I put in MTG and I like it. Easier to shift ,I don't know what was in there before.
The dealer here wants $32 a qt for syntorq.

 

I put Amsoil GL4 in my truck about 10k miles ago and so far so good. It is the stock NV4500 with 205k miles on it. Never rebuilt. I spoke to a transmission shop out in Texas when I did it, and they said they run the Amsoil in all of their NV4500's with no associated problems whatsoever.

I spoke to a Amsoil dealer the other day and he said there was no reason for me to run GL4 in my NV4500. He said that all the new Amsoil GL5 lubes will not cause any corrosion on the metal syncros, etc, and that I would have been better served with GL5. Would someone like to comment on this? I don't know the answer.

 

Is the Amsoil GL5 the same as the MTG?
If it isn't I'm not sure I'd trust it.
You're messing with an expensive part of your truck, I'd rather let others do the experimenting and just go with what's proven.

Speaking of Texas, Standard Transmission & Gear in Ft Worth, who specialize in Dodge NV4500s sells and recommends the MTG.

 

Run the factory oil! You fill it once and it lasts the life of the trans. No other oil matches the Syntorq its a 75w85 LT synthetic which is a special low temperature oil. It pulls heat from the cast iron case and improves shifting in colder weather.
Yes you can use Amsoil etc...you can also use Fram filters and any 15w40 motor oil.

 

HAHA. You use fram filters and any 15w40 oil? Not smart. Oh wait I did not realize we had reached such a high level of sarcasm. Maybe you don't use those. I hope not.

Anyway, the Amsoil that I used was the GL4 MTG. Based on my experience it has been great. My truck shifts perfectly and shows no signs of wear. Others I have spoke with share the same results. Without real test data, we do not know for certain which one truely is "best". Just my $0.02

And, I use Purolator pure one filters and Rotella T 15w-40 oil. Fram filters are chinese made trash.

 

You should find someone thats more knowledgeable to give you advice.

The synchros on a NV4500HD are carbon fiber composite - NOT metal as your AMSOIL guys says. I believe youre not worried about corrosion on the synchros - youre worried about the fluid physically breaking down the integrity of the synchros.

 

Castrol is the only oil with test data and approved in the NV4500!
Amsoil,Royal P and the rest just say it should be OK to use with no test data.

 

I did not take his advice. I do not mind hearing what someone has to say. That does not mean I will believe it as fact. That is why at the end of my post I stated "Would anyone like to comment on this, I do not know the answer."

However, thanks for the info.


I knew the NV4500 came with GL4 Syntorq, so I replaced it with MTG, a GL4 oil, recommended specifically for it, by Amsoil. Scary I know. Non OEM oil!

I should take the $40 bucks I saved by buying Amsoil and invest it now. That way, when (if ever) my transmission fails: I could use the earnings to hire a team of scientists and engineers to conduct a failure mode analysis on my transmission. Using this data I can then sue Amsoil for false advertisement.

 

If it is true that Castrol is the only one with test data to support using their oil in the NV4500, then it would be best to use Castrol.

I would much rather base my opinion on test data, than hearsay. I may even switch mine over to Syntorq if I find that Amsoil has no data with which to compare their MTG to Syntorq.

 

I asked Amsoil if they had test data to compare their MTG to Syntorq. Their emailed response:

Joe;



Please supply the test data that Castrol supplies for their product and we can then supply comparisons between the products.



Thank you for this opportunity to respond to your question(s). As always, please feel free to contact us again if we can be of further assistance.





Sincerely,



Byron Selbrede

Technical Services



The accuracy of this e-mail response is dependent upon the information provided. AMSOIL INC. is not responsible for wrong recommendations that were based on inaccurate or incomplete information.



So if anyone could send me the data for Castrol Syntorq, I will pass it along to Amsoil, and we can hopefully get a comparison.

 

Well do any of you who swear by Syntorq have data to back it's use in an NV4500? If so we can possibly get comparible data from Amsoil.

 

This was copied from another forum. It's up to you how long you want your trans to last.


