Allison Transmission Tech Advice

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allisonman

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     I just want to say hello and a little about myself.  I am an Allison transmission technician with 10 years of experience with working on them.  I've rebuilt just about every model of their transmission you could think of from the AT545 all the way up to the CLBT9800 in oil field service. if you have a question on them feel free to ask.  I'm not representing any company or soliciting work, just giving free advice on Allisons.  I work on a lot of motorhomes at work and while I have a lot of knowledge with the Allison, I have little knowledge of the rest of the coach, that is why I came here,  because you guys/gals can give me info on all this other stuff.    while I don't have an RV at this time, my wife and I are planning to get one in the next few years but it will be an older one.  it may be a trailer I can pull behind my dodge durango (has to be small for that) or an older motorhome.  not sure yet.  it needs to be big enough for our 3 kids who are 6, 2, and 8 months now and us but not too huge that I can't drive into some of the smaller less developed campsights next to lake superior.   we're probably not going on too long of trips because the kids DO NOT like to sit long in the car  ;D  you get the old "are we there yet"  routine. a motorhome may be better for them I think.

         a few things on asking me questions, if you have say a workhorse chassis and it has a 1000series allison and you want to know whats wrong here is what I need.  I need to know if it has a CHECK TRANS light and if you have a code.  if you tell me your 1000 series trans is defaulting into "limp home mode" without a code I won't be able to help much because just about ANY problem makes the 1000series go into "limp home mode".    if you have never experienced "limp home mode" then here is what it is.  when the trans sets a code, most of the time it will default the trans into 3rd or reverse ranges so you can SLOWLY and CAREFULLY drive the coach to a safe location A SHORT DISTANCE.  you will definitely know when this happens because the trans will HAVE NO AUTOMATIC SHIFTS and the coach will take off very slowly from a stop.   remember your taking off in 3rd gear when this happens stay out of the throttle on take-offs when you can because it builds a lot of trans fluid heat in the torque converter.   its like taking a stickshift trans, putting it into 3rd gear and slipping the clutch to get going.     you guys with a 3000/4000 series won't have to worry about this because if your trans has a problem it will default you into the current gear or go into neutral.  if yours defaults to the current gear and locks you there, you will have to cycle the ignition to shift to neutral.  if you have to do this you are most likely going to be stuck in neutral when you start the engine back up.   so if it sticks in gear on you find a spot that you can stop and retrieve codes from the shifter.  you can clear the codes with the shifter but write them down first (the shifter stores up to 5 codes) so that the mechanic working on it has a quicker/easier time troubleshooting it which equals less downtime and money saved.  we all know how expensive that is now days.  my shop charges $98.00 an hour in the building(and this is probably cheap for some of you) and $120.00 an hour plus mileage for road service.   :eek: :eek:  
           
                   so go ahead and ask away with Allison questions, and I'll try and answer them for you.  I'll need your help when I get an older motorhome and have questions with repairing the rest of it  :D  
          Luke


[edit]Changed message title[/edit]
 
Howdy, Allisonman.
Welcome aboard to the RV forum!!! 

For an older motorhome you might want to check out a Bluebird Wanderlodge.  Built like a tank. We have an Allison tranny in our Bird, it is a 5 speed, four forward and reverse. We really do wish that we had the Allison 6 speed. For info on Wanderlodges, there are many Wanderlodge web sites online.


Regards,
Liz Pearce
 
We really do wish that we had the Allison 6 speed.

you may be able to make that happen with what you have now. if it is a 3000 series (it may say MD3060 on the tag) they ALL have the capability of being a 6 speed.  you just have to go to a dealer and have them program it to a 6 speed.    Allison WILL NOT change it to a 6 speed without an authorization from the manufacturer of the chassis  because the driveshaft or axle may not be able to spin that fast.  I've changed quite a few to 6 speeds but in a few instances I was not allowed to because the driveshaft wasn't supposed to spin that fast.

I'll have to check out some wanderlodges and see if I like them.  I like stuff that is built like a tank  ;D
 
Hi Allisonman,

It's really nice of you to make yourself available. Don't hesitate to ask questions out here when you are shopping because there are allot of knowledgeable, helpful people out here that are always willing to share their knowledge and/or experiences. Good luck in your search and thanks again for making yourself available, to date we are extremely happy with our 6 speed Allison and hope we don't need you but it's nice to know your there if we do have questions/problems.
 
