I have a 1991 Chevrolet Camaro Z28 with a 5.7liter tpi matched up with a modified 4l60(th700r4)automatic transmission that has an aftermarket Corvette shift kit and a 10-clutch kit pak and the rear end ratio is 3.23:1 with no posi traction. My first problem I'm having is the gear shifter. Whether if it's in park or any gear the shifter has excessive movement while in gear and I will also notice that the red marker moves with it not staying in place with the gear selector letters(P,R,N,OD,D,2,1). Before this happening, the shifter was fixed in place and the red marker stayed whereever I selected the gear. Is there something in transmission selector cable I can adjust? or are the bushings in the shifter worn out? My second problem is the downshifting. Everytime, even prior to rebuilding the trans, I have always had this loud hammer-like noise coming from underneath the rear part of the car when downshifting from second to first as I decelerate or apply the brakes to slow down to a stop. Is this what all 4L60'S do when they are downshifting? If not, please let me know where the problem lies. Your response is greatly appreceiated. Thank you.

 

My experience: NEVER downshift from D to 2nd, or 2nd to 1st unless you know there will be no engine braking! Just a few downshifts (maybe 20 total), and I burnt up my overrun clutches. Read here: (I'm not the poster, but this guy has the same problem).

https://www.thirdgen.org/techbb2/sho...hreadid=200888

Downshifting in an auto is hard on the drivetrain. As for the noise, it could be u-joints.

 

When using a 700R4, only downshift from [D] to D, just to get out of overdrive. Have you ever felt the car jump in RPMs when it downshifts? That is because automatic transmissions have a hydraulic cushion for downshifts, but forcing it into a lower gear is very hard on it... don't do it.

 

No, I have not shifted down to lower gears. It happens when I am in D or OD on deceleration and coming to a stop. I have replaced the u-joints a year and half ago. May someone further explain to me the purpose of engine braking? Is it normal to feel a firm downshift when slowing down? Does the transmission make noise when it is engine braking and has anyone experienced any problems with a loose console gear shifter? If so, how can it be ajusted or does the shifter have to be replaced?

 

Check the shifter cable mount and the cable end bolt on the transmission. Sounds like one or the other has come loose.

RBob.

 

my car in drive has that same wierd harsh endine drag when downshifting from 2 to1 in drive. i have no clue it feels damaging so i just keep it in od unless racing. just wanted to let u know u r not alone and yes it does suck!!

 

I get ya know. I know what you are talking about. I have the same porblem, except ONLY in D and never in [D]. So if I am driving around in D and I am coming to a stop I just push it into OD before the 2-1 shift. However, I don't know what is causing it... I just don't like it.

My tranny is custom built for over 600ft/lbs torque, and as I am only putting out less than 400ft/lbs I think I am pretty safe... but I don't want any damage to come to it.

 

As for the shifter problem, it sounds like your cable might have broken, this plastic thing on the shifter side of the cable. Check it out and get a new cable. Mine is broken right now and I am putting in a Hurst Dual Gate 2 next week.

So right now, with the excessive gear play and the guess and check of moving it around until I feel it move, just put the sifter into drive, and move it as far forward as you can to make sure you are in OD instead of D. That MIGHT stop the hard downshift.

 

As far as the shifter problem goes I have gone through 2 shifter selectors and both have taken a crap as you have described. I finally bought an after market shifter. Although the new shifter didnt come with any kind of selector. So for a while I ran around with no top on my shifter. It was kind of ghetto looking, and I had to mentally count gears at first, but I got use to it. Now I'm building one out of polished stainless steel. I say poop on GM's cheap crappy plastic gear indicator!