Allison problems

I recently brought a 1994 diesel pusher (1994 contentinal 3.8 with push button allison tranny). We went to the lake and the next morning the do not shift light was on and it would not go into gear. Finally was able to hit the drive the same time as the engine started and got it home. I went out several times and started it and it worked fine then the next time the do not shift came on the display on the push button panel flickered a little. I took the unit out and had it checked out and was told it was fine but there was a code for a power interuption. Put it back in and it worked great. I went out and drove it around yesterday all was well. Went out this morning and it is dead there is no power to the push buttons not a fliker. Sometimes in starting the engine I can turn the key but it does nothing. If I do it several times it starts. My senses tell me its a relay or something.

Any thoughts or ideas would be appreciated.
Re: Allison problems

Check the TCM power and ground connections. Make sure they are tight and clean. There is also an ignition power to the selector. I would trace it and look for opens, shorts, shorts to ground. Make sure its connections are tight. Could be a lot of things. Sometimes technicians probe connectors and distort terminals. May also be a defective selector. Eliminate the vehicle wiring first. Hope this helps.
Re: Allison problems

I have a 1993 American Eagle with MD3060 transmission and have the exact same problem. I worked on it all day yesterday trying to trace out wiring, etc. If I knew where any of this equipment (ECU, TCM, etc) was located, it would make things easier. I have all of the manuals and books and none show where the ECU is at and I'm not even sure what a TCM is. Having been an electrician by trade, I believe there is a loose ground somewhere. When I turn the key on, the shifter will flicker a little and then go out with no display except the "Do NOT Shift" light is on. If I wait and come back in ten minutes, the shifter will light up with an "N" for about 3 seconds and then go out again. After about three hours of looking at connections, etc., I turned the key and all was normal. Then I put it into Reverse and the shifter went blank and the "Do NOT Shift" light came on. Of course, did shift it back to Neutral and turned everything off. I went back 30 minutes later and it all worked again. This time it even shifted without going out and I managed to back it out and get it turned around and parked where it has an electrical source to plug into. Everything worked perfectly for many more attempts and I quit for the night thinking it might have been a ghost or something! Went out this morning and it worked great and I got it started and the air pressure built up. Just as the air pressure turned the buzzers off, the shifter started to flicker a little and then went off and on and the OFF! There are no diagnostic buttons on my shifter to even get a code and if there was a code, I wouldn't see it because the shifter is blank and appears to have no power. The nearest RV shop is over 50 miles from me and I am on a fixed income with very little cash on hand. Does anyone have a 1993 American Eagle, Cummins engine, Allison transmission, that knows the location of the ECU, etc.? I sent Spartan (the Chassis Manufacturer) an e-mail with the chassis model & serial number and ten minutes later, they sent me the wiring schematic of my motorhome. Now that's service! Unfortunately, it ends in with an arrow that says "ECU" that direction. I guess the chassis maker didn't wire the transmission.
Re: Allison problems

Well, i do have a Diagnostic button after all. It is recessed and looks like an LED. t also appears that the ECU is bolted directly to the shifter.
Re: Allison problems

Still working on no shift light problem. I was finally able to get a diagnostic code of d1-69-32. All other codes were blank -- --, this proves there IS a God! The d1-69-32 code says it is a "SPI Communications Link Fault in ECU". Does this mean the ECU is bad or that something it is trying to communicate with is not communicating? Several web postings from others with the same symptoms said that their Key Pad was dirty and once it was taken apart and cleaned, the trouble went away. However, they never mentioned the d1-69-32 diagnostic code. I have cleared the code several times, but it appears to come back immediately even when everything is working correctly. Any help or suggestions would be greatly appreciated, especially if you can tell me how to remove the shift lever from the ECU. It looks like they are directly mounted to each other. Needless to say, I have to twist up like a pretzel to get at any of the equipment crammed under the dash. I have taken the VIM out and checked the two fuses and relays and they appear to be functioning properly. However, I have NOT done a through OHM/Voltage check on each of the pins in the VIM. Could a bad relay in the VIM cause the "SPI Communications Link Fault in ECU"? The motorhome starts and runs normally now, but will have the same problem if left there over night again. I would just send the whole thing to the repair shop, but it belongs to my 86 year old mother and neither she nor I can afford an expensive fix if I can manage to fix it myself by doing something like cleaning the shifter contacts. Four days ago, I couldn't even get it started, much less move it into gear. By the way, I have a two digit lever style shifter. Anyone out there ever clean one of those? Got any photos or links to photos? :)
Re: Allison problems

