Allison Transmission Tech Advice

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Allisonman:

10 months ago  I had our MH3000 series flushed and refilled at Freightliner as part of an M-3 service check at 100,000 miles. Freightliner replaced the Transynd that I have used at all service intervals for the past 90,000 miles with an Exxon equivalent.

My tranny temps have gone from running 190 degrees on a 75-80 degree day (while the engine coolant is cycling between 195-201 degrees) to now running 196 degrees with the same engine coolant temps.

My concern is this: When I pull off the interstate or slow down coming into an urban area the tranny instantly goes to 200 degrees and will be up to 206 within a couple of miles of city driving. If I start pulling a grade in 90 degree weather and down shift to 4th or 5th to keep the engine (Cat 3126E) up at 2000 RPMs the tranny goes over 200 degrees and will reach 206-208 in a couple of miles of pulling. As the tranny builds heat it takes several miles to get it to cool back down.

If the tranny gets up to those temps the engine temp will also start going higher than it used to do as the fan fights the increased temp buildup until the fan is running continuously and I have to back off another gear or two to cool things down. (Until I had the fluid changed this had never happened; engine temps always were higher than the tranny and were the controlling issue for climbing grades.

I have a side fan radiator that I cleaned last fall and looked clean. Just in case I spent a couple of hours last week with simple green making sure it was clean but it did not affect the temps. My gut feeling is there is something restricting the fluid flow through the radiator and will probably replace the filters again to make sure the new ones aren't the problem.

No codes and fluid level is staying normal.

Any other suggestions?
Click to expand...

        when you say they "flushed" your trans do you mean just draining out the sump or did they hook up a machine to your cooler lines?  if they removed the cooler lines and flushed out your trans then its possible that the lines might be on the wrong ports. if installed backwards the trans temp. will be higher.  the trans fluid through the cooler should flow opposite of engine coolant flow.  the line marked "to cooler" should go to the port in the radiator closest the lower radiator hose.  the trans. is marked by the ports to inspect this "to" and "from" cooler.  the cooler lines can go to the front of the oil pan (control module) in deep sump equipped transmissions or to the back of the trans main case.    hopefully your lines are out in the open and easy to inspect this  ;D    was the Exxon fluid they installed a synthetic fluid?    if it was Exxon brand dextronVI then it is not compatible with the seals in your year of trans if built before 2008.  the seals can harden  in the earlier Allisons using dextronVI and can crack and leak.  if I remember correctly I think Allison removed dextronVI from an approved fluid for this reason.  did they install the genuine Allison high capacity filters?  the Allison filters flow a lot better that the aftermarket ones.                                another possibility is your lockup clutch is not applying and the convertor is building a lot of heat.  lockup should apply right after 2nd gear and it usually feels like another shift.  the only way to positively check for this is to have a dealer monitor it using a laptop. 
   
 
Hello all... Allisonman or anyone that can assist I would be grateful!

Getting these 2 error codes and I havent even moved the RV, still has park brakes engaged..
3060-P with WTEC-II Controller. The ECU and keypad are one piece mounted in the dash, not two seperate units.

I get the N N and then select 1st and 5 secs later get the beep, goes into limp mode and I get a 2511. D2 shows me 2216. D3-5 are empty.

I clear the codes get the N N then select reverse and it will sit there forever and never toss a code until i put it back in drive.

Additionally, if I turn the key off the keypad stays on. If I physically disconnect it's negative wire and reconnect it will stay off until I turn the key on again.

Allison manual says 2511 is the output speed sensor @ 0 in 1st. The 2216 simply says OUTPUT SENSOR. I know where the one is on the transmission right near the output shaft, but is there another sensor for the 2216 code?

Allison manual says that the ECU is always on and is triggered by IGN.. however, the keypad will stay on as long it the output sensor senses the vehicle is in motion. Im thinking that whatever sensor is related to 2216 might be bad and the ECU always thinks that there is forward motion, thus making sense that it would toss a 2511 that it's not seeing any output from that sensor. Any ideas on the location of the other sensor? Any ideas on ohms I should be seeing from it or the other one should i find it.

Thanks in advance.
 
UPDATE:

At the ECU connectors I pinned out B5-B14, B6-B15 and B7-B16 and came up with 304-308 ohms across each pair which verifies that the sensors in each of the 3 positions in the trans are reading correctly. Sending the ECU to John in Texas.. he feels that the 5v powersupply is bad or defective and not sending voltage to the sensors properly. Will keep posted.

