Does anyone know what size the rear diff is for the x-type? I've been looking on multiple forums and everywhere else I can think of with no luck.

I'm interested because I'm considering doing a crazy build on a mercury milan and I want to use the MTX-75 trans with the awd setup that the x-type has, but if the rear diff is not that strong it will cause me problems in the end.

thanks for the help.

 

davis, not to question what you are thinking, but I would trust the rear diff from the X-Type a lot more than the transfer case from this car. I can't think of a single rear differential that has failed due to excessive power, but I can think of numerous transfer cases that gave up with just the stock power.

I'm sure if you look around the boards here, you will see all sorts of failures of the transfer cases due to cracking of the housing. These transfer cases flex too much and ultimately get stress cracks in the metal, leading to the complete destruction of the case. so, unless you are planning a re-enforcement of the case to minimize flexing, you are going to have more issues with the transfer case than you ever will with the rear diff.

 

is that flexing happening because of how its mounted to the car or because of the internals causing force on the case during driving.

thanks for the info.... this is helping me make up my mind on what i want to do.

 

davis, honestly, I am not sure what is the cause of it. All that I can tell you is the rear axle output develops a lot of torque on the case and at about the mid point of the case, you will develop a crack that runs front to back on the bottom side. As the crack gets bigger, things move farther inside the case and as you can imagine, there reaches a point where the teeth can no long hold the power and things start going awry.

I would think an extra point of mounting would not hurt. Looking at pictures, there are mounts on the front half of the transfer case to hold the case to the tranny and then another mount on the other side near the half shaft for the passenger front wheel. But, there is nothing near the tail shaft. But, I would want to get under the car to confirm that. It could be nothing more than adding a simple 2 point flange to the transfer case near the output shaft for the rear driveshaft to give the needed support.

The big question is whether you have the ability to weld on cast aluminum or not. The transfer case is made from cast aluminum. If there is something that is going to be difficult to weld, that is it.

 

Thermo, thank very much for all of this information. I i go forward with this and find a solution to the flex I will make sure to post my results.