12 replies to this topic

[FTodaro]

In 2017 Mazda will make available a splined spacer for the counter shaft.

I am told the spacer will be provided by Mazda soon. I am not sure what the cost will be. You can fabricate one but they are expensive to produce.

 

I just thought I would explain the part and the problem.

 

 

The counter shaft is fat on one end that drives gears 1-4, but the back part of the counter shaft that drives Reverse and 5^th gear is thin and spindly. Ignore the damaged teeth in this picture.   IMG_0189.JPG   158.8KB   7 downloads This is the 5/R end notice the difference?  IMG_1332.JPG   118.49KB   4 downloads

 

When the transmission is over loaded in 5^th gear,  the thin end of the counter shaft twists. If it twists enough, It’s difficult and then impossible to disassemble the transmission making the box unbuildable.

 

There is a hollow spacer between the idle gear and the R/5 counter gear. This hollow spacer is replaced with the splined spacer. The splined spacer is thought to help bolster the counter shaft so it will not twist, thus allowing the box to be rebuilt many times.

 

 IMG_1330.JPG   66.75KB   5 downloads  IMG_1333.JPG   106.61KB   5 downloads  IMG_1335.JPG   119.88KB   5 downloads

 

There are some other durability modifications that we should propose. There is going to come a time when uses transmission parts will be hard to find.

 

I hope that SCCA and NASA will continue to listen as these types of modifications do nothing to make you faster, its all about making our racing equipment more durable thus affordable.

 

Thank you SMAC for getting this one done.

 

Now lets fix the contact rules enforcement issue LOL

[wheel]

The new part is a Mazda part.  You cannot fab one, you must use the Mazda part.

[davew]

The new part is a Mazda part.  You cannot fab one, you must use the Mazda part.

If you want to be 100% compliant

 

This is my idea, and it works. I started doing this about 3 years ago. I used damaged 5th gears that I machined into a spacer. None of the boxes that I did this too have had counter shaft issues. I just scraped 5 boxes that otherwise would have been rebuildable due to twisted shafts. One was a virgin street box.

 

Mazda is in the process of getting real spacers made. The real spacers will be available only through Mazda Motorsports. The gear shop making the spacer also makes quick change gears and clutch hubs for circle track racers, so the quality will be excellent. And the gear shop is owned by a SM driver. Way to keep it all in the family.

 

Dave

[FTodaro]

The new part is a Mazda part.  You cannot fab one, you must use the Mazda part.

I know but this example was not for an SM box  its for an unregulated class. I assumed since Mazda had a part number on it it would be required. Lets hope their cost is reasonable.

 

I also hope they put a flange on it to help remove it with a puller if the shaft does twist. The home grown version is made from the old gear which is hardened. I wonder if the new one will be hardened or not. may be or may not be as effective.

 

I know my fab part will add 2 seconds on the track.

[Bench Racer]

And the gear shop is owned by a SM driver. Way to keep it all in the family.

 

Dave

Would the SM gear shop Dude's shop be in Joliet, IL?

[davew]

Joliet? Yes.

 

Frank, add 2 seconds or subtract 2 seconds????????????????????????

[wheel]

Frank,

Sorry, assumed it was an SM post.

wheel

[FTodaro]

Frank,

Sorry, assumed it was an SM post.

wheel

No Worries, it was not clear and we don't want to send people down the wrong path.

 

Making these like we have is totally not feasible anyway. the cost of a new counter shaft gear, to cut down starts at 95.00 then your machinist has to cut them down and due to the hardness it consumes lots of tools to do it.

 

Glad Mazda is taking this on.

[wheel]

The main reason that we went with a Mazda part number was that it makes it financially feasible for Mazda to do it.  It originally just had a description of the part, with no part number, but we changed it this month to include the Mazda part #.

[davew]

I can't say an exact price, but the retail price of the custom spacer will be a lot less than the price of a gear

[Bi11]

So when will it be available?

[davew]

Since Mazda is handling this through their "in house" purchasing dept, I would expect January. But do not quote me on that as I know only slightly more than you.

 

dave

[SaulSpeedwell]

Some of our more exuberant drivers are still able to twist the shaft clean off, even when a support spacer is used - in my experience, most commonly seen on the "crate" transmissions, which appear to have countershafts made to a specification reminiscent of the same frozen butter that BMW makes its wheels from.

 

I have never tried buying a new $341 countershaft to see if it is a NOS 1990-2005 part, or if it is the same thing going into the "crate" transmissions. 

 

In any case, this is a great part and rule for the competitor and the class, and it certainly isn't making Mazda or the vendor rich.  Nice work.