Back to a 3 speed - custom bobble mount

So I finally managed to kill the 4 speed automatic I had been trying for about a year to get working. I got pretty close to having it work perfectly. In the end, it seems that it's weakest link, the overdrive hub, snapped off, leaving the trans with no 3rd or 4th gear. I might try again at some point in the future, but I'm not making any promises.

I went to the junkyard on Friday looking for a good 3 speed donor. I decided to get one from a Neon, simply because it's easier to bolt up to this 2.4L engine than an older Turbo Dodge one would be. I managed to find a '96 Neon with 85k miles on the odometer (assuming the solder joints in the cluster didn't simply fail at 85k). I also dropped the pan off the trans before pulling it out of the car, the fluid looked decent, and there was nothing shiny in the pan at all. So it looked like a winner. I got out of the junkyard for just a hair over $100, with the torque converter. Not too shabby.

I spent all of Saturday on the swap. When I had both transmissions out and on the ground, I decided to compare torque converters, mostly because I really wanted to keep the high stall torque converter from the 4 speed (it came from a turbo vehicle), if at all possible. I'd never heard anyone mention them being compatible, but I figured I'd go ahead and find out. So I grabbed my calipers and started measuring things. Everything measured exactly the same, so I went ahead and swapped the torque converters between the two transmissions. They both popped right into place, with the normal amount of fuss getting them to go that last 1/2". I called that compatible, and went ahead and installed the trans in the car. My friend/neighbor was kind enough to lend a hand lifting the new trans into place, which really helped a lot. The 4 speed didn't have an extension housing on the passenger side, so I had been using the mexican turbo equal length setup that came with the transmission. I simply went back to the Omni's stock axle with the 3 speed.

Once I had it installed and everything reconnected, I had to weld a hole in the trans pan shut, the JY likes to just punch a hole in the pan to drain them, then stick a rubber cork in the hole long before they're actually done draining. heh.. So I cleaned out the pan and welded the snot out of it. I welded from the inside, I welded from the outside, I went back and did the inside again, I went back and did the outside again. And in the end, it doesn't even weep. I sealed it perfectly. :) I put a fresh filter in the trans and it ended up taking 6 quarts of ATF+4 to fill it all the way up. These 3 speeds are supposed to be ok with the old Dexron fluid, but I've always found they work far better with Chrysler's ATF+4 fluid. I actually saved a dieing one in my wife's van with a fresh filter and a refill of ATF+4 fluid.

And finally, today, Sunday, I came up with a new way to attach the Bobble Strut (solid version I made in a previous blog entry). I could have attached it to the 3 speed in the same way as the 4 speed, the bosses were there, but they weren't drilled/tapped, so it would have been a lot more work to have been able to use them.

pan n bell1

You can kind of see what's going on here. There are two big bolt bosses on the bottom of my oil pan (SRT4/PT Cruiser pan), and two big bolt holes on the transmission. One of those two big bolt holes on the trans is actually unreachable, because of the bolt boss on the pan. Normally these locations would go unused by me, I found a way to tie them together, and use them for my needs.


This is what I came up with, simply a piece of angle iron, with two holes and a notch drilled into it. I'll probably weld a nice thick washer to that notch in the future, for now I just installed it as you see it. The two holes go to the pan bolts, the notch goes to the bellhousing bolt that I can actually get to. But what does this have to do with the bobble strut?

pan bell frame1

That's my heavily reinforced k-member in the background there. Notice the bobble strut bracket lines up pretty well with where I plan to put this angle iron?


I welded a bit of steel pipe to the corner of the angle iron.

mount installed1

And there's the money shot. A very unique way of attaching the bobble strut to the engine/transmission. Here's a couple more shots.

mount installed2
mount installed3

I plan to put some urethane bushings between the nuts and the bit of pipe that it's bolted to, but the vibration isn't too terrible as it is. The end of the bobble strut is still well isolated with polyurethane.

And before someone asks, that's an oil temp sensor in the oil pan, they a gauge with that sensor at Harbor Freight for like $20, I haven't actually wired it up yet.

© Una 2011