Author Topic: How to have the auto trans always start in 1st gear?  (Read 7862 times)

GGR

  • Inactive
  • Platinum
  • ******
  • USA, DC, Washington
  • Posts: 1470
How to have the auto trans always start in 1st gear?
« on: February 11, 2011, 10:55:27 »
Some time ago I drove a W111 Coupe 3.5 auto trans that was always starting in 1st gear, no need to position the lever into "2" or to floor the gas pedal.

I thought this would be nice on a Pagoda when fitted with a 3.27 rear end ratio. Does anybody know how to do that?

Thanks!

66andBlue

  • Full Member
  • Platinum
  • ******
  • USA, CA, Solana Beach
  • Posts: 4733
Re: How to have the auto trans always start in 1st gear?
« Reply #1 on: February 11, 2011, 17:21:32 »
Add a switch as described here: http://www.sl113.org/forums/index.php?topic=4914
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

GGR

  • Inactive
  • Platinum
  • ******
  • USA, DC, Washington
  • Posts: 1470
Re: How to have the auto trans always start in 1st gear?
« Reply #2 on: February 11, 2011, 18:44:27 »
Oh, that's great. I don't fully understand the part where the gas pedal has to be slightly engaged, but I will contact Tom as we live in the same area.

mdsalemi

  • Pagoda SL Board
  • Platinum
  • ******
  • USA, NC, Davidson
  • Posts: 7032
Re: How to have the auto trans always start in 1st gear?
« Reply #3 on: February 11, 2011, 20:13:52 »
Of course I don't have a 3.27 rear end...but the only reason I would want my trans to start in 1st gear is if I lived on a 12% grade and pulled a caravan at high altitude.

I think the last time I had 1st gear I was doing about 8 MPH....at 2,000 RPM.

...and that's why it starts in 2nd!  :D
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2023 Ford Escape Hybrid
2024 Ford Mustang Mach Ex PEV

GGR

  • Inactive
  • Platinum
  • ******
  • USA, DC, Washington
  • Posts: 1470
Re: How to have the auto trans always start in 1st gear?
« Reply #4 on: February 11, 2011, 21:31:45 »
My rationale is with the 3.27 rear end. My W111 has a 3.5 engine with what I think to be a 4.5 three speed auto (first is equivalent to 2nd on the Pagoda) and a 3.27 rear end. True the W111 is a bit heavier, but frankly it's not faster off the line with the 3.5 in 1st than the Pagoda in 2nd. Given that the 280 has only 24 kg of torque compared to the 29 of the 3.5, I thought that starting in 2nd with a3.27 on the Pagoda would be quite slughish. So why not taking advantage of that 1st gear without having to slam the gas pedal or play with the lever each time? Especially if we can flip the mode at the touch of a button, so that both of us would be happy.
« Last Edit: February 11, 2011, 21:34:51 by GGR »

DavidBrough

  • Guest
Re: How to have the auto trans always start in 1st gear?
« Reply #5 on: February 14, 2011, 12:40:16 »
Whilst I'm fairly sure I can guess the answer to this I'll ask anyway as, if I'm honest, the worst thing about my car, apart from the fact it's off the road at the moment, is the auto gearbox ratios. I don't want a manual but I really would like 4 useable gears in normal driving so is it possible to change the internal ratios on at least 1st and 2nd?

wwheeler

  • Vendor
  • Platinum
  • ******
  • USA, TX, Dallas
  • Posts: 2893
Re: How to have the auto trans always start in 1st gear?
« Reply #6 on: February 16, 2011, 20:48:51 »
The reason the accelerator pedal has to be slightly engaged is because of the double acting transmission solenoid. At idle, the solenoid is engaged because of the throttle switch on the venturi. When you depress the pedal, the switch opens and the solenoid is in neutral position.

If you activated the kick down switch while the throttle switch is closed (at idle), the solenoid would fight for a position and probably burn up.
« Last Edit: February 16, 2011, 20:50:26 by wwheeler »
Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6