Allison reprogram

[Robbbyr]

Originally Posted by Mark S

If the OEM has not provided any means of controlling this wire, then you will always be in economy mode.

That explains a few things. I do indeed have 2 shift schedules since I have "the switch". Now it remains to be seen whether it is feasible to add it to newer units.

[Dustdevil]

My 2003 Chevy truck with Duramax Allison options had both a "Tow/Haul" mode switch and an "O/D Lockout" switch. That was the Allison 1000 model. My current Seneca on the Kodiak chassis has the Allison 1000-MH, which is the same trans without the "Tow/Haul" switch. But it still has the "O/D" lockout switch. So, they took out the ability on this chassis to switch to tow-haul mode, and I assumed they simply defaulted to tow-haul permanently by leaving out the switch. It appears that on later Senecas on the M2 Freightliner chassis, they have eventually left out even the "O/D" lockout switch on the Allison 2500. I'd bet there are terminals for both of those switches on all these transmissions, and Jayco simply elected not to have them all wired when they specified the Kodiak or Freightliner chassis. If anything, I'd prefer the unit be in tow/haul mode all the time, since a motorhome always has a load. But my O/D lockout does come in rather handy when climbing or descending hills. The Allison 1000 only has 5 speeds including O/D. The O/D lockout works to keep it in 4th, and the shift lever works to keep it in 3rd or below.

I bet you all have terminals suitable for those switches somewhere on the transmission.

[Mark S]

Originally Posted by Robbbyr

That explains a few things. I do indeed have 2 shift schedules since I have "the switch". Now it remains to be seen whether it is feasible to add it to newer units.

I just got off the phone with Matt from Allison. He states that the "performance" program will raise the shift points by about 300 rpm, which is what I felt I needed. In lieu of an "OD' switch, this seems to be the solution.

I did follow up with the email question of can I add the OD switch and waiting for a response.

Obviously the better solution is to have the option with a switch, but other than a possible small loss in fuel economy when accelerating, do you see any downside to changing the tune? Matt felt that there will be a significant difference in the climbing ability. Seems like it would be like being in Tow-Haul all the time, which I think would be ok

[Mark S]

From Matt at Allison:

Mark,

The package included in your calibration does have Overdrive Disable as an option, but it is currently disabled. Your service outlet can enable it with DOC reprogramming. The function will at that point be controlled via wire 161, so there will need to be a switch or other means of controlling that wire.

The performance shift schedule would be more suited to a tow/haul-type of duty cycle than the original economy shift schedule, but the only difference between them is the shift speed; the performance shift schedule will have wide open throttle shift points about 300 rpm higher.

Thank you,
Matt Lazier
Calibration Support Service Engineer
O 317-242-2287 | M 248-640-9421

[Dustdevil]

I would think the reprogram is more like a default to Tow Haul, and that's fine. Economy only works for long flat days of driving, or a pickup truck that is not currently pulling a load. In the case of a motorhome, it always has a load, and is never as light as an empty pickup truck. Long term effect of the trans being always in economy mode likely have a greater chance of clutch slippage due to shifting at a lower RPM, which is closer to the torque converter lock-up RPM. Not likely on a new transmission, but as things wear a bit, might become a wear accelerator. Better that the shift points are higher in the RPM range to ensure firm lockup while climbing. These transmissions were designed to be customized to the power curve of the engine so they can be matched for performance in either a gasoline or a diesel application. The two engine types develop peak torque at very different RPM, and it's always best for the trans/torque converter to be in lockup when the engine is producing high torque numbers. Your reprogram makes this far more likely when climbing hills with a load. The older models left it up to the driver with the switch for Tow/Haul mode in the pickup trucks.

Locking out Overdrive is a very handy tool to help the trans operate further into lockup if you prefer to do that. I like mine very much. I would think this would be an excellent mod for newer units without the O/D cancel switch to add one.

[WaltW]

I understood that the 2500MH was really a 5 spd with an OD added for MHs. With 5th also being an OD from the original trans before modification explains why the stupid trans won't upshift to 5th with the OD switch off. I find that I am frequently having to switch between OD on and OD off. If tranny would shift to 5th with OD off frequent OD switching would not be necessary.

[Dustdevil]

Originally Posted by WaltW

I understood that the 2500MH was really a 5 spd with an OD added for MHs. With 5th also being an OD from the original trans before modification explains why the stupid trans won't upshift to 5th with the OD switch off. I find that I am frequently having to switch between OD on and OD off. If tranny would shift to 5th with OD off frequent OD switching would not be necessary.

