Rear spring perch fix procedure

[1912Krit]

Gents:

I just powder coated wheels for a 1930 coupe driver that I just picked up locally. So happy to dress up the black plain-Jane coupe! When removing the drivers side wheel, I was horrified to find the shock arm dangling from the chassis. The spring perch broke into halves and the rear spring shackle is riding on the axle housing - not a good day but happy I found it.

Now I ask for advice on the repair procedure:

Do I have to remove the rear end or can I just remove the axle housing, leaving the rest of the rear end in place?
I am picturing jacking up the frame and removing the axle housing from the banjo, and going from there. Is this a feasible procedure?

Thanks,
Don

[mcgarrett]

It is possible to remove and replace the damaged housing without removing the entire rear axle assembly. I highly recommend that you recruit the services of a Model A owner that has some experience with this procedure. Special care needs to be taken when dealing with the rear spring.

[1912Krit]

Thanks. For reassembly I do have a rear spring spreader. Thanks, I just didn't want to proceed without checking first if I was overlooking something.

[BRENT in 10-uh-C]

After looking at the picture, to me it appears this has been going on long enough that a huge divot has been worn into the housing. Therefore, has the housing integrity been compromised where a stress riser could cause the housing end to severely crack, -or even break off??

I think there is more to this than just a chance fracture. Either this perch has been poorly repaired in the past, -or either a shock absorber has frozen, ...or maybe an incorrect or oversized spring hanger (shackle) bushing was installed into the perch at one time where the metal is too thin around the bushing area. Realistically, no amount of welding is going to repair that safely.

My initial suggestion would be to remove the entire rear axle assembly and replace the entire housing. This will require setting-up the preload again, ...but not the end of the world. One axle seal and a few Diff Housing Shims are all the new parts you should need to purchase. You can likely even replace the Diff Bearing Race from the present housing and install it into the donor housing to have a better match on the present bearing.

One other option (-depending on your skillset) would be to find another left Mid-1928 to EoP axle housing with a good perch and remove it by cutting thru the factory weld. Then replace yours. The only two issues I see with that idea, is ensuring you get the replacement perch piece exactly perpendicular to the centerline of the housing, ...and making sure you get great weld penetration between the two pieces. Again, I think it would be faster and safer just to replace the housing, but this is another option.

[1912Krit]

Brent

Thanks so much for your good advice. Fortunately I do have another axle housing I can use.

I'll get the existing one off first to see how badly it is worn, and if salvageable, use that to keep the same assembly compatible.

I'm hoping that the shackle wasn't riding on the housing for too many miles, since the break in the perch is still Shiney and not rusted.


Will post what I find.

Thanks,
Don

[1912Krit]

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Shock seems to be working ok and moves with hand pressure.

But you are correct to say to find the cause of the problem to begin with.

[mcgarrett]

Found this slide from Bob Bidonde about the repair you asked about. Maybe it will help you...

https://onedrive.live.com/view.aspx?...FxIRwiGLKDSsgE

[mcgarrett]

Check out slide 17 on this Powerpoint - has the info you're interested in.

[1912Krit]

Great info, thanks very much

[BillCNC]

Originally Posted by BRENT in 10-uh-C

The only two issues I see with that idea, is ensuring you get the replacement perch piece exactly perpendicular to the centerline of the housing, ...and making sure you get great weld penetration between the two pieces. Again, I think it would be faster and safer just to replace the housing, but this is another option.

Brent,

I agree, replace the housing because I'm sure that housing has been work hardened for sure. If one was to do a repair, alignment shouldn't be an issue if you build a jig between the two perches to hold everything in perfect alignment. One just needs to use the good perch along with the tranny side of the tourque tube as master referance .

Yes, careful mesurements are surely needed, but completely doable. Would I do it if it were me, Probably just to have fun doing it, but I wouldn't put it on my car.

Regards
Bill