 
It's late for me, so excuse the typos. --but I'm buying in Sault Ste. Marie a '94 Itaska Suncruiser with a 5.9L Cummins without an exhaust brake. I am adding one for the mountains of the west where I live. It has been difficult to find a Cummins dealer in the Springfield IL area to install as they don't have a way to read the codes on that older engine. Cummins Central Power in DesMoines can install the brake and may require new valve lifters. The Allison is the 6 speed MD3060? push button which I understand has to be reprogrammed after the brake is installed. ?How long and how big a job will that be?

This is my first diesel but I've many years in gas RVs --isn't that like staying in a Holiday In Express last night? 
Click to expand...

        the Allison ECU might not have to have an entirely new calibration loaded into it.  the feature may only need to be turned on by the Allison dealer.  an entirely new calibration takes about a half an hour to install,  turning on the feature takes about 5 minutes.  the computer work is the easy part, running the wires from the exhaust brake switch to the Allison computer will be the time consuming part.  the time it takes depends on how far away the trans ECU is from the switch and how difficult it is to get to it. 
 
Allisonman,

Here is an earlier post from me regarding a anomaly with the transmission.
I have a 2005 Itasca Suncruiser 37B. It is on a W22 Chassis.I have an intermittent problem. The previous owner had the same problem and had it at a Workhorse service center (Cummins- Bridgeway, Novi Michigan) and they were not able to diagnose the problem.

The problem has occurred mostly when I start the engine in the morning and take a short ride to the gas station. When I fill the tank and leave the gas station the problem occurs. Normally when I am in cruise control running at 62MPH the RPM's are about 2200 RPM's and holding steady(unless I hit a rise in the pavement it downshifts and maintains a steady 3000 RPM's, or a steeper hill downshifting and maintaining a steady 4000 RPM's). The problem has occurred 4 times this year and specifically when I use the cruise control. At 62 MPH the RPM's go to 2200-2600 and do not remain steady (The RPM needle drifts up and down). On a hill it will down shift to about 3600 RPM's and at 4500 RPM's on a steeper hill. If I pull off the road and turn off the engine (for a couple minutes) the shift RPM's go back to the normal steady 2200 RPM's when on cruise control. When I came home from the last trip we unloaded the coach and when I left to go back to the storage lot, RPM's again went off what I consider as normal when I am using the cruise control.

I had the coach in to the shop that does my service for me and here is what they found. I took it in to have the fuel and air filter changed, and oh by the way could you check out the ABS system as the ABS light is on all the time now. The shop owner (Dennis) used the scan gauge to clear the faults and then drove the coach with the scan gauge attached. The fault codes indicated a fault with the right rear sensor (the sensor had been replaced by the folks at Cummins Bridgeway).Dennis got under the coach on his creeper and first check the ABS sensor on the right rear wheel. It was spot on with the clearances as it should be. He then traced the wiring all the way to the connection block that (I think) is located on the outside under the passenger seat somewhere. He found the block had come loose and one of the clips was there but was loose. He reconnected the block and the loose clip and drove the coach with the scan gauge connected. The result was no more fault codes.
I also had an issue with the fuel gauge not reading until I had driven the coach for approx. 7 miles. When I picked up the coach there was no more ABS light and the fuel gauge was reading as it was meant to. The other thing was that there is no more eratic on occasion engine RPMs.

The connection block, so it seems, has solved my problems. If I have one complaint it would be that I paid the Workhorse people to solve my ABS problem and the previous owner had taken the coach to the workhorse people to solve the eratic RPM problem with the transmission. The result was that the problem was not solved and a bill was rendered for work not properly done. 
 
The connection block, so it seems, has solved my problems. If I have one complaint it would be that I paid the Workhorse people to solve my ABS problem and the previous owner had taken the coach to the workhorse people to solve the eratic RPM problem with the transmission. The result was that the problem was not solved and a bill was rendered for work not properly done. 
Click to expand...
There are technicians who replace parts based upon a code and there are technicians that understand the circuits and make sure the circuit is good before replacing parts and then confirm that whatever was done actully repaired the problem. It is hard to find good techs who have spent the time educating themselves on all aspects of the systems.




