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Discussion Starter · #1 ·
Been lurking here for awhile and just created an account. I searched the forum for an answer but was unable to find what I needed.
I have a 70 Chevy with a 6v53. It had an Allison MT41 that lost its input shaft. I would like to replace with an Allison 2000
I have two major questions.
1) The MT41 supported the back end of the motor. Is the aluminum case on the 2000 strong enough to do the same or will I need to fabricate rear motor mounts?
2). I’m doubtful the flex plate/torque converter will be a direct swap both both depth and bolt pattern wise. Are there Allison/Detroit parts I can purchase or will this be a custom flex plate?

appreciate the help!
 

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Hey Jon, the Allison 2000 should be a direct bolt on. Parts are available from Allison and I'm sure they have flex plates that will work on the 6V53. The MT41 plates might match as well but I can't confirm this. The mounts on the Allison should hold the weight no problem.:) I was going to swap an Allison 1000 onto my 4-53T, but chose to use the Ford 5R110 instead. CA Conversions would be the guys to talk to, I phoned them about my Allison swap and they were very helpful. CAConversions | Custom Automatic Conversions | Call 865-253-1133
 

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I've done this! I don't think I did any write-up on it, but I know I used the flexplate from a Cummins application and machined an adapter that centered the torque converter on the Detroit crank. In my case, I also had to adapt from SAE2 flywheel housing to SAE3 torque converter housing.
I know that the flexplate from an Allison 645 will not bolt up to the 2000 series torque converter.
I will try to find pictures of what I did.
 

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Discussion Starter · #4 ·
Awesome, appreciate all the replies & suggestions. Look forward to pictures wolf-creek-steve

I’ll be looking for a ‘06 2000 as I was told it’s the only year the 6 speed came with an integrated input speed sensor
 

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That PDF says 2200 has park pawl but my 2400 has the park pawl also.
Tons of information here, a must read!
 

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Jon6v53, I know I had to make an adapter that positioned the torque converter a distance behind the Detroit flexplate. This adapter was bolted through the flexplate into the crank. It had a snout that mimicked the torque converter snout, so it was centered perfectly in the Detroit crank/flexplate. On the opposite end it had a counterbore for the torque converter snout. The exact length of this piece is important as it controls the engagement of the torque converter in the transmission. I don't remember the exact length, but somewhere around 1 1/2" IIRC.
I know I incorporated the Cummins flexplate that came with the transmission to drive the torque converter, but don't remember how I fastened it to the Detroit flexplate. Regardless of what I did, I know that I had to make 3/8" thick spacers that fit between the Cummins flexplate and the torque converter.
I'm sorry I can't be more precise with my information, but for some reason I didn't take pictures or keep any notes. I have a couple Allison drawings that Neodan sent to me that may help you.
Schematic Handwriting Font Parallel Technical drawing

Schematic Font Parallel Handwriting Plan

Schematic Handwriting Font Parallel Technical drawing
Schematic Font Parallel Handwriting Plan

 

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Been lurking here for awhile and just created an account. I searched the forum for an answer but was unable to find what I needed.
I have a 70 Chevy with a 6v53. It had an Allison MT41 that lost its input shaft. I would like to replace with an Allison 2000
I have two major questions.
1) The MT41 supported the back end of the motor. Is the aluminum case on the 2000 strong enough to do the same or will I need to fabricate rear motor mounts?
2). I’m doubtful the flex plate/torque converter will be a direct swap both both depth and bolt pattern wise. Are there Allison/Detroit parts I can purchase or will this be a custom flex plate?

appreciate the help!
Jon------You didn't indicate whick bell housing was on the 6V53, but I assume it was SAE 3 adaptation , but could have been SAE 2 . The 1000,2000, 2400 has 3 different converter housings available, but 2 or 3 is usually on 2000/2400 .Those sheets I sent Steve were copied off a CD , I may have something for the SAE 3 adaptation , it was several years ago when I tried to glean the info off the CD that was applicable to 53 series. But I think i recall that the flywheel flexplate combo for AT545 will work, considering you may have the SAE 3 housing . As Steve said, the "Complete Allison Thread" is what you need to study . Advice as an ex-DDA application person 36 years ago .
 

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Discussion Starter · #10 ·
I’ve been chipping away at that thread, great information so far.
I have the SAE 3 housing so I’m hoping it won’t take too much adaptation. AT545 parts seem to be east to get around here. Once I get a trans and see what I’m working with it shouldn’t be too bad. Anyone know of the best throttle positioning sensor for a 6v governor? I’m currently thinking one of the cable ones would be best as it’s already quite busy on top of the gov.
Thanks again, I’ll try to document as best I can for any future projects.
 

