Allison Transmission Questions

Discussion in 'General RVing' started by AllisonMan, Apr 5, 2003.

  1. Hulkamaniac

    Hulkamaniac Junior Member

    Allison Man: I have an allison 1000 on a 2004 Chevy 2500HD Duramax with 180,000 miles. I had the dealership flush the system in May 13. I change the filter every oil change and just change the filter 5 days ago. All of a sudden, my reverse has a delay and then clunks into reverse, and my lower gears have an extremely elevated RPM before they clunk into gear too. Changed the filter in case I had a bad filter. It didn't help. What do you think?
  2. BrewE2

    BrewE2 Junior Member

    Question - I have a 2009 American Coach DP with 425hp Cummins with a 3000MH Allison Trans. On our most recent trip we stopped to unhook our toad after about 450 miles, so we were shut-down for perhaps 20 minutes. When I restarted the coach and selected the "D" it would not go into gear. The display would indicate "6 N" I tried "D" "R" etc. no change, the "N" remained no matter what the selection. I released and reengaged the parking brake no change. I shut down the coach waited about 30 seconds and restarted everything worked normally. Any thoughts on what could have caused this? TIA
  3. Sumguy572

    Sumguy572 New Member


    Been a fan for awhile but now I need some help if you could. I have a 2000 Bering Later to become Hyundai light duty landscape truck with a detroit 638 in line six cylinder and Allison AT542 with 57000 miles. I had no trouble with it but did have leak around pan gasket on Tranny one day in a hurry I over filled it by half quart to quart. I know but I did it somehow. Anyway didnt know it then so I drive about 3 miles and stop at local store for fuel with no issues get in to leave and its like the tranny was slipping badly could barely get away from the pump to go get other truck and trailered home. Cusing and crying as I had all my dreams in it of course and basically broke of course saw rebuild tranny and wanted to cry.

    Parked and ignored it for a week hoping it would fix itself....I know, i Know. But I begin to try to see if this time my non-knowledge and luck with automatic transmission has magically changed. Say stick to basics could be simple after warming found it over fulled and fixed that got on the net and found your site and new hope, Discovered limp mode and which I didn't know existed as the angels sing in my ears. Read all the forums twice and try several of the thing to clear codes I assume is from over fill. The Bering Truck Company had went defunct and they had no support so tried all combination suggested for any model and make here and off couple other sites. Nothing. Started ask around and got 3-4 service people to come out but their code machine would connect to the plug in the Bering Truck.

    Was told have to go to Allison problem is they are a long way from me and cost has prevented me doing it. Now trying to get it going again so fire it up and nothing now. Its like in neutral almost in reverse it will move some but engine rpm are very high and it just barely moves at all nothing forward. The truck has not ever lit an idiot light and it is analog/Mechanical speedo so no read out. I have tried all anyone has offered including burt goat offer on 3rd blood moon while naked.

    So I was wondering if you might be able to shed some light on the subject for me. I have had no hint of a problem and I just can believe it is much at all.

    Here is a site I made with pictures and specs if needed I have it for sale and would much rather fix it and keep it because I will be giving it aweay with tranny like it is and when you tell folk I believe it is limp mode they look at you like of course it silly man and interest in it is gone except for parts and low ball offers/ In almost 5 years it has not has 3000 miles on it, just sad it a great truck I love it plz help.

    This is the sale ad I have made and has all the trucks specs and many pictures

    Thanx AllisonMan
  4. Sumguy572

    Sumguy572 New Member

  5. Paul Scott Hasson

    Paul Scott Hasson New Member

    Dear allison man,

    I have a 01 bluebird 84 passenger bis with a m3060 tyranny, and I've read to use a dextron I I, and stay away from dextron III as it will be harmful to the seals. Would like to know your thoughts and Insitell. Thankyou.
  6. Sumguy572

    Sumguy572 New Member

    Is this thread open or am I doing this wrong? Allison Man are you here?
  7. Cindy Spencer

    Cindy Spencer Administrator Staff Member

    I've reached out to AllisonMan, but as of yet I haven't had any luck in getting a response. I'll keep trying and post an update when I know more.
  8. Paul Scott Hasson

    Paul Scott Hasson New Member

    Well I called around andspoke to a allison certifies tech and the answer for my question was TranSynd TES-295 stay away from dextron III for the
  9. dbarton291

    dbarton291 Senior Member

    Yes. TES-295 is the spec for the fluid you want to use. There's lots of fluid out there that says things like "engineered to meet TES-295", but they aren't approved as TES-295 fluids. You can go to and find all kinds of info on approved fluids. They even have a fluid and filter change interval calculator you can use.
  10. dbarton291

    dbarton291 Senior Member

    You are reading old information. The specs for the approved fluids for your MD3060 are TES389 for mineral based fluid, and TES295 for synthetics.

