Swapping a transmission 403

CHARLES EARTH

MEMBER
1990 DODGE VAN
5.9L
V8
2WD
77,000 MILES

I switched a 1996 403 transmission into a 1990. Worked before, now as a test, it lags. I converted the speedometer module, the other two module plugs fit. One is a three-pin round, the other a two-wire like-a-molex. Anybody know anything about this "delemon". Is it possible that three-pin is upside down? Ironically one flywheel hole-to-converter did notT Line-up. But 3-DID. That was very unique. YES, I did try spinning the converter in all 4 combination. Can any one help this fool? (Although, sometimes being a fool can be fun. Lol. CRZ)
1996 was 3500, regular length, the 1990 is extended 3500, same general casing, but the 1996 has that 2 wire sensor at cross member, the other was slightly different, but same fitting-plug. Also I have no clue what ST LB rwd means. Mine-both were RWD, only.

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning,

First, you have the wrong transmission in the van. You have a van that uses OBD2 for controls where your original did not.

You cannot use the torque converter with 3 out of 4 bolts. All the bolts must be there and secured.

ST and LB mean short wheelbase or long wheelbase.

You need to find the correct transmission and install it for it to work properly.

Roy

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Wednesday, January 29th, 2020 AT 3:32 AM

CHARLES EARTH

MEMBER
1 POST

Thank you this site and Roy. You both rock. My question answered is very sensible. The 96=obd2, 90=obd1, but on a repair manual the internal parts look the same, and both sensors fit. The third I swapped out no-problem. Anybody know why they "know" that it-is-a obd1, or 2? Special thanks to Roy. And-also, I did slightly open up the fourth hole on fly VRS converter to get a bolt in. Added a dot of quick weld, cooled as-fast, to counter balance-it as well. So, anybody know what makes them diff, when the look exactly? 403 1990 vrs 1996-403 transmission. Sincerely, Charles

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Thursday, January 30th, 2020 AT 9:59 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

You are welcome.

By drilling the plate, you have altered the balance of the torque converter and the flex plate. If it worked. You most likely will get a vibration from the power-train.

As far as OBD 2, it knows from the electronics.

Roy

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Friday, January 31st, 2020 AT 11:19 AM