Rear hub adjustment

Is the axle moving in the upright or is the upright moving in the control arm ends? If the axle was that loose I would think the rotor would be rubbing big time on the caliper frame.

Mike

Pretty sure I have bad news.

This sounds like classic worn stub axles.

Briefly, there was a mismatch between the stub axle O.D. and the bearing's I.D. This allowed some wobble in the assembly. Over time, the softer stub axle gets worn down by the harder bearing inner race.

Fix?

Spray weld the axles and re-machine.

Or, much easier, buy new stub axles. Wilkinson now offers a set, with nuts, for about $400.

You can also easily upgrade to a double-wide inner bearing at the same time. Wilkinson sells them with the shortened spacer you will need.

OOOPS - your GT5 may have the double wides already, if a true GT5. Not too sure on that, though.

The tool can be bought from any vendor for about $100, or from IPSCO for about $70:

http://www.ipsco.org/Pantera%2...s/AXLE%20SCOKETS.htm

To answer you question, the torque for the nut is about 400 foot pounds. Do not use red loctite!

Larry

Thanks Mike and Larry.

Pretty sure my car is a GT-L with flare kit. It originally came out of Georgia and a well known owner did the work on it.

With the 13" wide rear wheels, I expect that it puts one hell of a load on the standard stubs.

All of the bushing was done on the car recently so the contrl arms should be fine, but this morning I do need to check the upper ball joint to see if the movement is there.

In an early Ferrari, when you do up the ring nut (168ft/lb only) then there are two grooves into which you tap a raised section of the locking ring nut so that it can't come undone.

Is the Pantera a similar system.

The nut is self locking but you need to first check where the slop is. From my experience, I would be surprised if the caliper is letting the rotor move that far indicating that it is not the axle. But I don’t know if you have stock calipers or not. Also if you had that much play in the axel, with stock rotors they would be rubbing on the upright caliper mounts when you tried to drive the car. It makes a heck of a noise. The upper ball joint may have come loose or the lower shaft assembly letting the complete upright assembly move. Just check it out very carefully before you start taking thing apart. Check out this page on Pantera Place for detailed info http://www.panteraplace.com/page87.htm


Mike

Thanks again Mike.

I just had a good look, fitting a standard ford skinny wheel on so I could move it easy and still get my boof head in there from behind.

Definately in the hub.

Brakes are standard. Seems to be in the outer wheel bearing. IE: most movement is originating from the outer and with the car lifted and standing under the car, if I push outwards on the lower edge of the tyre, it rocks inwards and outwards at the bottom. You can actually see where the axle goes through the rear seal, it's moving there and the universal is moving up and down also.

So I'll pull it down today and see if it's all okay inside. You always wonder when someone has been in there (relatively recently) and changed wheel bearings etc, wether they actually did it right.

Shall keep you posted.

If that is the case Bob may have upgraded to tapered rollers and the preload has been lost from the nut coming loose. I guess we will know soon. Let’s hope it doesn’t have ball bearings and the axle is trashed.

Mike

Spot on Mike. Yes, it's BR's old car. Had a brief stint in Boston for 18 months and has now found a dedicated and caring owner 'down under'.

...Yes, thats what I first thought, that the Nut had come loose. Been done before; that the axles were installed on the wrong sides. The left side (Drivers-in America) Has the 'Left-Hand' Thread so the torque of 'forward rotation' keeps tightening the nut, and keeps it Tight! And Visa-Versa for the Right side. I machined the '4-Prong' Tool in School, lathed and Milled it out of Chrome-Moly in about 3 hours. Perfect Fit onto the Nut! Drilled a 3/4" Hole through it, so a 3/4", 4 foot Bar of steel could be used to touque The Nuts on. The torque setting? As tight as You can get it!! You'll Know You attained the Correct Torque, because You won't be able to rotate the nut any further!! Don't ask Me to Machine one for You, it would be way too expensive...

Got it apart, sure enough, the shaft is worn.

Middle of shaft measures 40.04mm, and the area under the outer wheel bearing is 39.75mm.

