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Topic: Allison Transmission Fault Codes, Retarder not working (Read 5303 times) previous topic - next topic

Re: Allison Transmission Fault Codes, Retarder not working

Reply #25 –
I don't drive the toad that much, but had to take the new computer from Payson to Camp Verde for a hot rodding. There is a very steep grade down to the valley and I reached over and instinctively REACHED FOR THE RETARDER!! Whoops, wrong rig.  :facepalm:
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: Allison Transmission Fault Codes, Retarder not working

Reply #26 –
Quote from: Realmccoy –
Drove home the 160 miles from Longview to McKinney late this afternoon into the night. This was my first experience with a working retarder. I like. The retarder is oriented so that pulling it back is whoa, forward is go. No brake light activation with joystick. Replacement of temperature sensor means the trans temperature gauge now reads accurately and that also allows the remote oil level check to work. No codes after trip home and level read OK. Driving US 80, 635, and US 75 in dark during rush hour required some careful checking of mirrors, but traffic moved rather well. Even had two motorists allow me to switch lanes after signalling my desire to move over. Maybe they just didn't like 55 feet of motor home and toad headed in their direction in the dark.

FYI
The gauge on the dash, is not controlled via the retarder sensor. It has it's own separate sender in the cooler line. The warning light is controlled by the Retarder sensor.
Actual retarder temp, may be much hotter then the gauge reads when in use.

Glad you have it fixed.
Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: Allison Transmission Fault Codes, Retarder not working

Reply #27 –
Chris is the dash gauge normally the trans sump temp?

"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Allison Transmission Fault Codes, Retarder not working

Reply #28 –
They also found a bad temp sensor and replaced it. I had two separate problems. I understand from previous discussions that the temp sensor location doesn't reflect spike in trans oil temps from retarder use. I'm re-reading older discussions about retarder use from the more expert board members. Will take a slow approach with gears, retarder and service brakes as needed. Always amazed by wealth of information here.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: Allison Transmission Fault Codes, Retarder not working

Reply #29 –
Transmission retarders do one thing for a living-- they turn momentum into HEAT.

That is why transmission temperature needs to be monitored if using the retarder on those LONG grades.

On long grades, use the down arrow to select a gear that will keep engine RPM near the high end of the engine RPM range. 
Why??  Yes, there is a little more engine braking, but much more importantly, the water pump is sending a lot more cooling water through the transmission heat exchanger.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Allison Transmission Fault Codes, Retarder not working

Reply #30 –
Quote from: Realmccoy –
They also found a bad temp sensor and replaced it. I had two separate problems. I understand from previous discussions that the temp sensor location doesn't reflect spike in trans oil temps from retarder use. I'm re-reading older discussions about retarder use from the more expert board members. Will take a slow approach with gears, retarder and service brakes as needed. Always amazed by wealth of information here.

That is correct. The dash gauge does not reflect spikes in retarder cooler, or retarder area of the trans.

On ours, the trans temp never went up to anything abnormal, but yet cold, it would flash the warning light (and dinger).

I pulled the retarder sensor put it in hot water, and based on correct ohm readings, as the sensor warmed in the water, the ohm's would spike for a flash.

My fear was, if it (retarder sensor) went bad, going to max ohm's, it could (and would based on tech info) send trans into limp mode.

Cheers
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: Allison Transmission Fault Codes, Retarder not working

Reply #31 –
Quote from: Caflashbob –
Chris is the dash gauge normally the trans sump temp?

Correct, but not the retarder area including the cooler.

There are 2 sensors. The one FT put in the cooling lines which controls the dash gauge. Then there is the retarder sensor in the retarder area in the back of the trans.That one controls the over temp light and dinger.

My Understanding is, retarder temp is much higher them sump temp when in use.

My understanding is they did this, because people would panic if the saw the temp rise quickly, and to the level it goes to in the retarder cooler area.

Just going on what I was told, and read.

Cheers

Retarder sensor:
29512616-S Sensor for Allison Transmissions | eBay

If you buy it with the harness, it's $500.00. Harness rarely goes bad.


Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: Allison Transmission Fault Codes, Retarder not working

Reply #32 –
I think my dash gauge is the sump as you posted. 

VPMS trans temp moves fairly quickly with the retarder engaged down grades.

Dash gauge does not.

Ding seems to match the VPMS's trans temp

Ding and shutdown notice at 250?

Two -Three  miles flat ground at 70 degrees ambient turns off the shutdown ding.

Very pessimistic system.  Wonder what retarder temp has to be to shed load?

If memory serves me it's 300 degrees. 

Might have my shop reprogram the light and ding's temp setting up a bit  so as to not scare other coach passengers unnecessarily.

Fun to play with a jake if one drifted my

"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Allison Transmission Fault Codes, Retarder not working

Reply #33 –
Bob

YIKES! 300 degree's

Interesting, never seen anything above 205 on dash gauge. Our silverleaf and dash gauge read the same all the way.

Ours is hooked to Cat computer.

I have head of people moving the dash gauge sender some where else.

I threw my trans temp gauge away in the drag car. Don't want to know anything like that going into the final money round!

I have a shut off switch on dinger. Scares the cats when building air.

Cheers Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348
 

Re: Allison Transmission Fault Codes, Retarder not working

Reply #34 –
Yes 300.  My garbage trucks guys fleets ran over 250 degrees forever. I rode along as I did not believe him.  Busses the same. Gillig.  I have had mine to the 230's many times. Live in the Rockies.  250+ once just to verify that the dinger works.

300 for an hour to burn trans oil is what I remember.  Turns orange.  Smells burned.

My engines dash temp gauge was too high.  Not from the engines ECU.  separate sender on the block. 10-15 degrees high.

"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4