It's the little knob on the back of the tractor--between the tires, above the tow hitch........you probably had to unscrew the knob to get the tranny out....

Check your manual - you should find instructions for "purging the transmission" or something similar. It basically tells you how to purge trapped air inside the tranny so it works properly. You might even find the info in the "Getting Started" section of your manual. If all else fails, talk to your dealer.

Good Luck!

Thanks for the replies. Now I have another question on this subject. I put a new drive belt on during this process & I had to readjust the pulley, the one beside the idler pulley, as far as I could go with it and the belt still seems loose. It is the correct belt from a JD dealer. How tight should this belt be? Are there any other adjustments to tighten this belt other than that pulley?

Hmmm....

I just replaced that belt on my LT155. What a joy (not) that was. Are you positive that the belt is routed correctly, and that all the tension springs are back where they belong? With the parking brake off, the belt is pretty tight on my tractor.

I would get underneath and double check that everything is where it should be.

And just because the belt is the right one, double check that, too--I got a bad timing belt for my Freedom 42 cutting deck once--it had a few teeth that weren't right and would cause the whole belt to jump a few teeth every rotatation--resulting in the clash of metal under my mower deck--very frustrating until I figured out what was wrong.

I'm guessing that either the dealer gave you the wrong belt, the belt is mislableled, or some part of the pulley system isn't properly reassembled.......

Let us know how you make out. These things can be frustrating!!!!

Your traction belt may be adjustable in 2 places. An adjustment with the flat pulley on the arm and an adjustment on the very front v pulley in front near the drive pulley. I assume the 180 is similar to where the tension is set by the length of the spring on the brake rod 1- 1 1/4"?

I adjusted the idler pulley as much as I could and it is still fairly loose but the tractor does seem to run ok. I'm pretty sure the belt is on correctly & I see no other adjustments. I don't have anymore adjustment left so if the belt wears I guess I'll have to replace it.
I have instructions on how to purge air from the transmission but I am somewhat confused. It says to "run engine at low idle speed and repeat opening and closing the bypass valve while alternately depressing forward and reverse pedals".
What I did was open and closed the bypass valve then I depressed & released the forward pedal, then depressed & released the reverse pedal. I repeated this several times. I had the tractor in park while doing this.
Is this the correct way to purge the tranny??

Here's what the TM says:

1. Raise rear wheels off the ground. Support rear axles with jack stands.
2. Start and run engine at SLOW idle.
3. While alternately depressing the forward and reverse pedals, engage and disengage the freewheel valve lever. Continue this procedure until the rear wheels start to rotate. This step may take
5 to 10 minutes to perform.
4. Lower the machine to the ground.
5. With control pedals in neutral, push the machine forward and then rearward to turn the motor rotating group.
6. Start and run the engine at FAST idle.
7. Quickly depress and release the forward and reverse pedals until the machine moves without hesitation.

Be patient, it will take at least 5-10 minutes before the air will be worked out.

If you were in Park I think that loosens the belt, so you may not have been actually spinning the trans pump like you thought. Follow the above directions with the unit on jacksstands and it will probably solve the problem.