2 questons Redline 75w140 or 75w140ns and nv4500 fluid

[Taylor13]

I recently purchased two 4oz bottles of Mopar limited slip additive and have been trying to figure out what fluid to get for my Dana 80 with limited slip. All of the fluids I come across already have a limited slip additive in them besides 80w90 which is what my owners manual says to use unless towing. Is it ok for me to get the Redline 75w140ns and add my own LS additive? Is the regular Redline 75w140 and the 75w140ns the same other than the LS addititve? Or should I just run Redline 75w140 with its premixed friction modifier
Also my service manual says to add 7oz of additive to my Diff my owners manual say 5% which is correct?
Lastly which is the better choice for an all around rig 80w90, 75w90 or 75w140?

2nd Question Im having a very hard time finding NV4500 transmission fluid the Gm fluid I found is
19369226 I called the dealer and gave the the 12346190 parts number and they told me it had changed to 19369226 anyone used this only difference I can see is one is a 75w90 and the other is a 75w85. Is the Redline MT-85 and Amsoil MTG just as good if so which do you prefer?k

 

[Shiner]

I recently purchased two 4oz bottles of Mopar limited slip additive and have been trying to figure out what fluid to get for my Dana 80 with limited slip. All of the fluids I come across already have a limited slip additive in them besides 80w90 which is what my owners manual says to use unless towing. Is it ok for me to get the Redline 75w140ns and add my own LS additive? Is the regular Redline 75w140 and the 75w140ns the same other than the LS addititve? Or should I just run Redline 75w140 with its premixed friction modifier
Also my service manual says to add 7oz of additive to my Diff my owners manual say 5% which is correct?
Lastly which is the better choice for an all around rig 80w90, 75w90 or 75w140?

2nd Question Im having a very hard time finding NV4500 transmission fluid the Gm fluid I found is
19369226 I called the dealer and gave the the 12346190 parts number and they told me it had changed to 19369226 anyone used this only difference I can see is one is a 75w90 and the other is a 75w85. Is the Redline MT-85 and Amsoil MTG just as good if so which do you prefer?k

I run the 75-140 in my dually C&C because I haul and tow frequently. Amsoil 75-90 GL-4 in the NV4500. I have always juiced a little extra additive in my clutch type LS diffs.

 

[JeepBuilder]

Torque King has trans fluid specifically labeled for the NV4500. I just ordered some.
Limited slip additive is designed to keep the LS clutch plates from sticking, chattering and galling. It makes the friction between the plates less which translates to less LS action. That is why it gets called friction modifier. It is always good to add the recommended amount in, but if it has good manners while cornering or figure 8's then more is not always better. In the baby jeeps I run offroad, I would only add 1-2 teaspoons only if the clutches chattered severely. The extra traction that gave (usually with no additive) was appreciated off road. Now with selectable lockers additive is a thing of the past. I know apples and oranges rig wise. Putting in extra additive won't hurt a thing either. It will probably preserve the clutch plates and keep them in very good shape. The only real drawback is it may make some of the transfer of traction to the non spinning tire a little less.

 

[MAYoung]

You can also go to Summit Racing and find an equivalent fluid. It matches the spec on the original transmission fluid. I forget who makes the fluid. Just match specs.

Dodge has now approved ATF 4 for the NV4500. I'm not a lubrication specialist but I could find no reason why changing to such a light weight fluid would be a good idea.

 

[JR]

The NS is specifically for manual transmissions - most GL-5 rated gear lube is bad for the synchros in manual gear boxes so for whatever reason rather than make a GL4 rated fluid Red Line makes a GL-5 but holds the friction modifiers. You want the other type. It already contains the additives you need for your differential.

As to viscosity you didn't mention where you tow but unless you live in a part of the country where it is hot year round 75w90 is more than adequate. I've read documents posted by Dana axle and they stress the importance of staying with factory recommended viscosity. Some of their stuff is FF with 75w/140, others not. The gen 4 Ram 1500 is FF with 75w140 yet the 2500 and up FF with 75w90. Viscosities are specd for a reason, i tend to stick with them.

 

[BigPapa]

Dodge has now approved ATF 4 for the NV4500.

Say what? You have some documentation on this?

The GM 12346190 is still available on Amazon:

https://www.amazon.com/Genuine-GM-12346190-Synthetic-Transmission/dp/B000QIR1V2

I used the Amsoil MTG in mine for over 300K miles. Of course, it’s your truck and you can run what, but I’d at least stay away from GL-5.

-Scott

 

[JeepBuilder]

From the TDR new owners guide. The reason to avoid GL-5 in the NV4500. I remember reading that the syncro's were non metallic and the GL-5 harmed them. I can't remember what they were made from. Carbon fiber maybe? So I know this topic has been discussed a quarter million times. But having it surface in several places and be available to a new truck owner is a good thing. I found the info while searching for any information I could find a few months ago before going to Seattle to pick up my new used rig.
From the TDR new owners guide. Hope this helps.

