Allison MT-647 into MC-5C update - finally!

[bevans6]

Some of you may remember that I came to a grinding halt on this project when I figured out that the flexplate I ordered was for an SAE 1 bellhousing, and the MCI bellhousing is unique - it is SAE 1 on the mounting flange and the starter motor is in a SAE 2 ring gear position.  So you need a different ring gear and flex-plate.  I found one, but it was $1700 and non-returnable.  I already had a non-returnable SAE 1 flexplate, so I looked for other options.  Digging through various Allison diagrams, we found one that had a bolt-on ring gear that sandwiched a separate flexplate, intended for a Cummins application.  I found that ring gear on Ebay, NOS, for $350 and ordered it.  I plan to cut the SAE 1 ring gear off the flex plate and trim it to fit, bolt the SAE 2 flex plate to the torque converter over it, and make a crank adaptor to space it all out right so it engages the starter motor correctly.  One little hiccup so far - the new ring gear is 1/16" larger in radius than the ring gear on my old flywheel.  I won't know if that makes a difference until I get to a point where I can bolt it up and measure the pinion to gear clearance on the starter motor.  But at least I have a way forward now....  BTW, this ring gear is no longer available new and MSRP is $2700, if it was available.  This project is not for the faint of heart, it turns out... 

[Fredward]

Yep. It's make it up as you go.
Anytime you're doing something that never came from the factory that way it's challenging. Well, kind of like converting a bus!!

The only guy I found who had done lots of SPicer to Allison conversions had a stroke and couldn't speak or write.

[luvrbus]

Only took me 2 of those conversion to figure out the easiest way was to find a SAE 2 bell housing from a 6v71 with the MCI arrangement I bet those are hard to find now too,I would buy the bell housing and the flex plate from Sam for 300 bucks back then   

[Dave5Cs]

Brian where did you put the shifter left or right of Driver?
Dave

[bevans6]

At this point I am making a mechanical shifter using the original shift lever.  Only time will tell if it works or not, but a shifter and cable is pretty expensive.

Brian

[chessie4905]

Clifford, does the V730 use the same flywheel as the 740? I have a flywheel with ring gear off a V6-71.

[eagle19952]

At this point I am making a mechanical shifter using the original shift lever.  Only time will tell if it works or not, but a shifter and cable is pretty expensive.

Brian

from what I have read so far...the cable might be the least expensive item on the list. You will enjoy the result I am sure

[Lin]

 this 40 ft cable is on ebay for under $70

http://www.ebay.com/itm/MERCURY-40-FOOT-QUICKSILVER-GEN-I-BOAT-SHIFT-THROTTLE-CONTROL-CABLE-/141036127504?hash=item20d6688510:g:wTQAAOxyTMhSCRaJ&vxp=mtr

Just search for 40 foot (or whatever size you want) shift cable.

If you buy a shift tower, make sure it is for a 640 series transmission.  A 740 shift tower has different throw.  Although it was several years ago, I got a new one cheap from Direct Machinery Outlet, 410 799-9530

[bevans6]

I'll probably end up doing that after the mechanical shifter doesn't work...   

[Fredward]

I got a cable and a shift tower. Then I drilled and tapped the clutch rod; screwed the cable into it and pulled the cable into place by pulling the clutch Rod out the back through the engine compartment.  Easiest part of the entire project.
Fred

[bevans6]

Great tip.  When I installed a new throttle cable I used the old cable to pull the new cable through.  Do you recall the length of the shifter cable you used?

Brian