Rebuilt transmission shift issues

[Wags391]

1992 S10 Blazer, 4x4, 4.3L Z, stock 4 speed tranny

I recently had the transmission rebuilt. The pump was replaced instead of being rebuilt. I'm having shifting issues mainly when the tranny is hot. I've had it back to the shop three times and I'm becoming increasing upset with the mechanic, naturally.

When cold, the tranny will shift normally thru 1 to 4. The shifting from 3 to 4, however, varies more than it should. I understand the variations in shifting points due to throttle position, but having paid attention to the throttle for weeks now and where the shift happens, it is not consistent.

When hot, the tranny will shift normally thru 1-3, but into 4 may happen anywhere between 40 and 55 mph. Again, with the understanding of various shifts points depending on throttle. At normal throttle, it may shift anywhere between 40 and 55 mph. Also, when cruising above 55 mph at light throttle or no throttle, the tranny will slip back into 3 or just out of gear all together. I then have to stay off the throttle or rev the engine in order to get it back into gear.

When detent shifting (correct me please if that doesn't mean WOT shifting to accelerate quickly), the tranny will release out of 4 and not into any gear. The engine will rev until I release the throttle and the tranny will eventually lock into 3. Also, to get the tranny to downshift at all, I have to push the gas completely into the floor.

I went through the throttle valve cable adjustment procedure in my shop manual. After I adjusted the cable casing all the way towards the tranny, then turned the throttle to WOT to "ratchet" the casing to it's "set" position, it does not ratchet forward at all. Does this mean there is an issue with the cable, valve, plunger, or other part of the TV cable system? Are those parts usually a part of a rebuild? Should the mechanic be able to match the cable to the spring so it works perfectly??

I know my first mistake was not taking it to a dedicated transmission shop. What information can take to the shop in order to get this figured out?

[MT-2500]

Originally Posted by Wags391

1992 S10 Blazer, 4x4, 4.3L Z, stock 4 speed tranny

I recently had the transmission rebuilt. The pump was replaced instead of being rebuilt. I'm having shifting issues mainly when the tranny is hot. I've had it back to the shop three times and I'm becoming increasing upset with the mechanic, naturally.

When cold, the tranny will shift normally thru 1 to 4. The shifting from 3 to 4, however, varies more than it should. I understand the variations in shifting points due to throttle position, but having paid attention to the throttle for weeks now and where the shift happens, it is not consistent.

When hot, the tranny will shift normally thru 1-3, but into 4 may happen anywhere between 40 and 55 mph. Again, with the understanding of various shifts points depending on throttle. At normal throttle, it may shift anywhere between 40 and 55 mph. Also, when cruising above 55 mph at light throttle or no throttle, the tranny will slip back into 3 or just out of gear all together. I then have to stay off the throttle or rev the engine in order to get it back into gear.

When detent shifting (correct me please if that doesn't mean WOT shifting to accelerate quickly), the tranny will release out of 4 and not into any gear. The engine will rev until I release the throttle and the tranny will eventually lock into 3. Also, to get the tranny to downshift at all, I have to push the gas completely into the floor.

I went through the throttle valve cable adjustment procedure in my shop manual. After I adjusted the cable casing all the way towards the tranny, then turned the throttle to WOT to "ratchet" the casing to it's "set" position, it does not ratchet forward at all. Does this mean there is an issue with the cable, valve, plunger, or other part of the TV cable system? Are those parts usually a part of a rebuild? Should the mechanic be able to match the cable to the spring so it works perfectly??

I know my first mistake was not taking it to a dedicated transmission shop. What information can take to the shop in order to get this figured out?

The detent cable is not part of a transmission rebuild.
But it should have been checked/fixed and adjusted when the transmission was installed.

Who installed transmission?
You or the mechanic that worked on it?
If not working and adjusted right it will wipe out a transmission very fast.

[Wags391]

The mechanic did the entire job. There is still the warranty, and of course, they said bring it back in and they will look at it. Unfortunately, it is harder to get it back to the shop because i live in a completely different part of town. I'm hoping next week I will have some time.

So, if the casing doesn't ratchet forward when attempting to adjust the detent cable, what does that mean? Is the cable too old and worn out? Is the mechanism at the tranny malfunctioning? What info can I take to the shop in order to tell them what they should be doing? They obviously don't know what they are doing completely, even though they have been "rebuilding transmissions for 20 years".

[MT-2500]

Originally Posted by Wags391

The mechanic did the entire job. There is still the warranty, and of course, they said bring it back in and they will look at it. Unfortunately, it is harder to get it back to the shop because i live in a completely different part of town. I'm hoping next week I will have some time.

So, if the casing doesn't ratchet forward when attempting to adjust the detent cable, what does that mean? Is the cable too old and worn out? Is the mechanism at the tranny malfunctioning? What info can I take to the shop in order to tell them what they should be doing? They obviously don't know what they are doing completely, even though they have been "rebuilding transmissions for 20 years".

If it is under warranty take it back.
Cable may be bad.
Cable Not part of transmission rebuild but they should have adjusted it when installing trans.