Engine/Transmission (1994 - 1998) Fluids recommended for rear axle and 5spd.

[PWeber]

I just got this truck and do not know the history of the fluid changes. I want to have the front and rear axle fluids and the trans fluids changed. Anyone have the recommended Dodge and any other input on synthetic lubes that seem to work well in these along with capacities?

 

[wcjp]

I use Valvoline full synthetic 75w-90. I usually only tow once or twice a month. My Jeep and trailer are about 5,000pds.

 

[Andy Redmond]

5spd. NV4500. Purchase 4qts.



GL4, rated. Castrol Syntorq. Available from Castrol directly (jobbers) in a 16 gal. barrel.



From DC for $20 plus per qt.

From GM dealers for less than DC.



Available from Standard Transmission for apprx. $60 per gal. (they are repackaging from the aforementioned drums likely).



Most gear synthetic gear lubes are a 75w90 GL 5, which is not so kind to brass syncros. .



Both (4x4 / 2x4?) diffs likely were synthetic factory filled.





On the rear diff. I run full syn 75w140 gear oil year round (Southwest). If you live in a colder climate 75w90 is a good year round choice unless you tow, then I'd change to the heavier lube for the warmer months.



I have used Torco full syn. or you can source a good synthetic from the dealer as well.



It should hold about 5 qts. Remember your limited slip modifier if yours is so equipped.



I also run the Torco full syn 75w90 in the front diff. year round.



The font diff capacity is around 3. 5 qts.



Good luck.



Andy

 

[Matt42]

What I use:



Front Diff: Royal Purple synthetic 75W-90

Rear Diff: Royal Purple synthetic 80W-140

5 speed: Castrol Syntorq. I wince and pay the price to save the yellow metal synchros.



Syntorq is clear when new. When it looks like "regular" transmission fluid, it's probably time to change it.

 

[esommer2500]

How many qts in the front diff?



What about the transfer case?



The haynes manual says 6. 8 to 10. 1 qts for the Dana 80?



How do I find out if I have limited slip?



Can I run 75W-90 (synthetic) in all of these components?



TIA.



Eric

 

[Matt42]

If you have a limited slip rear, you should have a thin strip of embossed steel between two cover bolts that says to use limited slip fluid. If the strip is missing, there should be an unpainted rectangular strip where it was. If it's been painted, try this:



Jack up the rear so that both rear wheels are off the ground. (Chock front wheels, of course. ) Put in neutral and release parking brake. By hand, rotate one wheel. If the other wheel rotates the same way, you have limited slip. If it rotates the other way, you don't.



Capacities. Yours is probably the same as mine. Front diff: 7. 3 pints. Rear diff: 10. 1 pints. D/C calls for 80W-90 in both axles, and 80W-140 synthetic in the rear for frequent towing. 75W-90 synthetic will probably be just dandy. Many TDRers find that they need to add the MoPar LSD additive to the rear, even if the synthetic they buy says it has an additive. I added it on spec, and had no chatter.



Do yourself a big favor and buy the Factory Technical Service Manual (TSM). It's pricy at $90 (it was $150 for my wife's Saturn), but it's been worth every doggone penny.



Cheers!

 

[BigBadDodge]

Here is what I do !!!



Engine Oil = Amsoil 15w-40HD Diesel and Marine (11 quarts)



Transmission Oil = Amsoil Series 2000 75w-90 gear lube (4 quarts)



Transfer Case = Amsoil Automatic Transmission Fluid ATF+4 (3 1/4 quarts)



Front Differential = Amsoil series 2000 75w-90 gear lube (4 quarts)



Rear Differential = Amsoil Series 2000 75w-90 gear lube (8 quarts) Mag-teck cover



BBD

 

[Texas Diesel]

Here is my approach:

Dino 90W in the front diff,

Royal Purple Synchromax in the transfer case

Royal Purple MaxGear 75W-90 (5 speed) and Royal Purple Synchromax ( six speed)

Mobil 1 75W-90 in the rear diff.

Consider a Fastcooler and PTO filter on the 4500.

Royal Purple is fully API certified, some oils are not, PM me for details. Royal Purple is available from JCWhitney mail order.



Read here: ( the post by GMORRISON about Eaton extending tthe warranty if Mobil 1 is used) https://www.turbodieselregister.com...threadid=38708&highlight=eaton+warranty+mobil

I saw a 15*F drop when I switched to Mobil 1 from dino 90W. I will try Royal Purple in the diff at the next change.



Royal Purple says it is safe for GL-4/5 and gearboxes with yellow metals (synchronizers). It works like a champ in my 4500.

http://www.royalpurple.com/retail/retailpdfs/maxgear/maxgearps.pdf

 

[MDW]

GL4, rated. Castrol Syntorq.

Where are you finding this stuff?

I have tried O'reilly's and Autozone no luck.

 

[redram]

Originally posted by Matt Shumaker

What I use:



Front Diff: Royal Purple synthetic 75W-90

Rear Diff: Royal Purple synthetic 80W-140

5 speed: Castrol Syntorq. I wince and pay the price to save the yellow metal synchros.



Syntorq is clear when new. When it looks like "regular" transmission fluid, it's probably time to change it.

Matt, use the RP MaxGear 75W90 in the NV4500..... I have for 120,000 miles now and it shifts smoother and better than the Castrol product did - and no problems with the 5th gear or attacking the synchros. At less than 10 / quart and availability at many Napa's, performance shops or Jegs, it is a good choice.