Steering Clutches – Brakes JD 450 loader

I'm new to the forum, and from reading some of the topics, I believe you guys are the ones to help me. I've had a late 60's dry clutch JD 450 loader for the last 15 years. It's just for my use around the house, and I recently have another issue (of many) with it. The engine probably has less than 250 hours on it since I've owned it, and it was completely gone through just before I bought it. I know this 'cause a friend of mine had it and sold it to me after it was finished. I am a fairly good auto mechanic and have had my backhoe into separate parts a few times for engine, clutch, freeze plug, etc. type of work and have been inside a diesel engine or two, but I have limited knowledge about the steering and braking system on heavy equipment. The brake and steering clutches on the right side of the loader have been inoperable for at least 3 years, so I use the left stick only to maneuver. While I was trying to push up a tree stump last weekend, I found that the left track is no longer pulling - AT ALL - but the right track pulls fine. I had the left side drive gear, clutches and brake band replaced about 4 years ago while the broken frame rails were being replaced. I periodically have to adjust the brake band on the left side because the adjustment rod jam nut is stripped. I know - fix it you say, but time is not on my side sometimes, and I will eventually get around to it. How do I get the left side to pull? Do I adjust the clutch pack (13/16" box end wrench nut) under the left side cover plate just above the track? If so, what is the starting and end point of this adjustment? These clutches have fewer than 25 hours on them since replacement, so I hope they aren't worn out. When the last 2 jobs I need the loader for are finished, it's time to get rid of a lot of equipment I've collected over the last 30 + years - this JD first on the list. Thank you in advance for taking the time to help.