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mayco · 02-02-2017, 04:23 PM

I'm about to change the oil in my differential, do you fellas recommend using any product in addition to the gasket on reassembly? Ive read about spray-on gasket sealer and others but is there a general consensus for the differential gasket? Is the gasket sufficient by itself? Thank you for any guidance!

Mike

r carl · 02-02-2017, 05:06 PM

Paper gasket?

vintagemotor · 02-02-2017, 05:33 PM

I clean all of the mating surfaces and add a small bead of Permatex "The Right Stuff" sealant in addition to the paper gasket. Properly re-torque the cover bolts (over tightening will cause a leak).

mayco · 02-02-2017, 06:00 PM

http://shop.advanceautoparts.com/p/f...014/19780723-P

Molded rubber. Getting conflicting info on the torque spec from the web. Looks like 30 ft lbs.

"Dana 80 fill port location
• Reinstall the differential housing cover. Snug all bolts in a star pattern, alternating from side-to-side. Finally, torque the cover bolts to 30 lb-ft in an alternating pattern.
• Allow the silicon to cure per the manufacturer's recommendations (24 hours is relatively common if no time interval is given).
• Remove the square drive fill plug and add fluid until it reaches the fill plug level and begins to run out of the cover. Replace the fill plug (torque to 25 lb-ft), test drive the vehicle, and check for leaks."

mayco · 02-02-2017, 06:10 PM

I haven't bought the gasket yet, just had the parts house get it delivered tomorrow. I could get a paper gasket if that's what is recommended.

shepherd57 · 02-02-2017, 06:47 PM

Mike

I changed mine about a year ago and all I used was Permatex and it is not leaking yet.

mayco · 02-02-2017, 07:04 PM

Thanks John, maybe that's the way to go. Seems like a lot of folks skip the gasket and just use the Permatex.

Mike

shepherd57 · 02-02-2017, 07:18 PM

I have used it on my gravel trucks on the diffs and on axels with good results

cliffcharb · 02-02-2017, 07:41 PM

I've always followed, cork dry, paper with spray tack, or just good old RTV no gasket

Smartstream · 02-02-2017, 07:56 PM

Mike I like this stuff.

https://www.amazon.com/Gasgacinch-GA...10WQMA2M3SN7XN

It's been around forever but getting harder to find. Edelbrock also makes a version of it. It's very easy to deal with next time you remove the part.

Also a few posts back you called it a Dana 80 and I believe it's actually a Dana 70HD.

tevake · 02-02-2017, 08:09 PM

While we are talking diffs, is there a favored oil for reducing the whine coming from back there?

I do travel solo most of the time so pretty sure it's the diff.

Cheers Richard.

tjdonahoe · 02-02-2017, 08:28 PM

When you fill, stop about 3/8" from top.....as it is cold....when warm it will be completely full....same way with big trucks....my ram has a line about an inch below the plug.....I always use permatex hi temp silicone gasket maker, black..

Isuzusweet · 02-02-2017, 09:33 PM

Quote:

Originally Posted by tevake

While we are talking diffs, is there a favored oil for reducing the whine coming from back there?

I do travel solo most of the time so pretty sure it's the diff.

Cheers Richard.

I've always had good luck with Amsoil severe gear products in all of my vehicles.

Cheers
Tony

mayco · 02-03-2017, 06:01 AM

Thanks for all the information fellas. The few times Ive changed rear end oil in the past there has always been a drain plug in the cover. I was pretty surprised to find that there wasn't one in this cover. I get it, it forces you to inspect the innards. The oil looks and smells ok but I'm just not sure when it was changed last. I think it has been serviced at least once though because I can see some black gasket material that oozed out around the edges. I don't suppose that would be an OEM install.

Mike

tjdonahoe · 02-03-2017, 07:21 AM

Quote:

Originally Posted by mayco

Thanks for all the information fellas. The few times Ive changed rear end oil in the past there has always been a drain plug in the cover. I was pretty surprised to find that there wasn't one in this cover. I get it, it forces you to inspect the innards. The oil looks and smells ok but I'm just not sure when it was changed last. I think it has been serviced at least once though because I can see some black gasket material that oozed out around the edges. I don't suppose that would be an OEM install.

Mike

Some oem's use no gasket, some have a rubber reusable rubber ring, silicone gasket maker...is used without a gasket, all you need...

tjdonahoe · 02-03-2017, 07:29 AM

Quote:

Originally Posted by tevake

While we are talking diffs, is there a favored oil for reducing the whine coming from back there?

I do travel solo most of the time so pretty sure it's the diff.

Cheers Richard.

Oil isn't going to take away the whine, loose bearing, or incorrect gear alignment? 90-140 is a a thicker oil,will pull harder , maybe a drop in fuel mileage?

CRH · 02-03-2017, 09:04 AM

I have had two whining rear ends in different vehicles. Both failed over time.

CDONA · 02-03-2017, 09:49 AM

Make sure you use the limited slip/locking differential additive IF you are so equipped.
A standard open diff, not used.

MelGoddard · 02-03-2017, 07:40 PM

Quote:

Originally Posted by vintagemotor

I clean all of the mating surfaces and add a small bead of Permatex "The Right Stuff" sealant in addition to the paper gasket. Properly re-torque the cover bolts (over tightening will cause a leak).

I concur!

BIGED52 · 02-03-2017, 10:45 PM

It has been my experience when the ring gears are whining or chattering is heard it is time for a full rebuild or rear end replacement! Not a cheap fix at all. When you do this or pay to have it done use a good quality synthetic gear lube differential oil. My GMC 1/2 ton Pick up is currently having loud gear chattering and the rebuilt rear end being put in tomorrow will cost me about $650.00 with the install labor. I just had new brakes and rotors on all four wheels done for $450.00. Lucky the shop will move the new rear brake assemblies to the rebuilt axle. Ed