First off, some people on this forum talk about changing their allison over to synthetic fluid. Doesn't the allison come from the factory with transynd which is synthetic? Second, can I use transynd in my transfer case? Third and last if I run Schaeffers synthetic gear oil in my rear diff do I need to add the GM (or equivalent) locking diff additive?Thanks

The Allison comes with Dex III .... Yes, you can run Transynd in the T-case, capacity is 2 quarts ...


The Gearlube needs to be G5 rating and synthetic ... I'm running Mobil and I'm not familiar with the Schaeffer brand ...


Mac http://www.dieselplace.com/forum/smileys/Geek.gifEdited by: Mackin

did you put the additive in with the mobil? and is the DEX III that comes in it transynd? I see on DMAXALLITECH's store transynd is labeled as OE in the allison

No additive in the Mobil ... I dunno what Eric is reffering to .... Transynd is the perferred fluid of Allison ....


Mac

did you put the additive in with the mobil? and is the DEX III that comes in it transynd? I see on DMAXALLITECH's store transynd is labeled as OE in the allison


DEX111 is the GM spec and Transynd is the Allison spec. Two different fluids.
Edited by: TC Dmax

so what your saying is transynd is what allison would like you to use but GM is too cheap to use it as factory fill.

Transynd is for severe duty and extended drain intravels ....


For the average consumer and Hot Rodder such as myself it's cheap insurance and has all the great lubricating characteristics of synthetic oil ...





Ok GM is to cheap ...





Mac http://www.dieselplace.com/forum/smileys/Approve.gif

transynd it shall be thenhttp://www.dieselplace.com/forum/smileys/Big Smile.gif

Transynd is the OEM fluid for Allison, not GM. Therefore you only get plain ol ATF from the general.


As far as the Schaeffers lube is concerned, (741 for 75-90 and 740 for 80-140) it meets Eaton specs on there units and will be going in mine and many other local trucks here soon... Still getting my ducks in a rowhttp://www.dieselplace.com/forum/smileys/Geek.gif

Thanks Eric, thats what i needed to know about the schaeffers. I have a barrel of 75-90 waiting for me.And I ordered one of your "differential" siphon's to speed up the process. Aside from cracking open the allison or limping it ,is there any telltale signs that the clutches are starting to go? Thanks

I ran TranSynd and the deep pan in my Ally for 70,000 miles. Never had a tranny problem.

you can cut the spin filter open and look for heavy deposits or drop the pan and look for dark debris.


Your siphon gun shipped todayhttp://www.dieselplace.com/forum/smileys/Cool.gif

I was told by a Allison tech that when they make the Allison Transmission. Allison puts in a little TranSydn transmission oil. Then when GM gets the transmission they top the transmission with DEX III.Edited by: GMC-DMAX

Not sure on that. Allison builds the 1000 series trans specifically for GM trucks, so I would doubt it. Regardless, its not enough to give any type of advantage.