It's really nice of you to make yourself available.

  thank you, I'll try and help when I can.  most diesel techs HATE seeing a motorhome pull in the door because it is a lot more work for us in trying to keep oil and grease off of it and, it is usually harder to access the eng/trans. 

Don't hesitate to ask questions out here when you are shopping because there are allot of knowledgeable, helpful people out here that are always willing to share their knowledge and/or experiences.

    thanks, I won't hesitate to ask because  I will have a lot of questions on all the other stuff  ;D

to date we are extremely happy with our 6 speed Allison and hope we don't need you but it's nice to know your there if we do have questions/problems.

glad to hear you like it, they are good transmissions.  just keep the oil changed and it will run forever. I recommend transynd fluid, its pricey but it is great fluid, Allison pushes its use but its good, I've seen the inside of a lot of trans that had both and I like the transynd, in fact I even changed the fluid in my dodge durango to it. I've got 140,000 on a dodge trans with no problems.
 
Allisonman,

I have a 2004 Workhorse W22 with the 1000 transmission. Can you tell me how to add a mechanical temperature gauge in the cooler output line so that I can install the temp sender.


Tim
 
I have a 2004 Workhorse W22 with the 1000 transmission. Can you tell me how to add a mechanical temperature gauge in the cooler output line so that I can install the temp sender.

that fitting is like an A/C line fitting. it has a clip when you slide the plastic cover off the fitting you can take off with a pick. then you can pull out the line from the fitting(a few quarts of fluid will come out) then unscrew the fitting out of the bellhousing. it is an O-ring fitting so a pipe thread fitting WILL NOT WORK.  you will have to find some sort of "T" fitting with those threads and put the sender in the "T".   you will also have to bend your steel cooler line a little to get it back in.      if it were me I would not bother with putting the temp sender in the cooler line fitting.  the reason is that if you put it in the "TO COOLER" or "FROM COOLER" line you really don't get an accurate reading of trans temp.  in the to cooler line you will see spikes of fluid temp all the way up to nearly 300 degrees and you will think O MY GOD MY TRANS IS BURNING UP but really this is normal in certain driving conditions for short periods of time.   the real reading you are after is trans SUMP temp.  what the temp is in the pan is the one I want.    If it were me I would drain the fluid and remove the pan and have a reputable welder put a threaded bung in the pan and put my sending unit for the gauge in that.  that is the critical fluid temp you are after.

 the stamped steel pan is around $55.00 from an allison dealer so its not that expensive to get if it leaked
 
Thanks for coming here!  ;D

As I understand it, the Scan Gauge will not give out an Allison 6-speed Transmission reading, but will on an Allison 5-speed 1000 trans.....Allison is supposed to be working on this problem.....do you know how this stands?
 
As I understand it, the Scan Gauge will not give out an Allison 6-speed Transmission reading, but will on an Allison 5-speed 1000 trans.....Allison is supposed to be working on this problem.....do you know how this stands?

  I don't know what a scan gauge is. is this an aftermarket code reading tool?    what is available to me at work is a laptop computer with Allison D.O.C. (diagnostics on command) software. with this setup I can communicate with 1000 series 3rd/4th generation, 3000/4000 series WTEC2, WTEC3 and, 4th generation. 

  the reason it will communicate with a 5-speed and not a 6-speed is probably due to the differences in the trans TCM (trans control module)  a 5 speed 1000 series is a 3rd generation tcm where a 6-speed is a 4th generation tcm.  these 2 tcm's are totally different and can't be interchanged.  4th generation tcm's came out in 2006 and they are just our newest control system.
 
