1993C4LT1

Not a fan of the soft shifts with the trans in OD. In D, they are noticeably firmer. That's why I only use OD on the highway. I know a shift kit will firm up shifts. But will it only firm them up at WOT, or part throttle as well? Will it still shift at the same RPM/Speed when at WOT, and part throttle? With a shift kit, does the factory settings for TV stay the same? Because I was reading that it increases line pressure? Since the trans in my 93 was rebuilt May 2015, I just want to get the longest life out of it. And I understand that firmer shifts put less wear on the clutches. The trans is not a 4L60E, it's called a 4L60 in the FSM. Basically a 700R4. Only pointing that out because most think 93's have a 4l60e.

Kevova

Because trans was just rebuilt you should talk to rebuilder. See what he thinks of shift quality. Sometimes shift improver kit are installed during the rebuild. Also if someone tweaks trans and causes a failure; rebuilder is unlikely to stand behind it. Most the time shift kits are worth it, unless trans is already hurt. Most kits will cause clutches/bands apply quicker with more pressure or less dampening by removing check *****, enlarging apply orifices in spacer plate, changing springs, removing springs, disabling accumulators, etc. With electric shift it would be software and possibly component upgrades.

1993C4LT1

​​​​​​​So is the clutches/bands applying quicker better, worse or the same as a stock trans? I'll contact the rebuilder. I doubt he'll stand behind it even if he installs a shift kit. It only had a 1 year warranty.

Kevova

Quicker apply or release means reduced wear of bands and clutches. The 3-4 shift is not known to be harsh. Maybe because of the rear axle ratios. WOT shift into 4th is well over 120 mph in stock form.

1993C4LT1

I think the fastest I have been in this car is 120 Yea, I don't remember a 3-4 shift being harsh in my other auto c4. I don't want the tires chirping at part throttle, just want them firmer. 1-2 shift is firm with trans in D. It'll sometimes chirp tires into 2nd with gear selector in D. All other are soft at part throttle.

1993C4LT1

​​​​​​​It will sometimes chirp them into 2nd, when going WOT. Meant to say that.

vette196

started looking into this for my '96 with 91K miles on it. Will a shift kit add stress and speed up the demise of my old trans?

aklim

IMO with that much mileage, unless most of it was highway miles, I really wouldn't want to waste my money. I would do it all when I rebuild or just rebuild now and have it included.

Kevova

With a 4l60e a shift kit would be more of reprogramming transmission operation in PCM . There maybe some minor changes to spacer plate, but I not certain it's worth doing by itself. Reprogramming would change shift timing and feel and where I would start first.

tlong

You can program shift characterustics in the PCM. The major advantage of a shift kit is manual operation. Harmless downshifts and rifle shot upshifts are why it;s installed. It changed my car dramatically.

RVY

Why don't you consider a SONIC throttle cable spring. It increases tv pressure a moderate amount and may be all you need.
For about $5.00 cost and about$6.00 shipping it's worth the effort.
It takes about 2 minutes to install--unless you drop it. Look up PATC transmissions to order.

BlowerWorks

You might consider using Amsoil SuperShift trans fluid. 100% syn and less friction modifiers. I have used it in several transmissions and like it. greg

Charles.rogers1

I have a shift kit in my car.. donno brand or anything like that, came in the car. But my shifts are very harsh lol! its super aggressive just putting the thing in drive!!