ok first off i have an 89 LO3 with 700r4. in OD and D it does this. if i shift it myself 1st-OD it doesn't do this. but when it's shifting into 3rd when it's in D or OD it does something funny. now this is very hard to explain but i'll try my best. it doesn't slip but it just seems liek it either revs out or it shifts to 3rd and then down shifts and goes back in 3rd. it's got tranny fluid and i heard a filter could be the problem but i'm not sure. any suggestions guys? i'm going to the track soon with it and would like to get this problem fixed. and by the way, it has done this since i got the car.

 

Sounds more like a locked torque converter unlocking as you go from one gear to another.

Maybe not, though. But, I finally figured out that's what was happening to mine - TC locked in 2nd, then unlocked as it shifted to 3rd. However, mine is worse if I'm shifting it manually.

My symptoms showed up after the shift kit install. Have you done anything to your transmission?

 

nothing is done to it as far as i know.. doesn't shift like there is a shift kit so i don't think so

 

Is your speedo functioning correctly? If it is not, the computer may think you are going faster than you are, and shifting into a higher gear, and then it shifts back to the correct gear after it relizes that it is actually going slower. My car does this occasionally, because i have a dakota digital speedo calibrator, and is getting some interference from my tach wire, causing the speedo to fluctuate.

 

man you're right on the money.. my speedo is about 10mph off.


now what would i do to fix the speedo? pretty much all my guages are off. my gas guage is off, speedo is off, temp is off, voltage only works once in awhile, oil works once in awhile. tach works as far as i know

 

Not sure if all your gauges being off would be the problem. However if the speedo is off only two ways i know of fixing the speedo calibration is to change the speedo gears in the tranny, if you have 3.73 or lower gears.....If you have 4.10's like i do, I could not find the right combination of gears to make the speedo read correctly, so i bought a speedo calibration box(made by Dakota Digital), that converts the input signal from the tranny and coverts it correctly to my speedo.

Speedo calibration gear help is on the FAQ part of thirgen under Tranny/Drivetrain/Rearend

This is what the calibration box looks like