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Topic: Q about throttle position sensor (Read 545 times) previous topic - next topic

Q about throttle position sensor

If you don't have a tps can you still shift with pad on a 3060 Allison?  i.e. shift manually?

Im sensing possible trouble with king unit, and want to prepare in advance.  Cant install air or other at this point, rotator cuff has me single handed.
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: Q about throttle position sensor

Reply #1 –
The trans will ship without the TSP but properly and yes the shift pad will work.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Q about throttle position sensor

Reply #2 –
I'm curious about this also as I'm currently in the middle of the conversion from King Controls to air throttle. My question is why does the transmission care what the throttle position is? Wouldn't speed and RPM's provide enough info for the transmission to know what to do? (Where it gets that information I don't know, but it must from somewhere.)
1998 U295 36' No slides
Towing 2018 Jeep Wrangler
Previous rigs:
  1995 26' Fleetwood Flair
  1998 34' Fleetwood Bounder
  1997 40' Bluebird BMC
  1999 24' Winnebago Minnie Class C

Re: Q about throttle position sensor

Reply #3 –
From what I understand without tps up shifts happen at max rpm, like 2600 to get into 6th. Also have heard down shifts can be hard.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Q about throttle position sensor

Reply #4 –
The trans needs to know how much power engine is delivering. The more throttle the
longer the transmission will take to up shift and when down shifting the more throttle
the sooner the downshift. When I drove my Monaco when the King control was getting
repaired the trans would shift but not when it should.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Q about throttle position sensor

Reply #5 –
No first hand experience with issues with TPS, but I would like to suggest two things:

Select economy mode for earlier upshifts/later downshifts.

Try up arrow to see if that will cause a shift at a more appropriate/lower RPM.
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: Q about throttle position sensor

Reply #6 –
We recently had trouble with our TPS ( bolt at injector pump wore thru ).  The Allison did not like shifting beyond 4th gear in regular mode but would shift semi-normal  with the mode button activated.

  And..  trans retarder would not work via the joystick.  New bolt and back to normal. 
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: Q about throttle position sensor

Reply #7 –
Quote from: Doug W. –
From what I understand without tps up shifts happen at max rpm, like 2600 to get into 6th. Also have heard down shifts can be hard.
This is exactly what I experienced yesterday when I took the coach out for its first test drive after replacing the King Controls unit with an air throttle and a new TPS from Alison. Wouldn't upshift until it reached something above 2,200 rpm, and stayed high when cruising at steady 40 mph. I think I need to either adjust the at-rest (idle) tension on the TPS cable where it attaches to the throttle lever, or re-attempt the calibration sequence (cycle ignition on/off six times, then press accelerator all the way with ignition on). Hoping one of these makes a difference.
1998 U295 36' No slides
Towing 2018 Jeep Wrangler
Previous rigs:
  1995 26' Fleetwood Flair
  1998 34' Fleetwood Bounder
  1997 40' Bluebird BMC
  1999 24' Winnebago Minnie Class C
 

Re: Q about throttle position sensor

Reply #8 –
One of the forum members had his Bendix go out and set up a hand throttle. He said it shifted at max rpm without tps. He was at Q last winter and installed air throttle and tps. Had a mechanic in Yuma help set up tps.
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.