rgaynor85

ok this is not about f-body cars, i just picked up a 1993 oldsmobile acheiva. "FREE" but the guy i got it from says after u get it good and hot and drive it around for a while the trans will get up in like 3rd or 4th and then not downshift to a lower gear even if u stop. he said u can head it grind a little and struggle to try and get back into the lower gear. this guy isnt a car perosn so i dont really trust his discription lol. but what i know is once its hot and driven it stays in gears and then stall or sumthin. if anyones got an idea lemme know. oh its fwd so its a transaxle if it makes any diffrence

joecar

Check the fluid level and condition.
Check the downshift cable adjustment.
Check the vacuum modulator and vacuum line.

rgaynor85

were are the vaccum modulator and line located u think.(generally) also how do i check the cable adjustment

joecar

The Olds has a 4T60/THM440 trans.

The vacuum modulator is located on the front of the trans next to where it mates to the engine (everything is transverse, east-west);
it has a short rubber hose and a hard tube going to the intake manifold;
check for vacuum leaks;
if when you pull the hose from the modulator ATF comes out, or the vacuum hose has ATF in it, you need a new modulator.

The throttle/downshift cable adjustment is on the cable attached to the throttle lever right next to the accelerator pedal cable;
the accelerator pedal cable goes thru the firewall, whereas the downshift cable goes to the front/side of the trans, close to the modulator;
it has a button on it;
press the button and push the cable all the way into the housing (away from throttle lever, if I remember correctly) while still attached to the throttle lever;
then push the accelerator pedal all the way to the floor, should hear the cable adjuster click a few times;
before adjusting this, make sure throttle opens fully when accelerator is pushed to floor with no binding.

If these don't fix it, then you have internal problems.

Regards.

joecar

Rereading your first post, sounds like you have internal problems.

rgaynor85

ok well ill give it all a shot and try it was free so a little time is no biggy
thanks, u wouldnt happen to know what internally would go bad to cause this shifting problem would ya

joecar

Here's a diagram showing the cable adjustment (throttle lever would be on left).

joecar

More info:

Possible causes:
sticking governor
sticking throttle valve
sticking check ball
sticking valves

Also from your initial description, sounds like the TCC is not releasing
(caused by weak spring in solenoid or excessive sludge);
this happen when hot and will cause engine stalling.

rgaynor85

hmm maybe thats it cause the guy said that it stalls also when it does this. hmm how would i go about fixing that, would a flush romove the sludge, or am i able to change this spring in selonoid. also this other list:

sticking governor
sticking throttle valve
sticking check ball
sticking valves
are these thing i can change or fix myself or is this complicateds stuff i gotto have done.

joecar

The TCC solenoid would have to be replaced.

The Governor is on the RHS/rear of the trans near the RHS drive shaft.

The TCC solenoid, valves and checkballs are in the valve body
which is located on the LHS of trans, under the side pan with LHS drive shaft going thru it.

Also, with a car that old, there are other parts that may be worn (band, clutches, o-rings...) or broken (gearsets, sun shell, sprag clutch...) and need replacing.

If you're going to do it yourself, you're going to have to do some reading and there's various general procedures that have to be followed (e.g. installing o-rings without damaging them, scraping gaskets without damaging mating surface, etc.).

The general basics/procedures can be found in books sold at the local college bookstore (they run ASE classes).

The specific procedures for your transmission can be found in books such as the followiing: http://www.phoenixhardparts.com/brow...0-T4-Book.html

Going inside your trans is not trivial, takes alot of time if you've never done it before, but it can be done; some things can be fixed with trans still in car, while other things require trans removal.

Some people would rather have someone do it since it takes time, experience and tools.
While other people prefer to learn and do it themselves.

Still, you got ther car for free, so if you spend some money on it, it's okay
(getting a car for the price of a trans rebuild is a good deal).

Either way, good luck with it, hope it goes good.
Regards
Joe