Five-Speed NV4500 Manual Transmission (used from ‘94- ’04): Change every 30-50 thousand miles, depending on load. Use 75W-90, GL-4 or 80W-90, GL-4 rated synthetic oil. Often members will ask about the GL-4 rated Castrol synthetic gear lubricant (75W-90). If the GL-4 classification is good, shouldn’t a GL-5 rated lubricant be better? In the case of the NV4500 gearbox, not necessarily so. The GL-5 oil uses twice the amount of sulfur/phosphorous additive package as GL-4. At high temperatures, the phosphorous plates out and reduces the coefficient of friction of the synchronizer rings (New Venture Gear has seen this on shift stand tests). Since there’s twice as much of it, there’s more of a detrimental effect compared to GL-4.

 

[MAYoung]

Say what? You have some documentation on this?

The GM 12346190 is still available on Amazon:

https://www.amazon.com/Genuine-GM-12346190-Synthetic-Transmission/dp/B000QIR1V2

I used the Amsoil MTG in mine for over 300K miles. Of course, it’s your truck and you can run what, but I’d at least stay away from GL-5.

-Scott

Documentation? Dodge (FCA) actually has a service bulletin out on this issue. Check with your dealer although I have a copy of the bulletin buried (lost) somewhere on my desk. It came out last year. (Yes, very surprising.) If you try and buy the fluid at Dodge, they will say that the part number has been superseded to ATF 4+. I know all this since I changed the fluid in my NV4500 last fall. And yes, I believe that GM still sells the original fluid but they were too expensive. Summit Racing had a retail outlet in Reno so I ordered some from them.

I am very traditional on fluids and follow the owner's manual to the letter for spec fluids. Something may be the cat's meow according to everyone else but I generally stick with the manufacturer's guide----except for putting ATF 4+ in the NV4500. I'm staying with the original spec.

 

[BigPapa]

Documentation? Dodge (FCA) actually has a service bulletin out on this issue. Check with your dealer although I have a copy of the bulletin buried (lost) somewhere on my desk. It came out last year.

I’ll call Monday, but I just searched all Chrysler TSB’s listed on AllData for the terms “fluid”, “NV4500”, “manual”, “transmission fluid”, and “4874459” with no results.

-Scott

 

[Taylor13]

The NS is specifically for manual transmissions - most GL-5 rated gear lube is bad for the synchros in manual gear boxes so for whatever reason rather than make a GL4 rated fluid Red Line makes a GL-5 but holds the friction modifiers. You want the other type. It already contains the additives you need for your differential.

As to viscosity you didn't mention where you tow but unless you live in a part of the country where it is hot year round 75w90 is more than adequate. I've read documents posted by Dana axle and they stress the importance of staying with factory recommended viscosity. Some of their stuff is FF with 75w/140, others not. The gen 4 Ram 1500 is FF with 75w140 yet the 2500 and up FF with 75w90. Viscosities are specd for a reason, i tend to stick with them.

The NS is specifically for manual transmissions - most GL-5 rated gear lube is bad for the synchros in manual gear boxes so for whatever reason rather than make a GL4 rated fluid Red Line makes a GL-5 but holds the friction modifiers. You want the other type. It already contains the additives you need for your differential.

As to viscosity you didn't mention where you tow but unless you live in a part of the country where it is hot year round 75w90 is more than adequate. I've read documents posted by Dana axle and they stress the importance of staying with factory recommended viscosity. Some of their stuff is FF with 75w/140, others not. The gen 4 Ram 1500 is FF with 75w140 yet the 2500 and up FF with 75w90. Viscosities are specd for a reason, i tend to stick with them.

I dont tow often But the opportunity my present. I bought the truck to tow my boat and tractor with an to daily. may eventually purchase a camper and a goose-neck. I just want to get a fluid and stick with it. I dont want to have to swap to a heavier fluid later on if it wont make a difference to go with the heavier now. I live in TN so the temps never really get much under freezing. Also I was hoping some one had some experience with the Redline Ns fluid in the Dana 80 with added mopar friction modifier. I just thought It would be best to mix my own modifier that way I know I have the exact amount according to my manuals weather I should add 5% or 7 oz I dont know. Also Im absolutely not putting Atf +4 In my Nv4500 Thats why Im wondering if anyone has used this GM 19369226 according to the the gm dealer its the superseded part to gm 12346190 except the 19369226 is a 75w85 and the 12346190 is a 75w90. Also the Mopar fluid 4874459 was a 75w85

 

[MAYoung]

I’ll call Monday, but I just searched all Chrysler TSB’s listed on AllData for the terms “fluid”, “NV4500”, “manual”, “transmission fluid”, and “4874459” with no results.

