question Zetor 5718 speed increase? 40 km/h

[johnt]

Hi all,

I need some expert advice on increasing the speed of a 5718. It travel at 19.5 MPH at top speed and I am trying to get it up to 25 MPH. Do you know if exchanging the portals with those of a smaller tractor (e.g a 3511) will achieve this?Are there different sized driver & driven gears inside the portals of smaller zetors to compensate for their smaller wheels?
I will be replacing the brake slave cylinders shortly so I could do this at the same time.
I'm trying to steer clear of modifiying the injector pump or adding larger wheels(currently has 16.9/14x30) to get the extra MPH's .
Hope you can advise.
Thanks,
John,
Ireland

 

[Renze]

Our local dealer made 40 km/h versions of 6011 and 6211 tractors (before the 40km/h versions became available) by replacing the final drives to those of a 4511.
I dont know if this has the same effect on a 5718.

The best way is to mount 16.9-34 or 18.4-30 or 18.4-34.
That's the best and easiest way to achieve this, i think.

Some years ago, we had a classic Zetor 2011, for a respray.
When we had it on the road, my brother allmost pissed in his pants when the tractor, due to a defective revolutions regulator of the fuel pump, ran over 3500 rpm, my other brother drove behind him and the speedo got over 65 km/h...
That's a freaking speed for a popping two cylinder with a 40 year old, saggy steering system.

 

[johnt]

Thanks Renze,

Is the final drive another name for the portal section inside the back wheel or is it internal to the gearbox?
I can get my hands on a donor 3511 (now parked-up) which was a flyer in its day.

 

[Renze]

Yes teh final reduction gears are inside the portals.

I dont know if the 3511 has trhe same end reduction ratio, but what's even more important: I thinkt he 3511 had much smaller end reduction gears..... Bigger tires is the best way. You could also put it to 2500 rpm to get another bit...

By the way i think that the 5718 has a bigger sized shaft so that the gear of a 3511 cant be put on unless you do some serious miling and grinding.