Allison MD 3060 Problem

[Kjlunda]

My transmission went into default today while traveling down the highway. I got a do not shift light and the shift console went blank. Anyone have any suggestions?

[Mike Canter]

What do you mean by the shift console went blank. Do you mean all the lights went out for all the functions. Then if so most likely either the 12 volt input has a bad connection or bad splice in the wire which has been very common. Same guy must have done all these butt splices. Or a fuse went or a cable/plug has come loose on the transmission or the shift console. The shift console also contains the ECU for the transmission. It seems like we ran across a lot of these bad butt splices on the power wire and they were all in the same place but I can't remember where that was. Hopefully somebody can chime in here that remembers or had the problem.

[Papa_Jim]

I think the transmission is set up to default into 'do not shift' mode if the batteries are low. If the batteries are low, maybe the alternator has quit charging, or the battery isolator has burned out.

[slickest1]

Originally Posted by jimkate

I think the transmission is set up to default into 'do not shift' mode if the batteries are low. If the batteries are low, maybe the alternator has quit charging, or the battery isolator has burned out.

I had that happen with mine, the alternator quit and when the batteries got down so far the shift pad flashed a couple codes and kicked into neutral and went black.

[HarveyP]

When mine did that, it turned out to be a small wire with a fuse near the chassis battery. The fuse was fine, but just out of sight forward of the battery was a butt splice that was corroded. Once that was cut out and replaced, all was well. Only a 150 mile tow plus a couple hundred $ paid to Allison. Bad thing was they only redid with another butt splice, which failed a year later. This time, I did it myself and SOLDERED the wire with shrink tube over all. Good luck, HarveyP

[Kjlunda]

Originally Posted by Kjlunda

My transmission went into default today while traveling down the highway. I got a do not shift light and the shift console went blank. Anyone have any suggestions?

Nice guy arrived with wrecker. Knew something about Allison tranny. Found the bad wire and fixed it.
Thanks for replying everyone. I learn something about this every day.

[Mike Canter]

Kent, we sure are glad that was easy to fix. Just for interest so we can file it away and maybe help somebody in the future. Can you tell us exactly where the problem was? Where was this wire located and what was the problem with it........Thanks

HarveyP, thanks. That was the butt connector I was thinking of that so many people have problems with in older MHs. Does that wire that you fixed come directly off the positive battery post? Is there an easy way to identify it as the power to the Allison?

[HarveyP]

Mine does come directly from the positive post of the engine starting battery. It has a fuse holder with a cover, but nothing to indicate it feeds the Allison transmission. I checked the fuse when I broke down, and it tested good. Only later did I find the bad butt splice about two feet forward of the battery on that small gauge wire. HarveyP

[Mike Canter]

Thanks HarveyP. Got someone else with the same problem here
http://www.irv2.com/forums/f258/no-l...ad-112447.html

[Kjlunda]

Mike,
As HarveyP pointed out, it was a 12ga wire off the positive side of the chassis batteries. It had been fixed with a solderless eye connector which had corroded and was just weak from flexing when battery box was slid out and in. All I had was another eye connector, so when I got to Florida I went to parts store for a cable type connector. Wire isn't marked in any way, but must be on my wiring diagrams.

[mel s]

Originally Posted by Kjlunda

Nice guy arrived with wrecker. Knew something about Allison tranny. Found the bad wire and fixed it.
Thanks for replying everyone. I learn something about this every day.

When I had a "Do Not Shift" display on the shift pad, CoachNet paid the tow to Detroit Diesel near the Mall of America, (the nearest "authorized Allison service" dealer).
Four days later they had it fixed.
After trying most everything else, they finally had found one BAD wire.
They replaced both the pos and neg wires from the batteries to the Allison VCM, (up under the dash).
The original bill was over $2400.00.
I refused to pay that, for 40ft of 14ga wire, 4 connectors and labor, (NO OTHER PARTS)!
They finally reduced it to a MERE $1700.00!

I'm sure your repair was a BARGAIN, for basically the same solution.

Mel
'96 Safari Sahara

[Mike Canter]

Sure sounds like they are missing basic troubleshooting logic. We don't pay these guys to learn on the job. If the shift pad does not light up then the first thing is to check the power in.

[mel s]

Originally Posted by Mike Canter

Sure sounds like they are missing basic troubleshooting logic. We don't pay these guys to learn on the job.

Oh yes we do!
(At least I did).

That was my argument for not paying the $2,400.00, and to trying to get a more sensible price.
As you read, it did not work very well.

The very 1st thing they had done, (while I was still there), was connect their computer.
They told me they "had 12v but not enough amps to run diagnostics".
(I then left for home, 250 miles away).

As unbelievable as it sounds, on the morning of the 4th day they called me and said that they "COULD NOT FIX IT".

I said, "You HAVE to fix it, what I'm I going to do with it"?
Their answer: Maybe they would BUY it from me!

I said, "And then you would fix it,...... so FIX IT"!

I asked if they had gotten good clean power to the Allison and they said, "No, but we will try that".

Three hours later they called and said it was FIXED!

Mel
'96 Safari, 6 speed Allison

[SteveSkinner]

Same thing happened to me 5 miles after I picked it up from the storage facility.
Service guy came out and 2 hours later diagnosed a fried transmission ECM
Apparently there has been a spate of failures at about 10 years life.
$3500 + labour
Wow that hurt day one.