I can see where that might be annoying. Such as on a very slight upgrade or into a moderate headwind, trans might try to hunt between 5th and 6th a lot, but if you lock out of O/D, 4th gear is way too low. If the reprogram mod raises RPM for upshift for 5th and 6th as well, that might displace the shift point high enough that it can remain in 5th on those particular stretches without trying to drop into 6th.

[SloPoke]

Originally Posted by Dustdevil

I can see where that might be annoying. Such as on a very slight upgrade or into a moderate headwind, trans might try to hunt between 5th and 6th a lot, but if you lock out of O/D, 4th gear is way too low. If the reprogram mod raises RPM for upshift for 5th and 6th as well, that might displace the shift point high enough that it can remain in 5th on those particular stretches without trying to drop into 6th.

I see your point... Based on our experience last week coming back from a long trip last weekend.

We were descending US-191 as we were coming into Vernal UT. It is a long set of 10 tight switchbacks at 8% for over 5 miles. Posted Truck speed is 30MPH for anything over 10k-GVW. This is now the steepest descent we have taken, and we were at 32,200 Combined Weight.

Before we got to the steepest part - where the Speed Limit was 30, We had to force the Trans into OD-Off to keep the downhill exhaust brake working on speed. Initially the trans wanted to stay in 6th with the Exhaust brake - and that did not keep our downhill speed controlled... Forcing it out of OD helped keep our speeds in the 50mph range.

When we started down the steepest section, had to manually shift down into 4 and then to 3 to keep our speed at 30 w/o using the service brakes.

Overall, it works well

[RyRoRyan]

Originally Posted by SloPoke

I see your point... Based on our experience last week coming back from a long trip last weekend.

We were descending US-191 as we were coming into Vernal UT. It is a long set of 10 tight switchbacks at 8% for over 5 miles. Posted Truck speed is 30MPH for anything over 10k-GVW. This is now the steepest descent we have taken, and we were at 32,200 Combined Weight.

Before we got to the steepest part - where the Speed Limit was 30, We had to force the Trans into OD-Off to keep the downhill exhaust brake working on speed. Initially the trans wanted to stay in 6th with the Exhaust brake - and that did not keep our downhill speed controlled... Forcing it out of OD helped keep our speeds in the 50mph range.

When we started down the steepest section, had to manually shift down into 4 and then to 3 to keep our speed at 30 w/o using the service brakes.

Overall, it works well

Can you explain more on this. I go down 550 from Silverton to Durango CO and it is pretty much the same setup, 8% with many switches. I use the exhaust brake, but dont do much with the trans as it seems to upshift to 4 automatically, but does not really upshift to 3. For me it seems that going anything over say 5% grade with my exhaust brake on, my speed still increases...and I am right around your weight. I am having to tap the service brakes constantly to keep it under 40. The RPM's get to around 2500 and that is where I get nervous. I dont want to overrev the engine by forcing the trans in a certain gear. I guess what I am asking you and the others reading this, what RPM's are you comfortable with using your exhaust brake. I know that braking HP goes up as the RPM's go up...maybe I am just not allowing it to go high enough. When I see 2550 RPM's I tap the service brakes to slow it down from about 42 or so to back down to 30-35ish. I cant recall if it is 2nd or 3rd that will max out around the early 30 MPH's, but in any case, should I force it into that gear and let the RPM's climb? If so, where is the redline that I should not allow the engine to go past if it still cant hold the speed?

On a side note, I have an active website request into PacBrake to see if their LoadLeash product will work on our trucks. It appears the P55005 product will work on commercial trucks...I am just trying to get confirmation, because their install guides mostly deal with ODBII connections for the RAM trucks, but we dont have that so this is why I am asking.

[Dustdevil]

Originally Posted by SloPoke

I see your point... Based on our experience last week coming back from a long trip last weekend.

We were descending US-191 as we were coming into Vernal UT. It is a long set of 10 tight switchbacks at 8% for over 5 miles. Posted Truck speed is 30MPH for anything over 10k-GVW. This is now the steepest descent we have taken, and we were at 32,200 Combined Weight.

Before we got to the steepest part - where the Speed Limit was 30, We had to force the Trans into OD-Off to keep the downhill exhaust brake working on speed. Initially the trans wanted to stay in 6th with the Exhaust brake - and that did not keep our downhill speed controlled... Forcing it out of OD helped keep our speeds in the 50mph range.

