Only one fluid on the market!

[GMorg]

The GM recommendation for my AWD Rear Drive Module (RDM) is VersaTrak fluid (P/N 12378514). This is not AutoTrak II fluid. The closest thing to an alternative is RP Synchromax, but I have found mixed reviews as to how well Synchromax works in these RDMs. Even Amsoil does not make a public recommendation for an alternative. (I have seen some online Amsoil rep recommendations, but I cannot verify them as original.)

Does anyone know what makes VersaTrak so darn special. If I knew more about VersaTrak fluid, I might be able to logically consider an alternative. I can't even find an MSDS for the stuff. Does anyone here know what sort of additive strategy is used in this fluid.

 

[Whitewolf]

Yes. I will try explain tomorrow.

 

[[email protected]]

Strange...over on saturnfans VUE forums, people are regularly using RP without issue.

My parents 2003 VUE AWD had the rear carrier clutch packs disengrate @ 40,000 miles. The think was humming and grumbling. Thank god for extended warranties. I told my Dad that every 15,000 we HAVE to change the rear carrier fluid, no questions asked.

 

[NHHEMI]

RP Synchromax is the only fluid I know of that has successfully been used to replace Versatrak fluid from GM. I have not heard any mixed reviews or horror stories. Just good results. My 08 Chevy Equinox( AWD )called for it in the t-case( rear diff was 75W-90 not the Versatrak ). As big an RP fan as I am, and as many good reviews as I read using Synchromax to replace it, I had reservations using it at the least while under warranty.

Your best bet, to be safe, is to just use the Versatrak fluid. It pretty much is the same situation as the Autotrak II fluid from GM. No real aftermarket replacement specifically for it.

 

[GMorg]

I don't know of any horror stories either. But, I do know of two examples of trying Synchromax to remedy the "RDM groan" and it it not working for more than a few months. In both cases, VersaTrak fluid was tried and the groan was held at bay for at least a year. I have read of many people using Synchromax successfully without the groan. I don't personally know any though.

I recognize the my personal sphere is small and that two observations will not prove anything. I would still like to know what makes VersaTrak tick.

 

[ryan2022]

I'm not sure about the original question, but I'll be the first to admit, GM uses some top notch fluids.

 

[NHHEMI]

Originally Posted By: GMorg
I don't know of any horror stories either. But, I do know of two examples of trying Synchromax to remedy the "RDM groan" and it it not working for more than a few months. In both cases, VersaTrak fluid was tried and the groan was held at bay for at least a year. I have read of many people using Synchromax successfully without the groan. I don't personally know any though.

I recognize the my personal sphere is small and that two observations will not prove anything. I would still like to know what makes VersaTrak tick.


Is this on an older vehicle? Say early to mid 2000's? I read about a lot of issues back then with AWD systems from GM. Poor design and no matter what you did they failed up.

 

[GMorg]

The vehicle is a 2005 Pontiac Montana SV6. I think that driving style has a lot to do with problem too. There doesn't seem to be many issues with vans that do mostly highway driving. Since the clutches only engage when the wheels are spinning at different speeds, the RDM doesn't get much use while driving in a near straight line or when there isn't much spinning. I think that my problem is that the van was driven primarily on curvy mountain roads until recently. Since I have moved, it has to go though a lot of parking lot maneuvers. I wish that there was a way to disengage the AWD in the warm season.

 

[GMorg]

Well, I was a little surprised that I didn't get any input on the additive strategy for VersaTrak. I guess that it is such a low volume product that it doesn't spark much interest. I bought some RP SynchroMax yesterday and I will give it a try when Spring finally comes. If the RDM starts to moan early, I'll let you know.

 

[GMorg]

I did a RP Synchromax replacement of the VersaTrak fluid in my RDM - including the recommended 5 minute circles in each direction and rinse. I now have the loudest moan yet! I will give the RP a few days - its quite as long as I don't make slow, deep turns. If it doesn't improve, then I will switch back to VersaTrak at $20 per pint. It's still not a horror story yet, but I am not pleased with RP Synchromax in this application. I am tempted to just throw in some Molybdenum disulfide and loose the rear traction.

