No Move with Allison & Cummins


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mikel

New Member
Hi from Germany,

I have a Spartan Chassis with 5,9 Cummins and a MD3060 Allison Transmission (Its a german RV called Rockwood Classic Royal, www.tsl-mobile.de). 3 Days ago I wanted to go on a short Holliday, started the Engine with no Problems, waited till the Airpressure was OK, put in the gear from Allison and.......nothing. My RV does not move at all. The Display says 6 and 1 as usual, and there is no peep out of the Transmissionpanel. Parkbrake is off, but no movement. The Engine runs good, the max RPM are 3000 rpm in neutral and 1700 when i have in the first gear, so there ist something happening in the transmission, but the RV is not moving at all!!! Oil Level is OK. There is only one Code in the Panel wich says D1 2 - 1 1 - 2, but this code is shown since 2 years.

Anybody knows why??? Anyone can help - PLEASE

THX
Mikel
 
G

Guest

Guest
RE: No Move with Allison & Cummins

are u for sure that the airbrakes ,, if u have them ,, are releasing??? air brakes work oposit of hydraulic brakes ,, on air brakes ,, the air holds them (off position) on hydraulic ,, the springs hold them in ,,, i would ck and make ,, for sure that they are releasing ,, and that goes for the park brake also ,, if this is the first time u have had this happen to u of course ,,, i know the guages and warning lights will show full air pressure ,, but they monitor the tanks ,, and somtimes u get a stuck valve ,, be it a pedal valve or a main axle ck valve ,, if u can jack up the coach and see if any wheels turn ,, with full air psi ,,,
u can also watch the brake system without jacking it up ,, but getting the wheels off the gorund is u'r best bet ,, let us know back on what u find :approve: :approve: ;) :)
Bty ,, JMO :)
 
T

TWX

New Member
Re: No Move with Allison & Cummins

Unless you've dropped your driveshaft, if the engine is running then the problem can't be any further forward than the torque converter. The starter actuates a starter ring gear located on either the torque converter or flex plate in most vehicles, and I assume that it does on the Cummins system too.

Typical automatic transmissions engage two of many internal systems at one time in order to create various gear ratios. Some transmissions use a combination of hydraulically controlled bands and clutches, in concert with a mechanical one-way clutch, other transmissions use only clutches. Either way, two given systems will engage first, replacement of one of those two with a different system will engage second, replacement with the other one will yield third, etc. Reverse is usually similar.

Most transmission cases have test ports where one can hook up test gauges to look at the pressure. If you have pressure but no function then something's probably mechanically broken or worn, if there's low pressure then an internal seal might have failed, and if there's NO pressure then the pump, torque converter, or flex plate might have failed.
 
M

mikel

New Member
Re: No Move with Allison & Cummins

Thx for the answers. Yes, my brakes do work on air pressure. Have not think about a broken Valve in the System - but - isn´t the Engine strong enough to move the RV altough the brakes are still on? No fats ride, but at least move at all? Guess so, but I am not sure. Next, I will Jack the Car to see if Wheels are turning at all.
@TWX ist will take me some time to understand your post, it is to technical for me, I do not even know what a Torque Converter is (is ist what we call "Differential?" the thing more or less equals turns of the Wheels (like Corners)? 4WD can lock them?
 
L

LEN

Senior Member
Re: No Move with Allison & Cummins

Quick test if the trans is working and the brakes are locked. At Idle go from N to D then to R you should feel and hear torque or a clunk as the trans goes from D to R and the differential slop is taken up. If not then the trans most likely has the problem.

LEN
 
G

Guest

Guest
Re: No Move with Allison & Cummins

Damn ,, Len ,, why didn't i think of that ;) :eek: :laugh: :laugh: :laugh:
 
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elkhartjim

Senior Member
RE: No Move with Allison & Cummins

I thought of it but since we have so many experts on this board....I ain't saying nothing.
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P

par

New Member
RE: No Move with Allison & Cummins

I had something like this last spring. One rear wheel brake shoe actually stuck, "rusted" to the drum. It had only sat for two months.
Easy fix, bring up air pressure, BLOCK the coach, putting it on the jacks might be a good idea. Slide under and look for a small gap between the brake pads and the drum. If you do see a gap all the way around the drums you've got a different problem. If the pad looks to be stuck grab a hammer and start tapping on the drum. It might take a while but it will pop loose. :blackeye:
 
T

TWX

New Member
Re: No Move with Allison & Cummins

Basically, a torque converter is a fluid power transfer device. A simple comparison would be two fans. Imagine two fans pointed right at each other, inches apart. Turn on one fan and the other fan is acted upon by the airflow. A torque converter has two impellers, one attached to the crankshaft of the engine, one attached to the input shaft of the transmission. As the engine turns, its attached fan forces transmission fluid through the other fan, forcing the other fan to spin, which forces the internal mechanisms to turn as well.