    Dexron II is no longer produced. Dexron III can be found, but stick to the current TES spec markings and you won't have any problems.
  11. Patrick Agin

    Patrick Agin New Member

    Hi AllisonMan
    I just bought 2 days ago a Safari Sahara 1996 (CAT 3126 and Allison transmission). When I drove it for the time, I noticed that sometimes, it's long before it shifts in 2nd (for example, after restarting at green light, it stays in 1st for what seems an abnormal long time, maybe 10 seconds and the shift to 2nd is not very smooth). I'm a newbie in the RV world, so I'm not sure if it's normal or not. Your lights will be greatly appreciated!
  12. dbarton291

    dbarton291 Senior Member

    Generally, the shift points in the Allison are a function of output speed, operator selection and throttle position. Temperature can have an effect, but only in certain extreme temperature ranges. If it takes slightly longer to reach a shift point, there's usually an external cause like grade, throttle position, etc. If there's a problem in the transmission you'll get a check transmission light on and a diagnostic code. I wouldn't worry unless you get engine flaring between shifts or trouble codes or excessive fluid temperature. Check the fluid hot and make sure it's got clean fluid and the level is OK. You should be good to go.

    This baby is 20 years old. Just a few questions that may be helpful. How many miles are on this unit? When was the last time the transmission fluid and filters were changed? Does it have a throttle position sensor for the transmission on it or is it a vehicle with a controller area network?
  13. dbarton291

    dbarton291 Senior Member

    The display "6 N" indicates the TCM was thinking there was some inhibit in place preventing it from commanding the transmission into drive. It knows you are asking for it, but it's saying "hey wait a minute, until you clear X condition I can't give you drive".
    If you have to step on the brake to get gear, the switch may not have been closed all the way. If it has a throttle position sensor for the transmission (probably not), the cable may have been pulled slightly out. If it has a range inhibit for the leveling jacks, one of those switches may have been sticky. Maybe the engine idle RPM was too high for some reason. It could be a lot of things.
    Bottom line is, the computer thought some condition was present that was telling it it was not okay to command drive.
  14. Patrick Agin

    Patrick Agin New Member

    Thank you for your answer DBarton. My baby has 80K miles, vendor said last maintenance was 5000 miles ago (next in 4000 miles). For the throttle position sensor, it "seems" I have one (I found on the net the owner of a 95' Safari that talks about his TPS).
  15. dbarton291

    dbarton291 Senior Member

    OK. One pretty common cause of what you described is the TPS cable being sticky and not always traveling with the throttle exactly. Still could be a lot of other stuff, but that's generally pretty easy to check.
    Last edited: Oct 4, 2016
  16. Patrick Agin

    Patrick Agin New Member

    Thank you again DBarton! I'll ask my garage mechanic to check that TPS.
  17. lazer man

    lazer man New Member

    Hi allisonman! My name is lance im new here.i posted a thread but i guess i should have came here?anyway im an rv/camper guy but have a issue with my work truck.93 ford f600 7.0litre (429)75000 miles runs great serviced reg.a couple issues the may or may not be related?transmission at542,lucas grilling assisted brakes.sometimes truck will idle high when going from neutral to d.and at a steady 45 mph it will downshift u pshift downshift u pshift etc.until either let off accelerate or doesnt do this every time at that speed but normally.had truck 5 years done this whole time.a couple years ago i replaced bad vacuum hoses @ engine checked for leaks.also checked modulator on tranny found tube was rust and blocked.repaired the end and checked vacuum function of mod it was ok. (I depressed diaphragm while holding trans side port let off had suction).trans hasn't been serviced,truck is driven seasonal from may-oct maybe 20 mile trips.a few times monthly 60 miles @45 50 mph.i normally have someone else driving truck so ive kinda forgot about it.but im recently divorced and things have changed so i drive it more and obviously i noticed it mechanically inclined just not familiar with the setup,engine vacuum,power steering,assisted brakes,transmission.what i mean to say is the transmission symptom related to a vacuum or pressure somewhere tied in that system?or are you going to say its isolated to a transmission part,control etc?sorry this is lengthy but wanted to be informative.this may be common to you.i just dont want it to all of the sudden be a major repair as now ill depend on it for livelihood one day i can enjoy my camper again which i have issues with in another thread ugh! Thank you much allisonman if can assist!
  18. dbarton291

    dbarton291 Senior Member

    Please see my response in the other thread you posted this in. Sure doesn't sound like it's necessarily a transmission issue. I suspect you still have an engine vacuum or emission controls issue.

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