 

[benjamming]

Any UOAs?

 

[GMorg]

No, I haven't done a UOA. I was surprised at how clear and clean the VersaTrak looked when I drained it. I have heard that others sometimes see suspended metal in the drained fluid.

 

[NHHEMI]

Originally Posted By: GMorg
I did a RP Synchromax replacement of the VersaTrak fluid in my RDM - including the recommended 5 minute circles in each direction and rinse. I now have the loudest moan yet! I will give the RP a few days - its quite as long as I don't make slow, deep turns. If it doesn't improve, then I will switch back to VersaTrak at $20 per pint. It's still not a horror story yet, but I am not pleased with RP Synchromax in this application. I am tempted to just throw in some Molybdenum disulfide and loose the rear traction.


Are you sure you don't have a problem unrelated to fluid?

 

[GMorg]

I don't think that I have another problem.

The moan first arose around 25K miles. I went to the dealer. The service department found the TSB and performed the service. They changed fluid, drove for 20 minutes, did 5 minutes of tight circles in each direction, and changed the fluid again. Everything seemed fine. At around 50K (past fall), the moan became noticeable only when hot and only in the tightest turns.

All winter, the groan was gone (still on old VersaTrak fluid). I assume that it never got hot enough to drop the viscosity into the groaning range. In the past month we have had some warm days. The groan was back on the warm days. It wasn't bad, but I thought I should go ahead with the TSB recommendation again - before any issues appeared. After few responses here and nothing really negative anywhere else, I decided to give RP Synchromax a try.

Everything seemed fine with the flush except that the groan was immediately louder with RP. It eventually quietened down with the circles. I replaced the fluid after the exercise and the groan was back and loud. I did a few circles and the groan quietened again. I check the level and topped off. This morning, the groan is back and loud. I did a few circles and the moan was reduced. When I got to my destination, I turned into the parking lot and the sound is back. A few circles later, it is reduced.

I don't have each access to a slick surface to test the AWD and I don't think that we will get much more ice. So, I suppose that the RDM could be stuck in AWD and I would not know. The sound is only present during slow, deep turns. I am beginning to conclude that there is no counterpart to VersaTrak fluid on the market and that RP Synchromax is not an equal substitute.

 

[GMorg]

I am headed to the dealership tomorrow for VersaTrak fluid. The weather guessers say that it may rain, so I may be switching fluid in the rain. My RDM groan has become very apparent at nearly every turn. It's still quiet when not turning.

If the RDM goes back to silence with VersaTrak fluid, I will be convince that RP Synchromax it not appropriate for this application! If it stays noisy, I will admit that I still don't know.

 

[NHHEMI]

I will be curious to hear what happens. I would be leaning towards mechanical issues at this point simply because so many other people have used Synchromax without problems but it could be the fluid??? Let us know.

 

[GMorg]

I thought that Whitewolf would chime-in based on his first response...

 

[GMorg]

Whoo! Hoo! VersaTrak quietened things down immediately! I didn't even get through my first circle before the groan had gone. I tried the opposite direction and, same thing. RP Synchromax seems to have made a fine flush. But, Synchromax does not replace VersaTrak in the RDM of a 2005 Montana SV6! I don't think that I should start a separate thread, but there may be value in a subject heading that says, "Synchromax is NOT an alternative to VersaTrak."

 

[bmwtechguy]

Thanks for the fine thread and letting us know what finally worked for you. It would still be nice to get some insight from Whitewolf on this fluid.

 

[Whitewolf]

I'm sorry. I seem to have overlooked this one. The T-case fluid issue is complicated because they are manufactured by suppliers and bought in. Therefore there are a number of different fluid recommendations.