770 power booster

Olliejunkie

Well-known Member
I picked up a 770 a few weeks back and finally got it running good enough to drive. The power booster does not work in low. I thought it went in once but I'm not sure. The lever has a very long throw. It comes so far back that it's hard to get my foot on the clutch. Can this be adjusted out? Also I have not checked the trans oil. Would the power booster not work if it was low? Alot of oil came out of somewhere when I was loading and unloading it.
 
Low range is the sprag clutch. You have a lot of wear in the linkage. Also how much effort does it take the Power Booster clutch over-center?. You need to take the cover off and look in there!
 
it moves pretty easy when its not running. It seems it is kind of hard to get out of high when running. I will try to get a closer look. Thank you!
 
I had the same problem with my 880 with the long throw of the lever. Mine has the old style throw out bearing. It's like the brass collar in the PTO. It was worn almost all the way through. I replaced that collar and the lever throw was cut in half. If the clutch won't grab in low range, the sprage clutch and the shaft it rides on is probably worn.
 
Did it still have the hose to grease it? There were 2 versions of them and the first ones would break.Your 880 must not have gone through the Power Booster program back in late 1960
 
mine does have a grease hose coming out of the top. I assumed it was for the engine clutch. Does this mean it was updated?
 
Yes it does have a grease hose to the throwout bearing and another for the power booster throw out collar. Replaced both hoses. It did not go through the update. Don't know why that never happened. Had a heck of a time convincing the parts person that I needed the brass PTO collar to fix my power booster.
 

I only saw one hose on mine. I'm a fair weather mech . It may take a few days to get back to it. I should quit buying tractors and build a shop. Lol.
Thank you all for the input so far.
 

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