Is Red Line MTL 70W80 ok to use in an NV4500 manual transmission?

[Ducati996]

I have 1990 Dodge W350 with an NV4500 manual transmission that requires redline MT 85 oil or equivalent.
I have several quasars of redline MTL 70w80 GL-4 gear oil which is slightly lighter.
Are they interchangeable?
This is not a work truck. It is driven only for pleasure.

 

[ArrestMeRedZ]

I am not an oil expert and the research I did on the subject is dated. With those limitations, I will pass on my research on the subject.
I had a '97 Chevy C2500HD with the same NV4500. At the 50k mile point around 2002 I decided to change the transmission fluid. Much to my disbelief, there were only 2 fluids that met spec for that transmission, a specific GM Synthetic Manual Transmission Fluid, p/n 12346190 and the Chrysler equivalent (I don't have that part number). I read a lot of horror stories of damage caused by any other fluids.

It is feasible that Redline (and Amsoil) makes an oil now that meets spec for that transmission as you mentioned above, but I would double check with New Venture that it is acceptable. I would not use oil that was not specifically cleared for the NV4500.

 

[CleverUserName]

Coworker didn’t put the right stuff in his NV4500 and it caused a lot of problems. He thought his transmission went out and dropped it only to find out it was the fluid he used wasn’t compatible

 

[ArrestMeRedZ]

Looking at the subject again I see Amsoil MTG and Redline MT 85 claim to meet spec for the NV4500. Previously only Castrol Syntorque LT, mostly only available with the GM and Chrysler part numbers, met the spec.
Sources I'm looking at now indicate the NV4500 wasn't installed in GM trucks until the 1991 model year, and in Dodges not until 1992. Was your NV4500 retrofitted, or are the sources wrong?

 

[Ducati996]

I retrofitted the NV4500 into my Dodge in 1999 to replace the failed Getrag. . I purchased it thru Advance Adaptors.
I’m aware of the necessity to use the proper oil. Red line doesn’t show the MTL 70w80 because it’s several years old.
Was hoping I could use it. I would not use anything not specified as I just rebuilt it with $1300.00 in parts.
I’ll call redline tomorrow, if it’s not compatible I’ll buy 5 quarts of the MT85.
Thanks for the reply’s
Ducati996

 

[louguy]

I have 1990 Dodge W350 with an NV4500 manual transmission that requires redline MT 85 oil or equivalent.
I have several quasars of redline MTL 70w80 GL-4 gear oil which is slightly lighter.
Are they interchangeable?
This is not a work truck. It is driven only for pleasure.

I lost an NV4500 in my old Dodge almost two years ago due to changing the transmission fluid and using a "non-recommended" fluid. I highly recommend using the exact transmission fluid that they call for, trust me. Funny enough, when I ordered a replacement from these guys, https://reman-transmission.com/transmission-codes/?code=NV4500, they gave me specific information on what transmission fluid to use and not to use. Their number 1 pick was Amsoil 75w-90 manual trans fluid and that's what I've used ever since I got the rebuilt tranny installed, haven't had any problems since. Hope this helps

 

[kschachn]

What fluid was used that caused the failure and what exactly was the failure?

 

[louguy]

What fluid was used that caused the failure and what exactly was the failure?

Valvoline SAE 80 I do believe and it just started popping out of gear in 2nd and 3rd and within a day or two I couldn't even get it in those gears without horrible grinding

 

[kschachn]

Valvoline SAE 80 I do believe and it just started popping out of gear in 2nd and 3rd and within a day or two I couldn't even get it in those gears without horrible grinding

All due to the fluid? No way.

 

[930.engineering]

I have 1990 Dodge W350 with an NV4500 manual transmission that requires redline MT 85 oil or equivalent.
I have several quasars of redline MTL 70w80 GL-4 gear oil which is slightly lighter.
Are they interchangeable?
This is not a work truck. It is driven only for pleasure.

I'm not familiar with the NV4500 transmission, but I believe it's
a somewhat tricky point going thinner on transmission oil in a
warmer climate. You'd be taking 'some' of a risk. Despite I was
going thinner on my Mini Cooper's Getrag my self once and I'm
planning on doing the same again as it was simply better shifting
compared to the much thicker factory fill I still wouldn't generally
recommend doing the same to anyone. It's not that hot where I
live.
Remember hotter environment makes for thinner gear oil. It's the
resulting (actual) viscosity which is relevant (along with additive
package).
If Redline recommends using MT85 and Redline is you favourite,
that's what I'd go with. Transmissions are too expensive to repair
or replace.
.

 

[kr_bitog]

If you want to use MTL I would suggest to mix it with MT90 to prevent problem and you do not waste your MTL

 

[Cdn17Sport6MT]

I'm not familiar with the NV4500 transmission, but I believe it's
a somewhat tricky point going thinner on transmission oil in a
warmer climate. You'd be taking 'some' of a risk. Despite I was
going thinner on my Mini Cooper's Getrag my self once and I'm
planning on doing the same again as it was simply better shifting
compared to the much thicker factory fill I still wouldn't generally
recommend doing the same to anyone. It's not that hot where I
live.
Remember hotter environment makes for thinner gear oil. It's the
resulting (actual) viscosity which is relevant (along with additive
package).
If Redline recommends using MT85 and Redline is you favourite,
that's what I'd go with. Transmissions are too expensive to repair
or replace.
.

Sorry, 'gotta jump-in here with a graphic, and in which I believe... (Sorry, small text).

 

[Cdn17Sport6MT]

My over-riding sense, here, is that very few people want to accept that manual transmissions, transaxles... most-of-them shift poorly when cold, and when I say cold, I mean in reasonably temperate locations. In prairie- or midwest- or eastern cold, they often don't even shift at all when cold (start in 2nd gear, a few times). Many, many folks seek that nirvana-feeling shift (when cold). That just isn't the nature of the beast, per my experience. Focusing on cold shift feel is fraught with normal operating temp danger, in some cases, of poor gear and bearing protection with too thin an oil.

So I've mebe overdramatized matters a 'wee bit... I still believe manual 'boxes need to be "nursed" to operating temp...

Flamesuit on...

 

[930.engineering]

'in some cases'? Yes, perhaps. Not generally though. Very most MTFs
of the past two decades are 75W or similar and the vast majority of
transmissions still live a long life. IMHO it's better to perform frequent
oil changes (remember many manfacturers spex so-calles 'lifetime' oil
fills) instead of going thicker. I've tried both thicker and thinner as well
as retaining viscosity. I've never found going thicker to be satisfactory.
However I'm aware that thinner transmission oil can increase wear and
that's why I posted what I posted above.

Sorry, 'gotta jump-in here with a graphic, and in which I believe... (Sorry, small text).

I know and it's probably still true, however 'shifting feel' ist important
as well, since it both is an indicator for synchonizer work (and oil sync
compatibility) as well as shift quality is an important part of the driving
experience. Poor synchronizer performance isn't acceptable regardless
of gears and bearings being subjected to the lowest imaginable wear.
I also monitored overall wear by observing deposit built-up a magnetic
drain plug each time.
.

 

[Cdn17Sport6MT]

I am advocating sticking with OEM viscosity, and generally, the OEM fluid itself. I am zero into going thicker. I have a Mazda6, and the transaxle has oil funnels and centre-drilled shafting, effectively pumping oil out of the shafting (radial holes)where the speed-gears live, thereby lubricating them. Going heavier impairs the flow, makes for poorer/no lubrication! No, I don't advocate heavier! But at the same time I don't advocate lighter, either. Just stick with OEM/mfr specified SAE weight and GL-4 (in my case) spec.

I believe that Redline, MTL specifically, focuses on shift feel to the detriment of transaxle longevity. There is some substantial talk, as well, of the ad-pack settling-out, or centrifuging-out leaving gray spooge in sumps, on ledges, etc., leaving little AW properties in the net fluid that is left.

Good idea re the strong magnet on the drain plug; also, if possible, on the fill plug...

 

[kschachn]

I am advocating sticking with OEM viscosity, and generally, the OEM fluid itself. I am zero into going thicker. I have a Mazda6, and the transaxle has oil funnels and centre-drilled shafting, effectively pumping oil out of the shafting (radial holes)where the speed-gears live, thereby lubricating them. Going heavier impairs the flow, makes for poorer/no lubrication! No, I don't advocate heavier! But at the same time I don't advocate lighter, either. Just stick with OEM/mfr specified SAE weight and GL-4 (in my case) spec.

One wonders how this fragile transmission operates properly in cold climates.

 

[ArrestMeRedZ]

It's not a fragile transmission. It's a manual built for heavy duty operations. It was designed to be used with a specific fluid. In gas engines, with the specified fluid, it has been bulletproof. Without the correct fluid they tend to go south fast.
There have been some problems in heavy duty Ram diesel applications, but at a fraction of the rate of problems with the corresponding auto transmission.

 

[930.engineering]

OP is in Florida, so thinner transmission oil is even more so going to bear the
potential of increasing wear.

I am advocating sticking with OEM viscosity, and generally, the OEM fluid itself. .......
Just stick with OEM/mfr specified SAE weight and GL-4 (in my case) spec.

I agree on that.

I believe that Redline, MTL specifically, focuses on shift feel to the detriment of transaxle longevity. There is some substantial talk, as well, of the ad-pack settling-out, or centrifuging-out leaving gray spooge in sumps, on ledges, etc., leaving little AW properties in the net fluid that is left.

Never heard about that. Where did you hear or read about such issues?

Good idea re the strong magnet on the drain plug; also, if possible, on the fill plug...

I did fit magnets to both the fill and drain plugs on both the Mini and the Porsche
and to the drain plug only on the GTI since it doesen't even have any conventional
style of a fill plug. As filling is performed from the top a magnet wouldn't see much
of oil. That said the plastic plug already has a steel ball at its end.
I forgot to mention after trying the thinner 75W-80 in the Mini's Getrag there wasn't
any ferric residue sitting on the magnet worth worrying and the fluid has been clear
after almost two years of use.
.

 

[MolaKule]

...I believe that Redline, MTL specifically, focuses on shift feel to the detriment of transaxle longevity. There is some substantial talk, as well, of the ad-pack settling-out, or centrifuging-out leaving gray spooge in sumps, on ledges, etc., leaving little AW properties in the net fluid that is left....

I don't believe this line of misinformation for a second. Opinion without proof is conjecture.

Redline GL-4 MTF's have high Anti-Wear chemistry as well as a good dispersant. This dispersant + the ester component insures all chemistry is mixed well.

If the OP's transmission requires 12 cSt@100C MTF, then MT-85 should suffice.

 

[bulwnkl]

OP, what did you decide to do, and how is your decision working out for you so far?