Ok I am going to change oil, rear diff fluid, tranny fluid, and coolant. Besides the oil, what quantity of each do I need to put in? And besides the oil, what brand and kind do I want? Axle is c8.25 and tranny is aw4 this is in a 99. Also, any suggestions on which oil I should get? I think I want to get a puralator filter.

 

I work at advance auto. We can look up required fluid and capacities and everyone on here reccomends quality filters. Mopar filters run about 7 bucks

 

As far as oil I hear rotella is good stuff and it's cheaper at Walmart

 

for tranny fluid if your not changing the filter, then I believe it calls for 4 quarts Dexron III fluid, fill through the dipstick till reading is good.

for the diff fluid, run 75-90 or 80-90 gear oil, fill till fluid starts coming out the fill plug. If you have limited slip then make sure you get some that is for a limited slip diff or you get the additive to mix, using a gear oil for limited slip wont hurt if you don't have limited slip.

for brand stick to a name brand, like lucas, royal purple, mobile one, etc.. same for filters. Don't use any fram products they are basically cardboard.

 

Oil: Depends on your climate. If you're going into winter in a cold climate, use 5W30.
Gear Oil: 80W90
Transmission and Transfer Case: name brand Dex/Merc ATF (I say name brand, because Dex III is no longer licensed by GM, so there are no quality control checks, per se. I would want a national name brand [Valvoline, QS, Shell, etc.]).

Note that with all these fluids, conventional is fine, synthetic is better. It all depends on what you want to spend. Also, there are different grades of synthetics.

Oil filter: Purolator, as you mentioned, is good. I personally like Wix/NAPA Gold. Baldwin/Hastings are also good.

Coolant: Use the conventional green. If you want to extend the coolant change interval, you could use G-05 (Mopar/Ford/Zerex). I would avoid Dexcool and the Dexclones (universal coolants).

 

Thanks! How are duralast wires?

 

a good or even decent shop manual will have all that info. I buy one for every vehicle I own.
I use full synthetics for my diffs and tranny.

 

If you see an Autozone, keep driving until you find yourself a NAPA.

 

NAPA or some really good 8mm wires from places like Summit racing. I hate to keep ragging on Auto Zone, because not everything they sell is crap, but for things you only want to do once go with NAPA or dealer parts.

I spent along day last week replacing my front axle joints (AZ Premuim-Lifetime Warranty) after only 20K. They replaced them with with new ones without a problem (I'm saving them for a gift to someone I don't like). But who wants to do that every couple of years?

 

So I have a C8.25 and went to Advance Auto and they brought up on the computer that the rear took 75-140??? Everyone on here says 75-90 and 80-90, which is the proper replacement?

Also, I went to AZ and Advance Auto to get a front diff gasket for the D30 and neither of them even carry it nor can they order it. Would NAPA generally have this item in stock or be able to order it?

Here is the info from my build sheet.
DGB All 4-Speed Automatic Transmissions
DGSS 4-Speed Automatic AW4 Transmission
DHAP Lock-Up Torque Converter
DHNS Command-Trac Part Time 4WD System
DHSP Floor Mount Automatic Shift Lever
DJKS Dana 30/181MM Front Axle
DMDP 3.55 Rear Axle Ratio

This vehicle has the towing package on it with the tranny cooler. I jacked it up to check and see if it is an LSD and when turning the right rear forward the other does not spin, but turn it backwards and it does, but only part of the time? Is this an LSD?

 

Do you tow? If not, 75w-90 is what you want. If you do tow, you want 75w-140. And don't bother with a diff gasket. Grab a tube of RTV and just use that.

 

OK, thanks. I do not tow, nor do I plan to. This is a DD vehicle.

 

don't go without it. add it first then fill.

 

Don't forget your Transfer Case fluid (important). Use the same ATF that you will be using in your Tranny (Dexron III/Mecon) to avoid confusion.

Avoid Purolator; use Wix 51515, or NAPA Gold equivalent filter.

 

Does anyone sell gallon jugs of dif fluid? I was looking to buy new fluid for them but didn't want to buy 4 separate quarts...