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I’ve been chipping away at that thread, great information so far.
I have the SAE 3 housing so I’m hoping it won’t take too much adaptation. AT545 parts seem to be east to get around here. Once I get a trans and see what I’m working with it shouldn’t be too bad. Anyone know of the best throttle positioning sensor for a 6v governor? I’m currently thinking one of the cable ones would be best as it’s already quite busy on top of the gov.
Thanks again, I’ll try to document as best I can for any future projects.
When the previous generation of Allisons came out in the early '70s,[AT545,MT643,HT700] , we were supplied with a 3" application manual with the detail and potential sources of modulators, coolers, shifters, output flanges etc . Now, you're on your own !
 

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Wolf Creek, the 2400 is shown as a separate series from the 2000. Yes it has the park feature as well as the 2200 and 2350. There may be 20 model versions or more within that 2000 series. Each number often has 4 or 5 versions. There are 5 2200 versions, 1 2300 version, 3 2350 versions, etc. As far as I know, the sub series is 2000, 2100, 2200, 2350, 2400, 2500, and 2550.
 

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Wolf Creek, the 2400 is shown as a separate series from the 2000. Yes it has the park feature as well as the 2200 and 2350. There may be 20 model versions or more within that 2000 series. Each number often has 4 or 5 versions. There are 5 2200 versions, 1 2300 version, 3 2350 versions, etc. As far as I know, the sub series is 2000, 2100, 2200, 2350, 2400, 2500, and 2550.
Char------That just looks like RPM calibration for shift points .
 

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There are all kinds of little differences in the various sub models. Some have different load capacity. On top of that there are 4 different torque converters so you might come up with near 100 versions. Allison designed these so they could have one to fit any possible application. Although some of the differences are very slight, that difference can mean getting the perfect transmission for your application. I'm sure they planned that any customer would come to them and they'd work out the perfect model for your intended use.
 

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"I'm sure they planned that any customer would come to them and they'd work out the perfect model for your intended use."
If this were my #1 priority, I (like many others here) would go buy a new pick-up.


All this discussion about the minor differences is great, but I'm assuming all these varieties don't grow on the same transmission tree out behind the garage. I also assume the original poster is going to either shop at a salvage yard or purchase a parts vehicle, if this is true, he should have an understanding of the differences, but be willing to compromise. (stay away from a trans from a chevy gasser pick-up, both the bell housing and the torque converter are wrong)
Mine is a 2400 that came out of an 07 Ford F650, but I'm unsure if it was a 5.9 or a 6.7 Cummins. I was lucky and got both modules and a chunk of wiring harness with the trans.
 

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Discussion Starter · #17 ·
I want to stay away from a park pawl, so I currently have my eyes on several 2000s (the stand alone harness guy said to stay away from 2010 and up due to the variable boost control solenoid). I’d really like one from between ‘06-‘09.
The torque converter part is certainly the oddball part of this swap since I think the 1600-1600 stall speed of a torque converter from say, a Chevy 8100 vortec will fit the power band of the high-reving 53 series verses the 1100-1200 stall from a Cummins/Allison application.
All that aside, I should be picking one up this week so I can at least start dealing with any mount / driveshaft modifications. I’m pretty confident any flex plate mods will be a fairly straight forward modification if I can find a guy with a plasma table.
 

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Allison doesn't state a torque converter stall speed. They specify a stall ratio. TC-210 has a ratio of 2.06 which translates into a stall speed of 2100-2200, TC-211 has ratio of 2.01 and stall speed of 1900-2100, TC-221 has a ratio of 1.75 and a stall of 1700-1900, and TC-222 has a ratio of 1.63 and I couldn't find its stall but it will be under 1700. To make matter more fun Allison has revised the torque converter 5 times so you have a bunch of part numbers to guess what you really have. Below is that list.
 

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I want to stay away from a park pawl, so I currently have my eyes on several 2000s (the stand alone harness guy said to stay away from 2010 and up due to the variable boost control solenoid). I’d really like one from between ‘06-‘09.
The torque converter part is certainly the oddball part of this swap since I think the 1600-1600 stall speed of a torque converter from say, a Chevy 8100 vortec will fit the power band of the high-reving 53 series verses the 1100-1200 stall from a Cummins/Allison application.
All that aside, I should be picking one up this week so I can at least start dealing with any mount / driveshaft modifications. I’m pretty confident any flex plate mods will be a fairly straight forward modification if I can find a guy with a plasma table.
Jon-------You misjudge the unique characteristics of the 2 stroke engine..............in that their torque at clutch engaging speed, [ T-800 ] is almost equal to peak torque, which may be 16-1700. Personally, I'd select that 11-1200 stall .
 
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