Pointers on rebuilding a BCS tiller gearbox

[farmerboybill]

Hey,

I just got in from working on a BCS 735 with 26 inch tiller I'm getting ready to sell and wanted to pass along some pointers -

1. I swear I haven't bought a used tiller with any oil in it. Seriously, I SWEAR IT. Don't assume the previous owner knew what he was doing. He didn't. The tines will be shot (pointy like a steak knife? They're shot), one or both seals will be bad, and the gearbox will be outta oil. If you buy a used tiller box, rebuild it right away. It'll last forever with proper care. It'll die fast with no oil.

2. You can get away with reusing the bolts when replacing the tines, but I do not recommend reusing the nuts. Frankly, I've not seen bolts worth reusing either, but maybe you'll get lucky. When replacing the bolts, use grade 8 standards or grade 10.8 metric bolts. Skip the slightly cheaper grade 5 or 8.8 bolts. I use the all-metal lock nuts, not the nylon ones. Make sure they're TIGHT. If they come loose and the tines worry them for awhile, you'll need a sawzall to cut them out, I have on one tiller. The older flat top tillers don't apply as they have a better type of tine. Those bolts are always reusable. You can still get these tines from Joel at Earth Tools, but not anywhere else.

3. DO NOT reuse the lock nuts that hold to tine assemblies to the main shaft on the gearbox. I've now seen three gearboxes that apparently had the nuts reused and come loose. Those lock nuts are very cheap vs. a new tiller box

4. At the end of every season, take the assemblies off the gearbox and clean out the space behind the seal protector. Crap gets up in there - long weeds, plastic twine, metal wire, dirt, sand, gravel, telephone poles, small furry woodland critters, you get my drift. If it's left in there, it WILL destroy the seals. An hour cleaning these out is much preferable to replacing seals and bearings.

5. When you go to replace the seals, you WILL break the bearings, even if they're in perfect shape. Don't buy the fancy throw-out bearings found in there. A $9 standard 6205 M25X52X15 will last just as long as the $50 one they recommend.

6. Pay attention to how the tines go together. You'll have an aneurysm trying to remember how they go together if you don't pay attention. The innermost tines should be timed a special way to prevent rock from lodging between them and the gearbox. It's hard to explain, but each side should be pointing the same way as they go around.

I'm sure I'll think of more. If you frequent other sites I do, you'll see this post again.