Hey everyone! Hope everyone is doing well! I finally got some money on hand that I saved for my truck and I'm planning on redoing everything to make it run like it was when it was new. I'm gonna be doing the intake plenum (plate and gasket) distributor cap and rotor, plugs and wires, valve cover gaskets, pcv, oil change, transfer case fluid change, transmission gear oil change, and rear diff fluid change. I already have most of the supplies but I need a little help.

1. What type of fluid do I need for the transfer case and is it worth flushing?
2. What type of gear oil does my transmission take and is it worth flushing? (I have heard from some people that I shouldn't bother doing the transmission and transfer case.
3. What type of fluid does my rear diff take and do I need any additives?
4. What is the best engine oil for my truck? I have OCD with my Volvo and only run the best fully synthetic oil in it but I'm not sure about dodge.

I'm waiting for some nice warm weather to get all this done so it may be a week or two before I'm ready but I really want to get all my supplies ready beforehand. I also plan to treat the rust and undercoat my truck but I'll save that for later.

My truck is a 1998 Dakota sport ext cab with 5.2 and a 5 speed manual transmission with 166k. It has 4x4.

Thanks guys- Justin

 

1) Transfer case takes ATF, not sure which type. I wouldn't worry about flushing it.
2) Transmission takes special oil that you can get from Mopar (and pay too much) or you can use Pennzoil Synchromesh or Royal Purple Synchromax. Personally, I use Red Line MTL in mine with good results.
3) Rear diff takes 80W-90 gear oil (Synthetics will be 75W-90). If you have a factory limited-slip you need a friction modifier additive. Some synthetics claim not to need it, but I would use it, anyway.
4) I only run synthetic oil, but I'm not necessarily loyal to one brand. Currently, I'm running Castrol Edge. Follow your owner's manual for viscosity requirements.

BTW, you might as well change the oil in your front diff while you're at it. It has just as many miles on it as the rear. It takes the same oil as the rear, but doesn't require an additive.

 

Hmmm OK I'll skip the transfer case for now probably. Not sure if my truck has a LSD if it does where can I get that additive? Would I have to order it or could I get it at my local auto zone? Also is there any special pump I can buy online for pumping this fluid or is the elcheapo one from my local auto store OK?

Also thanks for all the info so far. I didn't even know you had to change anything in the front diff. No one ever mentioned it. How would I go about doing it?

 

You can get the additive at pretty much any parts store, including Auto Zone. The cheap pump works fine. No reason to spend a bunch of money. Basically, you change the front differential fluid exactly the same way you change the rear, except that it's much more cramped to work on.