I'm going to be away for a few days so if you post something from now until Wednesday it won't be answered until I get back.  see ya in a few days and keep the questions coming  ;D
 
Have a great trip.  When you get back and see this, I'd appreciate your thoughts.  We have one of the smaller Itasca MHs with a 5.9L Cummins and a 2500 Allison 5 spd tranny.  I don't know much about DPs but this one seems to do fine and gets about 10mpg if I don't push it too hard.  I do have a few general questions though... when do I use the mode option?  And after the vehicle has been unused for 3 weeks or more and I start it up, the transmission icon on the dash stays red for about 30 seconds (with a beeping sound), then the light goes away and everything is fine... is that normal?  Lastly, how often do you check the transmission fluid level... I mean, it's not difficult but there's the hot level , the cold level, the "in gear" level and it never changes as far as I can tell...  I've read the manual and if I checked everything per the manual... it's like that's about all I'd be doing so I tend to stretch things out some.  Of course then I worry about "not" checking so I thougt I'd ask a pro.  It also says change the fluid every 60,000 miles or so OR annually.  It's going to take 10 years to get that many miles and I don't push it very hard so is it really necessary to change the fluid every year?  I surely don't do that with the cars and trucks we have.  thanks, G.
 
Hi Allisonman,

I've got a 1991 Beaver Marquis that is build on a Gillig chassis. It has a CAT 3176 engine with an Allison HD7474 transmission with an air shift. Lately the air shift has been refusing to shift into drive when the vehicle has been sitting for 3-4 weeks or more. It will go into reverse with no trouble, but will not shift back to neutral or into a forward gear. When this happens, I have to turn the engine off and crawl under the vehicle to manually shift back to neutral.  Sometimes if I hold the shifter paddle in the forward position for 30-45 seconds, it will eventually shift into drive. Once I get it into drive and things warm up the shifting is OK and will remain OK for 3 weeks or so.

I'm thinking that I probably will need to take it to the local Allison shop and get the air shifter rebuilt. Is this correct or is there anything else I can do?

Chet18013
 
allisonman said:
 If it were me I would drain the fluid and remove the pan and have a reputable welder put a threaded bung in the pan and put my sending unit for the gauge in that.  that is the critical fluid temp you are after.

 the stamped steel pan is around $55.00 from an allison dealer so its not that expensive to get if it leaked

Thanks allison man, I'll look into modifying the pan.

Tim
 
Well... Thanks for posting.. I do indeed have a Workhorse Custom Chassis with an Allision but it's the 2005 version (5 speed) not the new six speed.

and so far my problems with that transmission have been... SUE's (Stupid User Errors)... And someone already explained what was wrong with my thinking.. So the result is.. I have no questions at this time.
 
when do I use the mode option?

the mode button is "economy mode".  it is used when you are driving on relatively flat roads and non-city driving. the only thing "economy mode" does is lower the shift point (when the trans shifts into the next gear) by about 200-300 RPM.  basically it just makes the trans shift sooner.  it does this to lower the engine RPM's  and give you a little better fuel economy.

And after the vehicle has been unused for 3 weeks or more and I start it up, the transmission icon on the dash stays red for about 30 seconds (with a beeping sound), then the light goes away and everything is fine... is that normal?

the check trans light should come on and go out after a few seconds on engine start-up. 30 seconds seems a little excessive. are you certain its the check trans light and not the low park/service brake air? the low air light is usually accompanied by an alarm like you are hearing.  will the trans shift into drive or reverse when this occurs? a plugged spin-on filter can cause this and I have seen fluid (torque converter) drain-back issues on pre-2006 1000-2000 series transmissions.  if it takes more than 30 seconds to go into drive or reverse then this may be your problem. what happens in the trans is that the fluid drains out of the converter after sitting for long periods and then when you start the engine the fluid has to pump back into the converter and the pressure manifold switch on the valve body does not see any pressure so, the trans computer will not command the trans to shift until it see's the pressure in the valve body( after the converter is done filling with fluid of course).  the only way to tell this though is with an Allison computer reader and you may see some pressure switch fault codes but the switch will not be the problem, just a symptom of the real problem of pressure.  there are valves in the front support that can stick and cause these problems on pre-2006 models. they can be updated using a shift kit from a company that I can P.M. the name of if you want. the trans will need to be removed and the front of it will have to come apart to install the valves.  before I did anything, if it were me, would be to install a new spin-on filter if it has more than 5000 miles on it. this filter should be replaced at the transmission's first 5000 miles then at 50,000 from then on out. the initial filter change is to get rid of any break-in debris.