When we started down the steepest section, had to manually shift down into 4 and then to 3 to keep our speed at 30 w/o using the service brakes.

Overall, it works well

My Allison is only a 5 speed (4 + OD). So, although ratios are probably a bit different, they behave similarly. My saving grace is that I only have one OD. So, when I lock out, I am only one gear down from top gear OD, not two. So, on downhills, I can let it run in 5th, or lock out OD for 4th, or manually downshift to 3rd, 2nd, or 1st. A bit more complicated for your 6 speed, as locking out OD takes you from 6th all the way down to 4th. Although a step on the brake pedal ought to drop from 6th to 5th until speed picks up again. On steep slow downhills, I just keep it in the highest gear that will allow me to avoid continually mashing the service brakes, and will hold its speed on the exh brake. Even if it's a bit slow, it keeps the brakes cool for any time I may need them badly.

On uphills, I often start uphill in OD, and as soon as the trans automatically kicks out of OD, I lock it out and keep it out until the grade eases near the top. I'll drop down manually one gear at a time to keep the ability to run the engine in its peak Hp range without mashing the throttle more than about 30 seconds continuous.

My Duramax seems comfortable up to about 3200 rpm. I try to keep it under 3000. Don't know about the Cummins or its redline. When I climb, I usually choose the gear that will maintain speed at 2500-2600 rpm.

Oh, and I'm only sporting somewhere around 24,500 GCW with the Jeep in tow.

[Mark S]

I have an appointment at Premier Truck Sales and Service in Knoxville Tennessee on September 22 to have the transmission reprogramed. I will be able to provide feedback after that.

[RVermont]

Mark
Are you putting in the od switch or just getting the new set points installed.

Hope your family and home safely weather the storm this weekend.


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[Mark S]

Originally Posted by RVermont

Mark
Are you putting in the od switch or just getting the new set points installed.

Hope your family and home safely weather the storm this weekend.


Sent from my iPhone using Tapatalk

I am going to start with the reprogram only. I will be in the Smoky Mountains so that should be a good test. If I determine I need to add the OD lockout I will do that after I get home.

I figure the program will not take too much time as we will be waiting for it. On a plus note, the said they have electric receptacles and I can stay on their lot the night before.

I'll keep you posted.

And yes, thanks for the well wishes. My son is will be on duty either during or right after the storm. So far there seems to be no good projections

[Wandermuch]

Originally Posted by ready2retire&drive

I was speaking to my Allison service department and told them I pull a trailer behind my unit about 80% of the time. He suggested I contact Allison engineering and see if they would recommend a program which would pull better and not lug engine as much, After they talked to the Cummins engineers, this was the response, they were pretty good and quick with some suggestion's which may help me.
Gord:
These were the three options that were suggested to me:
·******* Variable – same WOT shift points you have now, but lower part-throttle shift points
·******* SB – same WOT shift points you have now, but part-throttle shift points that are lower than Variable
·******* SA – same WOT shift points you have now, but part-throttle shift points that are lower than SB – this is potentially the highest economy option

Variable is going to lug the engine the least. I went ahead and made a calibration ,with that schedule in case you want to try it.
Matt Lazier
Calibration Support Service Engineer

I am anxious to try this, will take it in after I get it back from RV dealer (having some warranty work performed). Anything to help the unit work easier and keep it healthier. Will update after next trip, hope this helps, gord

So how is the reprogramming done and by whom? Mine is a real dog and can't even get out of its own way on hills. Like someone else said, if you can keep it wound up to 65 or 70 MPH, you're in the power band and it will pull pretty good. Should have had more HP built in in the first place. Just another case of Jayco shoving them out the door and letting the customer sort things out.

[SloPoke]

Originally Posted by RyRoRyan

Can you explain more on this. I go down 550 from Silverton to Durango CO and it is pretty much the same setup, 8% with many switches. I use the exhaust brake, but dont do much with the trans as it seems to upshift to 4 automatically, but does not really upshift to 3. For me it seems that going anything over say 5% grade with my exhaust brake on, my speed still increases...and I am right around your weight. I am having to tap the service brakes constantly to keep it under 40. The RPM's get to around 2500 and that is where I get nervous. I dont want to overrev the engine by forcing the trans in a certain gear. I guess what I am asking you and the others reading this, what RPM's are you comfortable with using your exhaust brake. I know that braking HP goes up as the RPM's go up...maybe I am just not allowing it to go high enough. When I see 2550 RPM's I tap the service brakes to slow it down from about 42 or so to back down to 30-35ish. I cant recall if it is 2nd or 3rd that will max out around the early 30 MPH's, but in any case, should I force it into that gear and let the RPM's climb? If so, where is the redline that I should not allow the engine to go past if it still cant hold the speed?
.

