Harsh 1-2 shift

4L60E, 2000 Camaro

Anyone on this board know about valve bodies? My 1-2 shift is abnormally firm and slightly delayed. All other shifts are smooth. Stock trans tuning. What is the first thing I should check? Replace 1-2 solenoid? I changed the fluid and filter not very long ago. It did not help.

Is your Service Engine light on? If so check the code. Also I had the same thing to happen ended up being the Mass Air Flow sensor.

Viper

No. It's the trans.

Originally posted by poniekiller
No. It's the trans.

I know its the trans, what I am telling you is I had the same exact thing to happen to me and the MAF was the problem. Would shift very harsh from 1-2 and then fine from 2-3 and 3-OD. Now this may not be your problem but take it from a very experienced F-Body owner, DO NOT DISMIS IT. If you have a friend or something with a F-Body switch MAF sensors and reset your Computer then try it. If not then try to reset the computer by itself and see if it goes away temprarily. If not then look at the solenoid. I replaced mine first and did not fix it. Sometimes the most obvious things are not the cause.

Viper

Viper (isn't that a Dodge?!?) could be right. Some engine management problems will cause the PCM to spike line pressure, especially if it can't accurately tell engine load and determine how much line pressure the trans needs. If your engine is ok then the things to check are: #8 and #1 check balls for proper location. If the trans has never been messed with they are probably in the correct locations, check the spacer plate for peening where they seat. If the plate is damaged then replace it. Also check the 1-2 accum. for a split seal or binding in the bore or on the shaft. Make sure the accum. spring isn't broken. Check the 1-2 shift valve for binding. Check the 4-3 sequence valve, I think it's the 4-3, it may be the 3-4. There's only one and it's purpose in second is to control the bleed of the 1-2 accum. oil. If it's sticking the fluid won't bleed and cause a harsh second. Also check the spring under the bottom servo piston, if it's broke it won't cushion the band apply. Also, not all codes will turn the check engine light on. Some need to see two or more failures before the light comes on so you may have a code stored, no light on, waiting for another failure. Emissions failures will turn the light on ASAP. Trans. concerns typically don't turn it on as quick. Let us know how you do. Good luck.