2001 C6500 cat 3126 eaton 6 speed to Allison MT643 trans swap.

[SQ is the SQUAD]

out of all the forums i have been on, you guys seem to know the most these Allison transmissions.



long story short, i keep snapping clutch cables. the cable if great the first few days, then it starts binding and getting really hard. at the end of a hard days work the bottom of my foot is sore from clutching. i just want an automatic tranny. i originally planned on swapping in a electronic 2400. but due to a tight budget, i may just settle for MT643. a guy locally has one for $500 that came out of a Ford f600 that has a 429 motor in it.


are these torque converters mfg (motor) specific? will i have to find a TC for a cat 3126 motor or do i just need a cat flex plate setup designed for allison transmission.



i need reading this thread that has tons of good info
http://www.skoolie.net/forums/f33/at...ead-18221.html


did the MT643 have an electronic speed sensor?


i found a floor shifter on ebay that has R N D 3 2 1 which should work.


i am not sure how my rear end gears will effect this or what gears i actually have. with the eaton 6 speed my top speed is around 75 mph.


i understand i may have to build a mount brace for it. my eaton just hangs in there. no mounts what so ever. ill build a mount bracket once i get it in.


did the MT643 have a rear parking brake option? my eaton has the rear park brake, but it never worked so i have a line lock. id really like to add a rear parking brake if i could.


i would also have to custom a transmission cooler. any suggestions on what size. i assume just get a universal aftermarket unit.


ill have to measure the overall length of my eaton and compare it to the mt643 hopefully its close enough i wont have to custom my driveshaft.



here is the transmission for sale locally

[Kubla]

Going to be the wrong torque converter if it came off a gas engine

[PNW_Steve]

The Eaton six speed is available in both overdrive (FS) and non-overdrive models.

If I remember correctly the FS series has a 1:1 ratio and the FSO has a .78:1 ratio.

If you have the FSO and switch to the MT643 you will lose some top end and perhaps fuel economy.

[djdalfaro]

The MT643 came equipped with multiple torque converters with different stall ratios, ranging from 3.04:1 to 1.82:1. In addition there are MULTIPLE components that are application specific ranging from engines governed from 2200 RPM to 4000 RPM. If you are planning on swapping ANY transmission from a vehicle with a gasoline motor to a diesel powered bus (or any vastly different motor), it would behoove you to have a transmission technician go over it before you swap it.

In other words, unless you familiar with rebuilding transmissions, I'd probably pass on this one. It has been noted on here that LKQ currently has MT643s for sale from International applications for $645. You'd be much better off considering one of those (due diligence still required).

[SQ is the SQUAD]

does anyone know exactly what transmission came in the 01 c6500 trucks as automatics?

[PNW_Steve]

Originally Posted by SQ is the SQUAD

does anyone know exactly what transmission came in the 01 c6500 trucks as automatics?

I have seen mention of the 4L80E and the MT643/653 transmissions.

I am sure it depends on the engine installed and likely there were different options that could be ordered from the factory. I wouldn't be surprised to see the AT545 as well.

[SQ is the SQUAD]

i sent an email over to my local transaxle dealer to see what he comes up with for TC, adapter and flex plate, hopefully he can point me in the right direction. ill call LKQ and a few other "truck" places to see what they have on MT643 in stock.

[SQ is the SQUAD]

i still havent found the info i needed. i did find a MT643 from a diesel international for $200, but i am still lost on what i need for flexplate to adapt it


i did find this which looks like something i need but i still need to find the part with the starter ring gear


https://www.heavytruckparts.net/deta...26&searchnum=1