Another Transmission Temp Question

[Joel Weiss]

You may recall that we bought this coach a couple years ago.  It had no maintenance log.  How might I tell if it has Transynd.

It would be pretty easy to pull a sample and send it for analysis.  I'm pretty sure most labs could tell you which one you have.

BTW, IMO if you bought this MH "a couple of years ago" with no maintenance logs and you haven't replaced the fluid or the transmission filters by now then you should definitely do both ASAP.  Filters are an every 3-4 year item and if your coach still has Dexron it should be changed at least every couple of years. JMO

[Gerald Farris]

Keith,
I would run the only Allison approved fluid in an Allison transmission, TranSynd. If anything, TranSynd will have a less tendency to cause a leak in your transmission cooler because it runs 10 to 15 degrees cooler, and therefore it will have slightly less thermal expansion fatigue on the cooler.

The proper way to tell what type of fluid your transmission is running and it's condition is to have a fluid analysis preformed. With a good fluid analysis, there is no guess work. You will have all of the information you need to make your service decisions for your transmission.

Gerald     

[Bruce Sieloff]

This may be one of those YMMV posts where anecdotes don't bring much clarity, but for my 2 cents if you have any concerns about your transmission intercooler get an extended warranty NOW. I read all the posts about Transynd and when I finally made the switch was disappointed to find that it didn't make much difference, THEN my intercooler went out stranding me on the roadside (close to home) indicating that I was running mixed fluids for some time (had a previous post on this adventure). After a new Allison 4000, new radiator and CAC (possibly not related) and a refill with Transynd my trans temps are consistently 15-20 degrees cooler than the coolant temp. How much of this is due to Transynd and how much to the new radiator I can't say. The weakness of the intercooler system as a single point failure in the cooling system would lead me to never purchase another used coach without a robust warranty for the first two years. I had my coach for three years before the failure but put few miles on it so mileage may be more important than age. BTW, according to my service shop mixing a cup of coolant with your trans fluid will cause the plates to delaminate and enlighten you that a new Allison costs $6500 after the core exchange.

[Keith Moffett Co-Admin]

Thanks for that Bruce.  I should probably switch to Transynd as Gerald suggests but my last go round with it was not good.  Having a leaking solder joint would put a lot more than a cup full into the Allison.