|
|
Posts: 6
| OK, good. No, no retarder in my system. By the way, what are your thoughts on a pac/exhaust brake in my installation. It's a 34' MH, 19,000lbs GVW, cummins 5.9 230 HP turbo, MD3060.
|
|
| |
|
Posts: 3
| dbarton291 - 9/12/2009 3:38 AM
Raye3k - 9/11/2009 2:32 AM
Has anyone experienced an Allison MT654 transmission jumping from 1st gear to second when going down hill?
Thanks
Ray
You bet. You need to check the RPM of the valve body by using the assembly number on the side of the trans and check that against the engine you have.
You may have a mismatch of transmission RPM cal vs engine RPM.
You may also have a weak, or the wrong, 1-2 shift signal valve spring. Or the engine is simply turning real fast going down that hill.
Thanks again.
Say the engine is turning real fast going down the hill, do you have an idea of what vehicle speed or engine rpm would cause a change from 1st to 2nd and then 2nd to 3rd? or what would be the top vehicle speeds possioble in 1st, 2nd and 3rd gears going down a hill without braking?
Thanks
Ray
|
|
| |
|
Posts: 257
 
| ratherbflyn - 10/7/2009 1:11 AM
OK, good. No, no retarder in my system. By the way, what are your thoughts on a pac/exhaust brake in my installation. It's a 34' MH, 19,000lbs GVW, cummins 5.9 230 HP turbo, MD3060.
Nothing wrong with a pac brake. They do require engine RPM to be efficient. You should interface one with the trans ECU. The Trans ECU can go to a preselect downshift schedule when the pac is active. It can preselect to either D4 or D2 to put you on a preslect downshift schedule which keeps engine RPMs up while the pac is on.
I think the installation would best done by a pro with access to Allison DOC and a knowledge of the available calibration options for the trans. Just putting the pac on without interfacing with the trans is a lot of money for not much braking. |
|
| |
|
Posts: 257
| Raye3k - 10/7/2009 1:26 AM
dbarton291 - 9/12/2009 3:38 AM
Raye3k - 9/11/2009 2:32 AM
Has anyone experienced an Allison MT654 transmission jumping from 1st gear to second when going down hill?
Thanks
Ray
You bet. You need to check the RPM of the valve body by using the assembly number on the side of the trans and check that against the engine you have.
You may have a mismatch of transmission RPM cal vs engine RPM.
You may also have a weak, or the wrong, 1-2 shift signal valve spring. Or the engine is simply turning real fast going down that hill.
Thanks again.
Say the engine is turning real fast going down the hill, do you have an idea of what vehicle speed or engine rpm would cause a change from 1st to 2nd and then 2nd to 3rd? or what would be the top vehicle speeds possioble in 1st, 2nd and 3rd gears going down a hill without braking?
Thanks
Ray
I know enough to tell you you'd be in an engine overspeed situation to force an upshift out of a preselected range.
As for top vehicle speeds, that depends on the vehicle. Can't really help you there. |
|
| |
|
Posts: 257
| Raye3k - 10/7/2009 1:26 AM
dbarton291 - 9/12/2009 3:38 AM
Raye3k - 9/11/2009 2:32 AM
Has anyone experienced an Allison MT654 transmission jumping from 1st gear to second when going down hill?
Thanks
Ray
You bet. You need to check the RPM of the valve body by using the assembly number on the side of the trans and check that against the engine you have.
You may have a mismatch of transmission RPM cal vs engine RPM.
You may also have a weak, or the wrong, 1-2 shift signal valve spring. Or the engine is simply turning real fast going down that hill.
Thanks again.
Say the engine is turning real fast going down the hill, do you have an idea of what vehicle speed or engine rpm would cause a change from 1st to 2nd and then 2nd to 3rd? or what would be the top vehicle speeds possioble in 1st, 2nd and 3rd gears going down a hill without braking?