"So, let’s at least analyze some of the important pieces of information that NVG gave us. 300degF! How can a transmission get so blazing hot? Many TDR members might say their NV4500 never overheated and that they monitor their NV4500’s with a temperature gauge. I posted a question on the TDR website; “Who has a temp gauge in a NV4500?” to get a response. TDR members reported seeing as high as 225degF pulling hard in hot ambient conditions and averaged 190-200degF pulling hard in normal temperate conditions. NVG says temperatures can reach 300degF. Why the discrepancy? Kevin Dinwiddie is a TDR member who works for LE (Lubrication Engineers) and is a Certified Lubrication Specialist by the STLE (Society of Tribologists and Lubrication Engineers). Kevin has worked in the oil business for over 22 years and responded; “An overheated condition does not always show up on the temp gauge. It happens between the gear faces with lugging or heavy loads and happens over time. I have not seen any high temps that are over 230 degF in any transmissions all the time. 230 degF is where the sulfur additive starts to have problems. Since you will not see the actual temps between the gear faces on your temp gauge then you will not know that you are having any problems.” So even with a temperature gauge, we can’t see the whole picture. We certainly can’t see what NVG can see with the test equipment specifically designed for that purpose. They did test it didn’t they? I think we all thought that the filled for life concept from DaimlerChrysler was “questionable at best”! It stems from the liability problem of demanding a specific lubricant and not supplying that lubricant to the customer for free. Making it factory “filled for life’ came out of the legal department, not the engineering department, and obviously is not in the customer’s best interest. The Magnuson-Moss Act is not the scope of this discussion, so we won’t go there.

OK, what about the repair companies that rebuild transmissions? Standard Transmission of Texas is a transmission rebuilder of countless NV4500’s. They tried some different lubes in the very beginning to try to offset some of these lubrication costs. Mike P. of Standard Transmission responds: ”When we first began rebuilding the NV4500s, we couldn't find a good reason to use the expensive oil. We advocated using 30w oils of various kinds to keep the cost within reason. We soon found out that the Dodge units HAD to have the Castrol, but the Chevys were okay with just about anything. The Dodge units burned the gears up. The reason we came up with is that the GM units just don't have enough engine to make them work as hard as a Dodge, so they wouldn't burn up. The Dodge is usually used much harder than the GM, so it builds up more heat. So actually, we never did any exhaustive testing, just trial & error that led us back to the Castrol..” I can understand why Standard Transmission experimented with 30wt oils. A lot of transmissions required just that. For example, between 1988 and 1991 either Synchromesh OR 5w30 engine oil was perfectly acceptable in the NV3500. The reason many manufacturers use motor oils is that petroleum gear oils frequently do not shift well at low temperatures. Motor oils and ATF’s are more fluid at these reduced temperatures and are not harmful towards the synchronizers. Unfortunately, these oils provide little to no extreme pressure protection. The shearing action of a manual transmission is much greater than the shearing action in an engine or automatic transmission. Also, a 75w85 gear lube works out to be closer to a 10w40 motor oil than a 30wt oil. When the relatively large amounts of torque produced by the mighty Cummins powerplant was applied to the NV4500, it simply did not have enough protection with engine oil it and it simply over heated."

 

That's a good one! I never thought I'd ever hear anyone say they "saved" money buying Amsoil.

New Venture contracted Castrol to develop a new lubricant specifically for the NV4500 after they discovered it was not going to survive behind the Cummins. Rather than swallow and have to sell the cost of a more appropriate gearbox, the NV/Mopar geniuses decided to shift the burden to you, the consumer by putting a band-aid on it in the form of Syntorq.

Heck, why not just let the customer pay somewhere down the line, long after it's out of warranty?

 

Back before NV went bankrupt and had a website it said the development of the Syntorq was in conjunction with NV.

The 4500 was used in gasser GM vehicles before it was used with the Cummins.

Reason it's so expensive is Castrol has a contract that says only GM and Chrysler can sell Syntorq in small containers.
Price isn't bad at all in 30 gallon drums.
Most of the places that sell it cheaper have just bottled it their selves from a drum.

 

I have come to the conclusion. Although many owners have reported running MTG for tens of thousands of miles with no problems. For only a few dollars more, it is probably worth it to go ahead and use the Syntorq. Considering it is the factory fill, that alone is more compeling evidence that the Syntorq was fully tested and validated for the NV4500, over the Amsoil MTG. I plan to change back to Syntorq sometime in the future. Thanks for all of your input.