Automatic Transmission Locked In Park!!!

[wscheffer]

Hello everyone,

I sent my W126 1987 420 SEL over to a friend of mine that so happens to be a transmission mechanic for AMMCO (a transmission rebuild company over here in the states).

I asked him to remove my propeller shaft and to install new Flex Disks front and back, new centering sleeves both front and back, a new universal joint, a new intermediate bearing and balance it. Basically rebuild the entire propeller shaft!

The vehicle’s transmission was working correctly prior to raising the front of the vehicle and slipping a pair of jack stands under the vehicle at the front jack points. Therefore tilting the vehicle with the front end up in the air 14 to 18 inches.

After removing all obstructions we started to remove the propeller shaft...

First we disconnected the shaft at the rear by the differential. And then started to remove the front of the shaft up at the transmission.

We put the transmission in neutral and went to spin the shaft to finish it’s removal and discovered that the shaft will not turn.

It is as if the transmission is stuck in park! We put the gear selector back in park and started the engine briefly while moving the gear selector back to neutral to see if this would be the cure but to no avail this had no effect.

Any ideas as to what is causing the transmission to be stuck in park and how to rectify this problem would be greatly appreciated.

Thanks…

Oh by the way the transmission is a 722.324 :mrgreen:

 

[eric242340]

I hope this does not sound like a silly question, but have you released the park brake?

 

[television]

I hope this does not sound like a silly question, but have you released the park brake?

And at least one rear wheel will need to be raised

 

[eric242340]

And at least one rear wheel will need to be raised

Good point Malcolm, I missed that one

 

[television]

Good point Malcolm, I missed that one

Thats OK as I missed your point

 

[Ultymate]

Rear wheels should'nt make any difference because he's already removed the prop shaft from the diff

 

[television]

Rear wheels should'nt make any difference because he's already removed the prop shaft from the diff

Well I looked at that and read it 473 times and could not decide if it was right off at the diff or if there was a bolt left, other than that its unknown territory

 

[Ultymate]

In the initial post he does say he's disconnected the rear of the P/shaft

 

[eric242340]

Rear wheels should'nt make any difference because he's already removed the prop shaft from the diff

Has he actually removed the prop from the diff?

 

[wscheffer]

Hi Guys,

Thanks for the replies!

Yes the propeller shaft has already being disconnected.

My thoughts are after sleeping on this and please let me run this by you all.

In order for the transmission to make a gear change the car must be running and fluid must go through the valve body, even to perform such a simple task as to release the parking pin.

Agree!

So if this is true, with the car being on the angle it is now resting at, and if the vehicle started off a little low on ATF, which I am not sure of could this be the cause of such a fault?

 

[television]

Hi Guys,

Thanks for the replies!

Yes the propeller shaft has already being disconnected.

My thoughts are after sleeping on this and please let me run this by you all.

In order for the transmission to make a gear change the car must be running and fluid must go through the valve body, even to perform such a simple task as to release the parking pin.

Agree!

So if this is true, with the car being on the angle it is now resting at, and if the vehicle started off a little low on ATF, which I am not sure of could this be the cause of such a fault?

On all of the cars that I have had the engine does not have to be running to engage or disengage the parking pawl. I often move cars by just moving the selector out of P without the engine running. the only time this could be hard is when parked on a slope where the pressure needs taking off the pawl.
You have the prop shaft off. there is a valve in the box that is a safety device, is something stuck, you cant put the car in D and start as the prop is off. I would put the prop back loosely and start again.

 

[wscheffer]

Forgive me for grasping at straws on this one!

The prop is in the shop being rebalanced and we should have it back this evening.

I was going to change the filter and fluid also, but I will hold off until I get this one straightened out.

I' ll let you know how it turns out.

Thanks!

 

[wscheffer]

Leveled out the car last night, and still waiting on the prop shaft. Put the car in neutral and wha la! Transmission now is free and god only knows why!

Thanks to everyone for their thoughts on this!

 

[Ultymate]

Lord knows why but good news anyway

 

[television]

Lord knows why but good news anyway

I will ask him tonight

 

[BarryG]

I will ask him tonight

But I don't know Malcolm
This being omnipotent isn't all it's cracked up to be

 

[dava]

Couple of things come to mind here. When you put load on the bolts on the prop this in turn would have put the same load through the trans onto the park pawl, might off jammed it? Secondly, did you disconnect the battery? As the vehilce may not come out of park untill it has live to the switch.

 

[wscheffer]

Couple of things come to mind here. When you put load on the bolts on the prop this in turn would have put the same load through the trans onto the park pawl, might off jammed it? Secondly, did you disconnect the battery? As the vehilce may not come out of park untill it has live to the switch.

I belive that your correct about the load on the pawl as being the culprit to my demise. We are putting in the remanufactured prop shaft today, changing the transmission filter & fluid.

By the way pulled the pan the other night and it was free of shavings and the fluid was nice and pink with a little bit of silt as expected.

Going a head and throwing a rebuilt steering box in her to. It will be nice to drive vibration free and not having to top off the power steering pump before taking her out for a ride.

Oh' Boy all that and steering too! :mrgreen: :mrgreen: :mrgreen: