twfinch

Also does not downshift when I step on it, only by slowing down. It just stays in 4th until I slow down to stop. Then it returns to second. It shifts smoothly manually. KD solenoid clicks when switch is closed. I wired in a bypass to test with. Tried adjusting trans cable over large range with no result. Vac modulator line has 15 in. at idle (after fixing a couple of leaks). I do need to check vacuum holding of modulator. Fluid level is fine. Anybody know what inputs cause the shift points or what could be wrong? Thanks in advance of any ideas.

SeanR

Do a search on adjusting the "Bowden Cable".

This is what needs to be tightened up or checked out for proper connection.

Mrmerlin

Disconnect the ball end at the quadrant for the Bowden cable to the trans,
Then go the the right side of the transmission and press the tab in on the white housing for the bowden cable,
gently lift the housing up and see if the bowden cable is connected to the arm inside.

it will either pull our with a hook dangling or it will be connected and you feel resistance.
You should have a helper to hold some pressure on the ball end so the cable doesnt come totally loose and disconnect itself.

atb

Disconnect the kick down switch under the pedal, take it out and romp on it and see if there's any change. If not, your kickdown switch may be T/U. Downshift on decel function sounds normal. The S4 A/T won't sequentially downshift on decel, it will hold the highest applicable gear until you reapply the gas or slowdown to a near stop.

atb

Oops, glossed over upshifting quickly, that is typically a bowden cable issue. I think if vaccuum is absent, like a disconnected line or toasted modulator, the tendency is for later, harder shifting.

Landseer

Modulator failure can cause fluid to be injested and burned away, too.

G Man

I had a similar shifting issue with my 84'. The shifts were too soon and somewhat clunky. Turns out the modulator would not hold a vac when tested. Replaced that, adjusted and all is good.

twfinch

I called Ted at Transmeister in Anaheim, Ca. He said to drop the pan and make sure the cable is actuating the valve. I did that and it was. He said to remove the valve body and bring it to his shop. I did. He immediately diagnosed the problem being a stuck valve. He spent a 1/2 hour and fixed it on the spot. Only wanted to charge me $25, but I insisted on paying $50. I put the valve body back into the trans, filled her up and it works great now. If any of you in SoCal have any transmission issues, I highly recommend Ted at Transmeister in Anaheim. He knows his stuff.

Mrmerlin

thanks for the update and info for a trans repair facility

Landseer

Nice followup, thanks!