IH 3514 transmission issue

[jc-ih]

Thanks to all the guys that identified my tractor...
Now the hard work will start....

So when I got tractor there was a gap between the transmission and engine...so I thought it was an easy fix by just tighten it back in....but than when I started and back out..it seem to move ok...and slowly have not torque...I put into forward same issue.

....at first I thought it was low on Hy fluid but than read the manual and it said there should be fluids at tip...there's not mark on dipstick. Also this tractor take up 18 gal of HY fluid..and I only added 3 gal and saw fluid at the tip..

The tractor has H/L 5sp forward and one Reverse..
Any advise on why this maybe the issue. Thanks