-Scott

I have to go to Dodge and return my starter core on Monday so I will investigate the changeover of Mopar P/N 4637579 to ATF 4+. Now that I reviewed my notes, I do not think it was a TSB but some type of engineering data sheet from FCA. The parts department at my Dodge dealer queried someone in their technical group in the search for documents supporting the changeover to such a light fluid. Everyone questioned it.

In any event, when I went looking for Mopar P/N 4637579 we could not find it at any Chrysler/Dodge dealer in California or Nevada. We were given the P/N for ATF 4+. What we did instead was find the original spec number (not P/N) for the fluid and based our search on that spec. We could only find it at Summit Racing at first but I have since seen other spec-matched products on auto parts stores.

Castrol Syntorque Synthetic 75W-90 is an approved product. (Please note that it is not Castrol SynTech or SynGear.) I could not find it and I believe that Castrol no longer makes the product.

This all happened about six months ago so who know what they are saying now.

 

[Shiner]

I was also told ATF+4 from a mopar tech...I couldn't find anything to spec other than amsoil, or through torque king that was for sure, so ordered a case from AMSOIL.

 

[BigPapa]

I couldn't find anything to spec other than amsoil, or through torque king that was for sure, so ordered a case from AMSOIL.

That’s what I did, too, Shiner.

This has been gone over time and time again over the past 25 years. The original spec back then was the Castrol Syntorq and Mopar and GM both had a part number for it. There was always a lot of confusion about the correct fluid for the NV4500 because there were other New Venture trannys offered by GM and Mopar at the same time that required another fluid and most all fluids at the time were called “SYN” something, Syntech, Syncromesh, Syntorq, etc. There was also the misconception that as engine oil specs progress, CG>CI>CJ, that gear oil did the same with the GL- numbers so that meant GL-4 must have changed to GL-5.

Since I haven’t owned or dealt with an NV4500 in over 10 years, I don’t remember the part numbers and I don’t know about the progressions over the years. As I said, I ran the Amsoil MTG for a long time with no problems.

-Scott

 

[TFucili]

On Redline stuff, if you send an inquiry to them Dave will usually answer pretty promptly, and is very knowledgeable, not reading from a cue-card.

 

[Taylor13]

So does anyone know about the GM 19369226 has anyone used it in their Nv4500 is it the same as 12346190? And has no one used Redlines 75w140NS in there LS Dana 80 and added their on mix of Friction modifiers?

 

[GAmes]

I don't use Redline, but I think I can put the viscosity question in perspective. 75-90 and 75-140 have the same viscosity when cold. When hot the 75-90 is thinner than the 75-140. For that reason I run 75-140 year around. My trips take me into the great white north in the winter and across the Mojave in the summer. My D80 is has never had any work done to it other than 2 sets of axle seals and 3 pinion seals. The LS still works as designed. My oil of choice is Royal Purple and I do not add any juice to it because it is premixed.

If I still had a NV4500 I would be using the new GM part number oil. Prior to the G56 upgrade I tried the Amsoil a couple times and didn't like the way the transmission shifted. I went back to the factory spec oil.

 

[JR]

If the viscosity issue was that simple they would just spec them all for 75w 140 and be done. My wifes Mercury (Dana axle) calls for 75w140, yet the Dana 70/80 in the gen 2 calls for 80/90. My 14 (AAM) calls for 75w90. Gen 4 Ram 1500 specs 75w140. See where I'm going, they are obviously designed with a certain weight in mind and it's not based on GVW or towing capacity.

 

[GAmes]

As far as I'm concerned it is that simple. My owners manual was written 22 years ago using the lubrication technology of the last century. All it says it was delivered with 80w90. No recommended replacement weights for any temp or usage. I do find interesting that severe duty calls for 12,000 mile changes. By their recommendation I should have changed it 113 times by now!!!

 

[Taylor13]

I don't use Redline, but I think I can put the viscosity question in perspective. 75-90 and 75-140 have the same viscosity when cold. When hot the 75-90 is thinner than the 75-140. For that reason I run 75-140 year around. My trips take me into the great white north in the winter and across the Mojave in the summer. My D80 is has never had any work done to it other than 2 sets of axle seals and 3 pinion seals. The LS still works as designed. My oil of choice is Royal Purple and I do not add any juice to it because it is premixed.

If I still had a NV4500 I would be using the new GM part number oil. Prior to the G56 upgrade I tried the Amsoil a couple times and didn't like the way the transmission shifted. I went back to the factory spec oil.

So just so its clear your saying the new GM part number is indeed 19369226

 

[GAmes]

Information on a different forum convinces me it is the same stuff. I don't have a NV4500 anymore.