Ever since I bought my firebird it hasn't had overdrive, I recently put a new filter and atf in with the aim of getting overdrive back but with no luck.
What would the next steps be to try to get overdrive back? 2800 rpm at 60 mph is frustrating me when I know I have another gear left haha.

 

2-4 Band should be good since you have 2nd gear. Same applies to 3-4 clutches since you end up in 3rd gear.

I would start by taking out the 2-4 servo and checking the 4th gear piston and seals.

 

Thanks for the reply, do you have a photo of it? Im very unfamiliar with the 700r4 and automatic transmissions in general. I know where the 1-2 servo is but I cant figure out where the 3-4 is in a diagram.

 

Pasenger side, first piston behind the round cover. If you have no experience with automatic transmission overhaul, I would advise you to bring it to a shop if it doesn't turn out to be this piston/seal.

 

I looked to see where you live. I have a 60K mile 700 that is working perfectly that's coming out next week as part of a 5 speed swap. I suspect NL is nowhere near utah but you can have it if we can work it out.

 

Wahaha..... I was reading your post and thinking: that's nice of you, but how do you know I'm from the Netherlands (NL)? Can't remember ever posting it on my profile. Then I checked the profile of the TS'er and now I understand

 

Yep, I was guessing NL was Netherlands, still looking for a good home for my 700. We'll see how that works out. If shipping wasn't a killer I'd suggest that but I'm betting that would be at least a couple of hundred, more??

 

Yes, that would be a killer.... just to give you an idea: received a box full of parts for a full rebuild of an AOD a couple of days ago. Shipping was $107 using the cheapest option (USPS). Go figure how much shipping of a transmission would cost... The only option would be to stuff it in a container.

Then for reference, a used 700r4 goes here for between $300 and up to $750....

 

NL = Newfoundland

 

Thanks for the explaination, Ill check it this week when a corvette servo goes in. Yes NL is sadly far from Utah, its across the Atlantic ocean hahaha. Its not difficult to get a 700r4 around here, even at the closest junkyard I know they have atleast 1 or 2. My dad rebuilt a 700r4 himself a long time ago and said it was difficult and discouraged me from trying. Ill see what it looks like when I take out the servo. Here's my Firebird by the way, it has a 3.4 from a 4th gen.

 

Corvette servo is good update. Just be sure to install it without the seals first and aim at 0.060 (1.5 mm) cover movement (retainer to fully depressed). Then install the whole assembly (with all seals) and cover in one piece, or you're running the risk of cutting the rings on the 4th pinion when installing the cover afterwards.... Hanging the return spring in the case instead of on the pin helps also.

Once you're at it, you might grind oil release holes in the piston cover as per transgo instructions.

Succes ermee!

 

Are you sure it is a 4th gear issue, and not that the TCC isn't locking?

RBob.

 

Don't think that's he's problem. You need some very low gears and/or very small tires to turn 2800 rpm @ 60 mph.

 

The cover was stuck and it was very difficult to get it loose but I put the servo in, cleaned and greased everything and it shifts great and I'm now doing 2000 rpm at 60 mph. Sadly due to rain I went thru a corner but my front tires lost all grip and it instead went straight ahead into a pole. I need a new hood, bumper and I hope that the area behind the bumper isn't damaged. Hard to tell, I cant open my hood. Very depressing, I was driving behind another car so no speeding either.

 

Man, this sucks!!!

 

Do you realize how loose the 3.1/3.4l torque converters are? They don't really couple until 2600 RPM. They will rev to the moon even in 4th gear. Remember too, that at 60 MPH there is a bit of a load on the convertor. They are loose.

OP, good to hear you have the issue solved. Sorry to hear about the mishap.

RBob.