Daytonaman wrote:
This has been covered before, but I was wondering what the cutoff date for allison using transynd on MH4000 xmisions. The coach has a model year late 2002 w/ISM. I changed the fluid and filters at 77,000 one time and wondering if it should be done again. There is only a 1,000 or so on the new fluid.
Daytonaman,
TranSynd was used in the Allison factory in 2002 but it depends on what was used at the chassis manufacturer for "top off" (factory fill). Some folks don't understand this; but, the chassis manufacturer purchases the transmission from Allison and then builds it into a chassis along with the engine, driveline and cooling system. Then, the cooling system and transmission are topped off with whatever the chassis manufacturer has for "factory fill" transmission fluid. So, it could have been TranSynd but not necessarily. The best way to tell it to do fluid analysis once a year to watch the viscosity and oxidation state. If it remains stable from year to year, then it's no doubt TranSynd. Did you install TranSynd at the 77,000 mile change? If you only changed it once, then you could be running a mixture. The oil analysis would sort this out for you.
