Replacing spindles on mower deck

rt2726 · Aug 17, 2014

I bought three brand new spindles, high-speed grease and a new grease gun to rebuild a mower deck. I scraped and cleaned and painted etc. I'm getting ready to put everything together to give it a try but the thing that really bothers me is that after reassembly (and possibly over-greasing) two spindles are noticeably tighter than the third when rotated by hand. I removed the grease bleeder valves from the bottom to see if there was any excess pressure. Not much came out so I rotated the blades by hand to see if any more would come out. So far nothing... Rotating the blades by hand wasn't enough to heat up the grease or anything so I was wondering if I should attach the deck and run it for a minute or two before reattaching the bleeder valves? I'm not planning to cut the grass with the valves off, just run it for a but in the garage to heat up the grease and work things in a bit.

I'm usually pretty handy but this is new to me so I'm a little clueless on why three brand new spindles would vary so much. I know it has to be my fault. I'm guessing too much grease or over tightening. I used an impact wrench to tighten so that's the next thing I'm going to investigate before mounting the deck. Any words of advice would be appreciated.

Thanks!

oldnslo · Aug 18, 2014

What type of spacers was between the bearings? How consistent in length were these spacers? I have seen some spindle assemblies where the spacer between the bearings could be moved up and down .02 - .03 inch with both bearings pressed fully into the spindle housing. Tightening the nut on the spindle just side loaded the bearings to the point they would fail in a short run time. Not sure if this was from the outer bering race spinning at some point and ruining the housing.

If you loosen the nut slightly and they spin freely I would suspect a tolerance issue.

KennyG · Aug 18, 2014

Spacers on correctly comes to mind as an obvious issue. Does your deck have blade brakes? These put drag on some (but not all) pulleys if the drive is not engaged.

rt2726 · Aug 18, 2014

Thanks guys. That makes a lot of sense. I couldn't get back out there tonight but I'll take another look tomorrow.

DuckSlayer1017 · Aug 18, 2014

oldnslo said:
What type of spacers was between the bearings? How consistent in length were these spacers? I have seen some spindle assemblies where the spacer between the bearings could be moved up and down .02 - .03 inch with both bearings pressed fully into the spindle housing. Tightening the nut on the spindle just side loaded the bearings to the point they would fail in a short run time. Not sure if this was from the outer bering race spinning at some point and ruining the housing.

If you loosen the nut slightly and they spin freely I would suspect a tolerance issue.

Agree, it only takes a few thousands difference in the spacers to change how free the bearing turns. Also, could be the harder spindle has a little more preload from tightening the shaft. IMO, running for a few minutes with the bleeder valves off will not hurt as long as there is grease in the bearings.