Mar 30, 2018

Will said:
It's not that sophisticated. If a manufacturer specifies something extremely weird they are either trying to crutch a design flaw or they are the only one making the specific product and trying to screw you. Honda is famous for never telling you what other compatible brands work. The low viscosity stuff is because they could only meet EPA mpg with thin oil. It's not at all like specifying the wrong stove pipe in a house. You could put straight 30 dino into about any mechanical object and it would be fine for years. That includes using it for 2-strokes and mixing it into JP-8 to lube diesel engine injection pumps.

All the specifications are polish. Main thing is to not run without oil.

That's a very broad statement and there is a pile of experience stating otherwise...

Noisy limited slip?

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