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Transmission Swap

oldfolksmopar

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Speedway, IN
Howdy, I haven't been on in a long time. My buddy, has a question about an Tranny swap. I am only going by what he is asking.

He has a 1983 D150 with a 318 and 904 trans. He also has a 1989 D150, 318 with a A-500 trans. The 500 Tranny has an overdrive unit on it. He states that the overdrive for this tranny has a button on the dash. When the button is pushed, it goes into overdrive. He states that the A-500 is about 3 1/2 inches longer than the 904. Both trucks are long beds, so swapping the drive shafts should work.

His question is, what controls the overdrive? Is it just powered up by 12 volts or is it controlled by the ECU or something else. If it is 12 volts, he is wondering if he could just hook up a switch on the dash of his 83 when he does the conversion.
Were assuming that the bellhousings are the same. So has anyone messed with something like this?

Thanks for your time. Oldfolksmopar
 
The A500 is basically a overdrive 904, like the A518 is a overdrive 727. Check out these guy's to see if they can help, they have things for the A518. The computer does control the overdrive. Yes it will bolt in, the bellhousing is the same.


Dodge 518 Conversion. 727 to 518 Transmission Swap Information. - PATC - TransmissionCenter.net
Thanks 65 sporty, this is exactly what we were looking for. Man it's great to have people with great knowledge and info. Thanks.
 
He will have to use the cross member from the 89 for the trans. Not sure if it will bolt in at the same location.
There is a company that provides the ecu bipass to make the OD function as normal. Cost about $60 I think.
If I had the 518 installed could tell you more.
 
Yup the crossmember will be in the same place on both trucks but the mount itself is way different between them. I've modified a 904/727 crossmember to swap in an overdrive before but it's easier just to get the one from the truck for the overdrive trans
 
i just put a 318/a518 driveline from a 1991 d 150 longbed into an 86 d150 shortbed. 88 up has a motor mount extension on the left front and the rt frt mount hole is also forward. thereby moving eng forward so mother mopar could use the same trans crossmember holes in the frame holes. when i mounted the eng in the 86 holes i had to drill all new holes in the frame. then the 30 gallon gas tank would not fit as it hit the crossmeneber. i did not want to move the eng forward so i moved the crossmember back 2 inches from the stock crossmember holes and modified the back side of the drivers side crossmember a little and now have approx 3/4 in clearance between the tank and crossmember. use the crossmember from the 89 as there appear to be 2 different crossmembers. 1 where the "u" of the crossmember is level front and back and 1 where the frt is dropped down lower than the rear part of the "u".
 
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