Allison Transmission Tech Advice

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Dear Allisonman... I have a 2005 Allegro Bay (W22 chassis with 8.1 Vortec and Allison 1000 series tranny).  My transmission fluid cooler sprang a bad leak right at the lower driver's side of the radiator.  A local (Jacksonville, FL) Allison mechanic said he'd have to remove the radiator to repair the cooler, but suggested a friend of his who is a welder might be able to repair the leak while in the vehicle.  I am sure all the oil will have to be removed and the cooler flushed before a torch can be used, but I'm still afraid of possibility of fire.
I am wondering if I can just purchase a different (OEM) cooler and install it in front of the radiator?  If this seems to be a viable solution, can you recommend a model cooler to use...
Thanks very much in advance.
Tony Bean (w1svu)  or if possible email me at [email protected]
 
Tony,

Allisonman hasn't been around for several months, so he probably won't see your message.
 
hello    i have 1992 gulfstream motor home 38 ft with a Cummings 250 and mt643 Alison transmission      my problem is when i shift from neutral to reverse the engine dies within seconds . i was told something about a reverse relay  but i have not been able to find it or could i have something else to check out instead the transmission only 20 k on it and i just purchased it
 
I have a 2005 National RV Dolphin 32' motorhome with Less than 30,000 miles and with a GM 8.1 and an Allison Transmission.  I have had the neutral safety switch replaced and the new one failed with less than a hours driving time.  It appears that it stripped the nylon gears in the center drive/shift area.  That unit was replace with another new NSS and it also failed in no time flat.  Same situation, stripped nylon gears.  Is the mechanic installing it incorrectly or is there a different problem with the transmission causing this?

 
I don't have an answer for you, Landman222, and Allisonman hasn't logged in here for quite awhile. Is the work being done at a Workhorse shop or an Allison shop? Maybe time to try Allison?

Since the original failed as well as the replacements, my guess would be that there is something wrong elsewhere that is causing the problem, but I don't know enough to suggest where to look.
 
Gary and Landman222, I agree with Gary that there must be another problem causing the switch to fail. I would definitely take it to an Allison shop. YHes they normally charge a higher shop rate but they generally take less time to do a job and they are much more familiar with your transmission.
 
I have solved the riddle.  The mechanic has been installing the NSBU with the transmission in the Park position.  After much research I finally found a website with the detailed installation instructions for this NSBU switch.  It must be installed with the transmission in the Neutral Position.  This is why all of the replacements have failed so quickly.  I'm having another one installed hopefully correctly in two days.  That should solve the problem for me.  Hope this lesson for me, helps someone else out.  Happy Camping....
 
Landman, glad you found the problem. I have found Allison Transmissions to be very reliable over the years even though I just had one fail in my MH. Mine would go in reverse but when put in drive it felt like it was in 2 gears at once and would not move. Allison replaced with new unit and all seems well now.
 
I have a 2008 freightliner chassis (Tiffin Phaeton) with a 3000 series allison tran.  I have 23000 miles on the engine. When should I change Trans fluid. How expensive is it?
 
hunter41 said:
I have a 2008 freightliner chassis (Tiffin Phaeton) with a 3000 series allison tran.  I have 23000 miles on the engine. When should I change Trans fluid. How expensive is it?
Click to expand...


Allison recommends 100,000 miles or 48 months for general duty. We are light duty for that transmission.
 
Your 2008 has Transynd (TES 295 synthetic) fluid so a change will be pricey - probably $350-$500 depending on the shop. You will need two filters as well.

Allison says this for your 3000MH tranny with Transynd in a  motorhome:

Change fluid at 300,000 miles, 48 months or 6000 hours of use, which ever comes first. Change filters at 75,000 miles, 36 months or 3000 hours, whichever comes first.

Here is the Allison fluid change calculator web page:
http://www.allisontransmission.com/service/changeinterval/

You can probably extend the change interval if you have the synthetic tranny fluid tested - it typically is fine for several years if the filters are changed as specified. I'm at 8 years on mine and it recently tested fine for continued use. I had the filers changed again and will keep on trucking!
 
Hello all & especially Allisonman,

I'm new here...1st post.

