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My Allison transmission is acting up

Lat week as we were headed into Brunswick Maryland to park for the weekend the Allison shifted real hard when going from second down to fist. I checked the fluid with the engine running and no sign of fluid. Oh crap what now. Parked and let everything settle, added as couple quarts and the level looked a bit low but acceptable, cold. Checked under the rig and couldn't see any leaks. Started out this AM drove 3/4 mile in first gear checked fluid and nada on the dip stick. Back to the campground. Going to be towed tomorrow to an Allison dealer in Hagerstown to check stuff out. I check my oil level in the Cummins and it may be my imagination but it seemed to be "overfull". wasn't before. Can transmission fluid find it's way into the engine?  Still can't see any signs of leaking under the coach but the stuff has to be going somewhere.

Roland

Re: My Allison transmission is acting up

Reply #1 –
Roland, you may want to check transmission fluid level at the keypad. On ours, press ^ and v at the same time. The transmission must be at operating temperature and the engine at idle. The transmission will go into a countdown mode to let fluid settle, then show values for quarts high or quarts low.

Best wishes for a simple solution.

Re: My Allison transmission is acting up

Reply #2 –
Roland,
My coach had an oil to water transmission oil cooler.
Have you checked your coolent for signs of oil?

Re: My Allison transmission is acting up

Reply #3 –
On 1993 Allison MD3060, there is no "check fluid level from the shift pad".

That feature was added later.

Your transmission cooler is in the radiator.  So, if transmission fluid loss, it would not be in the engine oil, but in the engine coolant.

Re: My Allison transmission is acting up

Reply #4 –
I think John and Brett may have it right. Another thing that happened to me on this leg,I had a lot of coolant leak out of the reservoir tank all over the side of the car. I assumed that I needed a new reservoir never thought the two may be connected. Will follow up with a post once this gets diagnosed and repaired. My appointment is with Truck Enterprises in Hagerstown Maryland,found them on the Allison website. Anyone have any experience with them.

Roland

Re: My Allison transmission is acting up

Reply #5 –
If you need a new Radiator, Keystone is an authorized service center and is probably 10 miles from you at exit one on I81

Re: My Allison transmission is acting up

Reply #6 –
Thanks John will keep that in mind.

Roland

Re: My Allison transmission is acting up

Reply #7 –
Also there is a allison detroit place in Manassas about 80 miles from you or so.

Re: My Allison transmission is acting up

Reply #8 –
Finally got the rig to the shop in Hagerstown, however they will not get to it until tomorrow afternoon. We have Sampson with us so the motel accommodations are a bit limited. Such is life. The tow truck drive did not have a 1 1/2 inch socket to remove the axles,and neither did I. you better believe that I will have that size socket in my tool,box after this experience.

Roland

Re: My Allison transmission is acting up

Reply #9 –
To get to the plate that is removed to access the axle you first have to remove the chrome "hubcap?". It is really removing the nuts for the outside dually. I did not have the proper socket and neither did the driver, although we both swore it would never happen again.

Roland

Re: My Allison transmission is acting up

Reply #10 –
Dave,

You are quite correct as I was thinking the same thing, however, you can't get to the axle nuts unless you remove the big chrome cover held down by EVERY OTHER 1 1/2" wheel nut. Roland also needs to buy a "flip" socket or he won't be able to remove the inside dual. Since we have the same year, the attached flip socket is the one. In case the specs can't be read, the inside stud takes a 13/16" square drive. That's why they call it a flip socket. Flip it over, put the extension in and off comes the stud (unless it breaks off).

Good to tell the towing service that it is a large RV so they send the right driver.

Attached is what I use. The long pipe is not in the photo and the "Big Bertha" 1" impact can be seen in the background (with the red cap on the quick connect).

Pierce

Re: My Allison transmission is acting up

Reply #11 –
The inside dually doesn't have to be removes for access to the axle does it?

Roland

Re: My Allison transmission is acting up

Reply #12 –
No, no tire has to be removed, just the chrome cover to get to the axle fastners.

Good to buy the plastic hub covers ahead of time or pull one axle, use a piece of cardboard as a template and then make a couple of covers from plastic, plywood etc. Be sure to pull both axles to tow not one like the lazy tow truck drivers want to do.

Pierce

Re: My Allison transmission is acting up

Reply #13 –
I forgot the biggest consideration. One side of the coach has left hand threads. Nuts are marked. Bad to forget!

Pierce

Re: My Allison transmission is acting up

Reply #14 –
I too have the plastic screw on caps so do not need to remove a "chrome cover and every other nut" so my comment is  removed.
JohnH

Re: My Allison transmission is acting up

Reply #15 –
The problem has been diagnosed as an accumulator tank failure. Engine coolant did make its way into the transmission, so they have to remove the transmission and fix whatever got messed up by the antifreeze. That may be the easy part as the accumulator tank is not available any more, at least there aren't any in Nacogdoches. The saga continues.I am wondering if it would be a good idea to replace the radiator at the same time. Might make it easier to repair?

Roland

Re: My Allison transmission is acting up

Reply #16 –
Roland,

Clearly, you need to determine the source of the "crossover" between ATF and coolant and fix that.  Yes, the radiator is the "first suspect".

Re: My Allison transmission is acting up

Reply #17 –
FT gets there radiator from Atlas in Texas or did for our model years. 

Re: My Allison transmission is acting up

Reply #18 –
 Hopefully the Transmission will be ok as Trans oil and coolant/antifreeze are a definite no-no together. It seems the coolant ruins the plates etc.
Sounds like lots of coach Bucks to me!!!
Good luck.
JohnH

Re: My Allison transmission is acting up

Reply #19 –
Cannot seem to locate an accumulator, and not sure these folks are interested in modifying to install an inter cooler. Is it possible to bypass the accumulator and drive the coach until I can get to where I can install an inter cooler for the transmission? I know I would have to watch the transmission temperatures, but I do that now in any case. Just wondering if it is possible to run for a distance without the accumulator.

Roland