I guess I am going to go ahead and order the new solenoids even though it is going to hurt the pocketbook a bit. Even if the old solenoids check out good, they are 19 years old and could fail shortly afterwards. It would be stupid on my part to have to go through all this work twice for $80.00.

What about the input shaft? I heard that the early models were prone to breaking the input shaft and they hardened the shaft to prevent this on later models. When did this happen? Mine is a '98.

Here is some information from a re-manufacturers website: " Starting in mid year 2000 models, all 4T65-E models received an upgraded valve body. Starting in 2003 the internal electronics were changed, hardened 4th gear shaft, ratcheting sprags for input and third gear were added. The last application was the 2011 Chevrolet Impala as GM has transitioned to the 6T70 family transmissions for 2012." I think what you were referring to was actually about the 4th gear shaft, which on earlier models was prone to stripping causing the loss of 4th gear.

I saw this on a transmission site:


Wont move in any gear
No movement in any range:

This problem can have numorous causes and on higher powered cars typically a broken input shaft or drive chain set is suspect. Below is a short list of potential broken or failing parts to cause it.

-Broken input shaft
-Broken drive chain or sprockets
-Extremely low fluid level
-Broken ouput shaft
-Clogged filter from excessive debris in fluid
-Broken oil pump shaft
-Stripped torque converter splines
-Broken Input clutch drum shaft
-Broken axle or CV joint
-Badly damaged geartrain or differential

Outside of checking the fluid level and axles there is not much you can do short of removing the transmission for a teardown to inspect the parts.

You could drop the transmission pan in hopes of an obvious fluid uptake issue, or even maybe to find chunks of what actually broke.

Here is the cause of no go. The splines on the oil pump drive shaft were stripped; the end that goes into the torque converter. What causes this? Was this the part that GM fixed by hardening the shaft? Don't want to install the new used tranny if I need to change this part out.

I examined the pump drive shaft on the new used trans and there are several damaged splines and others showing signs. Can I order a harden replacement shaft for this 98 4T65E?

I had one like you said broken input TQ shaft that would be a easy fix but trans would have to be pulled ?
I am not sure if it can access it from side cover if remover.
I am no trans expert but if the fluid changes on the stick from starting it I would say not broke.
But it sure sounds like that could be it with it working with no other problems before.

I Posted with out reading the last post or so. There is upgraded TQ pump shafts.
But why not just replace that in the old transmission ?

Yes, the turbine shaft can break on these; often where the o-ring sits. Mine was the pump drive shaft. I had a guy confused on this and he claimed 20 years dealership. To replace the pump drive shaft, you have to remove the valve body. I found a uses tranny with only 26K miles; must have been a Sunday drive car. Mine had over 204K miles so the clutches were worn. My plan was to drive until the trans started slipping and then rebuild. I knew it was only a matter of time. But this was a mechanical problem I did not know about. I am replacing the pump shaft and the solenoids and external seals and then installing the trans. There is a guy on YouTube that even rebuilds in the car; check out his videos.

Torque specs on the 4T65E anyone? Having to take the valve body off to change the input pump shaft.