Heymow - Lawnmower Racing Forum

Mower Building / Setup Help => Driveline => Topic started by: 84 prospector on December 28, 2022, 08:01:11 pm

Title: 700 transmission help
Post by: 84 prospector on December 28, 2022, 08:01:11 pm
Building a mower, already bought axle sprocket etc. just need to get a transmission and build steering, front axle. I have access to a 3 speed 726, but was wanting a 4 or 5 speed for more range. What?s the difference between the 3 and 4 or 5 speed? Is one more durable than the other and does the 4 or 5 speed offer a faster high gear than 3rd on the three speed? Thanks
Title: Re: 700 transmission help
Post by: leman on December 30, 2022, 02:20:30 pm
I think the only difference in the 3, 4, and 5 speed transmissions are the gear sets inside of them.  The 3 speed transmissions generally came in snowblowers.  That's why there were no 4th or 5th gear in them.  No need to run behind the snowblower haha.  Besides having different gear sets inside, everything should be interchangeable with the 4 and 5 speed transmissions. 

Most people race the 4 or 5 speed transmissions in 3rd gear anyways.  This is the strongest gear set to race with because the gears that transfer the power to each other are the same size (25 tooth gears i think...).  When you take your trans apart to race prep it, see if any of the 3 gear sets are two 25 tooth gears.  If there are, you can just race in what ever gear that happens to be and change your sprocket sizes to adjust your final ratio to the size track you are running. 
Title: Re: 700 transmission help
Post by: 84 prospector on January 18, 2023, 12:37:57 pm
Ok that makes sense. I got the 3 speed and mocked it up. When I?m race prepping it and putting gear oil in, can I leave the reverse chain in with the gear oil? I just need reverse for now until I start racing next year.
Title: Re: 700 transmission help
Post by: leman on January 18, 2023, 03:26:14 pm
You can leave the chain in for now if you want, but I would suggest taking it out now while you have it all apart.  When the chain breaks it will wedge itself between the case and the sprocket/gears and destroy case halves
Title: Re: 700 transmission help
Post by: RoMow on January 22, 2023, 05:22:26 pm
84, 

   Check out: http://heymow.com/index.php/topic,32459.0.html .  This post tells which gears and ratios are available for the 700s.  May help you decide on what ratios you want/need.  The 700s will accept up to five speeds. 

   The 700s with the ball-bearing main shafts are the most durable, like the 700-139 dedicated-racing transmission.  Leman's suggestion of removing the reverse chain for racing is a good idea, since you rarely use reverse when racing. 

   As for lube, gear oil isn't a good idea due to the 700s seals being O-rings and not lip-style seals.  They'll leak.  Peerless recently "changed over to a Renolit LSTO EP Grease (synthetic).  You can use essentially any grease that has an NLGI Grade of 0."  Not as thick as the old Bentonite Grease.  Renolit's website is: 
https://www.fuchs.com/us/en/product/product/112957-renolit-lsto-ep/ 

Respectfully, 
Rodney