FTSerg

Hello. Im looking for some help. My Mustang has a BBK CAI and a Throttle Body Spacer. It was shifting like a dream before today. Now it is shifting roughly and it's killing me. As I accelerate slowly, the car jerks hard as it shifts from 1st to second gear around 20 mph. This problem has manifested after I used motormedic engine flush and changed the oil. When attempting to drain the oil, I accidentally removed the wrong bolt. It was about 10 inches to the left of the oil drain plug. It was on the tail side of the oil pan. I put it back in and tightened it relative to how tight it was when I removed it. I'm not sure if that is what caused the problem.

howarmat

lose the throttle body spacer first and see if that helps. The CAI you installed might need a tune to work correctly as well.

JimC

As far as the spacer, that is simply a waste of $ and doesn't do anything. It isn't the cause of your problems

And as far as the jerking etc, it sounds like you have an automatic. You drained fluid out of your transmission. So now with it low on fluid your transmission is acting up and not shifting properly. Get it in to the shop so they can properly top off the fluid.

movielover40

The 5R55S automatic is a sealed transmission.

Take it in and they will fill it properly.

Derf00

Normally i'd say don't waste your time or money taking it in to have the transmission filled. It's a simple procedure on the 5r55s but, if the OP has indeed drained some fluid out of tranny while attempting an oil change, someone with more skill should be working on the transmission.

The 5r55s is a fickle one.

FTSeg - As Movielover40 and JimC pointed out, since it sounds like you drained some fluid out of your transmission, you need to have it filled back to the proper level. The 5r55s is very finicky about the correct fluid level and it takes some knowledge and skill to fill it correctly. If you over fill it you'll end up with leaks and potential damage to internal components. If you under fill it you end up with shifting problems (like what you are experiencing) and potential damage to internal components.