Third Member Original Color

[1969_Mach1]

Hello,

I am doing a gear ratio change on the 9" rear axle in my 1969 Mach 1. Last time I did this I repainted the third member semi gloss black. This time I would like to repaint the third member the original reddish-orange color. What is it, Glyptal, or Simply Red Oxide Primer? I am hoping Red Oxide Primer since Glyptal is over $50 per aerosol can.

Thanks,
Mike

[Mustangmike]

Mike,

I believe Glyptal paint was used on the inside of the carriers to seal the casting for better oil flow and residual sand left behind from the casting process. I know people also use Glyptal paint to seal the oil galley on engine blocks for the same purpose.

At $50 plus a can I am not sure there would be any added benefit to using Glyptal paint your third member. I used plain old red oxide primer on mine.

I hope this helps.

Mike

[1969_Mach1]

I am leaning toward the red oxide primer. It's almost an exact color match.

Now if I can get the mesh pattern better I'd be happy with it. I am using a Motive Gear 3.70:1 ring and pinion. I measured the pinion depth with a depth micrometer. Set that and the backlash per the specs engraved on the ring and pinion. The mesh on the drive side is perfect, centered on the tooth. But the coast side is towards the heel of the tooth. Tinkered with different pinion shims a little. The mesh on the drive side moves as it should with shim changes. But the mesh on the coast side is stuck on the heel of the gear. I know both need to be correct. Improper coast side mesh will whine when decelerating.

It might be my fault. In the past I used Motive Gear's higher end more expensive gears and they set up perfectly. This time I tried to save $50 and use their stock replacement line of ring and pinions. Any thought before Summit Racing gets these back to exchange for the better quality set?

Regards,
Mike

[Mustangmike]

If the drive side pattern is centered on the tooth and the coast side is stuck at the heel it sounds like the pinion depth is set too close.

I can't speak for the quality of the gears but when you measured the pinion depth did you account for the centerline of the axle? To do this, you measure the OD of the bearing and divide it by 2. Then using your depth micrometer measure the lowest point of the bearing saddle from the parting line. The difference between one half of the OD of the bearing and the lowest point of the bearing saddle must be deducted from your pinion depth calculation to set the true depth of the pinion. I believe mine ended being .004 of an inch.

[1969_Mach1]

I double checked that the parting line (the bearing cap mounting surface) is 1/2 of the bearing race O.D. Then I use a depth micrometer to measure the pinion depth from the bearing cap mounting surface. I had this mesh pattern issue happen once before but with a Precision Gear brand ring and pinion. Drive side was good but coast side wouldn't fall into place. I ran them and they made a little noise on deceleration and coast. As you know it's too much work to reinstall the third member if it's not as good as it should be.

Summit Racing is going to exchange this ring and pinion set. I'm also going to spend a little extra and get Motive Gear's performance line instead of their stock replacement line. Their performance line is the mid level line of gears they offer. I've used them in the past and they set up perfectly after setting the pinion depth and back lash per specs.

I'll post results with the new gears. I should have them tomorrow.

Regards,
Mike

[Mustangmike]

I have to admit Summit has a "great" return policy but it's too bad you have to do the work twice. I used a ring and pinion set manufactured by Yukon with no pattern/set-up issues. The Yukon gears are probably in the same price range as the Motive Gear's.

I tried to save some money on a hi-torque starter from DB Electric. Although the starter does the job it does seem to be noisier when starting compared to other Mustangs. Now I am thinking of purchasing a better quality/name brand one hoping it's quieter.

Keep us posted on how the new gears set-up. It would be good information for members to know when selecting gears for their cars.

[1969_Mach1]

I hear Yukon makes a good ring and pinion gear set. In my area National Parts Depot is the only source for Yukon. I didn't go that route because for one I had such good luck with Motive's Performance line in the past, and two, purchasing from National Parts Depot I have sales tax plus shipping charges. Summit's nearest location to me is in Nevada and I am in California so I have no sales tax from them. But, I am close enough that 95% of the time I get items next day with their free ground shipping. We'll see if this Motive Performance line of gear I am now getting is as good as in the past.

Regards,
Mike

[Mustangmike]

As far as the Yukon gears so far so good (knock on wood) but they have a had a pretty easy life so far. I haven't really driven the car all that hard.

Let me know how you make out with the set-up once the new gears arrive. I am curious to know if you get proper mesh with their (Motive) more expensive line. I am keeping my fingers crossed.

[1969_Mach1]

Well, I set up the new Motive Performance ring and pinion. Just as last time I used one their Performance ring and pinion gear sets, the pattern was great after setting the pinion depth and backlash to the specs marked on the gear set. We'll see what happens when driving the car. But I don't foresee any issues.

Regards,
Mike

[Mustangmike]

Wow...that was quick! I am glad to hear you achieved a good contact pattern.

When I first put my rebuilt center section in my car it did not make any whining noises but it was warmer than I would have liked when I put my hand on it. Now that I have logged some miles on the car it is no longer hot to the touch. I am assuming the rear end was just tight from being rebuilt and needed to be broken in.

Good luck with yours.