New to the forum. Thanks for having me. Considering buying a 1968 JD 450 from a very good friend. Looking to do some small tree work on my 14 acres. This is all new to me. Overall this machine seems to be in very good condition for its age. His father bought this machine 14 years ago. He says at that time the motor and steering clutches were rebuilt/replaced. The undercarriage seems to be good with no slack in the tracks. Maybe even replaced at one time. They used it to dig a bank out for a cabin foundation. Other than that it has had an easy life for the past 14 years. The only concern I have is with the left steering. He says forward, reverse and right work flawlessly. But with left turn he says the lever is really hard to pull but if you "double pump" the lever it turns left like it should. He says it has been like this as far as he can remember including when he used it to dig cabin foundation. What do you suppose this could be? Does this just sound like an adjustment or this part replacement related?
Issue is probably with the power steering, steering linkage, or clutch/brake adjustment. Lever pull @ 6" of travel should be less than 12lb with engine running and less than 40lb with engine off.
Thanks for the reply. He gave me the shop manual to look at while I decide if I want to do this or not. I looked at the components you mention. I will start by testing the lb pull on levers as you mention and detailed in the shop manual. I would think that could easily determine if power steering issue or not and it's an easy test to start with. It would seem to me from reading the adjustment process that the steering linkage would be part of the clutch/brake adjustment. It's all working together. Does that seem like an accurate statement? Are you able to feel somewhat confident in telling me from my description that this would not be transmission related?
The clutch/brake sets are what do the steering so, yeah, it's not the transmission. The steering system is what has given me most of my problems and is probably the weak point of these tractors. They went to wet clutch/brake with the C series to improve it. I only mentioned the steering linkage b/c there might be something binding up.
GREAT. THANKS FOR THE HELP.
Check with JD Crawlers.com. This issue is addressed quite often. There are guys that frequent that forum who are experts with these older JD crawlers.