Blown Transmission?

[Mercmarquis]

I think my aod in my 85 mgm is blown. I talked to a few friends and they say its in the linkage. Here's the problem, When its in park, it feels like its want to go forward but doesnt. Between reverse and park it actually moves forward. When its in reverse it does nothing like if it was in park. When in neutral it goes forward. All other gears move forward like they should (OD,Drive,1st). I cant find neutral to pull it to a safe spot to work on it. Thats why I dont think Its in the linkage. I'm stumped, any help would be greatly appreciated.

[Blaze86Vic]

Yeah that sounds very serious. It could be any number of things in the trans body that could result in that odd failure. If you know everything is ok outside the trans then work your way in.

One way to check for sure the linkage is to disconnect the linkage to the trans and position the gear selector manually in neutral and then starting the car.

Some key things to look for in the trans are broken springs and pieces of metal. A break in the gasket between the trans body and the valve body could also cause these issues.

[gadget73]

Get under the car and have someone work the shifter. Make sure the lever on the side is actually moving properly and not slopping around. Could be the bushing on the linkage disintegrated. Do this with the car not running obviously. To make sure your gear selector is in the right spot, loosen the bolt that holds the column linkage to the transmission linkage and get under the car to see where the lever on the tranny is sitting. It should be turned fully clockwise in Park if memory serves. If its not in the right spot, put it there and re-tighten the linkage bolt.

My transmission blew up somewhat similar, tho park still worked mostly. Reverse locked the engine up, park would also lock it up. Neutral wanted to go forward a little bit, and OD, D and 1 were like going directly into overdrive.

[grandpaslincoln]

Yeah, I would check the shift linkage first, to rule it out as a possibility.

[phayzer5]

Are you actually counting the detents when you change gears or going by what the gear indicator says? My indicator is at least 1 slot off what it actually is

[Blaze86Vic]

When you're in reverse and "it does nothing" , does it lock the diveshaft like park? If R is acctualy neutral then the car will be able to roll freelly.

[Mercmarquis]

Yeah when I'm in reverse the wheels are locked cause I chained the car to my dad's truck to pull it on stable ground but there is no neutral anywhere. Needless to say I couldn't pull it up on the driveway to get under it and chech the linkage. I also disconected the linkage from the colum to try and shift it by hand but it is the same, no reverse or neutral.

[Blaze86Vic]

Did you start the car after trying to find nuetral? If you didn't it might not let go of what gear it is in, if its in one. The park lever will disengauge without the engine running. Did you take it on a drive foward ar is that out of the question. There is a revesr clutch spring washer that was cracked in my tranny when I rebuilt it, it could if it failed in the engauged position remain engauged. I don't think that't it because it dont really explain everything, but if you could drive it you would be able to tell by the fact that in Drive or OD when it was in first or second it would hold the RPMs up with the speed of the car.

So you can't find nuetral, not reverse, and all you have is foward? I have so say that is a predicament.

If it's like that then it might be time to check into rebuilding that thing. But still, try everything else before you commit to that. It only takes a day or two, but it is very easy to get lost in them AODs.

[Mercmarquis]

"My transmission blew up somewhat similar, tho park still worked mostly. Reverse locked the engine up, park would also lock it up. Neutral wanted to go forward a little bit, and OD, D and 1 were like going directly into overdrive."

Sounds like mine, sadly. When you say "lock up the engine" did it sound as if it had an engine brake on it where it would not rev very high and stall. Because I had a night of bad luck where all these problems occured. My engine overheated and i limped it home and then the next morning I went to fix it, my trans doesnt work. My exhaust has a sweet smell and puffs a liitle smoke and my oil level is high and my coolant is very low so I think I blew a head gasket too. The car will start in neutral then go forward like in drive, antother reason why I'm doubting the linkage.

[Mercmarquis]

If i have to rebuild or replace it then I am going look into buying a 5 speed like I hear people have been doing. Along with rebuilding the motor or replacing it with a 351 stroked to 392 possibly. I think a 450 horse 5 speed merc would be sick.

[Blaze86Vic]

Sounds like that would be a sweet recovery!

[Grand Marquis GT]

Did someone say 5 speed? Im doing that swap too

[Mercmarquis]

Im not saying it would be easy, but someguy on crownvic.net did a HO swap with a t5 out of a mustang. Heck, I figure If he did it and its possible I should be able to do it as well. But first I have to get it out of the gravel that is way too unstable to jack it up on.This weekend Im going to dig a trench under it to see if I can yank the drive shaft out. Or does anyone have an Idea on finding a reverse or a neutral so I can avoid having to repair my gravel lot?

[Mercmarquis]

I'm gonna try the linkage and all that first. maybe by the grace of god thats all it is. That way I could drive it for a while until I get a 351 and a t5. This way I dont have to drive my sister's POS Focus hatch back around. But hey it gets me from point a to b then c and back again. Life could be worse, but then again seeing the merc sitting in the back hurts alot.

[Blaze86Vic]

Well if you are giving up on the AOD, then it is only 4 bolts that hold the drive shaft on. So it isn't that hard to get off, except that it has to be a 12 point socket!