Why Does NV4500 Spec. A "Special" Fluid?

[Pablo]

Wow - what brought this thread back? - 4 years to the day. Interesting.

But it's intriguing because it does address the same trannies used by different car manufacturers spec'ing everything from ATF to 75W-90.

 

[Pook]

Not to beat a dead horse, but...

From what I heard and read, (when I was changing mine) was that the nv4500 clutch materials were different; namely, I believe they were kevlar clutches (and yes, they do have a synchro).

As for the Gl4/gl5 issue, the GL5 while supposedly backward compatible, whatever gives it the gl5 rating also attacks the clutches.

GM stocks the synchromesh fluid, but is pricey. Autozone carries the Penzoil Synchromesh, which is supposed to be the same, but at less than half the cost.

Amsoil has made some wacky claims in the beginning, about what to add. Some dodge guys swear by it, and supposedly doesnt attack the material.

 

[deeter16317]

If you look at the differences between a NV5600 and a NV4500, you will find the only significant difference is the synchronizer material...The NV4500 uses a carbon fiber synchronizer where the NV5600 used bronze-over-steel synchronizers. The correct fluid for the NV5600 is a synchromesh-type fluid...the correct fluid for the NV4500 is a 75w90 gear oil.

With that said, we have over 200k on PZ 75w90 synthetic gear oil in my father's dodge CTD with the NV4500.

I researched this a long time ago, the only reason for the GL-4 rating is for "yellow metal protection," as expressed by NVG (the manufacturer). If you research most modern gear oils, they have a dual GL-4/GL-5 rating anyway, which makes them suitable for use in the NV4500.

There are only a few places you can actually get the "Castrol Syntorque" gear oil required for use in the NV4500...and most often its in 55-gallon drums!

 

[tdi-rick]

Does Castrol Syntorque (NA) = Castrol Syntrans (Europe and rest of world ) ?

if so, it's an excellent lube, but not unique. I do remember reading on another forum where someone ran a variety of lubes as a trial in an NV4500 and the only lube to run as cool as the specified OE Castrol Syntorque was Torco RTF, which is a bit heavier at around 14.5 cSt @ 100*C.
IIRC, RL MTL ran quite a bit hotter than the other fluids under comparable conditions.

 

[deeter16317]

Originally Posted By: tdi-rick
Does Castrol Syntorque (NA) = Castrol Syntrans (Europe and rest of world ) ?


IIRC, RL MTL ran quite a bit hotter than the other fluids under comparable conditions.



I don't think so, I was told the Syntorque is actually an industrial gear oil for machinery gear boxes, and was not even intended for use in the automotive world...IIRC, they told me it was for ship gear boxes??? (its been a long time since I inquired)

Considering MTL is a synchromesh-weight fluid, I'm surprised it shifted. The correct Red Line fluid is Red Line MT-90...

 

[tdi-rick]

Interesting, as Syntrans is a 75w-85 (11.9 cSt @ 100*C) heavy vehicle/race car transmission fluid.
It has approvals from Volvo, ZF and Mercedes for medium/heavy commercial vehicle applications.

 

[VinceF]

with the new S-P packages or other adds, how long will they hold up? Do they need to be changed regularly to do their jobs, and work well, and protect the trans?

Vince F

 

[deeter16317]

Originally Posted By: VinceF
with the new S-P packages or other adds, how long will they hold up? Do they need to be changed regularly to do their jobs, and work well, and protect the trans?

Vince F



My father's NV4500 has around 294k on it the last I checked...all he ever did was somewhat routine 50k mile fluid changes using Pennzoil 75w90 Synthetic Gear Oil.

For the record, his NV4500 is behind a Cummins in a 99 Dodge 2500...most of his miles are (were) highway (he only did 4k last year since he retired).

So to answer part of your question, fluid changes will probably add significant life to your tranny. IMHO, it isn't whether the fluid degrades, but the amount of [censored] floating around the oil causing damage because the manual trans lacks filtration.

 

[m37charlie]

Originally Posted By: tdi-rick
Interesting, as Syntrans is a 75w-85 (11.9 cSt @ 100*C) heavy vehicle/race car transmission fluid.
It has approvals from Volvo, ZF and Mercedes for medium/heavy commercial vehicle applications.


Kind of off topic, but...
my Unimog calls for Syntrans (11.9 @ 100C) but I'm running Delvac Synthetic Trans Fluid 50 (also GL4, but 17.5 @ 100C) in hot weather (Australia) and it shifts wonderfully; it's synchro but it shifts with computer controlled air servos.

Charlie