what model tractor is this

[jim cullison]

i have a oliver thats been in my family for many years. we think its a 77 or a 770. the hood was cut in half the front part is a 770 and the back part is a 77. the data tag says as follows. spec 372612 and ser 65037723. if anyone can help we would be greatful.plus we know what we are restoring. thank you.jim cullison

 

[B A Star]

You have a 770 that was built in late 1958.  It was built with a Power Booster drive.

 

[Tramway Guy]

Should be a 1958 770...
I presume the grill is one piece with the horizontal bars all the way across (no vertical center strip)?

 

[jim cullison]

thank all of you for your help. can you tell me what a power booster drive is.thx jim

 

[Tramway Guy]

Power booster is the same thing as a Torque Amplifier as used on IHC tractors. It is a two-speed auxiliary unit between the engine clutch and the transmission; provides both regular (direct) operation plus a lower-speed setting, selectable by a lever on the left side of the tractor. It is designed to be shifted at any time into either speed. The primary use is to get through a tough spot during drawbar operation; drop into low range under heavy load, then shift back to high speed once the need for more pull is reduced. Also to reduce speed for turning at the end of a row for cultivating or any similar operation. No engine braking was available in low range, due to the use of an overrunning clutch in the unit.
The successor to the Power Booster was the Hydra-power drive, a much improved unit first available on the 1600, 1800 and 1900 tractors.

 

[Mike (WA)]

Good explanation. Pay special attention to the "no engine braking in low range"- This fact is especially useful to know if you're just driving the tractor for the first time, and pull it down into low range going down a hill to slow down a little.

Don't ask me how I know.

 

[Anonymous-0]

Be careful when you try to use the booster for a reason to slow down, instead of using the throtle. The unit was not to be used for that reason as it was not intended to be used for a brake. this is the same for any one company that used a booster or amplifier with a the over running spraque. this is the major cause for most of the failures in all of the companies be it what ever manufacture. It is also advisable to not feather it when you shift up or down it will cause prmaaature wear on the cluthes in the booster or amplifier.