HST reverse speed adjustable?

[Egon]

Reverse speed control on a B7100 HST.

Parts # 90 and 100, bolt and locknut are all there is to it.

 

[dfkrug]

I think you will find that most HST's will be a little slower in reverse; this is because of the design of the hydraulic motor. The design is optimised for best power and speed in one direction - and doesn't work as efficiently in the other.

What, specifically, do you think is different about the hyd motor in the
HST, rev vs fwd?

I rebuilt my first HST this year and the HST's axial piston motor looked totally
symmetrical. HSTs DO have separate relief valves for fwd and rev, but they
had identical pressure specs (about 5000psi).

I am not saying you are wrong. I just did not find anything that indicated
that they had any differences, fwd and rev. Now pedal limiters...those
I have seen.

 

[KevPH1]

JD 4115: You must remove the right floor board for access to HST linkage.

(17 mm wrench) Remove and grind the shaft limiter linkage stop. (On reverse side only) or front facing stop surface. Grind a little, then reinstall to check. Grind a little more,than recheck. etc.

This will allow the HST shaft pivot arc to increase, hence faster reverse speed.
Hope this helps.