Thanks
Ray
Why do you ask? Do you have a vehicle that does this? |
|
| |
|
Posts: 2
| briggsey1
Hi sorry to jump in but I am having a problem with my allison trans and would like some help. I know next to nothing about these things. Here is my problem I recently moved to a new park and I believe I inadvertently turned the enigine off with the trans in reverse. Now the engine will not turn over and when the key is turned on the shift pad does not light up, the check transmission light is on, and the warning bell is going off. We have tried disconnecting the chasis batteries for at least 1/2 hour. and have replaced the 10 amp fuses in the box next to the TCM. We have also replaced the 4 relays in that box. Also, one of the chasis batrteries was weak (reading 2.5 volts) so we replaced both batteries. We have battery power to the TCM and to the wiring connector under the shift pad. We have also checked the ground to the batteries. I probably need to mention that the rear wheels are off the ground. (We were in a temp space until our actual space was ready) Someone said that the trans is hung up and needs to be "jumped", I don't know what this means and if it's a possible answer could someone explain to me how it is done. If anyone has any thoughts, ideas, solutions, or SWAGs I would appreciate the help. Iapologize for jumping in but I couldn't figure another way to post this.
Thanks
briggsey1 |
|
| |
|
Posts: 257
| briggsey1 - 10/8/2009 2:52 PM
briggsey1
Hi sorry to jump in but I am having a problem with my allison trans and would like some help. I know next to nothing about these things. Here is my problem I recently moved to a new park and I believe I inadvertently turned the enigine off with the trans in reverse. Now the engine will not turn over and when the key is turned on the shift pad does not light up, the check transmission light is on, and the warning bell is going off. We have tried disconnecting the chasis batteries for at least 1/2 hour. and have replaced the 10 amp fuses in the box next to the TCM. We have also replaced the 4 relays in that box. Also, one of the chasis batrteries was weak (reading 2.5 volts) so we replaced both batteries. We have battery power to the TCM and to the wiring connector under the shift pad. We have also checked the ground to the batteries. I probably need to mention that the rear wheels are off the ground. (We were in a temp space until our actual space was ready) Someone said that the trans is hung up and needs to be "jumped", I don't know what this means and if it's a possible answer could someone explain to me how it is done. If anyone has any thoughts, ideas, solutions, or SWAGs I would appreciate the help. Iapologize for jumping in but I couldn't figure another way to post this.
Thanks
briggsey1
To the best of my knowledge, turning the key off in reverse by itself doesn't cause such a problem. When the power is turned off and the engine stops, the trans goes to neutral. When the ignition comes back on, the selector wakes up in neutral.
This is most likely not a problem with the trans hardware itself. This is a no-start problem and should be worked on as such, so it may involve trans wiring interface to the vehicle, the engine starter circuit, neutral start, etc.
Engine that can't turn over, shift pad not lighting up, and check trans light on indicates ignition power not getting to somewhere it belongs.
You said the ECU has power, make sure it has ground. Gotta then make sure the ignition switch and the selector are getting power, ignition switch is feeding power to the ignition input to the ECU, the ECU is grounding the neutral start signal to the neutral start relay and the starter solenoid is getting power.
If you're working on this yourself, I would highly recommend getting an Allison troubleshooting manual so you'll have at least the schematic for the trans interface to the vehicle. I believe they can still be ordered at www.allisontransmission.com, service, publications.
Edited by dbarton291 10/8/2009 9:39 PM
|
|
| |
|
Posts: 1
| hey guys. I have a 2002 duramax chevrolet. out of no where i have no speedo, and the truck shifts to neutral if i go about a slow crawl, about when the speedo would start to read. has anyone ever ran into this?! this is my daily driver so any help is appreciated. if you do have info, feel free to call my cell phone asap 314 503 7586. Thanks!
Randy |
|
| |
|
Posts: 11
| Hey dbarton291, or allisonman. I've been checking since I've had time lately about the switch from the MT643 to the MD3060. Williams DD in Columbus is in over their head, maybe. I spoke with the service rep and he didn't think it could be done, until I told him that there are folks on this site who have RV's running the same set up. I had a friend who runs a truck shop check with another service rep, and he indicated that they (Williams DD) don't have the tools to set up the transmission in the way I'm looking to do it. i.e. with a TPS. As the truck I'm pulling the tranny from has an electronic Cat in it, they seem to think that my donor transmission is communicating directly with the engine ecu for engine speed since it's an electronic engine. Doesn't the transmission pick up engine speed from a pickup on the input side of the tranny. Any way, I am assuming that what they are saying is, if I do get the tranny installed into the truck, they don't have any way of programming the transmission. Why, I haven't a clue. They suggested that I find another engine/tranny setup similar to what I am trying to do and get the serial number from that trans and ecu, then there is a chance they can get the appropriate information.
