B1750HST Speed Control Pedal

[Tapeworm]

Hi all. Newbie on this forum. My 95 compact speed control pedal is getting stuck in fast fwd. Stuck is a harsh word perhaps...it does not come back to neutral when I let off the pedal.
Fwd engages slowly with increased foot pressure (as per normal), but then feels like it moves over some sort of threshold and simply drops the rest of the way into full fwd. Have to apply slight backward pressure on the pedal to bring it back to slower speed and neutral. Not really safe and easy to control the fwd movement of this tractor now.
Works as per normal in reverse, with smooth pressure all the way back.
After shutting down, and moving the speed control pedal forward, a "boing" sound can be heard right at the point where the pedal drops into full fwd - almost like a spring that is no longer doing its job.
I have not as yet crawled under the centerline of the tractor to check for worn bushings, broken springs, linkages or the like. I also have transmission oil and filter change on my to do list.
Any help in troubleshooting this issue would be most appreciated, before I haul a bag of money to the svc dept.

 

[Tapeworm]

Quick fix it turns out. The lever that provides for travel direction control on the HST, while still attached to the case by the bolt (12mm socket), provided for enough sideways movement so that the roller (which transmits the speed control pedal inputs or vice-versa) would slide off the lever's cam at the far front end (in the fwd travel direction).
Loosened the bolt to see what was what, and retightened with slightly more torque, and the lever has considerably less slop in it, and the roller now stays on the cam.
Has anyone ever taken this lever off the HST case? Is there a bushing inside that could be worn? Anyone have a part number for this lever? I cannot seem to locate the lever on the parts diagrams that I have on file.