ok i changed my 10 bolt drums to a 9 bolt disc,before it ran fine,now i finished last night and i tried to test it out by taking it to work and heres whats wrong:the speedometer says 110 when going with flow of traffic on freeway.when i let go of gas it fells like its downshifting,and when i get to a certain stable rpm it gives a weird kick in the rear,its wierd,please help

anyone?

need more input did u use same rear end or did you switch and what about spider gears or is there anyway you could have mixed up parts.or maybe left a thrust or 2 out. sounds like spider gesrs 2 me ....If I had 2 guess

It also could have something 2 do with clutch pack? like I said more onfo would help

What was the gear ratio of the 10 bolt rear and what is the gear ratio of the 9 bolt you have in now. When you change gear ratios you have to change speedometer gears in the transmission.

i switched the whole rear itself,and i dont know the stock gears but the 9 bolt is 3.70 or 3.73 i forgot i dunno wats wrong

The stock gear ratio was probably 2.77 or 3.08 since your speedo is so far off. You need the change the speedo gears for your new ratio. Go here to find out what gears you need:
https://www.thirdgen.org/newdesign/f...n.shtml#tranny
or
http://www.tciauto.com/tech_info/speedo_gears.htm

so a new speedometer gear would fix that problem,but how about the way it acts in the rear

Changing the gear ratio makes the car accelerate faster. When you let off the gas, it also makes it decelerate faster.

You need to explain the weird kick in the rear better. I'm thinking it might be a u-joint issue. Also, check your drive train alignment. I can't remember where, but I read a magazine article about checking to make sure everything is in a straight line from the tranny to the rear end. If your stuff has really bad angles, that might be something you need to fix with shims.

well its like someone hit you from the back, like a lil impact that made me jump when it happened,actually i still jump when it happens

I can't help, but for someone else who might be able to help, does it do this impact once when you get to a stable speed, or does it constantly do it, or does it do it as you go from speeding up to slowing down or vise versa?

I'd be careful driving it too much until it's fixed. It doesn't sound good.

You need to explain your problem more so the solution will be more evident. Does the kick happen at a certain specific speed? Does it happen constantly or just randomly?

Actually it may.
Depending what engine and computer you have the stock computer PROM on some setups is configured to lock the torque converter clutch around 75-80 MPH no matter if you are at wide open throttle or no throttle at all and it will remain locked above that speed. Also it is configured to lock the TCC around 35 MPH depending on TPS and a few other things. So if you speedo is reading 110 MPH on the highway so is your computer. That means the computer will lock the TCC much much sooner then if you had the right speedo gears in it. A quick way to see if it is the TCC locking causing the knocking problems is to unplug the 4 pin connector from your transmission and see if it goes away.