Engine/Transmission (1994 - 1998) Gear oils Front / Rear / transmission. Which ones???

[98ramtough]

I know this has been debated 15 million times. But I am still a little fuzzy on whats ok.



I want to change oil in my front diff, rear diff, transmission and transfer case. My new truck has 191k miles and I don't know when this was done. (Just bought it).



For the NV4500, it will be getting dealer Syntorq at $23 a quart. Nuff said on that one.



For the front and rear diff I want synthetic. But can you use the same in the front and rear? Mobile 1? Lucas? Castrol?



I was thinking about going with Mobil 1 LS 75W-90 Synthetic Gear Lube. Can this be ran in the front and back? Since it is LS does it not need any limited slip additive?



What about the transfer case?



Also, in the factory spec it says the D80 hybrid rear needs like 10qt. Does it really take 10 when you change the fluid? I am trying to figure out what all fluids to buy and how much.



Thanks guys...

 

[GAmes]

I can't recommend front differential, but I use Royal Purple in my Dana 80, LS. No additive needed and the bearings are the originals, even after 100s of thousands of miles towing. I have a Mag-Hytec cover and refill is 7 qts. Stock is 4.

 

[R C Cola]

6 spd

G. AMES... . how do you like the 6 spd for the job you do ?

 

[R C Cola]

98Ram ... When I was in Blumenthals for service they put the same synthetic in all 3 spots

 

[GAmes]

G. AMES... . how do you like the 6 spd for the job you do ?

It is definitely an improvement over the 4500. I especially like the 4th gear ratio. Time will tell if I get longer service from it.

 

[fest3er]

Current recommendation is to use at least 75W110 in the diffs, and 75W140 if you tow. Use the best synth gear lube you can get in the diffs. Factory fill of tcase was most likely synth, so, again, use the best synth you can get. I'm partial to Amsoil, and they do make synth lubes for both the 4500 and 5600.

 

[Driftwood Ram]

If I remember correctly the transfer case gets ATF and I have been using Amsoil there and in the auto trans. If I am wrong anyone can feel free to correct me.

 

[surfbeetle]

Well you said "nuff said" on the transmission, but I'll just say 202,000 miles and counting on my never touched, orignal NV4500 and I use Royal Purple.

 

[98ramtough]

What do you guys think of Lucas for the differentials?



I can get Lucas 75w-140 synthetic for around $10 a quart shipped to me. Would this be good for the front and rear?

 

[ksoren24]

I've been using schaeffers in my gear boxes, so far so good. I'm going to put it in my transfer case too but it takes atf so I'm going to do some research first. The schaeffer guy told me I could use his "superlube" (I think thats what he said) in the t-case.

 

[HerbW]

I think you need maybe 10 pints(5 quarts). My Dana 70 uses about 8 pints which is four quarts. It has a smaller pumpkin than yours by a bit.

 

[Missouri Mule]

If you want to go with Castrol the chevy dealers used to sell it by the gallon, it was a lot cheaper then what Dodge wants for it.



You mite want to check out the Standard Transmission and Gear Co. ( they advertised in the Magazine) they used to sell it by the gallon but a member stated that they had started selling/using Amsoil GL-4.

Diffs use GL-5.

 

[bheiting]

Consult your owners manual and the Buyers Guide (TDR home page, left column) Anything syn. that meets the specs will work. In TDR diesel oil tests, there was no difference between Walmart and Amsoil synthetics.

 

[GAmes]

In TDR diesel oil tests, there was no difference between Walmart and Amsoil synthetics.

That was engine oil, not gear box oil.

 

[98ramtough]

Thanks everyone for your help. I know all this seems repetitive, but I am very picky about everything on my vehicles performing correctly. I am a computer guy, not a mechanic, so this stuff isn't duh to me...



What type of ATF fluid goes in the transfer case? I know there are different types of standards. I want synthetic of course. And how much goes in there?



Here is what I am going to do so far.



Front and Rear diff 75W-90 Valvoline full synthetic. Bottle says no LS additive needed. I can get this for $8. 99 a quart local. I am going to get 9 quarts and do the front and rear with this. Any issue running this in the front?



NV4500 transmission will get Castrol Syntorq from Dodge dealer at $23 a quart. I will get 5 quarts. I called the Chevy dealer and it was $26 a quart!



Power steering already got the Lucas power steering fix synthetic fluid. I need to change it a couple more times, but I must say the whine when cold got MUCH better!

 

[SRath]

FWIW: The NV4500 and NV5600 require different oils.



Napa has (or at least recently had) Valvoline Synthetic 75W-140 on sale for under $12 per quart. No LSD additive necessary and it is fine for both front and rear axles. I like amsoil and use their 75W-140 in the diffs and their synthetic ATF in the t-case and their gear lube for the NV4500. I even used their grease in everything when I rebuilt the front end.



I'd be interested in reading any 'testing' that showed walmart synthetic to be 'the same' as amsoil.

 

[ksoren24]

When you change your front diff make sure not to top it off, if you do it will leak out of the right side. Your supposed to leave it an inch below the fill hole. It sounds like you have your mind made up but you should really check out schaefferoil.com before you make your final decision, its great stuff and now $23 a quart!

 

[SRath]

Lame reason to run low oil

When you change your front diff make sure not to top it off, if you do it will leak out of the right side. Your supposed to leave it an inch below the fill hole. It sounds like you have your mind made up but you should really check out schaefferoil.com before you make your final decision, its great stuff and now $23 a quart!

It sure will, but only because most dodges with the stupid CAD system are running around with egged-out passenger-side axle seals because it is located waaay outboard where axle wobble is greatest, and so is seal wear. Very dumb design.



I replaced my seal (a real pita), topped the diff all the way to the hole, and haven't leaked a drop. But eventually, it will again and I'll know the seal is again worn out.



BTW: If you have to run a low oil level to keep from leaking out the passenger side seal (or the drivers side for that matter), you WILL get water in your pumpkin if you cross a creek deeper than your tubes. Your seal is junk both directions. Oh, and your sliding collar that connects the wimpy dana 44-sized axles halves will be getting no lubrication and will wear or fail prematurely, too, if you choose to run low oil rather than fix the seal.

 

[Hammer]

As fest3er said above... .



I run Schaeffer's 75w140 in the trans and the Dana80 and in the front differential I use 75w90 Schaeffer's.

In the transfer case I switched it many miles ago to Schaeffers 30w synthetic gear lube and took the trans fluid crap out.

 

[bheiting]

That was engine oil, not gear box oil.

True, but as Martin pointed out, base oil is a commodity, and there isn't much difference in additive packages for gear oil. Oil companies will make their oil blends as cheap as they can. All that matters is that your oil meets the specs. listed in your owners manual.