Tips for differential fluid change?

[thatguy]

UPDATE - Finally got around to getting the front axle done and had no problems except for getting the cover off. Boy was that thing 'glued' to the axle with RTV... I had to take a hammer and punch to finally get it to break loose.. It is now freshly filled with Amsoil 75w90 'Severe Service' - just need to check for leaks

I ended up getting new gaskets from AutoZone - The front axle was a Dana 60 and the rear was a Dana 70, and the gaskets had different part numbers.. BUT the gaskets were the exact same size, and were made out of different materials though..

Anyone care to tell me what the difference between the two gaskets was? The front was $3.99 and the rear was $12.99...

thanks

Brian

 

[RobJ]

The front axle was a Dana 60 and the rear was a Dana 70, and the gaskets had different part numbers.. BUT the gaskets were the exact same size, and were made out of different materials though..

Anyone care to tell me what the difference between the two gaskets was? The front was $3.99 and the rear was $12.99...

thanks

Brian

Might be a heat thing, actually that's just a guess. I hope you bought the cheaper one.

 

[thatguy]

Might be a heat thing, actually that's just a guess. I hope you bought the cheaper one.

I couldn't get that lucky to be honest.. But if had know i may have bought 2 front axle gaskets instead.. Then again, i only wanted to do this once and if the gasket had leaked it would have cost way more in gear oil that the $9 price difference..LOL

The rear axle was completed yesterday.. It took a lot of banging and cussing to get the cover off.. The front cover had a slight lip that i could get a punch on to force it off, but the rear cover did not have a lip..

I was very leery of the RTV only as a gasket since I have never used it before.. I used just enough RTV to keep the gasket in place (small thin bead) and then bolted it up and torgued it.. No leaks on either end..

Brian

 

[LRH]

UPDATE - Finally got around to getting the front axle done and had no problems except for getting the cover off. Boy was that thing 'glued' to the axle with RTV... I had to take a hammer and punch to finally get it to break loose.. It is now freshly filled with Amsoil 75w90 'Severe Service' - just need to check for leaks

I ended up getting new gaskets from AutoZone - The front axle was a Dana 60 and the rear was a Dana 70, and the gaskets had different part numbers.. BUT the gaskets were the exact same size, and were made out of different materials though..

Anyone care to tell me what the difference between the two gaskets was? The front was $3.99 and the rear was $12.99...

thanks

Brian

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The Dana 60/70 do share the same gasket, but if the AutoZone gaskets were supplied by Victor; they list a regular gasket, and a HD version that has shim steel between 2 layers of premium gasket material. Maybe the parts guy just looked quickly and did not see that there were 2 choices. The shim steel versions usually have "TC" as a suffix; at least when using the Victor/NAPA numbering system. After 40-50 years of Dana/Victor-Victor/Reinze, NAPA has changed to Fel-Pro, but others still sell Victor, and usually use the Victor numbering system. Also; double check the rear diff fluid, some are calling for 75-140 synthetic in the Dana 60-70 rears; per the Chrysler 3 letter prefix on the axle tag or door sticker. Some that called for 75-90 syn originally, now state 75-140 is preferred, via a TSB issued at some point.

 

[thatguy]

Both Autozone and Advance Auto only had Fel-Pro gaskets around here... I looked the gaskets parts numbers up on line at home and then compared my results with the AZ counter guy and we got the same part numbers for both..

as far as the 75w90 vs 75w140 - it got 75w90 amsoil severe gear. But now that you mention it, I do recall reading online someplace that they recommended the 140 if you did a lot of heavy towing. it never occured to me to double check the specs though..

thanks

Brian

 

[QueBota]

Too late to help but I usually take some soap, and old scrub brush and the hose and try to clean the diff cover and housing and anything around it the day before I open up the diff. May be overkill but it makes for a cleaner job and keeps all the crap around the diff from falling in after you pull the cover. I also cover the opening as much as possible with a shop towel when cleaning the mounting surface of the diff, helps keep the crap out.

Dave

 

[ChuckV309]

Do you have limited slip diffs? If so, Dodge requires a friction modifier to be added to the fluid when you fill it. It is supposed to make sure the clutch packs in the diffs work correctly. You buy it from Dodge in 4 oz bottles. Costs about $9 for a bottle. Takes a bottle per diff. I'm not sure if the newer trucks require it, but my '97 does. They also say to change it every 8000 miles too. Mine gets changed about every 16-20K.

My 97 doesn't use gaskets either. Just rtv. I let it set for a couple of hours before I fill it. Never had a leak. Makes it a pain in the rear to remove the covers though.

Chuck

 

[thatguy]

Do you have limited slip diffs? If so, Dodge requires a friction modifier to be added to the fluid when you fill it. <deleted text>

<deleted text>

Chuck

Luckily I remembered to add the friction modifier. I ordered some from Amsoil when I ordered the gear oil... I made some figure 8's and I could not feel or hear anything, so I think its good to go..

Im sure everyone has their preference, but based on this experience I would prefer to use a gasket than RTV. Although it is more expensive, I was worried about not letting the RTV set up correctly or getting it too tight and having leaks..

Brian