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Would you do the tranny swap if you could get a nice 97 SLS for $1700 and some work?

  • Yes, that's a sweet deal.

    Votes: 1 100.0%
  • No, I'd rather buy one that was running for 2 grand.

    Votes: 0 0.0%
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Registered
2000 Dev, 94 FW (crushed), 96 FW Limo (sold), 95 SLS (sold)
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367 Posts
Discussion Starter #1
I've got a line on a 97 concours with a blown motor and a "torque converter problem". The owner before the current owner says it had the TC problem for over 40k miles.

I've also got a line on a 96 SLS with a blown tranny. The current owner says that the car can probably limp up on a trailer or take a short ride around town before it's completely gone.

So my questions are:
Can the 97 tranny drop straight onto the 96 cradle?

Are there any programming issues since the concours is a 300HP and the SLS is a 270HP?

Does the AC system have to be opened to drop the cradle and RR the tranny?

Can you point me toward any resources (besides the FSM, of course) that will help?

Thanks for any tips.
 

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2005 White Diamond STS N* 1SF RWD ACC/HUD
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2,053 Posts
There will be a problem since the Concours tranny has a different final drive ratio from the SLS tranny. This will be a problem for the PCM.
 

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1994 cadillac concours
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21 Posts
bro im having that problem right now.. i put a 97 sts tranny in a 94 concours..he is right the PCM is programmed for the gear ratios of a 94 concours and it is forcing my new tranny from the 97 to shift in those ratios and that is makin the shifts really jolty.. i havent found a cure yet.. no one here in toronto,canada can program or tune a 94 PCM.. :(
 

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Super Moderator
2010 DTS
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87,559 Posts
That's the problem with cross mating these transmissions. You MUST stay with the same trans VIN 9 to a VIN 9 or a Y to a Y. I think you need to find the correct trans and start over.
 

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2007 EXT Supercharged
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1,510 Posts
Are there any programming issues since the concours is a 300HP and the SLS is a 270HP?

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Its not really the 300hp vs 270hp, but the final drives are wrong. I believe someone said they tried doing this but wont shift past 2nd gear and throws codes, obviously the tranny is reporting one speed, wheel sensors are reporting another.
bro im having that problem right now.. i put a 97 sts tranny in a 94 concours..he is right the PCM is programmed for the gear ratios of a 94 concours and it is forcing my new tranny from the 97 to shift in those ratios and that is makin the shifts really jolty.. i havent found a cure yet.. no one here in toronto,canada can program or tune a 94 PCM.. :(


hmmm...concourse should be same vin as an STS, final drive the same, they are both 300hp motors....

only thing i see is the 94 is obd 1 and the 97 is OBD II

oh wait, take that back.....is a 94 concourse the 295hp version??
 
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