03 Dodge Ram oils needed

[Fuelman]

This is my first post on these boards, I must say that there is a huge collective knowledge here, I love it. I know model engine (airplane, car, boat, heli) fuel and lubricants and two cycle engine lubes well since thats my livelyhood, but lubricants other than that are less completly understood. So, here's my questions:

I have 30K on my truck and want to replace everything fluid on the vehicle, with synthetics.
Front Diff calls for 75w-90 conventional
Rear diff calls for 75w-140 synth w/ posi lube
Transfer case calls for Dex III
Trans calls for some Mopar part number that crosses with Pennzoil Synchromesh MTF.
I've been using synthetic engine oil since the factory oil was removed.

OK, the front and rear end is pretty simple, but can I use a synthetic 75w-90 with posi lube instead of the 75w-140 synthetic? or is the heavier viscosity absolutly necessart (I do haul large loads), Also, what brand of synth gear oil? I have available to me M1, RL, RP and I think Costal.
Same thing for the transfer case; Will I have a benefit going to say M1 ATF? vs the Dex III conventional?
The manual transmission, I just picked up RL MTF (I think its 75W-80) since I have friends locally that have had good service out of it. Is this a suitable substitute, I noticed tha M1 did not have a part number that equated to the needed Mopar fluid, and the RP tech rep said they don't have a suitable product.

I also got a deal on RL 5w-30 engine oil on a closeout, it was 3.95 per quart, I figured I could'nt go wrong so I bought all they had. I usually pay about that for the Havoline synthetic and about a dollar more than that for the M1 when I use that. What kind of oil change interval can I expect from the RL? (its a gasoline engine, 4.7L)

My overall objective is to increase the oil change intervals in everything and to squeeze out as much mileage as possible since I'm on the road making deliveries a lot.
Appreciate your collective help in advance.

Thanks for your help
Fuelman

 

[1sttruck]

I have a 2003 2500 4x4 with a diesel, and am currently using Mobil 1 75W-90 in the front axle, Mobil 1 75W-140 in the rear (I have an open diff but the limited slips use a Torsen type that doesn't need an additive, the 1500 may be different), Mopar ATF (+4 ?) in the transfer case, and the Mopar manual tranny fluid for the NV4500 that cross references to Castrol SynTorq. I changed my axles at 15k miles and the transfer case and tranny at 30k miles. The transfer case and tranny fluid looked fine, the axles with the factory fill looked like black snot at 15k miles, and looked like dark olive oil with the M1 at the next 15k miles.

 

[Fuelman]

1struck,
My tranny is the NV3500 and I have no idea which rear end is in it, Dana 60, or corporate 9.5, don't know, all I know is that its their "anti-spin"
I know the NV3500 takes a different oil than the NV4500.
Ohh, one thing is that I talked to one of the engineers at the Syracuse plant that was a techie on oils up there and he said that they test the snot out of different lubes for transaxles and trannys and that they liked the AMSOIL 5W-30 engine oil in the grand majority of the new trannys and transaxels calling for the ATF or Synchromesh. I'm still leary thinking a purpose formulated tranny oil is best. i could be wrong.

 

[Rebel Rouser]

You must have either the NV3500 or NV5600 manual transmission that specs the synchromesh fliud. It's a lighter viscosity fluid than the Castrol Syntorq LT used in the NV4500 5 speed. They are both GL4 rated fluids, ie., friction modified for proper synchro engagement.

I have a '98 Dodge Ram with the Cummins diesel and recently ordered lubricants for the driveline from Speciality Formulations, a site sponsor here. They are full synthetic and will offer extended service intervals. I have the NV4500 transmission, so ordered MTL-P for that. SF's Synchroglide I believe is the replacement equivilant to Mopar Synchromesh.

For the T-case, I ordered MTFglide, which is the same viscosity as ATF, but with 5 times more anti-wear additives. I've noticed in the past on changeout, the used drain ATF from the T-case has been very dirty. I use 4X4 alot during the winter plowing snow, and will see if this improves what appears to be excessive wear.

