My Gravely HD60 seems to have unbalanced strength in the drive motors.

[grsherfick]

When going down a hill the mower wants to drift left. I try to correct by pushing left lever forward but cannot correct the drift. I have to correct by pulling right lever back. Is it an illusion or does this mean the motors are not equal strength?

 

[MParr]

When going down a hill the mower wants to drift left. I try to correct by pushing left lever forward but cannot correct the drift. I have to correct by pulling right lever back. Is it an illusion or does this mean the motors are not equal strength?

Your hydros need adjustment. Consult your operators manual.
Do you service the units?
How long ago was your last service?

 

[grsherfick]

I will consult the manual. I have not serviced them yet the mower is a little over a year old .

 

[bertsmobile1]

The use of 2 pump/motor units on the same drive belt causes slip on whichever one is on the "push" or slack side of the belt unless they use 2 belts.
THis gets progressively worse over time and eventually the tension arm side fails because it is always running slower than the the unit on the pull side.\
The left side always seems to be dustier than the right except with out front mower decks so runs hotter to boot .

 

[MParr]

I will consult the manual. I have not serviced them yet the mower is a little over a year old .

A little over a year old and not yet serviced? Your first service is due at 75 hours.
You will need 2 transmission filters (Hydro-Gear 52114 or equivalent) and a 5 Qt. jug of 20W50.
Follow the instructions in the operators manual.
Adjustment of the travel needs to be done when the transmission fluid has warmed up.