To anyone else out there who has an rv with a mechanical 8.3 cummins mated to an Allison MD3060, could I get the make and model of your RV. Also, it would be helpful if I knew who you either bought it from, or who you would take it to for service of the transmission, since Columbus, Ohio doen't have the capability to work on such a setup.
Help please.
Thanks in advance.
|
|
| |
|
Posts: 11
| Oh yea, the trans ecu is a WTEC II. I have confirmed that.
|
|
| |
|
Posts: 11
| And I just ordered a troubleshooting manual for this tranny yesterday. It is backordered for two weeks though.
I also just remembered, I checked with DD about buying a TPS, and they said there are many different ones all with different length cables. I didn't think there were enough variabales between the transmission and the throttle linkage on the injector pump to justify a lot of different cable lengths.
|
|
| |
|
Posts: 257
| downard1 - 11/12/2009 5:18 PM
And I just ordered a troubleshooting manual for this tranny yesterday. It is backordered for two weeks though.
I also just remembered, I checked with DD about buying a TPS, and they said there are many different ones all with different length cables. I didn't think there were enough variabales between the transmission and the throttle linkage on the injector pump to justify a lot of different cable lengths.
The TPS is chassis mounted. That's why the different lengths. These go in a lot of different configuration vehicles. You want the TPS body mounted ABOVE its connection to the engine. |
|
| |
|
Posts: 257
| downard1 - 11/12/2009 5:13 PM
Hey dbarton291, or allisonman. I've been checking since I've had time lately about the switch from the MT643 to the MD3060. Williams DD in Columbus is in over their head, maybe. I spoke with the service rep and he didn't think it could be done, until I told him that there are folks on this site who have RV's running the same set up. I had a friend who runs a truck shop check with another service rep, and he indicated that they (Williams DD) don't have the tools to set up the transmission in the way I'm looking to do it. i.e. with a TPS. As the truck I'm pulling the tranny from has an electronic Cat in it, they seem to think that my donor transmission is communicating directly with the engine ecu for engine speed since it's an electronic engine. Doesn't the transmission pick up engine speed from a pickup on the input side of the tranny. Any way, I am assuming that what they are saying is, if I do get the tranny installed into the truck, they don't have any way of programming the transmission. Why, I haven't a clue. They suggested that I find another engine/tranny setup similar to what I am trying to do and get the serial number from that trans and ecu, then there is a chance they can get the appropriate information.
To anyone else out there who has an rv with a mechanical 8.3 cummins mated to an Allison MD3060, could I get the make and model of your RV. Also, it would be helpful if I knew who you either bought it from, or who you would take it to for service of the transmission, since Columbus, Ohio doen't have the capability to work on such a setup.
Help please.
Thanks in advance.
The electronic engine is communicating directly with the transmission for throttle position, % torque and some other stuff.
You will need to change the trans ECU program to be for a mechanical engine.
The trans does read engine, turbine and output speed from its own sensors.
Edited by dbarton291 11/12/2009 6:46 PM
|
|
| |
|
Posts: 11
| Thanks for the input. I just got off the phone with Ron at Pacific Allison Detroit a couple hours ago, and he's going to work up a parts list for me for the hardware I'll need, and he's getting me a name and number of a guy in Idaho who can build a custom wiring harness that will be a simple plug in for the MD3060 and my Ford main harness. Let me just say it here, the folks in the great northwest are awesome. Going out of their way to help out. Here in Ohio, I'm treated like an idiot, and they haven't a clue as to what's going on.
Again, thanks to all who have been so helpful.
|
|
| |
Allison Transmission Questions
