Allison shift pad

Topic: Allison shift pad (Read 712 times) previous topic - next topic

Allison shift pad

October 13, 2023, 04:32:21 pm

96 270 mechanical engine R 3060 Allison. Leaving the campground today after 2 week stay built up air and tried to go into drive then reverse... get the no shift blinking light drill. After doing all I knew to do I called Transmission instruments and told the man I have no codes as it stops with d1 then 2 dashes. He says it isn't going to be the pad rather a "inhibitor" concerning jacks, I told him I have no Jacks but have bags he said same difference. Where on the coach would such an inhibitor be.? I got it to shift and went to the dump station and leaving it failed again..... same drill. Next time I got it in gear I brought it the 45 miles to my barn where you guessed it I can't make it fail. Ive read the search and find hwh slide issues that can cause that but I have no slides. Does anyone have any input?

Re: Allison shift pad

Reply #1 – October 13, 2023, 06:17:09 pm

I know the Trans Pad guy told you it was not the pad, but if it was working fine, then the temps dropped along with dampness and you have a problem, I would suspect the pad, especially if you have the original soft touch pad.
I had the same problem until I sent my pad in and replaced it with a hard feel pad.
Working a heat gun or hair dryer over the pad for a few minutes could solve the problem.

Re: Allison shift pad

Reply #2 – October 13, 2023, 06:22:45 pm

Engine idle speedis too high

Re: Allison shift pad

Reply #3 – October 13, 2023, 06:29:16 pm

Ideling at 700 at the time which is a bit higher than the 6.25 to 6.50 it usually idles.

Re: Allison shift pad

Reply #4 – October 13, 2023, 06:29:59 pm

Quote from: turbojack – October 13, 2023, 06:22:45 pm

Engine idle speedis too high

Common symptom of too high an idle speed is the "D" flashes.

This will keep the ECU from allowing the shift from N to any gear.

Re: Allison shift pad

Reply #5 – October 13, 2023, 06:35:33 pm

The "inhibitor" is the ecu refusing to shift for a variety of reasons.

Re: Allison shift pad

Reply #6 – October 13, 2023, 06:37:37 pm

Cooled off some here Lon but still in the 50,s at night 70's in the day. I'll keep the hot air treatment in mind no doubt. Im going to be watching tach closely at start up and do some field testing in days to come. Have a trip in 2 weeks.

Re: Allison shift pad

Reply #7 – October 13, 2023, 06:38:55 pm

Quote from: Twig – October 13, 2023, 06:35:33 pm

The "inhibitor" is the ecu refusing to shift for a variety of reasons.

Will that be located on the trans or bell housing area? The inhibitor I think I need to find to either replace or do away with.

Re: Allison shift pad

Reply #8 – October 13, 2023, 07:35:29 pm

Quote from: Dub – October 13, 2023, 06:38:55 pm

Will that be located on the trans or bell housing area? The inhibitor I think I need to find to either replace or do away with.

It's part of the ecu. If all checks don't add up, the ecu will prevent shifting. Even if the shift pad doesn't communicate with the ecu, it won't even start. I would look at idle speed first. See if the cruise control might even be causing it.

Re: Allison shift pad

Reply #9 – October 13, 2023, 08:29:44 pm

If it was Idling at 700 that could cause it. I don't believe there is an inhibitor for our air bag
suspension.

Re: Allison shift pad

Reply #10 – October 13, 2023, 08:36:53 pm

I get that Twig, there has to be a sensor or "inhibitor" somewhere that sends the info to the transmission, the engine is manual, fuel air and compression and it starts off a 12 volt wire. I'm going to manipulate my idle speeds even though 700 if no higher should be no problem. I'm going under next week after I heal up a bit and find the Allison electronic controller module, I want to clean up some things. Check with Francis and get him to tell us where these Electronics are will ya.

Re: Allison shift pad

Reply #11 – October 13, 2023, 08:41:49 pm

It was at 700 Peter. True that should be the max but crap it may be too high for this one. Couldn't be as simple as a shift pad Hadez no, it's got to be a blasted mystery. I'm going to lower the idle and drive it some. Wife has a trip in 2 weeks and I need this rig to get her there and back but then don't we all.

Re: Allison shift pad

Reply #12 – October 13, 2023, 10:55:41 pm

Quote from: Dub – October 13, 2023, 08:36:53 pm

I get that Twig, there has to be a sensor or "inhibitor" somewhere that sends the info to the transmission, the engine is manual, fuel air and compression and it starts off a 12 volt wire. I'm going to manipulate my idle speeds even though 700 if no higher should be no problem. I'm going under next week after I heal up a bit and find the Allison electronic controller module, I want to clean up some things. Check with Francis and get him to tell us where these Electronics are will ya.

My ecu is on the firewall where my feet go. Yours might be different. You want Francis's number? Another thing that sometimes fix the Allison gremlins, is to reseat the 2 large connectors.

Re: Allison shift pad

Reply #13 – October 14, 2023, 10:35:51 am

I've got the same engine tranny combo and mine idles at 725 with no shift issues.

Re: Allison shift pad

Reply #14 – October 15, 2023, 10:44:05 am

I had trouble once just after I got my coach and it was idling at 700 so I lowered the idling to
650 and never had a problem.

Re: Allison shift pad

Reply #15 – October 21, 2023, 11:55:31 am

A follow up and fyi on my shift pad issue. Turned out being the new Throttle position sensor I added on from Allison, the linkage needed adjusted. Trans thought it was ideling to high to go into gear even though it wasn't. The good from this is I did uncover the Allison ecm box after I removed part of the firewall cover by the drivers left foot and up, at least on my coach. Twig and his pal Francis pointed me to that. I'm glad I looked farther before digging deeper into that needlessly. Thanks for the responses.

Re: Allison shift pad

Reply #16 – October 21, 2023, 12:55:06 pm

Did adjusting the TPS linkage correct the shift point issue you were having after installing the air throttle?

Re: Allison shift pad

Reply #17 – October 21, 2023, 01:41:24 pm

No, the only issue it solved was going from N to D and R... I still have to put it on cruise to shift from 5th to 6th at the correct rpm I have to run the speed up to 70's in 5th if driving by foot to shift into 6th. If I wasn't obsessive I could easily travel this way and will until I can get into Stewart Stevenson in Longview tx so they can set shift points using their lap top software. I have the software from Allison but I don't dare let anyone including myself start pushing lap top buttons not knowing what ones doing. One could really create a mess doing that. I don't even feel good about an Allison tech talking me thru it via phone. My Allison software came in a package with Detroit, Cummins and Cat I bought 10 years ago when I had trucks and a in house mechanic. Like owning a F18 with no one to fly it.

Re: Allison shift pad

Reply #18 – October 21, 2023, 03:13:46 pm

My 95 U-240 Cat 3116 Allison MD3060R with soft touch shift panel. There are no codes in the panel. It has a problem that on cold mornings(<40 deg. F) the soft touch panel lights will flash, display stars, beeps at first with no shift into any gear. The other morning I started the gen set so I could use the DW's hair dryer and warm up the ECU on fire wall in front of left foot. It worked, I had to kill engine and restart. It only took about 3-5 minutes.

Re: Allison shift pad

Reply #19 – October 21, 2023, 03:45:05 pm

Touch pad time will come no doubt but this time it was a different grimlin.

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