Adding Jumbo Servos to Transgo
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Adding Jumbo Servos to Transgo Hi
For a stock A4 that alread has a Transgo shift kit, will adding TCI Jumbo Servos (2nd & 4th) and a .490 boost valve work, or will it produce too hard shifts?
Any input appreciated.
JA
For a stock A4 that alread has a Transgo shift kit, will adding TCI Jumbo Servos (2nd & 4th) and a .490 boost valve work, or will it produce too hard shifts?
Any input appreciated.
JA
It'll probably break the band anchor in short time. Unless you have a heavy duty band designed for it.
Those servos only firm the second and fourth gear shifts.
You can get those shifts harsh with just a vette servo, bigger feed holes and modified accumulators.
Those servos only firm the second and fourth gear shifts.
You can get those shifts harsh with just a vette servo, bigger feed holes and modified accumulators.
You already have the .490 boost valve - it comes with the TransGo kit.
Like Jason said, don't make it shift so hard it jolts. The 4L60-E can NOT hold up to the impact of hard shifts.
This is not to say there is no merrit in what those apply pistons do. The one for second and the one for fourth have more "apply area" which means more pressure can be put on the band with the same amount of line pressure. To use these servos you would want the TransGo calibrations to the separator plate at the minimum diameter which I think they call "stock" or just "soft." Those holes control how fast fluid flows to the piston not the pressure of it.
Changing the apply pistons also gets tricky with the 2-3 upshift and 3-2 downshift because at that moment you have both the band and the 3-4 clutchpack changing status. If the sequence of events here becomes unbalanced from too much upgrade to one half of the mechanical frictions involved (band) then you'll get wierd shifting flare or feelings of the car lagging and/or lunging forward on a shift.
In my opinion (which ain't worth much) upgrading the apply pistons to the billet ones should not be done unless also upgrading the 3-4 clutch pack to high-performance friction materials or/and increasing the 3-4 feed hole. Even then band engagement should be kept as mild as possible with no jolting.
Basically, if you set up a 4L60-E to chirp the tires on a 1-2 shift, even if the tires are 235's, it WILL break hard parts in a VERY short time.
Like Jason said, don't make it shift so hard it jolts. The 4L60-E can NOT hold up to the impact of hard shifts.
This is not to say there is no merrit in what those apply pistons do. The one for second and the one for fourth have more "apply area" which means more pressure can be put on the band with the same amount of line pressure. To use these servos you would want the TransGo calibrations to the separator plate at the minimum diameter which I think they call "stock" or just "soft." Those holes control how fast fluid flows to the piston not the pressure of it.
Changing the apply pistons also gets tricky with the 2-3 upshift and 3-2 downshift because at that moment you have both the band and the 3-4 clutchpack changing status. If the sequence of events here becomes unbalanced from too much upgrade to one half of the mechanical frictions involved (band) then you'll get wierd shifting flare or feelings of the car lagging and/or lunging forward on a shift.
In my opinion (which ain't worth much) upgrading the apply pistons to the billet ones should not be done unless also upgrading the 3-4 clutch pack to high-performance friction materials or/and increasing the 3-4 feed hole. Even then band engagement should be kept as mild as possible with no jolting.
Basically, if you set up a 4L60-E to chirp the tires on a 1-2 shift, even if the tires are 235's, it WILL break hard parts in a VERY short time.
