I'm putting an AOD in a car that it didn't originally come in. I'm having some clearance problems. My questions is does anybody have any ideas what vehicle might have came with the shortest mount? I mean shortest distance between crossmember surface and transmission surface. I see the late 60s mustang trans mount looks pretty short. Anybody with any other ideas? I need as much space as possible. Thanks in advance.
@MtxRocket455 Have you considered modifying the crossmember in the area where the mount is located to increase the space available? Ray
Any mid/late-'60s Ford intermediate will have the most compact trans mount for your purposes. Ford made some that were more compact, but those only fit the matching purpose-built tailshaft housings which won't be available for the C6 or AOD. What kind of car? There's more than a few swap crossmembers out there...
When I built my pro street Morris Minor with a 5.0 and an AOD I just fabbed up a cross member out of 1 inch square tubing and a some flat 3/16 plate. Didn't take up much room at all and used a stock 86 Lincoln mount.
The car is a ‘50 Coupe. The AOD is behind the original flathead. So many threads I read said there was room. But this thing is up against the floorboard and still not even close to flush with the frame. I bought a universal 3” drop trans cross member from Trans Dapt. I had some mid 80s trans mount and I can’t get it even close to fitting. Took the floor plate off and I could probably make some very minor modification to get it flush. But I need the smallest mount possible. Rather not pay $50+ for a mount if I don’t have to. One thread I read the guy said he took the original trans crossmember and simply moved it back a few inches. Not only does it not sit low enough but the frame rails are angled. And original doesn’t sit low enough. I really don’t want more than a 3” drop that’s already going to be really low. So I’m going to make this crossmember work. I feel like I’m rambling now....thanks guys.
@MtxRocket455 Now that you have provided details of your car, it is clear the problem is less about the crossmember and more about the floor. Shoebox Fords were only available with a manual trans through the ‘50 models and the floor hump was no larger than need be. In 1951 models Ford offered the Fordomatic trans and the floor hump is signifcantly larger to accommodate it’s greater bulk. One solution is modifying your floor hump to increase clearance and put the trans centerline where it belongs. A three speed C-4 Cruiseomatic, being very compact, fit ‘50 models quite nicely, close but adequate. The AOD you have selected is not a particularly compact trans. Further, the limited torque of the average Flathead may not pull the OD all that well even with 3.70/3.90 gears. Going to a 4.11 or 4.27 can help with that, but quickly puts you into a ‘diminishing returns’ situation. A C-4 trans with a 3.00/3.25/.3.31 (the latter being a ‘51 Fordomatic ratio), will give decent performance and reasonable rpm in cruise. Most Cruiseomatic installation with small block V8 Fords used 2.79/3.00 rear axle gears. If you can locate a ‘51/‘56 Ford axle assembly from a Fordomatic model that would be an easy swap. Or, an 8” Ford rear end from a Falcon/early Fairlane, early Mustang, Maverick or Granada are all good bets. Width works and they are easy swaps. Ray
I have known people who have put a 51 trans humps in 49s and 50s to get more room for a automatic trans.
My plan is to get the transmission flush with frame or close to. And ensure the driveshaft is at an appropriate angle. And then I'll modify the floor and/or crossmember as needed. I didn't know the C4 would have been a better route than the AOD. But now I have the AOD already rebuilt, so I'm using it. I'm seeing now that the better route would be a C4 and a more modern rearend with numerically lower gears. But I'm too far into this route. Car was original OD car so it should have the numerically higher gears. I found a 75 maverick rearend at a junkyard but it only is a 4 lug. I happen to live about a mile and a half from Currie Enterprises. I went and talked to the salesman and he said those maverick rears they don't mess with. I'd be better off getting one out of a mustang. I'm not really sure. He said a lot of things. I'm getting a little overwhelmed with all the options and possibilities. I just want to get this transmission securely in the vehicle. I'll use my original rear for now. I'll see how it goes and make adjustments from there. I'm not going to dump a bunch of money into any rearend until I have this thing running. Car hasn't ran since around 1971. So I've been having to go through everything. I just need to get this thing on the road and I'll work out the bugs. I really appreciate everyone's input.
Oh and Currie said if I bring my original rearend they'll make me a custom rear with any gearing I want. But it'll cost me like $4500. That's more than what the engine cost me. I'll figure out another way.
The early Mavericks had 4 lug axles and they were a lighter duty Ford, I think known as the 7.5” model, not the same as the later Maverick 5 lug axle which was the widely used 8” Ford unit. Sorry the alternatives didn’t surface sooner and I understand your dilemma. As for $4500......that’s ridiculous, especially for your purposes. Best wishes with your project. Feel free to ask any other questions or for recommendations should wish some additional information Ray
What engine with the AOD ? Don't think you mentioned that. This picture shows an AOD on a '52 stock cross member.
Just cut out the hump and get the trans as high in the car as you need it and build a new trans hump or just make strips to add to your original hump and weld them in . If you don't know how to weld then rivet the hump back in or use short self tappers to hold it in place. I used a 4.11 gear behind my AOD and a small block Ford. It had 295-50 -15 tires . On the highway I got 20 plus mpg. That much money for a rear end is stupid money. Go find an 8 inch rear out of a V8 Fairlane or Comet Or a Maverick They will have 5 lug hubs. Then just buy a gear and learn to set it up yourself. It is not that difficult and their are plenty of videos on how to do it on you tube. Old cars are about enjoying the build and challenging your skill level and not just buying a kit and bolting it together. We are not building model cars or Legos. We are building hot rods something you can be proud of and say I built that when you go to cruise-ins or car shows.
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