Edit: Moderator fixed missing quote tag
 
ECU UPDATE: ECU tested fine. Chased down the 3 twisted pairs to each of the sensors, no cuts, no nicks, connectors all in good shape, no black wire disease on them, all ohm 304-310 ohms, nothing is shorted to ground.. we're miffed at this point... but something must be sending noise down the line to one or more of these sensors, darned if i can find it... any other suggestions would be welcomed at this point.
 
Hello all... Allisonman or anyone that can assist I would be grateful!

Getting these 2 error codes and I havent even moved the RV, still has park brakes engaged..
3060-P with WTEC-II Controller. The ECU and keypad are one piece mounted in the dash, not two seperate units.

I get the N N and then select 1st and 5 secs later get the beep, goes into limp mode and I get a 2511. D2 shows me 2216. D3-5 are empty.

I clear the codes get the N N then select reverse and it will sit there forever and never toss a code until i put it back in drive.

Additionally, if I turn the key off the keypad stays on. If I physically disconnect it's negative wire and reconnect it will stay off until I turn the key on again.

Allison manual says 2511 is the output speed sensor @ 0 in 1st. The 2216 simply says OUTPUT SENSOR. I know where the one is on the transmission right near the output shaft, but is there another sensor for the 2216 code?

Allison manual says that the ECU is always on and is triggered by IGN.. however, the keypad will stay on as long it the output sensor senses the vehicle is in motion. Im thinking that whatever sensor is related to 2216 might be bad and the ECU always thinks that there is forward motion, thus making sense that it would toss a 2511 that it's not seeing any output from that sensor. Any ideas on the location of the other sensor? Any ideas on ohms I should be seeing from it or the other one should i find it.

Thanks in advance.
Click to expand...

code 22-16 means the output speed sensor is bad or the wires going to it are rubbed through and are shorting out. this code just relates to the output speed sensor circuit.  since you ohms tested the circuit from the ECU connector to the output speed sensor and got a reading of around 300 ohms then I would bet there is either rubbed through wires or the terminals in the sensor's connector are corroded.  the 25-11 code should only set if the ECU see's turbine speed and no output speed in 1st range. most of the time when I run into this 25-11 code there is usually problems inside the trans like a mechanically stuck solenoid for example. a stuck solenoid will not cause a solenoid code because the solenoids resistance is at the proper level.  the stuck solenoid won't allow its controlled clutch to apply and you will get codes related to speed sensors or gear ratio errors.  solenoids usually stick when the trans cooler is leaking coolant into the trans fluid.  from the problems your describing, I would take the coach to an Allison dealer so they can look at the readings with their computer and make a determination as to whether its an electrical problem or a mechanical problem.                            the other problem of the ECU not turning off unless the grounds are disconnected is something I have never run into.  that is a very odd problem.  I would check the ignition power supply at the ECU's black connector  (B-12) and see if it is turning off when you cycle the key off. usually when a WTEC-2 ECU fails they just go blank or the display starts getting very dim. 
 
Posted by: codgerbill
? on: August 06, 2011, 08:08:56 AM ?

    Insert Quote


Allisonman,

Here is an earlier post from me regarding a anomaly with the transmission.
I have a 2005 Itasca Suncruiser 37B. It is on a W22 Chassis.I have an intermittent problem. The previous owner had the same problem and had it at a Workhorse service center (Cummins- Bridgeway, Novi Michigan) and they were not able to diagnose the problem.

The problem has occurred mostly when I start the engine in the morning and take a short ride to the gas station. When I fill the tank and leave the gas station the problem occurs. Normally when I am in cruise control running at 62MPH the RPM's are about 2200 RPM's and holding steady(unless I hit a rise in the pavement it downshifts and maintains a steady 3000 RPM's, or a steeper hill downshifting and maintaining a steady 4000 RPM's). The problem has occurred 4 times this year and specifically when I use the cruise control. At 62 MPH the RPM's go to 2200-2600 and do not remain steady (The RPM needle drifts up and down). On a hill it will down shift to about 3600 RPM's and at 4500 RPM's on a steeper hill. If I pull off the road and turn off the engine (for a couple minutes) the shift RPM's go back to the normal steady 2200 RPM's when on cruise control. When I came home from the last trip we unloaded the coach and when I left to go back to the storage lot, RPM's again went off what I consider as normal when I am using the cruise control.

