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99 STS with transmission problem


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Hello all,

today I saw a '99 STS with transmission problems advertised for sale. I called and asked what kind of problems the transmission has. I was told the car drives forward and reverse when the oil is cold, but shifts erratically through all gears. When warmed up, the car is no longer drivable, it only 'creeps' forward and backwards. The seller couldn't tell me anything regarding codes.

It's got about 80,000 mls on the clock, is fully serviced and second owner. Other than that the seller told me it's in perfect condition.

Question for the experts; does this failure pattern point to a typical problem, which could be rectified with the gearbox in situ, or is the box most probably shot and would need to be replaced?

Would a gearbox from a pre '98 model fit in this car?

The car is not located 250 mls away from me, so I can't go there easily to have a look.

What do you think; should I pass on this one?

Thanks for your opinions,


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If the owner cannot, or will not, pull the codes, I would pass.

I agree - it's a matter of pressing two buttons and then writing down the codes. (S)he should be willing to do that.

<!--fonto:Arial--><span style="font-family:Arial"><!--/fonto-->2007 DTS Performance - 50K


As a matter of fact, I <i>am</i> driving 70 MPH in a phone booth.

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Look at the worst case scenario.

Is the cost new trans. + the cost of the car less than the cars value?

If the owners trade it in they will get next to nothing for it. Low ball them (offer a VERY low price for the car) and see what develops.

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Even if she does pull the codes, I'll bet they are clean or have nothing to tell you about the tranny... If your lucky one of the shift Solenoids is shot... maybe the shift presure solenoid is "stuck" open or closed... all of these are common problems... in early N* transmission these solenoids were held in with plastic clips, later GM switch to steel one... I don't remember which year.. These can be fixed without removing the transmission...

Just about everything else will involve removing the transmission, maybe a swap or rebuild... at an independent shop the re&re will cost about $700 on its own (or over $1000 at a dealer)... and while just about any 93-99 transmission will work... Be careful there are at least 3 (maybe 4) different Axel ratios (STS, SLS, Aurora and autobahn Aurora)... Get the wrong one and your PCM will go nuts...

A "good" used tranny is worth 500-1200 (plus installation) and a "new" rebuilt unit from GM with a 3 year warranty is about $2500.

As noted above, if the car is nice and otherwise in nice shape... figure what that would be worth with a good tranny and then subtract at least 3500-4500 from that price...

Selling a car with a dead tranny really limits the number of buyers and will significantly reduce the car's value..

If the car is otherwise nice... this would be a good candidate for a "flip" buy it low... fix the tranny and sell a running car...


Easin' down the highway in a new Cadillac,

I had a fine fox in front, I had three more in the back

ZZTOP, I'm Bad I'm Nationwide


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thanks a lot for your opinions, it's much appreciated!

Called again today, the owner is not able/willing to do the code check, some people are not of this world I guess. Also unwilling to negotiate, so I'll pass on this one.

OynxSTS, good to know these figures, thanks!


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as a point of discussion, what do they want for the car as is? how does that compare to a running vehicle in your area? can they justify not discounting it if it requires a big repair? people are funny.

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good point. They are asking € 4,600 (US$ 6,000) for the car as-is. A comparable car in perfect technical condition could fetch € 7,500 to 8,500 (US$ 9,750 to 11,000).

But they don't move fast (in sales, that is).

I'm looking at another one tomorrow. We'll see...


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