1999 SC1 Tranny issue, Plz Help

[ryansaturn]

My son bought a 1999 sc1 auto back in August. It had 166K. Car ran great up until last Thursday. He came to a stop sign and started out, the tranny quit pulling at any rpm above 800....Car just wouldnt go. So thinking tranny went bad he replaced it this weekend with one from a salvage yard w/87K miles. No with new tranny installed car will upshift quickly and bang up to 4th. If you let off the throttle it will down shift to 1st or 2nd and stay there. SES light came on showing codes....P0732, P0733 and P0734. Gear ratio. I verified today with salvage yard that tranny came out of a sohc car. Checked alternator and it shows 14.3V oncharge voltage. We are totally lost here as what to do. He needs the car to get to work and is going to attend Wyotech in April. Any help would be greatly appreciated.

Oh forgot to mention last weekend he replace the head gasket.

[OldNuc]

On the transmission, between the top pair of mounting bolts there is a series of numbers and letters punched lightly into the bell housing in a dot matrix pattern. Clean off that area with some brake cleaner and then rub it with a big tip Sharpie marker. You will see them. Ned to look at the first position is a number or letter, this represents the model year. The second and third position will be an M and P. The forth position will be either a 6 or 7, this represents 6=SOHC and 7=DOHC

Gear ratio chart. These do not have to be exact match to function. But it must be out of a SOHC.

Model year decoder. http://www.differentracing.com/tech_...in_decode.html

If it is actually a SOHC trans and 98 or later year

It could be a defective pressure control solenoid or a oiled connector at the top of the transmission. Neither of these is a likely problem though.

What are you using for transmission fluid and what does it look like? Is tehlevel correct?

[chingondearmona]

when i was in the days of getting a replacement for my transmission, i went to the junkyard the mexican guy their was so sure that a single over head cam transmission would work on my D.O.H.C engine. but i had already been acknowledged about the difference, so i went out back and saw the saturns they had, chose which was gonna be the donar, and once they had it off i went back to see if the donar car was really missing the transmission. sometimes these lazy junk yard people dont want to do the work, and try to sell you what is already of any junked cars. but man i can imagine that afterward he didnt even believe himself.

[ryansaturn]

Well guess what...I just looked the old tranny and yes it had MP6 in the numbers. Looked at the one from the salvage yard and behold MP7 !!!!!!!!!!!

When I talked to the guy this morning I asked him again and he ensured me it was from a SOHC....here is the catch. He also said the tranny had markings on it indicating it was not the original tranny in that car...Hmmmm guessing that is why it was junked as sure enough that one was not working in that sohc saturn either.....

Oh well at least we got to the bottom of it........He is supposed to have another tranny also. Im going to have him verify the numbers this time.

Thanks for the help!

[OldNuc]

Bring your marker and check your own numbers. Remember 98 or later is best and MP-6. If you get a Z or 1 or 2 first digit then get the intermediate shaft also as there is a design change at 06/00. Be careful with a 2000 year. look at the right hand axle seal and if it has a metal cover the 99 intermediate shaft will work but if it has exposed rubber seal then you need the late shaft.