custom gears

[68glad]

(Not much help in general forum so i'll copy/paste here) I've rounded up the bronco & Dana 18 gears needed for this swap & even installed them in my d20 case only to discover that the gear on the th400/d20 adapter's are "special". They're a wierd 15 spline. I would like to have one made that would match the correct tooth count of the d18 gear & have the correct 15 spline i.d to fit on the adapter. I checked w/ a local gear maker (linn gear) & they can't do it w/ their equipment. Here's a pic.
http://i483.photobucket.com/albums/rr191/68glad/IMG_0182.jpg

Imagine the 29 tooth gear being able to slide over the 15 spline. I don't have a clue how to map a gear to submit it for a quote as some makers want. Also don't mind spending a few bucks to have it made. Anyone got any guidance or input? Thanks Oh, heres a link to the swap http://www.jeeptech.com/convxfer/2.46-20/ Bronco part # is incorrect in this link.

[onesunJ10]

I'm sure you have already been told this, but, IMO it's not worth it. The Dana 20 isn't anthing special to begin with and the coin you would drop just on that custom Bull gear would pay for a nice new Tcase that is meant to be slung behind the TH400.

Gear hobbers are obnoxiously expensive pieces of tooling/equipment...and obviously that is going to add to your gear cost. I'm curious what it will be when finished. Broaching the splines should be the easy part. Probably less the $100. Broaching is cool if you've never seen it before, youtube it.

Maybe these guys can help? I'm sure one of these guys can point you to someone who can.

http://www.custom-gear.com/

http://commericalgear.thomaswebs.net/custom-gear-cutting.html

http://www.precisiongears.com/

[JeepinPete]

If you are dead set on doing this, use your two gears to make one. Turn off the teeth on the 15 spline gear, and the hub of the Ford gear. Wire EDM a mating spline into each part, press together, then weld.

[68glad]

Time to rethink I guess. Sounds like it's easier said than done. Thanks for the responses.

[J20 project]

Try these guys..they have a chart which shows the correct input gear for the app you are doing. I just dont remember if it's the 15degree or the 17degree.
http://www.novak-adapt.com/contact/contact.htm
J20 project

[68glad]

Seen that before but no stock gear will work behind the th400 adapter. The d18 & d20 bronco case have a 29 tooth input gear & the th400 has the goofy 15 splined i.d. so I would need a 29t x 15 & there is no such thing. Oh well, mabey someday i'll end up w/ a t18 or some other 6 spline trans it'll work on.

[cable97526]

If you look a bit harder you will find a D20 with a 32 splined input made to go behind a TH400, This is the setup I have in my YJ at the moment. They came as factory replacements in quite a few internationals and some jeeps.

[joe]

If you are dead set on doing this, use your two gears to make one. Turn off the teeth on the 15 spline gear, and the hub of the Ford gear. Wire EDM a mating spline into each part, press together, then weld.
I think Pete has the most reasonable idea but still not cheap. In the 60's (pre-computer run machines) I worked in the gear dept of Det Dsl. and it takes some pretty fancy machines (gear hobbers, gear shavers) and expensive tooling to make gears. Even IF you found a shop that had the equip/tooling I doubt they'd set up for a one gear run. A long shot would be to try to find a wholesaler that sells gears, bearings etc and maybe you can get a lead on a blank with the correct external gearing and then find a machine shop that'll broach the internal splines but I doubt this is economically possible.
I'd spend the money on a more suitable tcase.

[68glad]

I'd spend the money on a more suitable tcase.

I agree on finding a more suitable t-case but this is what i got for now. Anyhow, I have a place that will "turn bore & spline" the gear I have. They need to know if it is heat treated. Anybody know??? I don't want to say it's not then wreck some tooling or something like that. Is the whole gear treated or just the helical part or not at all??? Thanks

[JeepinPete]

I don't know for sure, but I would wager money it is case hardened.

[68glad]

Ok, for the noob.............what's case hardened?

[EnigmaticEngineer]

Ok, for the noob.............what's case hardened?

It is a process where the outer surface of a solid object (in this case, a gear) is hardened with a heat then quench process. It makes the first .050 to .100 (thousandth's) hard as a rock (rockwell C rating of around 60 give or take) while the inside of the part remains more like the original non-heat treated metal.

Basically keeps the actual surface of the gears/gear teeth from premature wear.

Nathan

[EnigmaticEngineer]

I agree on finding a more suitable t-case but this is what i got for now. Anyhow, I have a place that will "turn bore & spline" the gear I have. They need to know if it is heat treated. Anybody know??? I don't want to say it's not then wreck some tooling or something like that. Is the whole gear treated or just the helical part or not at all??? Thanks

If you heat the gear till it is glowing a SOLID and Bright red/orange then let it cool slowly it will be Annealed...soft....after you've performed the machining you want you heat it back to the same bright glowing temp then drop it in a folgers can of Used motor oil. This will 'case harden' it and the used motor old infuses the surface with a lil extra carbon that aids in wear resistance supposedly (i've done this a few times with leaf springs and other items without trouble).

Just takes patience and the will do heat/cool/quench as necessary.

Nathan