[RobDob]

Morning all. Not sure if I'm in the right section but........

My 2010 Sierra 2500HD has started dripping oil from the rear driver-side wheel hub. When parked it leaves a little oily patch on the floor and when driven it spreads out all over the tire and splashes the wheel arch. There's not a huge amount leaking at the moment but I want to replace the seals both sides.

I've been trawling the internet but cannot find for sure which seals to get! I live overseas so want to get it right first time! Can anyone tell me which seals to get please, and where from?

Many thanks

Rob

 

[apcnc]

What is leaking, Gear oil or brake fluid? Could be the brake cylinder or the axle seal. If not sure just remove the drum and check to see if the which. Clean it with brake cleaner if you have to. Is the brake fluid dropping in the reservoir?

 

[MDHusker]

My 13 did the same thing days after I bought it - less than 15k miles. I took it back to the dealer and they replaced the right rear axle seal.

 

[RobDob]

Hi, it's not brake fluid (red in colour IIRC?) but is the same colour as clean engine oil so I believe its the gear oil leaking through the axle seal?

 

[19trax95]

Brake fluid isn't red. That's transmission fluid.

But it's pretty easy to tell gear oil from brake fluid. Gear oil is much thicker and more like oil feeling.

Brake fluid is thinner and really has its own feel. Take a look at your brake fluid reservoir and see if it's low. Of its leaking enough to sling everywhere, then it's leaking enough for it to be considerably low.

 

[RobDob]

I've just checked the brake fluid reservoir and it's full so I guess it's gear oil. Is that an easy fix with new seals?

 

[mjaffe]

My 13 did the same thing days after I bought it - less than 15k miles. I took it back to the dealer and they replaced the right rear axle seal.

My 2003 needed a new drivers side seal. Dealer did both sides since it had to be apart anyway. it leaked again and the Dealer fixed it again. so far so good. the job would have been do able but I was not in the mood to deal with it.

 

[esox07]

Check the level in your rear differential to see if that is low? If so, that will tell you it is the differential or Gear oil leaking. You may want to add some if it is low until you get the seal fixed.

Also, be careful, if any of that fluid starts making its way into the brake housing, you might find significantly reduced braking power in the rear.

 

[RobDob]

You'll have to excuse my lack of technical knowledge........how/where do I check the rear diff oil level?

 

[esox07]

There should be a nut on the rear cover. I think it is a square slot and you can just use a 3/8" ratchet without a socket to open it up. The level should be just below the hole. You can stick your pinky finger in to try to feel for the fluid level.

The Differential is in the middle of the rear axel just in front of the spare tire. Here is a photo of mine. The plug is circled in the photo. Just stick a 3/8" socket in there to remove the plug. Then test it like I said above. If you can stick your pinky finger in there and bend it down inside at the first knuckle and feel fluid, then you are OK, if not, add some until it is just below the hole.
Here are the instructions for filling and testing the fluid level in the rear diff.
============================
Rear Differential:
To get an accurate reading, the vehicle should be on a level surface.
For all 4.3L, 4.8L and 5.3L 1500 Series applications, the proper level is 1mm to 19 mm (.04 in to .7 in) below the bottom of the fill hole, located on the rear axle. Add only enough fluid to reach the proper level.

 

[mjaffe]

Also, be careful, if any of that fluid starts making its way into the brake housing, you might find significantly reduced braking power in the rear.

That was my first sign, when I bought the Truck there was no E Brake. I took it apart and everything was soaked.

 

[apcnc]

You'll have to excuse my lack of technical knowledge........how/where do I check the rear diff oil level?

Are you planning to DIY? The axle will have to be removed to replace this seal. Its not really a hard job but may not be what you want for a first if your not familiar. Just letting you know.

 

[19trax95]

Since he has a full floating diff, it's super easy to change the seals. Just pull your axle shafts out, remove the hub and your seal in in the hub right there.

 

[RobDob]

Great, many thanks. I'll take a look tomorrow in the daylight. I'll be getting a garage to do the work but I want to know whats required before going so I don't get ripped off!!

Many thanks everyone.

 

[RobDob]

Strange.......my Sierra doesn't have that nut on the rear cover........

 

[ferraiolo1]

It might be on the side of your diff then.

 

[esox07]

yes, you have a 2500, your diff is different. I think it will be on the other side of the diff and not on the cover.

 

[RobDob]

Thanks everyone for your help.

I bought new seals for both rear sides (I figure the other might go soon too!), had them fitted this morning and the problem seems to be solved!

Cheers

Rob

 

[esox07]

Good deal. Keep us posted if anything changes. I am glad you got the problem solved and hope it wasn't an expensive fix.

 

[RobDob]

Unfortunately, living in the Middle East, the parts were rather expensive! I could have shipped them from the US but I wanted it fixed ASAP so took the hit!! Labour wasn't too bad though!

Thanks again.