AggiePhil

I'm wanting to change my front and rear axle fluids today, but don't know exactly how to do it. That includes knowing what kind of lube to use. Do you have a choice (such as synthetic v. non-synthetic), or is it just one kind of lube you can use? The sticker on the inside of my glovebox says:

AXLE-FRONT-5200# DANA
AXLE-REAR-6500# DANA
AXLE-RATIO 3.55
AXLE-ANTI-SPIN DIFFERENTIAL

I did a search for info on this procedure and couldn't find anything, so if y'all could chime in, that'd be greaaaaaat. Oh, and yes, BigBlue, I know you know how to do it, but I'm just doing my homework before hand, for my sake.

PCarnathan

I posted this same question last Tuesday. It appears you have to unbolt the diffferential covers and let it splash out. That also gives you the opportunity to inspect the ring and pinion for unusual wear or damage. I put in Amsoil 75W.

Several aftermarket outfits produce alternative differential covers. They hold more fluid and come with a drain plug. I didn't go that route because the checking account's a little shy right now.

Pat in San Diego

AggiePhil

I believe there's actually a drain plug on there from the factory, right?

bluebull

You will need some silicon (grey preferred, but orange and black will do) to seal the covers back up upon reinstalling them.

If you tow heavy alot synthetic is recommended, if you do not tow then 75-90 dino is fine. You should also have a bottle of friction modifier on hand just in case you need it. Do not add unless needed. Since you have a limited slip differential. After you change the fluid drive your truck in a few figure 8's in a parking lot. If the rear end chatters or binds add about one ounce of friction modifier and repeat the figure 8' if still chatter then add one more ounce of friction modifier, keep doing this until the chatter goes away. The reason for adding a small amount at a time is if you add too much friction modifer you will no long have limited slip, it will slip all the time.

hotdram

The Dana covers use silicon as a gasket. You will have to remove all the bolts and then gently insert a gasket scraper in between the housing and cover and go around and around, until you can pry the cover off (I did this last weekend without the benefit of a gasket scraper, just a razor blade tool that I broke, I then had oil everywhere, because when I finally pried off the cover it came off quick, of course missing the drain pan). You will need new silicon to make a new "gasket". Be aware, that you need to let the silicon cure awhile before you use it.

~Rob

bluebull

No drain plug on the oem equipement. the plug is for filling the pumpkin. keep the fluid about 1/2 an inch to 3/4 of an inch below the fill plug is the proper level. if you can feel the fluid by sticking your finger in the hole and bending it then that is about the right level. Over filling will cause aeriation of the oil and cause excess wear of the contacting metals

hotdram

Also, check here for removal instructions: Mag-hytec Instructions page .
Click on the axle you have, (I believe you have a Dana 70 rear because you have the auto and a Dana 60 front). These will link you to a page that has removal instructions for the stock cover. (Be aware that the amounts of fluid these pages show for re-filling are for new covers that hold more than the stock ones did, so don't use these amounts if you are staying with the stock covers).

~Rob

bluebull

Another good tip is to leave the top couple of bolts in but loose this way you will not spill the oil all over as Rob stated.

hotdram

D'oh, where were you LAST weekend bluebull?
Besides, 75W90 doesn't taste that bad
~Rob

AggiePhil

Hmmmmm. This is sounding more complicated than I'd envisioned. How hard of a job would you guys say that it is? I was under the impression that you just remove a cover on the bottom (or something), let the fluid drain out, put sealant on the cover, put it back on, and fill 'er back up with fluid.

Also, could someone break down what you do for the front and then the rear?

hotdram

It's not hard, just takes awhile because there is no drain plug or access panel, you have to remove the entire cover (be it front or rear), drain the oil, remove the old dried silicon from the cover and housing and then slather silicon on the mating surface and attach the cover. Again, I would stress the importance of letting the silicon cure (as per manufacturer's directions) before you use the truck. Most silicon I've used says it takes about 24 hours to fully cure.
That's the reason I put a Mag-Hytec on my back end (pics in gallery), plan to do the same to the front when funds allow.

~Rob

Mike D

It really pretty straight forward. Remove all the bolt except just loosen the top couple. Use a putty knife to break the seal of the old silicon gasket, let the pumpking drain. Finish taking off the cover completely, prepare both the surfaces for the new silicon gasket and reinstall cover, don't overtighten the cover bolt. Just snug them up by hand plus 1/4 turn. You can go back after the gasket is dry and retorque. Fill the pumpkin up with new fluid after giving the new gasket time to dry, let call it about 1 hour. Most people have had good luck using a gear oil that doesn't require a fiction modifier. Don't over fill, bring the level up to just below the fill hole. EZPEEZE Front cover is the same concept.

Edit: This might be a good place to check for new diff covers in case you want one with a drain hole. http://www.yourcovers.com/

AggiePhil

Do you use the same fluid on both the front and the back? I don't tow much at all anymore. What should I use if I want to use a fluid that doesn't require a friction modifier?

Mike D

Try Lucas or any of the other brand of syn. Most will tell you right on the bottle, something like, "this gear oil requires no additional addivtives for limited slip diffs". Does your truck have a limited slip? You might not have to worry. Same fluid goes in both axles.

hotdram

I used Mobil 1 75W90 in the rear (haven't done the front yet). Their website states that you don't need a friction modifier, but IF you do hear chattering, you can add some. I have not added any to mine (yet). I paid about $8.00 a quart for the Mobil 1. It was hard to find, as most places were out. I would guess the Dana 70 (rear) uses about 4-5 quarts?? As was stated above, fill to just below the fill hole.

~Rob