[8my$]

I have a 68 Firebird with a 400/400 combo. I bought the tranny rebuilt (supposedly).It seemed to be working great untill I parked on a steep hill and did'nt set the e-brake.It started to roll.Now it won't stop rolling in park.It seems to still work(engage,shift).I don't know crap about AT's.Help. Thanks

[munchenbach]

could be the parking pawl...
http://en.wikipedia.org/wiki/Parking_pawl
or possibly just a simple adjustment needed in the linkage?

[steve25]

Disconnect the shift cable at the trans and place the lever all the way towards the engine and the car should not roll.
Then readjust the lenght of the shift cable so you have just a about a 1/8 inch of play. If the trans did not get screwed up you should then be ok.
By the way this is why teh emergency brake needs to function and be used when you park!

[73LeMans]

Love the screen name.

First thing to check would be the obvious linkage setup. Cable or mechanical linkage it doesnt matter, just see if there is any more room for Park to be engaged and then adjust accordingly if there is. Sometimes it will just barely engage the pin, and sometimes it wont. With a little more "push" into the Park location, maybe the pin can fully engage and lock the output shaft. Its also possible something is stopping the shifter from fully engaging the space it needs to be in Park, so make sure nothing is binding that up either. Hopefully thats all it is.

However, because you mention the incline as to when the issue first occurred, (and I assumed worked fine before then) more than likely,the parking pin or the wheel on the shaft in which it engages is worn to the point where it will no longer engage and will need to be replaced.

~Mark

[8my$]

It's not in the linkage.I took it aprart and made sure it was going into park at the tranny. What's a parking pawl? I'm preety good with tools, but know nothing about AT's. Its it something I could fix.Thanks

[73LeMans]

I'm such a slow typist.


Parking Pawl is the pin I mentioned that locks the output shaft of the trans to keep it from moving. Sounds broken.

[8my$]

Any clues as to what a shop would/ should charge?

[67 Lamnas]

Originally Posted by 8my$

Any clues as to what a shop would/ should charge?

The parking pawl on a TH-400 is NOT a pin...it DOES rotate on a pin, but the pawl itself is a rather robust chunk of steel that engages dogs on the output carrier of the trans.

The parking pawl is accessible after you remove the pan. My guess, however is that part of the INTERNAL linkage (the pawl bracket) is installed incorrectly which doesn't allow the pawl to fully engage the dogs.....the bracket CAN be installed incorrectly....

You can fix this yourself with simple hand tools and a catch can for your fluid.

I can post a pic of the pawl and bracket if that would help you.......

[smittyseng]

Originally Posted by 67 Lamnas

The parking pawl on a TH-400 is NOT a pin...it DOES rotate on a pin, but the pawl itself is a rather robust chunk of steel that engages dogs on the output carrier of the trans.

The parking pawl is accessible after you remove the pan. My guess, however is that part of the INTERNAL linkage (the pawl bracket) is installed incorrectly which doesn't allow the pawl to fully engage the dogs.....the bracket CAN be installed incorrectly....

You can fix this yourself with simple hand tools and a catch can for your fluid.

I can post a pic of the pawl and bracket if that would help you.......

I agree with this diagnosis,aside from the external linkage being out of adjustment or loose,the bracket that forces the shift rod to push down into the parking pawl can be installed turned around 180 degrees and in your case it most likely is. When this happens the parking pawl barely egages,on a hill or even a slight incline you will hear it/see it ratchet and slip fairly easy. When installed correctly, even on a steep hill the pawl engages so far into the output ring gear (about 3/8 plus inches) that it is nearly impossible for it to EVER slip unless someone has really rounded it off by engaging it driving down the road or something. You can easily tell if its installed correctly by unbolting it and looking at which way looks correct,the right way has a squared off edge facing the parking rod to help it engage further when the bulge passes by,Smitty

[8my$]

It sounds like the problem.It makes a clicking souund when it rolls.The pic's would really help. Maybe a brief step by step if you have time.I really appreciate the help.

[smittyseng]

Drop the pan,follow parking rod that is in the shifter rooster comb to back of the trans where you will find a shiny bracket about 2 1/2 long by about 3/4 inches wide that has 2 bolts w/1/2" heads. Unbolt the bracket being careful to not lose the orientation of how it was. You will notice a beveled bend on top of it that juts towards the pass side of the trans,this is what forces the parking rod to push the parking pawl deep into the output ring gear. If this piece looks backwards once you look at it then it needs to be turned 180 degrees so it functions properly. While the bracket is out you can inspect the output ring gear teeth and parking pawl,they should be square,if they look rounded over than your problems aren't so simple,Smitty

[8my$]

It doesn't sound to diffucult. I'll give it a try. Thanks for all the info.

[goatasaurus rex]

smitty, good to see you weighin in, brother.