The differential is way at the back of the drivetrain. Basically, the engine turns the torque converter. The torque converter turns the input shaft of the transmission. The various gears, clutches, and bands inside of the transmission cause the input shaft of the transmission to turn the output shaft of the transmission. The output shaft turns the slip (front) yoke on the front of the driveshaft. The slip yoke transmits power into the main tube of the drive shaft and into the rear yoke. That rear yoke turns a pinion gear in the differential housing, and the pinion gear turns a ring gear within the housing. The ring gear forces a differential to act, which distributes power to the axles, which then turn the wheels.
 
S

Sjholt

New Member
RE: No Move with Allison & Cummins

Code 21-12 is a throttle position sensor code. If you cannot get it to go into gear, what is wrong is at your engine throttle arm there is another cable (our TPS) I would bet that it is not returning all the way. Does your tower blink when you put it in gear? If it does it is reading that you have your foot on the throttle even though you do not. Anything over 9% throttle will not allow the transmission to go into gear. Also if you idle higher that 900 rpm, it will flash and not go into gear. A simple fix if it is not returning would be to put a return spring on the cable to make sure it is coming back all the way.
 
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dbarton291

Senior Member
Re: No Move with Allison & Cummins

Sjholt has a good point. You need to see if the 1 on the display is blinking when you select drive. If it is, there is an inhibit preventing the transmission from attaining gear. The TPS, and engine idle being too high are a common culprits.

However, if the one is not blinking, that means the trans has attained first gear as requested.

If the Allison six speed sees the request for drive, and the transmission has an internal problem that keeps it from getting first gear, it will set a trouble code. What happens is the transmission controller expects turbine speed (the turbine in the torque converter) to go to zero when drive is selected and attained with the vehicle at a stop. If 21 12 is the only code in the unit, and the 1 is not blinking, the transmission should be getting gear okay, and there's something else preventing the vehicle from moving.

The fact that max engine speed you can attain in drive is only 1700 tells me the transmission is indeed in gear. Don't do that too long. A full throttle stall like that gets the transmission fluid very hot very quickly. 30 seconds max.

There are no bands in an Allison. It's all clutches. The only Allison that ever had a band is in the M60 tank, and it's a HUGE band.

Once you get this fixed, get that TPS fixed. You'll be getting better modulation of the shift points and shift quality. You'll also prevent future problems with the transmission.
 
M

mikel

New Member
Re: No Move with Allison & Cummins

Hi,
thx a lot to everybody replied on my Problem. I tried everything, and "par" was right.

I had the Parkbrake renewed a while ago (the Brake which Brakes when no air is in the System) and this Brake was kind like glued and was strong enough to hold the RV that strong, that it was not able to move at all!! I used a Hammer which released it, the RV allmost made a JUmp.

To everybody who might have the same Problem one day: "please secure the RV before hammer on the Brakes!!!" It might save youre life!!

Thx again to everyboda

Mikel
 
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dbarton291

Senior Member
Re: No Move with Allison & Cummins

mikel - 6/2/2008 2:25 PM

Hi,
thx a lot to everybody replied on my Problem. I tried everything, and "par" was right.

I had the Parkbrake renewed a while ago (the Brake which Brakes when no air is in the System) and this Brake was kind like glued and was strong enough to hold the RV that strong, that it was not able to move at all!! I used a Hammer which released it, the RV allmost made a JUmp.

To everybody who might have the same Problem one day: "please secure the RV before hammer on the Brakes!!!" It might save youre life!!

Thx again to everyboda

Mikel
Click to expand...

I'm glad the vehicle is fixed and you didn't get injured in the process!
 
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