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for you NV4500 manual tranny owners

Odlaw

Odlaw

Redneck
Messages
577
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Location
Deep in the woods - near Waldo, FL
What fluid are you guys running? My manual says to use Syntorque AND THIS IS NOT CASTROL SYNTECH. It appears that many, many (even some experts) are confused and call syntorque "Castrol Syntorque" - a quick search on Castrols website will prove this not to be true.

A buddy of mine owns a towing business and he says they have always run synthetic ATF in their NV4500's due to the cost of syntorque....and that this was recommended by the shop that provides their tranny work.

Just looking for suggestions from the guys (and girl :D ) I trust (regarding these old trucks).

Thanks
Smitty
 
well, like I said - there is NO syntorque listed as a product on Castrol's website.
There is however a Syngear .

So, short of going to the stealership there is nowhere I can just go purchase it without ordering online?
 
The dodge trans use the same stuff and it is a small amount cheaper.

I think Royal Purple makes something. You will have to do a search on their website to see.
 
I just changed mine.The gm "synthetic manual transmission fluid" was about 19 dollars a quart. Royal purple was 17 at the zone..IO used gm.(dodge wanted 26).By the way I was grinding going into 3rd,the tran only had about a quart of what appeared to be dexron. It still grinds a little but doesn't feel dry.
 
www.nv4500.com is a good source of info on this trans. The site says using incorrect gear oil is the leading cause of warranty claims.

Apparently the carbon fiber portion of the synchronizers requires using this specific gear oil.

I've been told that in addition to GM or Dodge dealers, you can find Syntorque at some offroad parts sites, trans rebuild shops, & even some truckstops.
 
I defiantly wouldn't run ATF in one, I was told that 80W-90 would work by one dealership, and that only syntorque would work by another dealership. I just went with the the syntorque, I think it was 12 a quart here.
 
I used the Mopar brand synthetic equivalent.

Look also at quad4x4.com for more info. A couple of years ago I did some research and Castrol SynTorq isn't sold in quart containers but I was told you could buy it if you contacted a Castrol distributor then buy it in larger quantities ie drums. Places like quad4x4 buy it in bulk and repackage it.

I would use a high quality equivalent synthetic only. I wouldn't trust ATF. Some models of ZF transmissions use ATF but NV4500 is suppose to use heavier stuff iirc the mopar stuff is 75W-90 but again its synthetic and performs better than regular oil of the same viscosity grade.

You hear all kinds of stuff I was told by one shop they use synthetic SAE 30 motor oil to top off NV4500's ????? Not sure just one of those things you hear. In small quantities I imagine it would work but again would not FILL with ATF or anything other than high quality sythetic compatiable or equalivent with SynTorq.

Alot confuse Penzoil synchromesh also as its used in the NV3500. And I think that is very similar to ATF but not sure?????
 
I agree. With the info I've gotten here and what I've found out calling around -stealerships, NAPA and car quest. As long as it's gear oil, synthetic and at least GL4 rated it will be fine. I have mobile1 in it now - just don't know if it is GL4 or 5 rated.
 
I copied this from one of my other posts on another thread.

Castrol Syntorq LT 75w85 (may also be described as 75w90) GL4 full synthetic Gear oil
GM PN 12346190
Dodge PN 4874459

The Castrol comes in large quantities if Castrol branded, (15 gal mini-drums is the smallest, IIRC)
and quarts are the quantity (of course) from dealer, Dodge is usually cheaper than GM.

Some sources repackage the Castrol into smaller containers, such as quad4x4.com, which puts it in 2 qt. containers.

The only other oil I would use other than the Castrol is Amsoil Synthetic Manual Transmission and Transaxle Gear Lube

One needs to remember that some of the synchros are carbon fiber, which makes them picky oil wise. So only get the correct full synthetic GL4 (no gl4/gl5 combos, apparently)75w85 or 75w90 gear oil. I would highly reccomend the three labels of Castrol (GM, Dodge, Castrol) or the Amsoil. I am not a huge fan of the Royal Purple so called GM 12346190 equivalent. we are using it in the 98 gasser and it doesn't behave well.

Good luck!
 
what variety of Redline?

correct me if I am wrong, but doesn't Redline say to mix two of their products together for NV4500 Apps.
 
GM Guy said:
what variety of Redline?

correct me if I am wrong, but doesn't Redline say to mix two of their products together for NV4500 Apps.
Click to expand...

This sounds very similar to a trans I had in another vehicle that also had a carbon compound on some of the synchro friction surfaces. Redline suggested mixing some proportion of one of their products termed a "friction modifier" w/ their std synthetic lube of the appropriate viscosity index.

In that app, folks that swapped to the popular synthetics found they didn't shift as well. Forum posters theorized that the pure synthetics didn't allow as much friction btwn the synchros so gear speeds didn't match as quickly.

Typically swapping back to the recommended lube brought back better shifting on the two gears that used the carbon synchro surfaces. I had run pure synthetic for a couple years thinking it might offer flow advantages on the -20F MN winter mornings. Didn't really have any complaints about shifting.

When I learned about the recommended lube details, I swapped back & had to admit it improved shifting & the mfgr prolly had it right in that case.
 
There is a blurb on the back of the Mopar bottle about it being the proper fluid and helps cold shifting.

And seems I read that was the biggest part of the reasoning behind the special lube - cold weather shift quality or something like that.
 
I just spent $120 at the dealer for 5 quarts of the GM stuff. Says synthetic Manual Transmission Fluid on the bottle. Part # 12346190, which replaces the previously used 2 part numbers(it calls for 4 qts of fluid then a pint of some other fluid, probally friction additive for the syncros or something.) Aparently the new part number contains both at a predetermined mixture. I spent the 20+ bucks a bottle on this stuff cause the napa stuff I put in mine after an input shaft R2 stinks to high heaven. Also, when I drained the trans last time I already had the top cover/shift tower off so I just turned it over to drain it. This time I guess I will just remove one of the little rectangular 6 bolted covers on either side to drain it cause I aint taking it alll the way off again! Let me know if you may know a better way!
 
GM Guy said:
what variety of Redline?

correct me if I am wrong, but doesn't Redline say to mix two of their products together for NV4500 Apps.
Click to expand...


I have used Redline MT-90, 75W90. I had researched this before, the trans needs special friction properties for the fluid because of the graphite synchronizers. The fluid needs to be slippery but not to slippery like gl-4 gear lube. I have over 12,000 miles on the trans and have not had any issues hot or cold and I have towed big with it for over 1000 miles.
 
Dusting-off this thread . . .

Just looked at quad4x4 and it seems they are now selling what appears as the redline product for the NV4500.

Any updates in terms of what fluid is working well these days? Any long term reports of the redline mt90?
 
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