Engine/Transmission (1994 - 1998) Gear oil for NV4500

[BigPapa]

OK fella's, we're almost done with my transmission conversion. Just one more question, I hope.



My installer has changed the gear oil in my NV4500 (against my instructions) and he put in Valvoline Synthetic GL4 75w/90. Should I go ahead and change it back to the Castrol Syntorque? I've done the search's and read all the arguments but I've never seen the Valvoline mentioned.



Thanks,

Scott

 

[ABorchard]

I'm a firm believer in using the lube that the manufacturer recommends, they do so for a reason. Many people will say they've used such and such and it worked fine but you don't hear much about the results 100k down the road. Problem with incompatible lubes is the chemicals in some will eat the syncros in the NV like acid.

 

[Bloomy]

I agree that the manufacturer makes a recommendation for a reason. Typically it is based on their money making ability after the fact and agreements with suppliers. I know there has been a lot of discussion on this topic with many getting heated. Not my intent here. For the DC price of syntorq compared to GM's price there is a problem there. I have used Amsoil in my 4500 for the last 160,000 miles. That is a bit over 100k. No problems. 40% towing at near or max gcvw. Haven't ever had 5th gear problems either. In the end, use what you are comfortable with and call it good



Thomas

 

[JGheen]

I have been using Redline MT90 which is a GL4 75W/90 and it has been working great. A lot cheaper than the syntorq @ $8 a quart from Napa. The first time I put it in the transmission felt like it slipped into gear much easier than with the Syntorq and shifting while accelerating seemed much smoother. I too hear where the manufacturers are coming from on their recommendation but I think if you go with reputable oil manufacturers like Redline, Mobil or Amsoil then you should be fine. Just make sure the oil has the GL4 rating or, from what I have heard, the GL5 will eat up the syncros real fast. But still running the Redline and no issues after 50K. I even checked my Geno's aftermarket trans filter recently, it was fine, metallic particle free.



Joe

 

[PaulG1]

For a savings of $30 per oil change - is it worth the wory or even a shadow of a doubt that the oil is not going to cause some harm? I don't think so - not even if you only worry about it for the first hour - and not too consider all the work and worry you'll do before hand trying to select the right one.



Just my take on it.



Paul

 

[redram]

Stick with the current lube.

The Castrol Syntorq is spec'd because that was what NV tested. I have contacted them about testing better , higher performing products that would be less expensive - they did not care in that the savings was not enough for them to make the effort to requalify (test) another oil.



The Syntorq LT is not the end all of oils for this transmission, it is jsut the one with the endorsement. The Valvoline will NOT have any negative affect on your synchros as they are made out of metal. The synchros are bronze and the shift forks are aluminum.



You're wasting your money if you drain it out. I have 142K miles on my NV4500 on non Castrol oil with excellent results.



Cheers,



Redram