Which axle do I have?

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Dec 3, 2016 | 08:26 PM

#16

fordman75

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From: South central, Minnesota

Quote:

Originally Posted by wirelessengineer

Oh, I wasn't going to swap the brakes and the diff. I was thinking about the entire axle assembly as one piece. Looks pretty easy, really. 4 bolts on each side, the shocks, and the brake lines. Is there something I'm missing about that?

Yes I know I'm going to be doing this on my 89 E350. I'm still collecting parts. It may sound simple, just pull the old diff and bolt in the newer one. But there is much more required then that. Going to rear disc brakes requires changing the master cylinder, proportioning valve, driveshaft, parking brake cables, etc.

Modifying one part in a system usually requires a whole list of other parts that need to be changed or modified to make the whole system work.

Dec 4, 2016 | 07:59 PM

#17

wirelessengineer

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Yeah, I'd forgotten about the parking brake and brake lines, and the proportioning vavle. Those aren't really major, though.

Why would it need a new master cylinder?

Dec 5, 2016 | 05:23 PM

#18

fordman75

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From: South central, Minnesota

Quote:

Originally Posted by wirelessengineer

Why would it need a new master cylinder?

Residual pressure valves are different between rear disc and rear drum brakes. Along with reservoir differences on some masters, Piston sizing differences. Also I'm almost positive the master out of the newer van, that the disc brake diff would come out of, won't fit your brake booster.

I'm all for doing modifications. I'm the kind of person that has a hard time leaving well enough alone. On my van I'm rebuilding the van mechanically bumper to bumper. So I'd be replacing all the needed parts either way. But if you have a good drum brake rear diff, you have to decide if you really need the disc brake rear diff. Changing the rear diff because yours needs axle seals doesn't make a whole lot of sense to me. Because there is a good chance the used diff you would buy might need the seals replaced too. And all those "nothing major" items to do the swap can add up real quick ( in both time & money ) . It's very possible to have $800-$1000 into the disc brake rear diff swap, by the time you are finished. And that's if you can do the work yourself.

But it's your van, do what you want.

Dec 5, 2016 | 05:31 PM

#19

wirelessengineer

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Yeah, it only makes sense if I'm balancing it against having the shop do the seals at a $725 price tag. If I'm going to be out that much money, I was thinking it made sense to look into putting that into an upgrade.

But I'm just going to replace the seals myself. It does not look like a difficult job at all.