720 trans gear?

Neighbor has a 720 that he want to use on tractor rides but it has the slow speed transmission gearing. How many different options were there on a 720? How hard of a job would it be to change to the higher speed gears? How many different parts would be needed? Thanks Tom

there was 2 optional gears. an optional 5th which made 5th 8 mph and basically moved the other gears up 1, as in 1st became what 2nd was and 2nd became what 3rd was and so on, but with that gear set 6th stays the same speed. to put optional 5th in you have to remove flywheel and side cover behind it then it is right there. not a hard job as long as the top shaft is drilled and tapped already for the bolts that hold the optional gear on.

then there is the optional 6th which gains you 1 mph in road gear, also increases 4th gear a little, however that gear set requires removing both transmission shafts, which means both sides have to come apart, flywheel, cover on that side, clutch/pulley, first reduction cover, and so on. this isn't a hard job either if you have mechanical abilities but you will definitely want a book as it is much more involved that what is required for the 5th gear swap.

there is also a company that makes road gear sets that will get him 21 or 24 mph i don't remember which it was and i think those were around $1700 and you had to get on a list and wait till he had enough guys that he could make 7 or 8 sets at a time. this set also requires that you take the whole transmission apart.

with the optional 5th you will have to switch shift quadrants or renumber the one you have, but if just changing the 6th gear set you don't have to change the quadrant.

i put both the optional 5th and 6th in my 720 2 winters ago, i switched them from another 720 that i had at the time so i had to do twice the work but i wanted them in this one as i was selling the other one they came out of.

the quickest easiest way to increase his speed would be to put 16.9 38 tires on it instead of 15.5 38s like most have. my road gear gained 4 mph with the 16.9s over the 15.5s that were on it. i like the looks of the bigger tire on them too.

if you have more questions or need more details i can try to help, this just gives idea of his options

i found the link for the post that gives speeds and quadrant layout for each optional gear. may have to copy and paste in the address bar


http://forums.yesterdaystractors.com/viewtopic.php?p=7583058&sid=248b8ceaf81a9138c7b67886ec95586f

Tom : Looking at 730 specs.page, seems there were 3 Opt.'s on trans ; Opt.4th looks like it keeps the slower 1,2, 3, but gives fastest 6th. I've never had trany on one apart ,[only diffs & bull gears] , I'm sure it would be many hours, a complete tran tare down ,, 'Oh' and Tom read your post on forage sorghum, interesting to me , made some comments.... You may need a mag. glass to see specs..

Thanks for replying to both posts. I have been busy and not checking in as often and had not checked the sorghum post. I will talk with my seed salesman about rate and give the bean cup on the slow speed a try. I lost some hay to winterkill and want to plant something in it after first crop or maybe where we chop rye. Tom