Transmission issues

[adamj24]

Hi, i have a 1994 chevy k1500 silverado. I just replace the tranny with a freshly rebuilt one but im having same issues as before. It only shifts into 2nd gear if i let of throttle at about 3500 rpm. And once its in 2nd it is stuck in 2nd until i put the truck in park and shut it off. Any help is Appreciated.

 

[NickTransmissions]

Hi, i have a 1994 chevy k1500 silverado. I just replace the tranny with a freshly rebuilt one but im having same issues as before. It only shifts into 2nd gear if i let of throttle at about 3500 rpm. And once its in 2nd it is stuck in 2nd until i put the truck in park and shut it off. Any help is Appreciated.

Check your vehicle speed sensor, perhaps it isn't transmitting or doing so only weakly (because it's not plugged in or died). 4WD vehicles have it in the transfer case, not the transmission.

That's probably the problem.

 

[adamj24]

Ok ill check that. Thanks

 

[Sean Buick 76]

I would start by bringing it back to the shop that rebuilt the trans.

 

[NickTransmissions]

I would start by bringing it back to the shop that rebuilt the trans.

It's not likely his trans; could be servo (seals cut on install) but the fact it's not upshifting out of 1st points to VSS as that's usually the reason. What would be interesting is if he replaced the transmission due to the failure of a $35 part (VSS) in the transfer case. The other possibility is PCM and/or vehicle wiring harness to the trans and/or TC VSS.

All that stuff should have been ruled out via diag work prior to replacing the origional trans unless that failed for other reasons, not mentioned in his post (ie 3-4 clutch pack failure).

 

[Sean Buick 76]

It's not likely his trans; could be servo (seals cut on install) but the fact it's not upshifting out of 1st points to VSS as that's usually the reason. What would be interesting is if he replaced the transmission due to the failure of a $35 part (VSS) in the transfer case. The other possibility is PCM and/or vehicle wiring harness to the trans and/or TC VSS.

All that stuff should have been ruled out via diag work prior to replacing the origional trans unless that failed for other reasons, not mentioned in his post (ie 3-4 clutch pack failure).

I agree, that’s why I said to take it back to the trans shop for a diagnosis. Actually to be specific do not drive it at all and have it towed to the trans shop. Unfortunately they likely never did a proper diagnostic prior to taking in the trans job but you bet your bottom $ they will test the VSS etc now.

 

[NickTransmissions]

I agree, that’s why I said to take it back to the trans shop for a diagnosis. Actually to be specific do not drive it at all and have it towed to the trans shop. Unfortunately they likely never did a proper diagnostic prior to taking in the trans job but you bet your bottom $ they will test the VSS etc now.

True - I was thinking he pulled the unit and brought it to them for rebuild as they wouldnt have let it go out the door like that. Reading his post, it seems as though he removed and reinstalled it, the shop just rebuilt the trans then handed it back to them, but I could be wrong (nothing was explicitly stated in the OP).

Plus he can rule in or out the VSS before spending $75-$125 on a tow bill to get it back to the trans shop, unless they'd pick up the towing fee.

 

[Sean Buick 76]

Yes I thought the same thing.

 

[NickTransmissions]

Hi, i have a 1994 chevy k1500 silverado. I just replace the tranny with a freshly rebuilt one but im having same issues as before. It only shifts into 2nd gear if i let of throttle at about 3500 rpm. And once its in 2nd it is stuck in 2nd until i put the truck in park and shut it off. Any help is Appreciated.

Did you have the trans shop R/R your transmission as well as rebuild it or did they just do a carry out rebuild for you?

 

[adamj24]

It's not likely his trans; could be servo (seals cut on install) but the fact it's not upshifting out of 1st points to VSS as that's usually the reason. What would be interesting is if he replaced the transmission due to the failure of a $35 part (VSS) in the transfer case. The other possibility is PCM and/or vehicle wiring harness to the trans and/or TC VSS.

All that stuff should have been ruled out via diag work prior to replacing the origional trans unless that failed for other reasons, not mentioned in his post (ie 3-4 clutch pack failure).

I replaced the trans because it was slipping alot and the if it did shift it would shift realy hard and jolt the truck. Now its not slipping and when it does shift it shifts smoothly