A question for Allisonman. I aquired a used 1996 40' Newmar Kountrystar with a cummins and a MD3060 Allison trans. It has a Pacbrake engine brake that appears to work ok, but the Allison is programmed to drop down to 2nd gear when the Pacbrake is turned on....very annoying to have the trans jump from 6th to 2nd every time I take my foot off the gas. Can the trans be programmed to not downshift when the pacbrake is energised? I think it would work ok if I selected the downshift manually depending on the circumstance. I still need the trans to have convertor lockup when the engine brake is used. I realize that the efficiency of the pacbrake is reduced if the trans is not selected low enough.

Thanks in advance for any useful comments  :)
Chris
 
Allisonman hasn't been here for awhile, so may not answer.  The transmission doesn't immediately shift to 2nd gear when the Pac Brake (an exhaust brake, not an engine brake) is engaged, but the transmission preselects 2nd as the target gear.  It won't actually downshift to any lower gear than the engine RPMs will allow.  As the vehicle slows down, the transmission will progressively downshift until it reaches 2nd gear.  However, the ECM can be reprogrammed to preselect any gear, and some have chosen 4th as an alternative.  But I prefer letting the ECM do the work of choosing the proper gear for the speed and RPMs rather than have another item like manual shifting to think about.  The combination of Allison and engine ECMs is pretty smart :)
 
You also have to remember that the engine generates a lot more brake horsepower at higher revs, so the downshifting is important to the effectiveness of the brake.
 
Our exhaust brake came preprogrammed for 4th gear which did not help much slowing down for full stops. I didn't like the aggressiveness of 2nd gear so have it programmed for 3rd which has been a good compromise.
 
Thanks Bernie & Ned for your answers. Your both correct in my thinking, but I still would like the option of selecting the gear manually. I understand the process that the transmission uses when the pacbrake comes into play.

An issue that bugs me is for example, I'm in city traffic in drive (6th gear is selected) at about 45 MPH. Pacbrake is turned on. As long as my foot is on the pedal I'm in 6th. Take my foot off the gas and the trans immediately drops into 2nd with an abrupt increase in RPMs and a jerk of the coach. I would rather a higher gear and less of a result in the pacbrake's application. I guess the re-programming to select 4th would suffice in this instance, but I thought that if I'm getting a re-programming done anyway, why not ask for no auto-downshift, only the convertor lockup. I know what gear I should be in.

The only other alternative is for me to select a lower gear for city driving and leave the pacbrake off. I then have no benefit of the pacbrake helping the service brakes.

Thanks again,
Chris ;D
 
Just a added comment, I like the answer that Jeff gave with the idea of programming for 3rd. This might be what I'm after.

Thank you
 
Allisonman,

I just purchaced a chevy 2500HD with an Allison transmition.  I am wondering if there is a break in period for a brand new truck(transmision or engine)?  I read something in an owners manual for my old Suburban not to go over 50mph for the first X miles.  I forget exactly what it said and that was a gas engine.    Any advice would help. We bought this new truck to haul our 7000lb Keystone TT.

Thanks,
Bike Crazy
 
used2b said:
An issue that bugs me is for example, I'm in city traffic in drive (6th gear is selected) at about 45 MPH. Pacbrake is turned on. As long as my foot is on the pedal I'm in 6th. Take my foot off the gas and the trans immediately drops into 2nd with an abrupt increase in RPMs and a jerk of the coach. I would rather a higher gear and less of a result in the pacbrake's application. I guess the re-programming to select 4th would suffice in this instance, but I thought that if I'm getting a re-programming done anyway, why not ask for no auto-downshift, only the convertor lockup. I know what gear I should be in.
Click to expand...

Chris

I'm not sure what year your tranny is, but if there is only one gear display window you are not told what gear you are in, only which you are aiming for. Being in 6th gear at 45mph doesn't sound right, 4th or 5th is more likely. And like Ned indicated, it will probably downshift to 3rd first.
 
Hello, I recently purchased a 2004 Coachman 38D with an Allison HD3000 six speed. When I bought it the trans temp gauge was not hooked up, apparently from the factory. The dealership attempted to connect it via the engine control module but it still doesn't respond. I'd like to bypass the module altogether and install and aftermarket electric trans temp gauge. Where would the best place on the cast aluminum pan to install the sender? Could I replace one of the bolts on the pan with a sender or would it need to be removed and drilled?

Thanks

 
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