Tractor Speed ?

[Brockport Bill 1,971]

Does anyone have any insights into tractor speed ? I have a 1989 wh brochure which shows the speed of various models sold in 1989 -- also have gone on TractorData site to see the speed of various models. The 1988-89 Model 520hc is listed in my brochure as fastest at 7.5 top speed whereas most gear models listed at about 5.5. And Hydros faster including the 520h at 6.4 mph...........The reason I ask is I have a c175hydro from 1984 which we just installed replacement Briggs Twin 16 hp - - the tractor is notably faster than any WH I have driven in various models. The c175h is listed as Eaton 1100-032 with speed of 7 mph. Is there an explaination why/how C175hydro would be faster? Is there a different internal gear? Different pulley ratio? etc????? thanks, Bill

[Achto 29,432]

Running a bigger pulley on the B&S engine? Spinning the B&S engine faster than 3600RPMs? Just a couple of guesses. 

[Handy Don 14,129]

Turning a hydro faster isn’t a great idea so I hope that wasn’t what was done to your tractor. 

 

The WH “HC” models (for “hydrostatic commercial”) had higher final-drive gearing in the transaxle to give them the higher speeds. 

 

I've always assumed that WH engineered the hydros to go slightly faster than the the discrete-geared tractors partly for marketing (to be able to charge more) and partly because ground speed was less directly dependent on engine speed.

 

Only two gears need changing in the transaxle to alter the ratio between the hydro’s “motor" output and the final drive. 

[pfrederi 18,714]

FYI  Sunstrands in Charger electros are 7mph  The same hydro (different drive gear on the hydro motor in GT 14 is 7.5 mph

[Bill D 2,278]

I helped Bill with the engine swap.  The engine drive pulley is a standard engine drive pulley for a GT1800/1848.   We'll double check the RPM and make sure it's set correctly. 

Edited July 8 by Bill D