Drivetrain Clearance Question

Hi,

I've got some questions on transmission and t-case clearance. Background, I'm putting a 4.0, AX15, Dana300 on my 75 CJ-6 frame. The tub is off, motor is mounted, trans and case are bolted up, but everything looks to be sitting a little high. Trans and tcase are sitting about 7 inches above the frame rails, i'm concerned I'm going to have clearance issues when i come back to mount the body. Currently, everything is sitting flat. By that, I mean that the output shaft of the tcase and the rest of the set up are parallel to the ground. The AX15 also has about 6 inches of space between the mounting surface of the transmission and the cross-member. i'm less worried there, i'll sort something out for a transmission mount. Pictures below, looking for advice on whether I'm sitting too high. Would be great to see some picture of a stock drive train and how high it sits.

thanks in advance

 

The motor looks high in the back.........should be about a 3-5 degree angle down hill towards the rear.........put a level on something that is flat on your motor.......maybe the valve cover on the side where it's bolted to the head..............

 

If there should be an angle, then i'm too high. I'm sitting dead flat, put a level on it last night. tilting down will hep with my transmission mount needs as well i'd imagine. I'll shoot for 3 degrees and see how that looks.

 

Take a look at the motor from the drivers side.........I assume you have a Carburetor on there?.........normally the top of the carburetor inlet wants to be flat at ride height......( all weight in vehicle) so the float inside is also level at ride height............some manifolds will be made to accommodate that angle....or sometimes there is an adapter under the carb that is at an angle........Check it out as it could be a 3 , 4 or 5 degrees angle?

The old rule of thumb.......was the base of the oil pan being level / pickup inside.........but that may not be correct in all applications..........but if you had an auto transmission that pan or pan rail is normally where you would check you level........just suggestions...............but all the angles were talking about should also be merged into your drive line angles........sort of a compromise although in your case without a bunch of lift......you'll probably be fine!

 

When I put my 79 back together, it looked kind of funny at the time with the tub off but ended up being correct. My 258 / T150 / D20 has a 5 deg slope towards the rear.

 

What is the thickness of the rear mount on the trans? Should be less then the stack of wood in there now.

 

Hard to say what the thickness of the rear trans mount should be. The AX15 mount is only about 3 inches thick, as is the trans mount for the t-15 that was originally in the Vehicle. Given that I'm mix and matching, but sure exactly what should be where. I I adjusted the angle of the drive-line down approx 3 degrees, things look much better.

Trying to figure out where I can find/fab an adjustable trans mount to fit...

 

Do you have any shims/spacers where the trans crossmember mounts to the frame? Some of the intermediates can have four to six 1/4" spacers stacked up, lowering the crossmember and making the slope of the engine/trans.
-Donny

 

I am in the process of swapping the same drive train in my 74 cj6. 4.0L AX15 D300. I had interference issues with D300 and the tub, under the tool compartment. If you haven't discovered already. I went with one inch tub spacers, modified a portion of the hat channel, and hammered a bulge in the sheet metal floor.