[Rick C in Oakville]

I've done a search but only found info on 3rd gen rearend fluid changes etc.

My rear diff cover is leaking and going to change it and the front fluid.

What are you using and does it need the special diff lock lubricant additive?

Do you use a gasket or just RVT, I am just reusing the stock covers.

Thanks for any advice.

Rick

 

[burnin oil]

RTV sealent and 75w90 dino gear lube. From memory you need 5qts rear (I know for a Dana 80) and 4 for the front. Cant remember on the diff modifer for the posi but I think that it is not needed as long as the clutches arnt bitting.

 

[abe568]

Ive used rtv all the time. and for gear lube if i recall i went with 90w gear lube with an additive since i have limited slip.

 

[Rowingfish87]

Just changed mine: rtv for both diff covers and 80w90 gear lube with some ltd slip additive in the rear for me. just make sure you clean the mounting surfaces really well, a paint scraper, wire brush and brake cleaner work really well for this. What I always do as well is just snug everything up a little past hand tight and let it set for 20-30 minutes and then torque em down, helps the rtv set up and seal better.

 

[TrailTamer]

I had some bad luck with just using RTV so I used paper gasket (less than $5) with RTV coated on both side of the gasket and none of them that I did that have ever leaked again. I used only RTV on stuff that I know I'm gonna get it apart repeatly like a jeep.

Use gray RTV for best result

 

[cummins8-11]

just rtv them and make sure you clean everything really good and clean out the lower holes in the dif as fluid will go into them and come out as you put the bolts back in, use a additive in the rear as its a limited slip and regular 80w-90

 

[Rick C in Oakville]

Thanks to all for their advice, just 1 quick question, how long does the RTV have to set before adding the oil or does this vary by the type?

Rick

 

[pa coal roller]

i would wait for 15mins.

 

[Podhy]

I usually let it sit about 20-25 min before i add oil.

 

[wgr73]

Bumping an old thread for question:

1. Should I use synthetic gear oil?
2. Can I get the gasket (paper) from Autozone?...i'll use RTV as well.

Any links on "How-to"?

 

[kayden101]

If you use RTV make sure the surface on both the cover and diff is perfectly clean or it will leak.
put on the RTV, A nice decent bead on the cover, Then put it on the Diff and hand TIGHT all the bolts. 30mins torque them down to 18lbs
Then add oil

you can use the paper gasket if you want just make sure the surface is really clear.

As for the oil. I have used Supertech (walmart brand) gear oil 80-90w in all my 3 trucks for years with no problems.
in a 78 chevy 4x4 with Dana 60 and 14 bolt , 96 2wd dana 80
I will be using it in my 08 chevy too when the time comes. its only got 30k miles on it now

 

[illflem]

Dana says to use 80w140 synthetic if you tow.

I wouldn't even consider using a paper gasket.

Don't overfill!!!
Spec is 3/4" below the bottom of the fill plug up front, 1/2" below in the rear.
Overfilling often causes leaks.

 

[Gixxer340]

Dana says to use 80w140 synthetic if you tow.

I wouldn't even consider using a paper gasket.

Don't overfill!!!
Spec is 3/4" below the bottom of the fill plug up front, 1/2" below in the rear.
Overfilling often causes leaks.

I couldn't find where it specified 1/2" or 3/4" but I did find the capacity specification in the manual which was 4.8L + 190ml of friction modifier and I had all I could do to get that in before it started coming out the fill hole in the rear cover. Did I do something wrong? It is definitely right at the bottom lip of the fill hole.

 

[wgr73]

If you use RTV make sure the surface on both the cover and diff is perfectly clean or it will leak.
put on the RTV, A nice decent bead on the cover, Then put it on the Diff and hand TIGHT all the bolts. 30mins torque them down to 18lbs
Then add oil

you can use the paper gasket if you want just make sure the surface is really clear.

As for the oil. I have used Supertech (walmart brand) gear oil 80-90w in all my 3 trucks for years with no problems.
in a 78 chevy 4x4 with Dana 60 and 14 bolt , 96 2wd dana 80
I will be using it in my 08 chevy too when the time comes. its only got 30k miles on it now

Dana says to use 80w140 synthetic if you tow.

I wouldn't even consider using a paper gasket.

Don't overfill!!!
Spec is 3/4" below the bottom of the fill plug up front, 1/2" below in the rear.
Overfilling often causes leaks.

Thank you very much guys!!! I just wanted to over do the sealant/gasket/rtv so it wouldn't leak. I don't have that much faith in rtv but if you say it won't leak i'll take your word!

I'll give supertech a try and follow you guys instructions.

 

[moser11]

should not be a problem..I've thrown a jack under one side if the dif to get that extra little bit in there and slightly overfull will help the outboard bearings....I was told

 

[deezldude]

I overfilled my front diff, thinking it would be "better". The front diff has an overflow tube on the passenger side, and it puked it all over the engine compartment. The only way I figured it out is gear oil has a distinctive smell.

Don't overfill it!

 

[kayden101]

JUST MAKE SURE THE SURFACE IS REALLY CLEAN!!!!
REALLY REALLY CLEAN. then spray with brake cleaner and wipe it again with a rag.

I use a wire wheel to clean the diffs. Walmart/Home Depot/Lowes have it for 4 dollars. attach it to the electric drill and clean away!!

 

[RAMIT222]

How would I know if my diff's have Limited Slip ? Do I have to remove the diff covers & check on something or call the dealer with some sort of numbers ? I am guessing that there is only the limited slip in the rear diff & not the front ??

 

[kayden101]

could be in the front. I donno much of the Dodge dana 60s but my chevy did.

but the short way. Each axle should have a label on it. basically a Date of birt, Axle Type, Gear Ratio, and if its Limited Slip. the label might be dirty and have to clean it off to read it

 

[illflem]

How would I know if my diff's have Limited Slip ?

Open your hood and look straight up.
There should be a build sheet attached to the bottom of the hood.
Just be careful adding anti-slip additive, if you add too much you'll no longer have a LSD.
There is no set amount, it depends on clutch wear and the oil you use.
Every truck is different.
Add half a bottle at a time, drive figure 8s for a bit.
If it still makes noise in the turns add half a bottle more at a time.