Don Terrill’s Speed-Talk

Hi Everyone, Ive enjoyed reading engine tech on here for a long time. First time post. I have a Ford 9" rear end in my 69 camaro. I am not sure the vehicle it came from whether a truck , mustang, etc. I know it has 28 spline axles and 4.11 gears. I'd like to buy a used third member with a numerically lower gear. Does anyone know what I need to lookout for in terms of swappable third members? Is it a matter of just getting one that accepts 28 spline axles or is there more to it? I am also not sure how to decode the one that is in my car currently. Thanks for any input.

Even among Fords factory offerings there is a lot of variations, in housings, pinion supports, bearing sizes, yokes, along with 28 or 31 axle splines. Of the posi units there are Equa-locks & Traction-locks (better), which some are 4 pinion.

If you are changing the whole center section as a unit, it will reduce most of what you need to worry about.

From the factory, 9" came with a tag under one of the nuts on the center section. Many I've seen have gone missing.

If you're swapping the center section out, then it's like Marty said. You'll just need to know 28 splines and the gear ratio. Look for the tag, or the stampings on the ring gear (i.e., 9:37).

28 spline limits your options because the high performance options start at 31spline. Far more options with respect to spools and posi's/lockers are available with 31 and 35 spline axles.

I really appreciate guys. Sounds like since I want to change out the whole center section that as long as I get a unit set for 28 spline count that I should be fine. Is that a fair assumption? I would rather go that route than paying for labor to swap out gears in the current one. For the new one I don't mind if it is non posi even since its just a cruiser. The 4.11's and wide ratio muncie makes for a pretty deep first gear and I think it might be more fun to drive with a milder gear set.

I will have to look yet to see what size yolk I have on the current rear. I am not sure if it is 1310 or 1350 series. If I needed to swap that part is it as straight forward and removing and replacing? Providing I can break it free on my own..

If you are sticking with 28 spline your yoke could be swapped. When reinstalling dont over torque to the point it could change bearing preload.

There are different yokes based on U joint size, length and if it happened to have the Daytona pinion support which uses its own special yoke. There are also aftermarket big pinion yokes too.

I got underneith the car and looked at the yoke and U Joint. I believe it is 1310 series based on a 4" length , cap size, and distance between caps.
So that said I believe it is the same yoke setup as the one I found online that I am thinking about buying. If I do swap it out do you recommend using a gasket for the third member or some sort of sealant? Thanks

FRT15 wrote: ↑Tue Jun 02, 2020 4:16 pm So that said I believe it is the same yoke setup as the one I found online that I am thinking about buying. If I do swap it out do you recommend using a gasket for the third member or some sort of sealant? Thanks

I've seen it done both ways. Since I dont like silicone floating around inside and detest cleaning it up when changing gears, I use a gasket.

If the new pumpkin is sized for a different U-joint, be aware that adapter joints are available to make the connection.
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