CheezMoe

Hi Guy's long time no chat. I got a conundrum with the trans. Rebuilt by local shop in 08 (maybe 3k miles since) w a transgo kit and hughes 2.2k

Cliffs;
Yesterday; Took car out for first time this year. changed oil, went for ~20 mile ride. Everything nice and smooth, crisp shifts all good!

Fast forward to today; Warm car up, vacuum and clean interior, glass etc. hop in to go for a cruise,...and the thing wont shift. it will eventually shift into 2nd and then morphs into free spin when in drive. If I pull it back in second gear and can maintain torque to the wheels.

This is quite perplexing. I check and topped off the fluid. Nice and pink. it does not smell burnt at all. checked vacuum connections etc.

Im thinking maybe the hughes converter might have croaked?!

As always, any suggestions and/or advice would be greatly appreciated.

JimT

A bad/defective detent valve will cause the tranny not to shift out of first gear. Easy to replace, just remove the tranny pan and it is easily seen. Also check the vacuum valve at the transmission.

ajrothm

Check the kick down switch on the gas pedal and see if it is stuck or internally locked into contact position....

Easiest thing to do is unplug the plug off of the kickdown solenoid on the driver side of the tranny then go for a drive.....If it shifts fine with it disconnected, then either the gas pedal switch is bad or the solenoid is sticking.... My bet is the gas pedal switch.

This will cause the tranny to be stuck in passing gear and they will do exactly what you are discribing...

CheezMoe

Doh! Of course!.. that stupid kick down circuit! Thanks guys, I'll check it out!.

7T1vette

Vacuum hose came off the vacuum modulator (right side of tranny); or the vacuum connection at the intake manifold came off.

There is a small possibility that the vacuum modulator failed.

ajrothm

Did you check it out? I'm curious if it fixed your problem. It could be the modulator like 7T1vette mentioned as well but usually if the modulator is bad or disconnected, it never shifts out of 1st gear at all.. But some may I guess....

I hope you got it fixed.

Steve2147

A trans with a vacuum modulator will still shift with the hose disconnected. It sees it no different than a wot situation. You have to take it out and hold it to the pin and it shifts at the same points it would if the line were connected and you held it to the pin. I suspect that's what the op did when he got it into second, wound it out till it hit second then backed out of it. He was in d-2 which is why it freelwheeled. We never experience that because with a functioning mod as soon as you back out it hits 3rd or if your in selected 2 the over run band is applied giving you engine braking.
My money's on disconnected vacuum line/faulty mod.

Steve g

CheezMoe

Hi guys, thanks for all the pointers. The vacuum connection is sound from intake to modulator. The mod is "B&M Performance" type but it seems strange it would fail overnight. Other than crawling up under the dash to make sure the kickdown switch is functioning (seems to be), I havnt had a chance to inspect the detent switch at the trans end.

Just to clarify, I never got 3rd gear. When in D I would get free spin. In 2nd, it would eventually wind up and shift to second. But i had to keep the shifter in the "2" position to maintain traction. Unfortunately the man required all my attention today. hope to get back to it tomorrow evening. Stay tuned!

7T1vette

If you changed models of transmission, did you also change out the mounting brackets for the shift cable and lockout cable at the tranny oil pan? They are different for each model of tranny and are not interchangeable. You may just have a problem that the shift cable is not positioning the shift shaft properly in each range.

Steve2147

Unplug the electrical connector at the trans. Check for vacuum with the engine running at the modulator with a gauge if you haven't already done so to ensure no invisible leak. Check the modulator with a hand vacuum pump to ensure it holds vacuum/remove it and ensure the plunger is moving when you apply vacuum.

Road test it where you can allow it to wind right out to see if it will upshift at the points it would upshift in a wide open throttle situation. The engine brakeing/not breaking is normal. Only get engine braking in lower gears in selected positions.

Steve g

CheezMoe

Ok, Vacuum @ modulator 15hg - Check
Pump up modulator, no leak down - Check
Test Kickdown circuit - 12v @ WOT - Check

yet my problem persists!

I guess Im going to take it over to the shop that rebuilt the trans and have them check it out. If the pan needs to come off they will be doing it. Leaks anyway! Thanks for the help gents!

CheezMoe

Well, went out today jacked up the car
and disconnected the power to the detent switch at the transmission. (I really dont need the kickdown as Im always shifting down manually well before it engages.)

I then took a hammer and tapped around the switch and the pan right under it. Viola! The thing shifts like crazy now. Im not sure about coincidence of this but will be suspect of a re-occurrence. Thing ran like a banshie today though. thanks for the pointers!