Car in sig. just got done changing rear gear from 350 to 390 to have a bit more fun. First drive it seemed to shift into 3rd and 4th with hesitation almost like it was slipping. Drove it again today and it shifts hard as it always did to 2nd and slips into 3rd and 4th. if you gas it in the higher 2 gears seems to slip. There does seem to be a little vibration in the higher 2 gears as well. This trans was built when the 383 was built and upgraded by a gm mechanic so its not stock. Trans has 64K on it and 20k after it was upgraded. Is this the 3-4 clutch pack? Please help. do I need a new trans or rebuild this one?

 

Just curious, did you reprogram the shift points?

 

haven't yet was gonna have a dyno tune after I get my new nos kit setup, think that is a issue?

 

the gears really should not have anything to do with the trans slipping,, the shift points will be off, trans will shift way early with the new gears and probly hit the rev limit on a wot shift,, so a tune is a must with the gear change to make things work correct.

check the trans fluid and drop the pan to see if there is anything going on.

 

the fluid seemed fine in color and maybe smelled burnt a bit but it would as it slips pretty bad in 3/4. is this something with a fix or do I need to go a diferent route with the trans? there is a guy selling a pro built automatics rebuild kit -pro street elite 93-96 which is new in the box, is this a option? would you fix or rebuild the trans if I got it to you? I am now demotivated over the nitrous stuff (brand new never sprayed) I am gonna pull the kit and sell it and keep it a motor car till I get something else. performa built sells a level 1 trans for $1440 shipped to the door good to 500Hp or a level 2 pro race for $1740 good to 700Hp. If I can get mine right for less than $1000 that would be the route being you have alot of high end parts in it that I would never get much for.
is this a 3/4 clutch pack issue?
Shawn

 

Sounds like something is going on in the input drum, theres no way to tell for sure except pull it out and apart. If 1-2 is stout its likely not a press. solenoid. U will have burnt clutches to replace anyways. Take it out and tear it down.

 

It is a 3-4 clutch issue. Tear it down and see what happened. I have all of the necessary parts to fix this and for the additional horsepower you are thinking of adding. You might only need a few parts here to fix it. Let me know if I can be of help? After the transmission is fixed, get the computer set for the proper shift points.

 

Dana, sounds good. I have a plan a which is to fix this one as it has alot of $ in it if not plan b was to just get one of your level 2 trans before you even jumped on this post.

this trans has
billet servo
13 vane kit
raybestos pro series band
500 boost valve
1-2 acc spring
hd pump slide spring
6 3-4 blue plate clutches
then in 04 15K ago
blue plate deluxe performance rebuild kit
trans go shift kit
hardened input drum/shaft/sun shell assy
forward piston bonded
piston 3-4 clutch bonded

thus alot has been put into it to just dump it and start over