Gleaner GM250 inline 6 starter

Doing a few pre-season adjustments to my K2 Gleaner gas GM250 in-line 6 combine. Its engine starter drags some and/or just clicked with no crank. Anyway thinking it needs attention, I removed starter from combine, mounted it in bench vise, lubricated it’s bendix shaft, & wired it direct to good battery. Using a jump wire on solenoid, I got it’s bendix to move outward and then it’s motor seems to run good? It’s front nose housings armature bushing seems ok - it’s not excessively worn. So then I remounted starter on combine to which it will still only clicks hard, but no crank.
Why will it not crank? Need new Brushes? Thanks

Edited by AC7060IL - 08 Jun 2020 at 4:26pm

Same battery on work bench & combine. It load test good. I cleaned combine ground mount to frame. But I did not replace any combine battery cables. So, I’ll try connecting same work bench battery cables onto combine. Thanks A-C_220.

A couple years ago I had an intermittent no start condition with the lawnmower. Battery was good. Terminals were clean. At first inspection the cables looked just fine. Turns out the copper of the positive cable was completely green under the insulation near the battery connector. When I flexed the cable the insulation cracked and it became very evident. The cable appeared in good shape until I did that. The resistance was too high so the starter couldn't always draw enough current.

Edited by WD45 Aaron - 08 Jun 2020 at 10:25pm

My memory just jogged a bit. When diagnosing the issue I wasn't getting good continuity with my multi meter through that cable. That's what triggered me to take a look closer at it. Without the meter reading I might not have flexed it like I did to find the issue.

Check the starter draw with starter in place on engine.