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Trans Question

JESMAT5243

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I have a 87 D150 shortbed. Slant six with A904. My question is can I use an A904out of a earlier year car? I think the donor was a 77 volare with /6 a904 combo.
 
Thanks for the reply. So correct me if i am wrong but i will be going to a non lockup a904 from the volare to replace my lockup trans i currently have. Would i need to get a torque converter for a volare since i bieleve input shaft and spline count are different? 27 on the volare trans, i believe mine is a 26
 
That I don't know. Hopefully someone that does will chime in. I didn't think an 1987 904 had a lockup converter. If they have different input splines then you would need the correct converter. Also need the correct converter for the balance of the motor so might want to make sure the 87 and 77 /6 motors are balanced the same.
 
I did a little research and there is a difference in spline count between the non lockup and lockup torque converters. You can use the early trans as long as you use the matching converter.
 
If you’ve done the research and actually inspected the spline count, and they are different, that’s one bit of info you need for sure, the tranny has to be used w correct converter no doubt. Throwing this in,my 78 Aspen slant 6 904 was a lock up type tranny/converter. The 77 donor might be not sure.
 
78 was 1st year for lockup, some had it, but not all. When you have the TC off its easy to tell if the trans is lockup or not. if the splines go all the way to end of input shaft it is NOT lockup. If the shaft is smooth and turned down a little smaller at the end and the splines start about 1/2" back from the end it IS a lockup version.
 
all the way til at least '90 they built some each way. My son's W250 with 360 (gas) factory trans is a 518 w/o lockup. Original trans in his 360 powered 89 Ramcharger is a non lockup 727. Though now it has a lockup version 727 in it from an 80 Ramcharger. My own 78 Sport Fury (318,904) is NOT a lockup. (very early build 78 in Aug 77) And still has a drain plug in the converter. I know they eliminated the drain plug in everything whether lockup or not, right around the time that lockup came out. no lockup converters ever had a drain plug (from the factory, anyway) info I remember from some old Mopar factory training manuals I used to have around here. and various factory service manuals.
 
Here it is
 

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78 was 1st year for lockup, some had it, but not all. When you have the TC off its easy to tell if the trans is lockup or not. if the splines go all the way to end of input shaft it is NOT lockup. If the shaft is smooth and turned down a little smaller at the end and the splines start about 1/2" back from the end it IS a lockup version.
Great info Volaredon, now can't a person install a non-lockup converter in the place of a lockup, like on a 78 year model up, and it work, just won't have the extra final drive ratio that the lockup provided? They will fit in otherwords, somehow, I had one done years ago. There was mention of spline count difference but.....I dropped off a lockup 904 and got back a non lockup 904 with the agreement of the builder using a non lockup converter due to price. Teenager at the time, short of money, I ended up putting a higher ratio rear diff in the Aspen from a cop car from the bone yard, it work great, I had my highway ratio back.
 
You use to be able to just buy a non lockup converter for the lockup shaft.
The big reason for going non lockup was the lockup converter would not holdup to pulling loads and would burn out form the heat buildup in the lock clutch. I had such a set-up in a 727 la block transmission. Anyone needing such a critter make me an offer. I think it can from an 83 D150 and worked great when pulled. Have been sealed up since and still has fluid in it.
 
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