Don't know where your at on this since the date is about a month old, but thought I would post just in case... It is a possibility that the shift pad either needs to be cleaned and or rebuilt/replaced, but it is most likely a bad ECU. With it being a two digit display, that is WTEC II which is old electronics and technology, and this sort of thing can happen, especially in motorhomes. Aside from replacing the ECU which can cost anywhere from $1100-1800 is to check the fuses at the batteries. If everything looks good as far as connections and fuses, then you will need to replace the ECU.


New Member
Re: Allison problems

Hey AllisonExpert,

If, as your name says, you know a lot about Allison Transmissions, I have a question for you.

I'm trying to decide to buy or not.....a 95 Safari Motorhome, cummins with 91,000 miles. It's about 500 miles from me, but I have seen many photos and several phone calls. My plan is to negotiate the price, subject to personal inspection. Everything looked good......until I discovered that the Allison 6-speed transmission has not been serviced! The owner bought from his brother, who purchased new. Current owner got the coach when it had 35,000 miles and he has NEVER had the fluid or filters replaced! Said he does not know what his brother did. Worse case is it could still have the original Dexron and filters! 91,000 miles and no fluid or filter changes!

What are my risks that there may be transmission damage? Owner says that he has had no problems with normal operation of the transmission.

Any comments or advise would be appreciated. Thank you, Rook
RE: Allison problems

i have an older m/h with a 300cummins and a 4 speed allison transmission. I flat tow a jeep cherokee. My transmission seems to overheat in 1st and 2nd gear only. In fourth pulling a hill no problem, then downshift to third still pulls fine with no increase in temp. As soon as it gets into 2nd and is under load the temp starts going up fast, and its the same in 1st gear.
I have changed fluid, filter, flushed the cooler and cleaned the rads, but none of this seems to help.
I have changed the fluid three times in the last 4 months but only by draining the pan. It has an external filter which i change every time i changed oil.
Getting sick of pulling over every mile going up a steep hill.
Is there some kind of band adjustment required? or does it need a rebuild?

Any help is appreciated. I,m in the rural NW so a long way from any town.

John :( :( :( :(
Re: Allison problems


With that many Miles and having regular Dexron, you definetly want to have the oil changed along with filters. It also wouldn't hurt to have an oil analysis done just to make sure everything is still in good shape. As long as the oil is in good shape and the trans seems to be operating with no problems you should be ok. Depending on where you live, it would be a good idea to have an Allison Dealer/Distributor check it out just to make sure.

To johnfoster44,
It sounds like you probably have an AT545 in your MH...that has always been a major complaint with those is the overheating issue. The best thing you can do for that is to run a seperate cooler specifically for the transmission. In 3rd and 4th you are already moving at a good rate of speed so there isn't as much load being demanded by engine and trans, where as in 1st and 2nd especially on an incline, everything is working much harder so tempuratures tend to climb.

Hope this helps both of you.
Re: Allison problems

We bought a 1998 American Eagle, Allison 6 speed transmission, Cummins 350hp and had the same problem with the DO NOT SHIFT message. Unfortunately, the TCM has to be replaced - total cost about $3500 - The new TCM is $2500 and the rest is labor.


