Hi all,
Since my last post asking about swapping my 5 spd man to a 518 auto, I have just located an Allison transmission located right here under my nose at my local salvage yard. Can anyone tell me what pitfalls there is to installing this, what all I will need to buy, where to buy them, and how expensive it will be? Thanks everyone for you help.

 

Im not sure on everything but I know you will have to get a stand alone unit to control the trans, last I checked they were still very pricey.

 

What model is the Allison? I spec'ed an allison for an on airport application in the early '90s and I believe we decided on a 500 series - 545? - it was rated at 650lbft of torque. The problems to overcome as I remember were:
1. No parking pawl on tranny.
2. You will need an SAE bell housing Cummins techinical staff helped with that.
3. Flex plate. Needs to work with Dodge starter.
4. Torque converter - you will need to address preformance specs here.
5. Adapt to fit Dodge driveline.
6. TPS to control shift points.
7. Shift linkage in cab. I forget now who makes a tower and cable - probably close to $500 for this by now.
8. Possible rear tranny support - the Allison is heavier then the Dodge.
9. Gear selection - whats the 5th gear ratio? Should be an OD.
Might be more but I can't remember. It is do-able but probably cost prohibitive.

Bob

 

Thanks Bob for that info,
I love difficult projects-they make me feel good when I finish them. However, I can see where the $$ amount may make it a not too wise choice, since I will not be using this truck to make a living towing heavy loads lots of miles. I think the 518 would probably last me several years even though it isn't nearly as durable as the Allison. Thanks again Bob.......... So guys, I am still looking for a 518 out there somewhere.

 

[quote author=Bob Beauchaine link=board=9;threadid=23755;start=0#msg223869 date=1071518895]
What model is the Allison? I spec'ed an allison for an on airport application in the early '90s and I believe we decided on a 500 series - 545? - it was rated at 650lbft of torque. The problems to overcome as I remember were:
1. No parking pawl on tranny.
2. You will need an SAE bell housing Cummins techinical staff helped with that.
3. Flex plate. Needs to work with Dodge starter.
4. Torque converter - you will need to address preformance specs here.
5. Adapt to fit Dodge driveline.
6. TPS to control shift points.
7. Shift linkage in cab. I forget now who makes a tower and cable - probably close to $500 for this by now.
8. Possible rear tranny support - the Allison is heavier then the Dodge.
9. Gear selection - whats the 5th gear ratio? Should be an OD.
Might be more but I can't remember. It is do-able but probably cost prohibitive.

Bob
[/quote]

A couple of days ago I found on the net Allison 545 units that were in Fords against the ISB. Should not be too much of a problem.

 

The 545's are known to be a "throwaway" tranny. However, going to the 1000, 2000, or WTEC series Allisons will put alot of electronics into the picture and may not work since we have no ECM, such as the TCM, 1939 backbone, etc. I guess if the 545 is the only one that would work on our 1st gen mechanical B's then I would go for it if you wanted an Allison. But, IMO I would put the money towards a new tranny from DTT or ATS. I feel it would be cheaper in the long run.

 

Also remember the ISB has a different power curve so you will still need to make sure that the torque converter will transfer power correctly. Sounds possible but with the advancements in preformance trannys the question remains - why?

Bob

 

Scottmn1;
I looked into the same conversion (before converting to my ATS) ;D and according to a tranny tech. out a truck shop, the problem with the conv. in the 89-93's is there's no room in the front end for a tranny cooler large enough to adequatlly cool. :'(

ramguy

 

I'll swap ya my 518 stuff for your 5 speed stuff