Wednesday, September 23, 2009

Mounting the motor-transmission assy, Part 2

Completing the motor-mount and installing it took a lot longer than I expected. More than 4 hours last night, but it's done and it seems to work. The culprit was the bracket to hold the driveshaft support. Here's a picture of the mount as of 2 days ago.

The two studs pointing toward the camera were supposed to mate with the driveshaft support bracket. In order to make it easier to attach the bracket we welded the bolts to this mount. Unfortunately, with the driveshaft installed there wasn't enough clearance to swing the bracket into place. So, I had to grind off the bolts. Even with loose bolts, there was still not enough clearance. Besides with loose bolts it was going to be difficult to align the driveshaft properly.

That left only one other option: weld nuts in place on the motor mount. This will allow the bracket to be swung in place and still align the bracket properly. So, we installed the mount onto the motor, pushed the driveshaft into the transmission, and attached the driveshaft support using some short bolts (3/8" x 1" long).

Two problems arose:
1) Somehow the entire driveshaft/mount assembly needs to be taken off the motor so the nuts can be welded in place.
2) The driveshaft support bracket, even though it looks beefy enough, actually flexes quite a bit when lateral force is applied.

For #1, our first thought was to slide the bracket off the mounting grooves on the motor, which will also pull the driveshaft out of the transmission at the same time. That didn't pan out - the bolt heads are so snug in the grooves that they don't really slide. So we ended up disconnecting the transmission from the motor (again) to free the driveshaft. Once they were separated, we could take the mount off with the driveshaft attached.

To solve #2, we added a gusset to the bracket. The freshly painted part of the mount in this picture is the gusset. You can see the newly-welded nuts on there, too.

Here are a couple of pictures of the finished mount and motor installed, with driveshafts intact. Finally!

As you can see by these pictures, the driveshaft bracket can actually be attached in 3 places. We chose to ignore the top one and are only using the middle 2. That top bolt hole was actually in a different plane than the middle 2, so it had to be ground away so that it wouldn't interfere with the motor.

Lower Transmission Mount
This was quite simple. A block of aluminum with two tabbed bolt holes in the top which mate up with the transmission and a single bolt through the center pointing straight down which locates the mount through a hole in the cradle. This is a picture of it before the driveshaft was reinstalled.

Upper Transmission Mount
This is the main torque rod for the transmission. Not yet finished, the plan is to use a piece of angle, some bar stock, and a couple of spacers. More on that later.

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