Junior Member
Thank you

Any thoughts or ideas would be appreciated.[/QUOTE]
Hi Everyone,my first time to post on this site.
Want to say thanks for you guys posting all your problems out here. I am a South African who bought a 93 America Eagle with a Allison box on Monday the 11 Feb in a small town of Lady Lake. After driving for 400 miles with no problem , the gear lever indicator light started flickering. After checking for power and good earth, with no luck.
i went on to the net and found that their is help ,after reading the post.
Somebody had much the same problem as i had and after reading his complaint and the way they solved it i ,found the name of a guy called Jhon from Automatic Transmissions in Texas.
Gave him a call the next morning at 9. He told me he was sure it is the ECU. Took it out, send it with Fedex down to Texas. Jhon received it the next morning.
Thursday at noon i had my Ecu back completely fixed. Would like to take this opportunity to thank Jhon and his wife Judy for there swift and fantastic service. Started the motorhome up and drove 600 miles,no problem.
The charge for fixing my ECU was a mere $ 500 comparing to a new of over $ 2000 plus.
Thanks everyone for posting, joined the forum and will be a avid reader .


Junior Member
information for Automatic Instruments in texas,

Louw;82793 said:
If anybody need the number for Automatic Instruments in Texas i will be glad to share it
I could sure use the phone number and contact information of the person in texas that can address my problem which seems to be the same as the one you had.
Thank You Dale


Junior Member
information for Automatic Instruments in texas,

Louw;82793 said:
If anybody need the number for Automatic Instruments in Texas i will be glad to share it
I could sure use the phone number and contact information of the person in texas that can address my problem which seems to be the same as the one you had. Contact me at or call 541-619-6411
Thank You Dale


Junior Member
Hi I am new to this so here we go. I have just bought a 1995 Gulf stream D.P. Allison Transmission, and the push button key pad went blank. I cant start the coach either. I can jump start it. I have traced wires and so far everything checks out, This may be a stupid question but if you have the tilt out out will you not be able to start the coach? Other than that what in the world could it be?
This is my first RV but I know about wireing so that helps I guess. I am a elevator mech. Thanks so much for the help
I don't know why an RV manufacturer would prevent the engine from starting if the slide out is out. I could see using the Allison interface to prevent the transmission from going into gear.


Junior Member
Hello, I am also new to the forum, and just want to say what a great service you guys give to the rest of us. Thanks. I hope I can contribute sometime.

I have a V730 tranny that works perfectly when the fluid is cold. In other words, at first start-up. However, after fluid temp reaches approx 170 degrees, a problem appears. The hotter the fluid, the worse the problem.

But even when it is at normal operating temp, as long as the tranny is left in gear, it continues to work perfectly. However, once you put it in neutral, and then back in gear, the clutches will not engage untill the engine is reved up to approx 1000-1200 rpms. And then it hits really hard. But again, it will operate flawlessly until shifted to neutral and back into gear again. Mostly happens when shifting to any forward gear. Reverse seems ok.

1st gear pressure is 150psi @ 550 rpms. When working properly, upon shifting to 1st gear, pressure drops to 90psi briefly and then right back to 150psi. but after it is warm, it drops to 60-70psi and waits until reved up and then jumps to 150psi again.. hence the hard hit and lurch. And then same result: works fine until going to neutral again.

Any thoughts on the problem?
Thanks in advance for any help.

In first gear, you have forward and first clutches applied. In neutral, only first clutch is applied. When going from neutral to drive, the transmission is applying forward clutch. Forward clutch stays on through all drive ranges. It is my guess, you may have a forward clutch that is either worn or just slow to apply. That can cause the delay or need to increase rpm to engage first gear after re-selecting drive from neutral.

Reverse is a combination of first and third clutches. Doesn't sound like you have a delay going into reverse, so third clutch must be okay.

The common denominator to what you've described is forward clutch. Just my opinion.


Junior Member
Thanks for the info db. We are checking trimmer valves right now. After checking all valves, we will start researching forward clutch.

Thanks again