1999 Silverado Z71 Shift Kit

famouslee99gt · December 6, 2006

I have a 99 Silverado Z71 with the 5.3 V8. I use my truck on the farm to tow some wagons and installed a snow plow on it and will proceed to use it this winter. I was just curious if anyone had installed a shift kit on their truck. I was just going to go with the stage 1/level 1, which is for towing purposes.

If anyone has done this modification, do you regret it or not? When you are driving very nicely, can you feel the shift between gears?

Thanks, Lee

c4cruiser · December 6, 2006

What brand kit are you looking at?? I have heard that some kits have different firmness even though they are the lower levels.

famouslee99gt · December 6, 2006

I have found a B & M shift kit online. The only thing I have found only though is for a Silverado 2500, 5.3L, 3/4 ton....which I am unaware of GM ever making a 2500 with the 5.3. They also show 2 different kits, one costing $35 and the other costing $83.

Here is a link:

http://www.1motormart.com/parts/1/1999/200...ransmission+Kit

Nappers · December 6, 2006

fullsize chevy.com has a great write up on this topic with some comments, not sure if the guy bought a stage 1 or 2.

Link: http://www.fullsizechevy.com/forums/showthread.php?t=114807

Have fun.

Aaron

c4cruiser · December 6, 2006

Before you go with a shift kit, have you used the Tow/Haul mode? That will change the shift points and I think it will also firm the shfits up a little.

It's a pretty good system but you just have to remember to turn it on each time after shutting off the engine.

I wonder if any of the tuner/programming kits will allow for changes in either shift points or line pressures??

famouslee99gt · December 7, 2006

I talked to my local tranny shop today and they gave me some advice. They suggested not to do a shift kit, but to install a Corvette servo. They also said that you can adjust the pressure valve solenoid inside the tranny. They suggested to replace that solenoid and adjust the new valve. In addition to that, they'll perform a transmission service. All in all, it is an estimated $200 dollar project. I believe I'm going to pull the trigger and do it.

If anyone else has heard of this or has performed the upgrade, let me know your results

Thanks

famouslee99gt · December 15, 2006

My truck went into the shop on Wednesday for the transmission upgrade. The truck was completed in a day. They installed a used Corvette servo, installed a new pressure valve solenoid and serviced the transmission.

Upon getting the truck back, I noticed it wasn't shifting into overdrive. When I left work, I got in the throttle and it hit the rev limiter before shifting. When I took off from the stop light, the transmission was slipping severely. I then noticed in my mirrors that smoke was rolling from under the truck. All my fluid had puked out.

The next day I called them up and told them my story. They picked up the truck and fixed it free of charge. What had happened was the snap ring that holds the servo in wasn't seated right, and started to pop out. As it was popping out, part of it was still in there, and that bit cracked my case/housing. They say it'll be alright, but if it gives me any problem, they'll throw in a new case.

In the event that I need a new case, I'll pay the difference to have the tranny rebuilt since it's at 106k miles and I will be towing on the farm and plowing snow with it.

I can notice the truck does have a firmer shift now. I've only put 9 miles on the upgrade. I'm being easy on it for now, so I haven't done a full throttle run to see how it shifts.