Hard shifting & delayed engagement LS

[Carl Smith]

While driving the car at normal speeds of say 40 mph through 60 it will have random hard shift thuds & sometimes when going from reverse to drive it will have a slight delay before the trans engages. I have done some reading up on this issue with the LS and the diagnosis almost always points to the solenoid pack. Before I plan for that I have a question. The ABS light is on because of rear speed sensors. I swapped both off another LS I have and now the scanner just shows one bad instead of both, but still has the ABS service light on. Will this affect the trans shifting or enable any sort of "limp mode" ?

 

[joegr]

On gen II, it can cause a particular ETC failsafe mode, but not on the 1st gen. I don't know which you have. Oddly enough, it should affect shifting on either generation. A shaft output sensor is used for that.

 

[Carl Smith]

It's a GEN 1 V8. I get no sensor codes for anything aside from the rear drivers side related to the ABS but wasnt sure if that was playing a role. I would say its the solenoid pack. I had planned for the modified servo's as well so may just swap both.

 

[grizzlyls]

Order the valve body rebuild kit as well. You can look back at my early threads and see why. Been a few others found this out since I joined too. In my case the solenoids were fine, but heck mech was in there, no reason to leave 15 year old bothersome parts in when in the same area.

 

[BuckeyeBrass]

I had a Chrysler make thuds when shifting because the engine mounts were broken and the engine was moving around in the engine bay. You can have someone observe the engine doing this, looking for engine movement while putting in gear, and also while in gear gently rev the engine a little while applying the break with the parking break on.

 

[Carl Smith]

Thuds were to describe the hard shifting jerk I get at highway speed. Yes, after some further reading I've decided on at least reman pack & valve body replacements along with filter. May as well freshen everything up in one swoop. Going to add the o ring modified servo's as well.

 

[BuckeyeBrass]

Bump just because I'm curious if this was resolved.

 

[RollinLS]

Personal experience. New servos, rebuilt the transmission. Started shifting hard. Replaced PCM. Reprogrammed it. Runs and shifts like new.

 

[Carl Smith]

Bump just because I'm curious if this was resolved.

Not yet. Doing the timing chain & electric fan conversion right now.