Monday, June 4, 2018

Transaxle Refresh - Ring Gear

So progress is (as always with this project) slow. Currently I have a grand total 2 trans-axles, and had 0 freewheeling hubs, and therefore 0 functional transmissions. I got a new/used freewheeling hub but need to get the tools made.

Amazingly it turns out one of my friends for high school actually has taken up machining fairly recently and was more than happy to help me make the freewheeling assembly/installation tool for the cost of material and a 6-pack. Score!

The teeth of the tool fit perfectly in the teeth of freewheel cup. I haven't yet assembled the freewheeling hub but it seems like it will do exactly what it's supposed to. Ignore my thumb in front of the camera...


However now the other problem is the fact the old trans-axle sounds like a maraca with all the plungers, springs, and roller bearings bounding around inside it from when the freewheeling hub blew up. From that explosion the teeth of the cup also appear damaged. No way I'll get it all that crap out, not to mention if I did there is likely damage to the internal gears that may become problematic later. So that transmission is out.


The other transmission however didn't come with a freewheeling hub, I've solved that problem, but there is still an issue with it. Rust on the ring gear.

This is the worst of it.

Well the ring gear on the sploded' transmission is fine, rust free...

However simply swapping them isn't really doable. At least not by me in my tiny garage with cheap tools. The lash would be all out of whack plus the ring and pinion are lapped together from the factory, so swapping the ring would mean disassembling the ENTIRE transmission; which from exploded drawings I've seen, and the pressed construction of the shafts, would be literally killing that transmission. So that plan is out.

Well the only solution then is to take the rust off the ring gear and remove the minimum amount of metal so the gears still mesh. So the process is mask off all but 7-8 teeth, brake-clean, wipe down, 180 grit, 320 grit, 400 grit emery cloth with the shop-vac running. Once happy the rust is as good as it's going to get, brake-clean again, then carefully apply gun-blue to the cleaned teeth for 1-3 minutes, wipe off, brake-clean, then apply WD-40, rotate to the next 7-8 teeth.

Here's a finished section. You can still some pitting on the teeth but to get that out I'd need to completely destroy the teeth, so I stopped the rust from getting worse and got the loose rust out of the trans case so it didn't wear off and become grit to further destroy other things in the transmission.

When the whole ring gear is done I'll clean it even more with some Q-tips, WD-40, and install the freewheeling hub and reassemble the two halves of the transmission. Still to come...