Advice-PROPER way to service rear diff

[lilredtdi]

Ok, never serviced a rear before (lest wise not on a truck.......hehehe)

Want to do mine soon. Watched a bunch of youtube videos and some folks just remove cover, drain, clean cover, seal with RTV and fill.

Some do the above and use carb or brake clean on the gears. Yes/No?

What is the preferred method on our trucks? Can i just use RTV, or is a gasket needed?

BTW I bought the Pennzoil 75-140 synthetic lube and a tube of friction modifier. Is this correct?

Thanks in advance for the pointers..............Frank

Riot warrior- If you help me I am NOT paying you............LoL

 

[Hydro-idi]

You can use brake cleaner to clean the diff gears once the oil has been drained. Go in there and make sure all the oil and sludge is removed and use good rtv as the gasket. No need for gasket. I have found they just leak no matter what. Torque the diff cover back on and refill. Note: When refilling differential back up with gear oil, it is VERY important to use a hydraulic jack and jack up each side of the axle one at a time (after it is filled). This will make the axle "tilt" and gravity will carry oil down each tube during this process. Wait about 5 minutes for each side with hydraulic jack up. This will "gravity feed" fresh oil to your bearings. If this step is not done, the bearings will run dry for a few miles.....which is no good. Top off the gear oil and you are all set.

 

[Black dawg]

I usually drain, then clean with brake clean, and use a pry bar to check for loose carrier bearings.

 

[gdhillon]

Is there a fill plug on the rear end?

 

[Hydro-idi]

Is there a fill plug on the rear end?

Yes

 

[kc0stp]

As stated above just remove cover & drain, your welcome to use brake clean on the gears if you want, can also drill/tap a hole in the bottom for a drain plug for future use. For Diffs just use RTV to seal it (just dont go to overboard) most diffs you cant get a gasket for anyways.

Is there a fill plug on the rear end?

Yep, no drain plug but there is a fill plug should be around the middle of the diff (cant quite rember where on the diff it is but think its on the front/side)

 

[chris142]

The brackleener or carb cleaner will deteriorat the new oil if it's not all evapprated when you refill the diff. I'd skip that part, maybe use it to clean the area where the gasket or rtv goes. I would not spray the gears with it.

 

[lilredtdi]

THAT is EXACTLY why I posted this. I kinda feel that if you do not get ALL of it out it will break down your new lube. However, I am no expert.

 

[lilredtdi]

Good tip! However, if you do not do this step, wouldn't the old oil down there still be there to lube the bearings? What I mean to say is:

Should you tilt the axel to drain as well???

 

[lilredtdi]

If I knew what those were..............LoL............Back to youtube.

 

[Black dawg]

If the rear end is warm at all, the cleaner evaporates really fast.

 

[lilredtdi]

Humm...............Yet another good point.......Thanks!

 

[whiteboyslo]

You only need the friction modifier if you have a limited slip differential. Won't hurt it if you don't have, though.

If you're looking for a bit of bling, check into putting on the OEM finned aluminum diff cover of newer Super Duties. It's a common upgrade.

Mike

 

[Hydro-idi]

Good tip! However, if you do not do this step, wouldn't the old oil down there still be there to lube the bearings? What I mean to say is:

Should you tilt the axel to drain as well???

No need to. Just drain and try to follow the steps I explained for re-filling. It is just a safety precaution more than anything. But I have heard of people not doing that "axle tilt" step and overheating their bearings, eventually causing a bearing failure not much further down the road.
As far as the brake cleaner, go for it. It will clean all of the crap out of there and use shop towels to get all the sludge out and what not. Brake cleaner will evaporate in about a minute so no need to worry.

 

[DesertBen44]

I always use a gasket on rear ends, and have never had a leak. Gasket and rtv both sides. maybe its going overboard but my track record for leaks is better then my friends locally who dont want to spend the extra 10 bones.