I had to go out and look at the shifter again... and understand your question now!

I remember shutting down the overdrive (in D) and still needing to slow down. and dropped the trans shifter out of D (now into 3 (instead of the previous post as 4)) and we continued our descent into the switchbacks.

I think you are correct - that I used the service brakes and brought our speed down into the 30's and dropped into 2 (instead of 3 as the prior post) to maintain that speed. Once we were at a stable and sustainable speed at 30, I did notice that we were running below 2500, but when it shifted and we were dropping speed into the 30's it was at about 2700.

All this was going on pretty fast... we were heavy and I have been down this grade a few times before, but not anywhere near this weight. I wanted to get the Exhaust brake to keep our downhill speed constant **without having to use the service brakes at all** and we accomplished it.

NOTE: The trailer has Hydraulic Surge Brakes, not Electric Brakes - that also may have contributed some to the equation too. ( We checked them at the bottom of the grade in Vernal and they were not excessively hot)

[ready2retire&drive]

Originally Posted by Wandermuch

So how is the reprogramming done and by whom? Mine is a real dog and can't even get out of its own way on hills. Like someone else said, if you can keep it wound up to 65 or 70 MPH, you're in the power band and it will pull pretty good. Should have had more HP built in in the first place. Just another case of Jayco shoving them out the door and letting the customer sort things out.

I was hoping to get mine back last week but the main glide pad for the front slide is late due to shipping so maybe Wednesday. Then I will take mine to Wajac's as they service the Allison transmission there. Once back from there will take the dash out to install the air/electric horn switch,fog light switch, radio power to a switch (coach/house batt) so radio does not come on every time I open the side door. I found some electric/air solonoids and an electric manual air dump switch I want to install, will make leveling the unit easier. Once I have the set up working will post pictures and part numbers. I will duplicate trip with trailer at the end of the month so am interested in the difference after the reprogram

[Mark S]

I am having my transmission reprogrammed on September 22 in Knoxville, Tn. I will provide feedback after that.

[ready2retire&drive]

Originally Posted by RVermont

Makes sense that they produce a standard unit and then just use programming to control functionality. I believe your unit has the overdrive switch which has been removed. It will be interesting to hear back from Mark and Gord on the response from Allison.


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I just got back from road test after reprogram. I did this drive without the trailer but am excited for my next trip. After picking up unit from rv dealer (Finally) did some test's. From a dead stop pedal to the metal take offs my first shift point was at about 2450 rpm after that all the other shifts averaged around 2150 plus or minus 50 rpm. While driving anything over 35mph while cruising and stepping on throttle, acceleration was basically nil just waiting for unit to wind up to speed. After reprogram from a dead stop pedal to the floor take offs shift rpm points did not change, BUT when driving at any speed cruising between 35 mph and 60mph every time I hit the throttle the rpm jumped 300 rpm on average and the vehicle accelerated. It almost feels like a small kick down, but I believe maybe it come's out of torque convertor lock up???. So at 60mph, 1600 rpm cruising speed mash the pedal and it actually accelerates. He also turned LBSS to low from medium? Will be making a pull with it on the 27th, fully loaded trailer and loaded up for a week of boon docking through the Rockies. Will report after that weekend on how it works under full load. I then asked my Allison tech is there any thing I can do for maintenance at this time or is required 6548 mile on unit. He asked if I changed the spin on filter (Part #AL29539579) as most operators do not know or have been informed it needs to be change at the 5000 mile mark the first time. I bought the filter and oil and he said make sure you put the magnet back on the top off the new filter as when they see these back about 70% of them do not have then in any more. He said clean it put it back on top of the filter fill the filter up and spin it back on. So after all that onto the rear air bag dump solenoid's and switch, once it's all together and working will send pic's and part numbers, gord

[RVermont]

Thanks for a great report and all the research you have done on this. Can you provide a ballpark cost on the reprogram.




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[ready2retire&drive]

Yup looking at my invoice they charged a half an hours labour plus shop supplies and enviro fees plus taxes total all in 104.89 Canadian . I feel this is probably the best 105.00 bucks I have spent so far on this unit. Bring on the hills !!!