Hey all,

I just installed a performabuilt lvl2 4l60e and an FTI 3600 TC and now I'm experiencing a bit of a grinding in OD at low speeds. The install went well and I triple checked all of my measurements and tourqued everything to spec to make sure I would have no issues. The transmission shifts perfectly throughout all of the gears unless I hit OD while I'm going <40 MPH, then there is a grinding sound and slight vibration, but it goes away if i manually shift it into 3rd. It doesn't happen if I hit OD while at highway speeds. I haven't had the car tuned yet. Could this just be a tuning issue because I haven't adjusted the line pressure, shift points etc?

 

I'm guessing it is a tunning issue. I'm guessing it is your converter locking at very low rpm's. That can be taken care of in a tune. I have mine set so it will not lock in first, second or third at all and only in over drive if I am going faster than 40 mph.

When you are experiencing the chatter next time keep your speed but also gently apply your brake. This will unlock your converter and the chattering should go away in turn it being a lock up issue at to low of speed that will easily be taken care of in a tune

 

I will keep that in mind next time I am cruising around. I'm still babying it around to break it in and make sure I don't have leaks anywhere. How long does it take to unlock once the brake is applied? Will just a tap do or will I feel it unlock after I apply the brake?

 

It will unlock immediately and you will feel it and see it with a slight jump in rpm's.

Just barley hold your foot on the brake. As long as you have your foot on the brake the converter will stay unlocked.

 

My converter locks at 43 mph.