For the front axle I ordered 75W-90, and 75W-140 for the rear axle. I do have limited slip on the rear, and have never had to use "external" friction modifier in the past, no chatter on turns.

I have 125K miles on the truck, and this will be the third driveline service interval. Barring any contamination from moisture, etc., you should be good for extended drain intervals using a quality synthetic.

Regards

 

[pajim17057]

I have an nv3500 in my 96 ram. I ran 75w90 amsoil in it for about 50,000 miles. It worked ok except it shifted hard for the first few miles in the winter. I tried amsoil 5w30 hdd, but the shifting was notchy. I have penzoil syncromesh in it now and it workes great.

 

[TooSlick]

I'd get an oversized differential cover - I think that "Magnafine" makes one?? - and use a 75w-90 synthetic gear lube in the rear differential. This will lower the temps somewhat and reduce the rate at which the fluid degrades from oxidation.

I like the Royal Purple gear lubes, out of the brands you mentioned. I think 59 Vetteman would agree with me ....

TS

 

[unDummy]

Fluid choice is yours to make.

Mobil1/Amsoil/Redline/Neo/SpecialtyFormulations/RoyalPurple/Torco..... have you covered.

I would recommend synthetics everywhere. Mobil1 products are available almost everywhere and have everything but the manual tranny covered.
I'm betting that the synchromesh is best there.
Redline MTL, SF Synchroglide, RoyalPurple Syncromax, Neo MTF, Torco MTF.....are other options for the manual tranny.

I understand that some complain about sludging issues with the 4.7l. This is something for you to research. I wouldn't extend OCIs without UOAs.
Also, if there is room, a larger oil filter can be used for increased filtration and oil capacity.

 

[Fuelman]

Oil sludging in the 4.7L, that is the first I've heard of it.
Since this thing had about 1500 miles on it, I switched over to M1 or Havoline synthetic and changing it every 3000 plus or minus a couple hunderd. I do get a lot of condensation build up in the oil fill and cap area, but have yet to see any water come out of the oil pan when I change it.
I do want to extend the OCI out to at least 6000. I may do a UOA at that time. I will probably still do a filter swap and top off at the 3000 point. As I mentioned in previous post, I will be trying the RL 5W-30, so I'm hoping it will be good for the 6000 miles I'm looking for.

I just got the RL MTL for the tranny, $6.00 per quart at Advance Auto on clearance, So I got that covered.

Looks like RP for the front and rear diffs if you folks think its better than M1 since it does'nt matter to me because its the same price here. Will I need the lim slip additive that mopar suggests?

I'll just put M1 ATF in the transfer case.I need to get this done tomorrow night or Saturday, so getting product from SF is not practical at this change out, but will definatly do so next time around.

Do you folks think I'll be able to squeeze a mile or so per gallon out of the fluid swap to all synthetics?

thanks a bunch

Fuelman

 

[unDummy]

Some people get an MPG increase, others don't.

I get more consistent MPGs with accurate tire pressure, checked weekly.

LSD additive is needed if your rearend gets chattery after the fluid change.

I guess that DaimlerChrysler is capable of keeping their sludge issues quiet.

Good luck with that 6k OCI w/3k filter changes. It should work OK. But, keep an eye on crankcase ventilation.

 

[jmlangeveld]

quote:

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Originally posted by Fuelman:
I do get a lot of condensation build up in the oil fill and cap area, but have yet to see any water come out of the oil pan when I change it.

Fuelman

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I thought that Chrysler had a service bulletin on this. Is there are replacement oil cap available that doesn't let in water?

 

[JD Green]

04 Dodge Ram QC 4X4 with the 5.7L Hemi. It's on an Amsoil diet from bumper to bumper.
Engine:Series 3000 5W-30 (HDD Product) & SDF15
Front Diff: Severe Gear 75W-90
Transfer Case: Amsoil ATF
Auto Transmission: Amsoil ATF
Rear Diff: Severe Gear 75W-140 with 4oz of Slip Lock additive.

The truck is roughly one year old with about 37000 Kms on it and is as smooth as silk.