Overdrive Problems

[97JF]

I have a problem on my 2000 GT where it won't go into overdrive anymore, i'm going to try and get a diagnostic machine on it but just wondering if it will recognise transmission problems, or is it just engine ? Thanks

 

[07GtS197]

The most likely cause is your overdrive band going out Im sorry to say. I would get it diagnosed at a good shop first but its most likely going to need a rebuild. Smell the fluid for a burnt smell, and if you can put the trans in second and accelerate. With a good overdrive band it will not slip and youll have engine braking when taking your foot off the gas coasting (with the trans still in 2nd). Try those before taking it to a shop.

And if it is the overdrive band youll soon lose 2nd gear too.

Oh and yes a scanner should (depending on which one being used) read trans trouble codes.

 

[97JF]

Thanks for the reply, I tried what you suggested today in 2nd gear and it seems to accelerate ok with no slipping, no burnt smell to the fluid either.

Could it be just an electrical issue ? Solenoid maybe ? I will try and get a diagnostic machine hooked up to it and see what it says.

 

[07GtS197]

If there is an electrical issue it will throw a code and the overdrive off light will flash. Most likely its not a shift solenoid because 4th gear uses both shift solenoid 1 and 2 so if one doesnt work 4th gear and another gear would not work. The only way of losing 4th gear is overdrive cancel botton is somehow faulty or mechanical damage has occured. Have you pressed the overdrive cancel switch to see what happens? Maybe its just the torque converter not locking.

 

[97JF]

The cancel switch is the overdrive off button on the gear lever I assume ? Yes I have the overdrive off all the time now since the problem has started

 

[07GtS197]

Yes. So the light on the dash is always lit? Hmm Id get the codes checked asap. Im thinking at one point something happened and the od light flashed and now its just steadily on. Does it try to shift into 4th or just stays in 3rd?

 

[97JF]

The O/D light only comes on on the dash when I switch the overdrive off, it goes out if I press the button again like it's supposed to.

It jumps out of gear when it attempts to go into overdrive, as soon I press the button and turn it off it goes straight back into 3rd gear.

 

[07GtS197]

That sounds like band failure to me. When it attemps to shift but instead neutrals out there is an issue with the clutches or drums. The od band in these transmissions are small and prone to breaking, especially if the car has been run hard and had a lot of 4-2 downshifts and 3-4 at wide open throttle. Drop the trans pan and check for clutch material to confirm. There will most likely be material all in the fluid and on the magnet.

 

[Blackstang01]

So what would I need to do to fix this problem?

That sounds like band failure to me. When it attemps to shift but instead neutrals out there is an issue with the clutches or drums. The od band in these transmissions are small and prone to breaking, especially if the car has been run hard and had a lot of 4-2 downshifts and 3-4 at wide open throttle. Drop the trans pan and check for clutch material to confirm. There will most likely be material all in the fluid and on the magnet.

 

[r3dn3ck]

Take the tranny apart and replace the bands. Might as well replace all the clutches and steels and look for worn planetary sets that might need replacing or upgrading. It's a rebuild job. Not cheap and not easy to do for a shade tree mechanic. Clearances are really important, get it wrong and you get to do it again.

 

[96blak54]

To fix the problem you would need to remove said transmission and replace with a manual transmission. Dont forget all the other components...ie clutch pedal, shift fork, clutch, flywheel...etc

For real tho, r3dn3ck pretty much summed it up for the entire thread. Get yours rebuilt or purchase a rebuilt and swap it out. Could find a used one.