Lastly, how often do you check the transmission fluid level... I mean, it's not difficult but there's the hot level , the cold level, the "in gear" level and it never changes as far as I can tell...

I would check it before going on any trip.  you check it in neutral or park only with the engine idling around 650 RPM. the fluid should be in the cold run band if fluid temp. is below 120 degrees and in the hot run band if above 160 degrees.

It also says change the fluid every 60,000 miles or so OR annually.  It's going to take 10 years to get that many miles and I don't push it very hard so is it really necessary to change the fluid every year?

  it depends on what fluid you are running, if its dextron 3 then its every 50,000 ,miles or 2 years. if its transynd then its every 100,000 miles.  the spin-on filter should be replaced when the trans reaches the first 5000 miles of its life then every 50,000 afterwards (don't through out the magnet from the old filter, it must be reused) 
oil gets condensation in it after sitting for long periods without operation, in my area especially, so I'd change it after 2 years at least.

 
I've got a 1991 Beaver Marquis that is build on a Gillig chassis. It has a CAT 3176 engine with an Allison HD7474 transmission with an air shift. Lately the air shift has been refusing to shift into drive when the vehicle has been sitting for 3-4 weeks or more. It will go into reverse with no trouble, but will not shift back to neutral or into a forward gear. When this happens, I have to turn the engine off and crawl under the vehicle to manually shift back to neutral.  Sometimes if I hold the shifter paddle in the forward position for 30-45 seconds, it will eventually shift into drive. Once I get it into drive and things warm up the shifting is OK and will remain OK for 3 weeks or so.

I'm thinking that I probably will need to take it to the local Allison shop and get the air shifter rebuilt. Is this correct or is there anything else I can do?

ahh... the good ol' stone bennet shifter, or is it a rexroth?                I would make sure that the air line to the accumulator on the shifter was not leaking and I would take off the line and make sure I had good air pressure coming out of it. also look to see if there is excessive oil in the line from the engine air compressor, it can gum things up but,  it sounds to me like it may need a rebuild though, be advised that this shifter is NOT an allison shifter.  it is either a stone bennet or rexroth, probably a stone bennet so the allison dealer may not have the parts in stock for it. last time I heard stone bennet was out of business but don't quote me on that, so parts could be hard to find and take forever to get.  the only options you have with this trans is to have the stone bennet shifter or eliminate it and run a cable shifter setup. to do that you would need a shifter and a 50'--60 ' cable to run all the way back to the trans.
 
allisonman said:
you may be able to make that happen with what you have now. if it is a 3000 series (it may say MD3060 on the tag) they ALL have the capability of being a 6 speed.  you just have to go to a dealer and have them program it to a 6 speed.    Allison WILL NOT change it to a 6 speed without an authorization from the manufacturer of the chassis  because the driveshaft or axle may not be able to spin that fast.  I've changed quite a few to 6 speeds but in a few instances I was not allowed to because the driveshaft wasn't supposed to spin that fast.

I'll have to check out some wanderlodges and see if I like them.  I like stuff that is built like a tank  ;D

Nope, our Bird's tranny is an Allison HT-755 with retarder.

Regards,
Liz
 
Nope, our Bird's tranny is an Allison HT-755 with retarder.

you have a trans that is built like a tank then  ;D  they are in applications that see severe service..... for example garbage trucks.  in that application it see's constant stop and go driving and heavy loads so in your RV it should outlive anything.  make sure that the modulator gets checked often if it is a non-ATEC  controlled trans.  most HT-700 series transmissions in your application have air operated modulators and they can leak putting air pressure into the trans. this can cause the fluid to foam up. 
 
Allisonman I'm going to take you up on your offer. I'm looking to diag some 1000/2000 Allisons.
I've got a small tranny shop in Denver and have been seeing quite a few Allisons lately.
If I order the Allison Doc software for 1000/2000 and the Dearborn DPA4 PLUS USB kit, will I be good to go?
I'll put the software on a laptop with XP.
Thanks
Billy
 
Allisonman, have you ever seen an Allison swapped in place of a TH400 behind a 454 Chevy? If so what does it take to complete the swap? What trans would you use?
J
 
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