1999 MD306 Transmission

Neorush · 10-02-2019, 08:51 AM

This is my first post here, so be gentle. I've been researching for several months about the best bus for a skoolie or transit bus conversion. I've found one for sale that checks all the boxes, has an 8.3 Cummins, under storage bays, rear engine, etc. My only concern is that it has a 1999 Allison MD306 transmission. Doing some searching it appears the controllers for these are quite expensive, and for "early 90's" ones Allison doesn't even sell them anymore, you have to have them rebuilt, and some of them can't even be rebuilt. I'm looking for any feedback on this transmission at this point, the only other thing I found about the MD306 was that some did start having leaking seals overtime. Thanks for the help!
EDIT: I'm realizing I probably should have posted this under the Schoolie Tech -> Transmissions -> Cummins thread....sorry

PNW_Steve · 10-02-2019, 11:12 AM

Allison switched to WTEC3 in 1998.

If you are certain that it is a 1999 there are TCM's are all over wrecking yards and on eBay. You may even find one for sale here on Skoolie...... Unless I see it first

Neorush · 10-02-2019, 11:18 AM

Quote:

Originally Posted by PNW_Steve

Allison switched to WTEC3 in 1998.

If you are certain that it is a 1999 there are TCM's are all over wrecking yards and on eBay. You may even find one for sale here on Skoolie...... Unless I see it first

Awesome, just what I wanted to know! I am certain it's a '99.

o1marc · 10-02-2019, 12:03 PM

Isn't it an MD3060? If so, it is by far the most desirable tranmission to have.
Why are you concerned about the controller, is the one in the bus damaged?

PNW_Steve · 10-02-2019, 12:07 PM

That is an awesome drive train if I do say so myself

Neorush · 10-02-2019, 12:07 PM

Quote:

Originally Posted by o1marc

Isn't it an MD3060? If so, it is by far the most desirable tranmission to have.
Why are you concerned about the controller, is the one in the bus damaged?

It's not damaged as far as I know, I have not inspected it in person or anything at this point. Honestly it's mostly this post that scared me.

Neorush · 10-02-2019, 12:10 PM

Quote:

Originally Posted by o1marc

Isn't it an MD3060? If so, it is by far the most desirable tranmission to have.
Why are you concerned about the controller, is the one in the bus damaged?

Oh, and Yes, I typoed in the original post, it is an MD3060

o1marc · 10-02-2019, 12:21 PM

Quote:

Originally Posted by Neorush

It's not damaged as far as I know, I have not inspected it in person or anything at this point. Honestly it's mostly this post that scared me.

I personally would completely ignore that one in a million issue. The MD3060 is the most desired transmission in a bus IMHO. I've not heard the issue you posted as a common one. I have one in my 99 Genesis.

PNW_Steve · 10-02-2019, 12:38 PM

Quote:

Originally Posted by o1marc

I personally would completely ignore that one in a million issue. The MD3060 is the most desired transmission in a bus IMHO. I've not heard the issue you posted as a common one. I have one in my 99 Genesis.

I'm with Marc. In our application it is the most desirable automatic you can find in a bus.

Of all of the breakdown stories I have encountered here I can't recall one that involved a 3060 controller.

cadillackid · 10-02-2019, 12:52 PM

the TCMs can gio bad.. the software definitely has different versions in them.. the calibrations from one CIN to another do matter.. you can mix and match to some extent as long as the TCM you are going to use is for a similar vehicle.. same trans, generation, and engine and weight characteristics..

ive only seen one MD3060 destroyed in a bus.. and that was done by its owner trying to get the bus unstuck from mud and was just too rough on the trans and ruined it..

-Christopher

PNW_Steve · 10-02-2019, 01:01 PM

Quote:

Originally Posted by cadillackid

the TCMs can gio bad.. the software definitely has different versions in them.. the calibrations from one CIN to another do matter.. you can mix and match to some extent as long as the TCM you are going to use is for a similar vehicle.. same trans, generation, and engine and weight characteristics..

ive only seen one MD3060 destroyed in a bus.. and that was done by its owner trying to get the bus unstuck from mud and was just too rough on the trans and ruined it..

-Christopher

Christopher,

Can an Allison shop reflash a controller from with a CIN from a similar bus?
If you take one from a truck for example and program it with a CIN from a bus?

cadillackid · 10-02-2019, 02:03 PM

im guessing an allison shop is going to say no unless you find a really nice one.. they seem to be really tight to the chest with this stuff.. just like msanufacturers not wanting to turn on 6th gear..

I am not sure but I **think** every CIN in their mind is unique and no 2 should be alike.. maybe if you told them you were keeping a spare TCM just in case.. they would copy from one to another..

physically its easy to do. and only takes a short amount of time..

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