I had the coach in to the shop that does my service for me and here is what they found. I took it in to have the fuel and air filter changed, and oh by the way could you check out the ABS system as the ABS light is on all the time now. The shop owner (Dennis) used the scan gauge to clear the faults and then drove the coach with the scan gauge attached. The fault codes indicated a fault with the right rear sensor (the sensor had been replaced by the folks at Cummins Bridgeway).Dennis got under the coach on his creeper and first check the ABS sensor on the right rear wheel. It was spot on with the clearances as it should be. He then traced the wiring all the way to the connection block that (I think) is located on the outside under the passenger seat somewhere. He found the block had come loose and one of the clips was there but was loose. He reconnected the block and the loose clip and drove the coach with the scan gauge connected. The result was no more fault codes.
I also had an issue with the fuel gauge not reading until I had driven the coach for approx. 7 miles. When I picked up the coach there was no more ABS light and the fuel gauge was reading as it was meant to. The other thing was that there is no more eratic on occasion engine RPMs.

The connection block, so it seems, has solved my problems. If I have one complaint it would be that I paid the Workhorse people to solve my ABS problem and the previous owner had taken the coach to the workhorse people to solve the eratic RPM problem with the transmission. The result was that the problem was not solved and a bill was rendered for work not properly done.
Click to expand...

    good to hear its fixed.  did you see that I responded to your original post about this?  I figured it was probably ABS related, its a pretty common issue when the ABS is acting up it will cause the lockup clutch to turn off and on randomly.
 
Allisonman

I have a question on the difference between an Allison 1000 and a 2350 transmission.

The reason for the question is I have a motorhome on 2006 Chevy C5500 chassis with an  1000 5 speed transmission.  This chassis is rated at 26,000 lb CGVW rating. I know of another motorhome that is identical except that it has a 2350 transmission and it has a CGVW rating of 30,000 lb.

The two vehicles have the same engine, rear ends, springs, drive shafts and all else is the same except for the transmission.

What in the transmission will allow a 4,000 lb increase in towing capability? The base GVW for both of these vehicles is 22,000 lb.

Thanks for your insight.
 
Hi Allisonman,
Boy do I have a good one.
I have a International 4200 Chassis, a VT365 IH engine and a M2000 Allison Tranny all in a Gulfstream Super Nova (Super C).

The coach runs well when first started. After a while (20 Minutes) it starts losing power. Eventually it starts shifting down and I end up going 20mph and at 3000 rpm.

When I stop and shut down the engine followed by immediate restart the coach runs fine for another twenty minutes. I also noticed that at times when I slow down from 65 or 70 to 50 or 60 I start losing power and end up with the same situation.

No codes show for the engine or tranny.  No check engine light.

Any ideas. My shop and I are going nuts.

Thanks,

Don
 
Realkiler, Sounds like a fuel problem, have you checked your filters lately.
 
Realkiller, We had the same problem with one of our Armored Trucks while I was with Wells Fargo. It was easier to diagnose. as it was a stick shift. It was a pinhole in the fuel line.
 
Hello Allisonman,
I have an MD3060 that,when I parked it,all was good.I went to the coach to start  it and got a few flashes N N then the display went blank and coach was a no crank.What I found was if you try to start when the N N flash is happening,it will start but not engage in any gear.
Please Help,
Dave.
 
Try checking your fuel pressure, preferably, watching it when it starts losing power. We had a Lincoln acting the same way. Turned out to be sand in the fuel tank.
 
I hoe someone can help me with this.

I have an MD 3060 attached to a cummins 8.3 in my motorhome.
I was wondering if there is some saftey circuit for going into reverse because I can shift into drive just fine but when I push the R for reverse I feel a slight tug and the RPMs go down for a couple of seconds and then the display goes from R N to blank N and I never get the revese beeping from the rear. I then have to shut down the engine to clear the select panel because once it  does this, none of the buttons will respond until I shut the engine down and turn the ignition back on again, the it goes back to N  N.

Appreciate any helpI can get.

Doug
 
hi  allisonman i have a 06 c5500 chassis with a i think 1000 in it ser # 6310590778 i have gm tech 2 and access to gm dealer world can the tcm be reflashed to unlock 6 sp. gear on this or am i out of luck to make a 6 sp with out a valve body change if i can reflash do you know the calibration code thanks dan
 
Hello Allisonman,
I'm new here and I have a question about an Allison 1000 trany.
It was recently rebuild and the problem I have is after the trany was installed it will go in to reverse and neutral but will not go in to drive!
Any help willl be appreciated.
 
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