Jim@HiTek wrote:
Jim@HiTek wrote:
Thanks for your advice and help here on the forum, hzjcm8.
I had my Allison 4 speed back flushed and filled with Transnyd at 136,000 miles back in '07 at a bus repair shop that was just getting into RV's. They used a big fancy machine and told me they flushed it until the fluid was the right color, 3-4 times if I remember. At that time they told me there was no need to replace the tranni filters as the back flush would clean them like new.
Is that true?
At 142K miles, I developed a hydraulic leak in the boondocks of Canada. I had a couple quarts of Transnyd that I used up along with a couple pints of ATF stop leak I bought as I limped several hundred miles to Prince George. Also added regular ATF as needed along the way (small stores don't usually carry transnyd).
Had a leaking hose replaced and the tranni topped off with more transnyd. The mechanic told me it was OK to mix the standard ATF, Stop Leak, and the Transnyd but I would like to hear that from you.
Should I have it re-flushed, or is it OK with those other fluids in there?
Thanks!
Still wondering about this...it was definitely leaking tranni fluid from a tranni cooler hose. Once hose replaced, did not have to top off the tranni fluid level anymore.
Jim@HiTek,
No. That is not true. You can force new fluid through the main and lube filters. That's what the transmission pump does. But, you cannot "back flush" them like a "water softener" sediment bed. That would require the system to pump the fluid backwards from the inside of the filter to the outside of the filter. They didn't know what they were talking about.
Now, with regard to the fluids and "Stop Leak". Regular ATFs will mix with TranSynd. However, these regular ATFs aren't very stable from a viscosity standpoint and will lose viscosity over time. My bet is that your viscosity is low right now. The mix won't hurt anything but it will continue to degrade and lose viscosity over time. Also, I'm not sure about the effect of the "Stop Leak". It may just be a seal swell agent that wouldn't help with hose leaks. Also, it could be that the hose leak was caused by the use of the flushing machine since they would have had to disconnect and reconnect the cooler circuit in order to flush the transmission. I do not ever recommend the use of a flushing machine. You're always better off doing a double drain and refill.
Here's my recommendation. Drain the transmission, fill it with TranSynd, drive it for 1/2 hour to circulate the mixture through the torque converter, controls and cooling circuit, then drain it again, install new Allison "High Capacity" and refill it with TranSynd. This will give you the dose you need for the extended drain intervals. You can run it up to 300,000 miles (pretty much fill for life) and change the filters at 75,000 mile intervals. Check it once a year with oil analysis. I can counsel you on that since that's what I do now since retiring from GM and Allison.
This will minimize your problems and get you back on the road to "worry free" operation.
Call me on my cell phone if you'd like to talk. I can be reached at 317-430-3029.
