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Allison Transmission Temp Sensor

September 15, 2011, 11:01:27 pm

Stopped by my favorite Allison Transmission facility today, Lassetter-Lafour Equipment Sales and Service in Channelview, Tx.  Alan Lassetter fixes most of the Houston area school district bus trans and garbage truck trans plus truck maintenance.

I needed my hose to the retarder accumulator raised up as it was drooping and see why my temp gauge was not reading right.

The post that the wire to the sensor connects to was broken so we needed a new sensor.  This is a Foretravel installed item that feeds the VDO gauge on the dash so the Allison dealer did not have it.

It is always in stock along with VDO gauges, gauge repair and signal generators for VDO tach and VDO speedometer at

Instrument Exhange, Inc.
800.945.GAGE

VDO 323050 Temp Switch 801/13/1  $20 including tax.

Well an hours labor, $80, and $20 part made a quick $100 repair.

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Re: Allison Transmission Temp Sensor

Reply #1 – September 17, 2011, 11:44:16 pm

Most earlier coachs had the transmission cooler loop hanging down because both large hoses could not make the right angle turn from the rear of the transmission to the cooler mounted on the side of the transmission. We had Allison add a plumbing pipe extension out the back of one of the two transmission ports so the right angle could now be behind and on the same level as the other cooler line. Now neither of our transmission cooler lines are the lowest point under our coach and are not going to be a problem if we hit something under the coach.

Foretravel originally drilled the cooler return line's right angle fitting with a 1/8" pipe threaded hole where the dash transmission temp gauge sender was inserted. We had Allison drill and tap the transmission output cooler right angle and moved the temp sender, so we now have immediate retarder temps on the dash gauge. We see quick temp increases to sometimes over 250 degrees and a very quick return to 180 when we turn retarder off.

Thanks for the sender part number as someday, I could add a 2nd sender to cooler return line and with a dash switch to read either retarder to cooler or cooler to transmission temperatures.

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Re: Allison Transmission Temp Sensor

Reply #2 – September 18, 2011, 09:23:59 am

Barry,

The pipe extension was used by Lassetter Lafour to get my cooler loop up only they determined the need for the pipe without me needing figure it our for them.  Good folks.

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