Trans/diff fluid

[e99f2506sp]

Gonna be changing the oil this weekend and thought i'd change the transfer case, transmission, and both front and rear diffs. I don't know when it was done last and I'd like to get it in my maintenance log so I can keep it in the right intervals.

I was thinking of goin synthetic in all of them while im at it. Anyone have any suggestions on brands? I already run synthetic engine oil.

Thanks

[jgos929]

Originally Posted by e99f2506p

Gonna be changing the oil this weekend and thought i'd change the transfer case, transmission, and both front and rear diffs. I don't know when it was done last and I'd like to get it in my maintenance log so I can keep it in the right intervals.

I was thinking of goin synthetic in all of them while im at it. Anyone have any suggestions on brands? I already run synthetic engine oil.

Thanks

I use MerconV in the transmission and case. Mobile1 80-90 in the front diff and 70-140 in the rear diff.

[NCHornet]

Use synthetic in the transfer case and PS system, reg dino in a auto trans, and in the diffs. If you have LS don't buy any fluids like Ryal Purple that have the modifier already in them. Ford's limited slip has a bad rep cuz Ford used 8 oz of modifier, I reckon they were afraid of any possible chatter. This is way to much, add 2-3 oz and do some tight figure eights, if you hear chatter add another oz of modifier until it goes away. My LS have never worked so good, I have done this to several trucks and most take between 3 to 5 ozs.

NCH

[e99f2506sp]

Originally Posted by NCHornet

Use synthetic in the transfer case and PS system, reg dino in a auto trans, and in the diffs. If you have LS don't buy any fluids like Ryal Purple that have the modifier already in them. Ford's limited slip has a bad rep cuz Ford used 8 oz of modifier, I reckon they were afraid of any possible chatter. This is way to much, add 2-3 oz and do some tight figure eights, if you hear chatter add another oz of modifier until it goes away. My LS have never worked so good, I have done this to several trucks and most take between 3 to 5 ozs.

NCH

I've got the 6 speed, and if I looked in the book this morning and I think it calls for synthetic. the 5 speeds and autos call for regular and the 6 calls for synthetic if I remember right. Either way, I'll probably run synthetic in the trans and case.

Any reason not to run synthetic in the diffs other than the rear limited slip? I tow quite a bit if that makes any difference. not heavy all the time, but pretty often.

I've never been a fan of royal purple and a buddy runs mobile 1 in his race car and the insides are always real clean. Obviously out trucks are whole different ballgames, but they've got a good reputation.

[SyN]

e99: U will probably receive alot of different advice on Oil and Gear Oils and Transmission fluids... I myself am very anal about the oils I use... Maybe too anal... I poured in synthetic in my TCase... and synthetic in my front diff and rear diff... I also installed a PML rear diff cover when I replaced my rearend oil the first time after I bought the truck... It Is made from aircraft aluminum and has a fill plug on top and most importantly a drain plug.... So I will never have to take that dang cover off again... to change rear end fluid. I myself feel this is really a added plus esp if you tow alot and for long periods of time... to keep that rearend fluid fresh... But this is just me. Just an thought for ya.

[e99f2506sp]

Originally Posted by SyN

e99: U will probably receive alot of different advice on Oil and Gear Oils and Transmission fluids... I myself am very anal about the oils I use... Maybe too anal... I poured in synthetic in my TCase... and synthetic in my front diff and rear diff... I also installed a PML rear diff cover when I replaced my rearend oil the first time after I bought the truck... It Is made from aircraft aluminum and has a fill plug on top and most importantly a drain plug.... So I will never have to take that dang cover off again... to change rear end fluid. I myself feel this is really a added plus esp if you tow alot and for long periods of time... to keep that rearend fluid fresh... But this is just me. Just an thought for ya.

I appreciate the thought. Seein that your rigs got 275k, I guess synthetic in everything isn't hurtin anything.

Guess I'll run synthetic throughout unless I hear any heavy arguments otherwise. Like I said before, I'm plannin on mobil 1 just cause its easy to get and I've seen it at work.

I'll have to check into the diff cover. a drainplug really sounds like a good idea.

[NCHornet]

Those covers with the drain plug look nice but most have the hole up so high you leave a lot of fluid still in the diff. I would rather pull the cover because it gives you a good time to inspect the ring and pinion!! Many synthetics have the modifier in them so be careful. Modern Dino oils have come along way, but if it makes you feel warm and fuzzy run the synthetic, it won't hurt anything.

NCH