1983 Mercury Grand Marquis 2Dr "Mercules”

[sly]

I know a 94 that has the axle you want (pulled the bumper off of it) at the FW Pick-n-Pull... if you don't already have an axle.

[gadget73]

Didn't someone on here find that the axle tubes are the same for 31 spline, you just need to have the axle itself shortened to make it go? I know I remember reading that. Apparently the limo axle tubes are overly fat for whatever reason, but the late model whale 31 spline is the same diameter as the 28 at the bearing end. Someone will probably remember that thread, I think its a guy with an 80s Grand Marq, somewhere out west.

[His Royal Ghostliness]

The limo axle tubes are larger cause of the extra weight of the car, the non-limo housing is actually quite flimsy - remember that one that rusted thru and broke while driver was hauling ass down the interstate? lol

As for the axle diameters, looking up an '06 Panther it uses #5707 wheel bearing, same as the one in boxes and aeros, so that checks out. But one can't simply chopping an inch off the diff end of said longer axles, for two reasons:

1) cutting the last inch off the shaft also cuts off the thing that keeps the shaft in place, namely the C-clip. Therefore, if a 9"-type pressed-on wheel bearing conversion is not in the plans, one will need to throw the shortened shaft on a lathe and machine a new groove for the C-clip to live in.
2) splines length - typically factory axle shaft are splined just far enough to allow for full engagement with the diff side gear + a bit extra to account for sliding the carrier left-right while setting up the gear. Took some measurements for ya'll - box shaft splines are 1-1/4" long and the diff uses the last 1" of that allowing for 1/4" carrier positioning side to side. In comparison the aero splines are 1-1/2" long and again use the last 1" of that for the diff side gear, meaning when you trim the shaft you're only left with 1/2" worth of spline length for the diff to engage into, assuming the shaft won't jam up into the side gear when it runs out of spline to begin with (which it will with a box axle, aero looks like an interference fit as well just not as pronounced).

So the way to use the factory small-bearing 31-spline shafts would be to effectively widen the housing. Those "repair" bearings may be a reasonable way of accomplishing that, especially if one starts of with an aero housing. Will need to remove inboard seals from those repair bearings that have them, to allow oil to flow inside the bearings - never quite figured out how they're supposed to survive if the axle oil can never reach them anyways...

[Grand Marquis GT]

I'm using aftermarket axles, like Lincoln Larry did when he built his rear. I am going to use the later rear also because the increased track width is desirable.

Jason, good to hear about that. Fort Worth is def the closest yard

[gadget73]

The limo axle tubes are larger cause of the extra weight of the car, the non-limo housing is actually quite flimsy - remember that one that rusted thru and broke while driver was hauling ass down the interstate? lol

As for the axle diameters, looking up an '06 Panther it uses #5707 wheel bearing, same as the one in boxes and aeros, so that checks out. But one can't simply chopping an inch off the diff end of said longer axles, for two reasons:

1) cutting the last inch off the shaft also cuts off the thing that keeps the shaft in place, namely the C-clip. Therefore, if a 9"-type pressed-on wheel bearing conversion is not in the plans, one will need to throw the shortened shaft on a lathe and machine a new groove for the C-clip to live in.
2) splines length - typically factory axle shaft are splined just far enough to allow for full engagement with the diff side gear + a bit extra to account for sliding the carrier left-right while setting up the gear. Took some measurements for ya'll - box shaft splines are 1-1/4" long and the diff uses the last 1" of that allowing for 1/4" carrier positioning side to side. In comparison the aero splines are 1-1/2" long and again use the last 1" of that for the diff side gear, meaning when you trim the shaft you're only left with 1/2" worth of spline length for the diff to engage into, assuming the shaft won't jam up into the side gear when it runs out of spline to begin with (which it will with a box axle, aero looks like an interference fit as well just not as pronounced).

So the way to use the factory small-bearing 31-spline shafts would be to effectively widen the housing. Those "repair" bearings may be a reasonable way of accomplishing that, especially if one starts of with an aero housing. Will need to remove inboard seals from those repair bearings that have them, to allow oil to flow inside the bearings - never quite figured out how they're supposed to survive if the axle oil can never reach them anyways...

You couldn't just cut the axles down, you'd start with longer axles and have them modified to the appropriate length, along with re-cutting the splines and C clip groove. Much easier to make things shorter vs going the other way. The later axles are just something of a raw material at that point.

[His Royal Ghostliness]

C-clip groove is easy enough, the splines would be the hard part, as the axle shaft itself necks down some right after them - meaning where you extended the factory splines they will have a smaller OD than those 1/2" that are left of the original setup. Like you said harder to add material than subtract it...

Someone please remind me, when did the Watts linkage enter the Panther rear suspension scene? I'm thinking '03 together with the new drop-cradle front setup, is that correct?

[sly]

Watts started in 98. All whales have Watts unless fabbed with.

[gadget73]

aye, 98+. I wouldn't mind having that retrofitted into my car, but the frame mounts for that are completely different. I'd settle for a panhard rod, which would have to be less involved.

[Bobcat]

aye, 98+. I wouldn't mind having that retrofitted into my car, but the frame mounts for that are completely different. I'd settle for a panhard rod, which would have to be less involved.

Hey, my car has that already.

[gadget73]

yeah but I'm not interested in that goofy front suspension you got with the deal. Not planning on frame swapping anything either.

[His Royal Ghostliness]

Bummer on the '98 intro for the Watts, would have been nice to have at least one model year that has the super-wide housing with the older style suspension setup. And yeah, Panhard bar won't be too hard to fab up, already been looked into. Gadget, lemme figure out the shit with my front axle (metric D60 has different panhard bar that what I'm currently set up for), then I can apply what's learned from there to that 8.8 of yours too.

[Grand Marquis GT]

Looks like it's time to start working on this
thing again. Charged the battery and she fired right up the other days. I am going to do this little project, now that I finally have all of the parts!

I will need two tires, and to find the source of my coolant leak. Should be fun!

[Tiggie]

Got some real luck to find the Merc center for that wheel!

[Grand Marquis GT]

Got some real luck to find the Merc center for that wheel!

Took me 8 months to find it. 25 bucks shipped!

[87gtVIC]

neat looking steering wheel. Old school race car type!