4l60e to Muncie swap

[transitionbikes93]

Hey all, been a minute since I been on.
I picked up a Muncie HD 3 speed gearbox off marketplace for $150. It’s in good shape, and I am going through the process of replacing all the gaskets, bearings, and synchros before I put it in. Taking my time as I have never torn apart a transmission before. It’s going to go into my 1993 Chevy, to replace the 4l60e transmission. Very similar gear ratios, minus no 0.69:1 OD in the Muncie. Not worried about it as I have 3.42 gears and won’t be doing much highway driving.

However, I will be ordering and installing EBL Flash II before I get the transmission swapped over. I have some troubleshooting to do with the engine/tbi electronics and I feel like EBL is going to help me fix my issues, as the codes I got were generic and could mean a multitude of things. If I could monitor things on the what’s up display I feel like I could diagnose and fix things more accurately.

One of my mains concerns is, if I swap over to EBL and lose my transmission control for my 4l60e, would I still be able to manually put the 4l60e into park/forward/reverse so I can at least move my truck around the yard?

 

[NickTransmissions]

would I still be able to manually put the 4l60e into park/forward/reverse so I can at least move my truck around the yard?

yes. You'll have reverse, manual 2nd and 3rd when in Manual low/2 and Drive/D3, respectively.

To know what it will be like, pull the trans fuse, fire it up and drive it around. You're technically in limp mode so LP will be maxxed but for moving around in the yard it's fine.

 

[GoToGuy]

And bell housing, clutch pedal, mechanical or hydraulic clutch, flywheel, bolts, pilot bearing, different starter?, output shaft splines? , driveshaft length ?,

 

[transitionbikes93]

yes. You'll have reverse, manual 2nd and 3rd when in Manual low/2 and Drive/D3, respectively.

To know what it will be like, pull the trans fuse, fire it up and drive it around. You're technically in limp mode so LP will be maxxed but for moving around in the yard it's fine.

That’s excellent. Thanks so much. Now I can get this part of the project underway with more certainty.

 

[transitionbikes93]

And bell housing, clutch pedal, mechanical or hydraulic clutch, flywheel, bolts, pilot bearing, different starter?, output shaft splines? , driveshaft length ?,

The transmission came with a compatible bell housing. I’ve measure and all the bolt holes line up, and I have new bolts.

The transmission came out of a 350 powered 3/4 ton truck from the early 70s, so I can use a performance oriented clutch kit for a 67-72 truck. I am getting the hydraulic conversion kit from American Powertrain. It comes with everything needed, from the clutch pedal to the pilot bearing. It is a little pricey, but it’s made specifically for swapping an automatic gmt400 over to a manual, and the kit works with everything from 3 speed Saginaws to a T56. The whole swap is roughly $3,000 cheaper than building the 4l60e and getting a standalone TCM or trying to wire up a second ECU for transmission control.

I have yet to figure out if I need a new starter or not, but there are starters that work because I am not the first one who has done this.

Output shaft spline count is the same as my 4l60e, and the transmissions are both within an inch of eachother in length from the end of the tail shaft housing to where the bell housing bolts to the motor, with the Muncie being around 3/4 an inch to an inch shorter. I am lowering my truck back down form 5” of lift to 2” lowered, so I feel the driveshaft should be fine.

 

[transitionbikes93]

That’s excellent. Thanks so much. Now I can get this part of the project underway with more certainty.

I am also doing a flywheel out of a 67-72 truck. Should be the same bolt pattern as both are 350’s? I can double check and take more measurements.

 

[b454rat]

Could have swapped a 4500 a whole lot cheaper...