custom ring and pinions

I'm not talking about picking out something from a catalog or yukon gears, does anyone know of a source where people can make 1 offs? 

The problem is my pinion is 15" long...  with no aftermarket 

hell i don't even need the ring gear, i just need a custom pinion essentially. 

Google fu just turns up a bunch of catalog gears 

FC RX7? We used to have a machine shop take the stock long pinion and mate it to the 5.12 pinion that was available.  It was a common thing to do 15 years ago, somebody has to have the info out there.

Just had a set made for a 1913 Buick.

Straight cut bevel gears, not hypoid gears and it set us back around $1700 Canuck pesos.

Start calling your local machine shops.

In reply to jgrewe :

yes that is what I was hoping to do but mazdatrix lost their supplier to do this, and considering they only do about 1-3 orders of this per year its not a lucrative business ideal. They have fixtures and everything still but no supplier, they wire cut the head off of the desired pinion and weld it onto the existing pinion shaft. 

I have one potential source locally but they aren't returning my calls/emails...

I believe these are hypoid:

There is a shop in Souderton PA called Gearmakers. They definitely make some gears, but I do not know if they can do hypoid. I will be making a delivery there this afternoon. I will ask.

I just looked at the Mazdatrix site. It looks like the supply issue is that Mazda discontinued the ring and pinions in the short versions that fit everything back to my RX2. 

What ratio are you looking for? I have might have something in my stash.

jgrewe said:

I just looked at the Mazdatrix site. It looks like the supply issue is that Mazda discontinued the ring and pinions in the short versions that fit everything back to my RX2. 

What ratio are you looking for? I have might have something in my stash.

the OEM mazda 5.12s have been discontinued for a long time for the non turbo differentials. I need the non turbo one to work with the differential/axles I have.  I had contacted mazdatrix about their supplier problem but it doesn't seem like its getting fixed any time soon. 

I need either a 4.78 or 5.12 but I have only seen a handful of these go up for sale in my entire rx7 ownship history (~15 years) 

I have a 4.78 ring gear from an s2000 which bolts up (common with miata differential/NA rx7 FC) so I only really need the pinion and I can make this work. 

Houseman Autosport? 

I don't see any issue with welding it, it's not handling gobs of torque. 

Following. My FC also needs a 4.78 rear end.

EDIT: Only other option seems to be the Ford 8.8 IRS swap that's catered to the V8 swap guys. Lots of ratios available there.

So if you just need a pinion to weld onto the shaft, why can't you use the S2000 pinion?

In reply to matthewmcl (Forum Supporter) :

Or the S2000 diff? Could have the spider gears broached if the splines are different or use S2000 inner cvs? You've probably already thought through these options.

I have to dust off my RX interchange brain cells. Do you have rules to deal with that keep you from putting a 1.8 Miata diff in the aluminum RX7 housing? Then you would just need to fab up a front mount for the diff.

Shavarsh said:

In reply to matthewmcl (Forum Supporter) :

Or the S2000 diff? Could have the spider gears broached if the splines are different or use S2000 inner cvs? You've probably already thought through these options.

S2000 uses 29 spline axles like a Mazda 8" rearend.  What it does not do is use a dropout centersection like a FC/FB/NA/NB/etc. 

Kevin, ring gears and pinion gears are matched sets, I don't think there is any way of using a pinion from one and a ring gear from another.  IIRC they get lapped together after machining.

I talked to the boss at Gearmakers yesterday afternoon. He said "yes", but then quoted $17,000. Yes, 10X the number for ShawnG's old Buick.  Multiple sets would reduce that number. Not enough to be useful I bet

In reply to TurnerX19 :

That's a GTFO number, he didn't want to do the job.

Keep in mind, the gears we had done are straight cut. Hypoid gears require a different machine and more cost involved.

If you want, I can give you the contact info for the machine shop we used. They have a machine to cut hypoid / helical gears, it's not up and running yet but they are working on it.

Honestly though, for the cost involved, there must be another gear set that can be adapted. That is done far more often than having custom sets made. The only reason we did what we did was because there was nothing that could made to work in place of what was broken.