By the way, with the wheel bearings still mounted in the hub suction, outside to outside of the wheel bearings and spacer tube measures 98.94mm. Wonder if anybody can verify this measurement to see if my spacer tube has crushed at all?

Trying to remove the bearings now. An earlier post shows somebody pressing them out from one side, but each bearing appears to sit on a shoulder so I'm not sure which bearing to press so that it pops them both out with the spacer, in one hit?

Got the bearings out. Standard looking SKF bearings so no upgrades done there.

Certainly the outer bearing has been spinning on the shaft and has work it down a lot. Nearly 12 thou smaller than the centre of the shaft.

Looks like I'll have to get some of the Wilkinson specials but I'm having a bit of a hard time navigating the Wilkinson site. He doesn't appear to list any of his 'special' or modified parts.

quote:

I'm having a bit of a hard time navigating the Wilkinson site

His site is not updated. New items are not added and specials are not listed. He has an email list that receives the specials - ask to be put on it. Even without updating it is a great and easy source for lots of information as is.

He is closed on Mondays (which is what it is here right now), but phone calls are usually answered by him (Steve) or Bill.

A new, local owner with the same issue JUST ordered a set of the axles and paid something like $395 USD for the pair including nuts.
Tell Steve that Larry Finch sent you; it will be my second referral in about three weeks. Maybe I'll start getting a commission...

While you are at this task, are your lower a-arm shafts freely rotating? That shaft often freezes and is a BIG hassle - just ask Bill (last push button) who just had that fun chore.

As I mentioned, there is a double-wide bearing that can be added to upgrade things a bit. Steve can provide it and the new spacer if you want to go that route, too.

Welcome to Pantera Land - where the projects never quite seem to be complete.

Larry

Another source for stub axles is Mark Williams Enterprises. The Pantera items are not listed on his web site but they're in his catalog: Catalog - Page 16

As Larry Finch mentioned, factory GT-5 and GT5-S cars with giant rear wheels used a variety of different inner bearings. The latest I've seen is in an '87 which used a std ball on the outer position and a straight roller bearing of the same OD for the inner bearing (the upright was bored out), with a severely shortened inner spacer. Euro GTS and Gr-3 club racers used double-row ball bearings inboard and here, the small diameter inner bearing bore was not enlarged but the spacer was only shortened. Note that this was for "only" 10" wide rear wheels, and the double wide bearing gets pushed inboard a little so it hangs over the cast-in relief in the middle of the upright, thus a small part of the bearing race is sort of unsupported. This looks bad but apparently caused no problems in the factory cars mentioned. A local machine shop should be able to bore your inner bearing bore out in your carriers to accept the large straight rollers, since its only a slip-fit.
Note also that the problem is NOT with the bearings: the stock axles were fabricated 0.0005" undersized at the factory for some odd reason, which took away the required press-fit. Then with corenering loads, 300+ bhp and frictional heat, the soft axles began fretting in the extremely hard bearing races, wearing away the axles. Wilkinson's current replacement axles restores the needed press-fit and are made of better steel (EN-36) than OEM, fixing both problems.

quote:

While you are at this task, are your lower a-arm shafts freely rotating? That shaft often freezes and is a BIG hassle - just ask Bill (last push button) who just had that fun chore.

The lower shafts were nicely greased and the long bolt came apart easy.

Damn tight fit between the chassis uprights though. I thought at the time what fun this will be to reassemble.

Is there a thin thrust washer that goes inside of those large cups. There were two thin washers with grease on them left on the deck of the hoist once I had it apart. I looked indide those end caps and there looked to be a place for them, but better to check with you guys.

quote:

Is there a thin thrust washer that goes inside of those large cups.

From Wilkinson's online catalog.

...To reassemble You'll Need a Large enough 'C' Clamp, Your Floor Jack, and a Tapered 'Drift'...

Real good tutorial at www.Panteraplace on the rear suspension rebuild.

http://panteraplace.com/page87.htm

Larry

" Another source for stub axles is Mark Williams Enterprises"

OZ Gt5 I have an extra set of these M&W axles .. I purchased for someone and they didnt take them .. they sell for about 775.00 .. if your interested. They are top quality US made solid forged steel axles.

Ron