1993 Chevy 1500 with 4L60 Tranny question.

Question

I have a 93 Chevy 1500 with 4.3L v6. Motor and tranny are rebuilt recently. My question is on my tail shaft on the 4L60 tranny there is a speed sensor and it reads the speed of the speedometer gear on the shaft inside the tranny. Anyway the gear is hitting the sensor making me not be able to see how fast I'm going on the road.When i am going down the high way it usually reads 80 mph up and down when I'm going 55 or 60 mph and just jumps all over the place. The cause I believe is from a bad bearing allowing the shaft with speedometer gear to be a little sloppy and hit the sensor. This is what i learned from a different tranny shop also letting me know it would cost $1350 to fix this bearing Should’t this be something covered by the tranny shop that did the rebuilds warranty??? This is my question. I mean if they are professional and all, why was this over looked. When I get a rebuilt tranny back it should be just as good as a new one. Heck i can buy a new tranny for $1350 if i shop around. I think this is ridiculous and i may have to sue the place. What do you think??????

Answer 1

take the vehicle back to the trans shop that rebuilt the trans it should be covered under warranty for at least 1 yr or 12k miles. they  can look at it and fix the problem if it is the trans for free. make sure you let them know that you want to know what the problem is before they repair it and if there is going to e any cost to you first.

Answer 2

Something doesn't make sense here.  The speed sensor doesn't get its information from a gear but a magnet on the tailshaft.  If your tailshaft is loose you have a far more serious problem than a speedo but I doubt that is the case since by now there would be trans fluid all over the place as it wiped out the tailshaft bushing and seal.  I think either your speed sensor is defective or a wire to the sensor is shorting out or going open causing the erratic speedo behavior.  If thats not it then the speedo itself is defective and not related to the transmission rebuild.  I have seen a lot of defective speedo heads doing just what you are saying so my money is on a bad speedo head.  If you can get access to a scanner you can read your speed digitally and see if its the head or the sensor.  Good Luck.