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

They look great, but now I'm confused. Wilkinson axles run around $395 per pair including nuts.

Then we have the Mark Williams option at twice the price. but what is the difference. Do they both take standard wheel bearings and spacer tube?

Don't mind spending a bit extra if the quality is better but need an explanation if available.

quote:

Do they both take standard wheel bearings and spacer tube?

Yes.

quote:

Don't mind spending a bit extra if the quality is better but need an explanation if available.

MW is a long time, excellent quality axle specialist. Established good name and good quality.

Wilkinson is a long time De Tomaso importer/supplier/restorer. His offering is from a recent production, done in about 1200 pieces, probably offshore forgings and machining. Would he risk his reputation on low-grade items?

Without a side-by-side testing, saying one is better than the other is not possible.

If the forging is well done, the metal quality is controlled and the CNC machine is set-up properly, it really doesn't matter (quality wise) where something is made nowadays.

I installed the Wilkinson axles this past winter. I've put about 3000 miles on them by now and have had no issues.

Larry

I believe the Mark Williams stub axles are machined to accept either stock 12mm x 1.5 Pantera wheel studs or stronger 1/2-20 studs. They are also available gun drilled.

quote:

They are also available gun drilled.

Wilkinson's accept the stock studs.

Wilkinson's come gun drilled.

Larry

Well what an interesting couple of days. As previously noted, the rear drivers wheel was loose so I pulled it apart for a look. Outer wheel bearing had spun on the axle and created a groove, 19mm wide and 12 thou deep.

Okay, so I need a new set of axles, but they are on the other side of the World and my new car is right here wanting to be driven.

Be creative I say to myself. Surf the Web, ah "Loctite Quick Metal" designed to fill voids in shafts and keyways. Off to the local bearing store who highly recomended the product, along with the appropriate spray primer.

Home I go, instructions say to sandblast the component to allow better keying. No worries, into the cabinet then mix up the product and apply. It's Winter here and pretty cold at 17 deg C, so into the wife's oven at 40 deg C for an hour or two. Package said machinable at 6 hours, but I forgot it and went to bed. Sure, it was still in the hot oven when I got up for breakfast.

Onto the lathe and the product machined beautifully. Shaft size was 40.04mm but I took the quick metal down to 40.02mm as I didn't want it to be crushed too much by the bearing.

Here's images of the damaged shaft and the quick metal after machining.

Shaft damage

The stuff looks pretty rough, but it's actually amazing. The darker parts are bits of Kevlar which are right through it.

So after machining it all down, I went through the standard assembly process for new wheel bearings. It only took 1.5 hours to put it all back together and have it sitting on all four paws.

Result: Zero movement of the wheel when rocked vertically and lateraly. Excellent product.

I spoke to a local Ferrari mechanic later in the day who had repaired a shaft on his motor bike with it nearly four years ago and it was still going strong. Perfect for damaged keyways on cranks etc.

I'll conduct weekly checks and see how it fares with road use, but on first drive impressions, it seems like I'm out of the woodpile, and have escaped the fire for the time being. Now I can get onto sourcing the new components and do it all again. At least I've had some practice now.

By the way, that bloody nut is tight!!!

I had to make the tool to do up the ring nut on the back of the hub as there is no local source for such a thing.

To do it up, I fitted the hub to the lower control arm and also fitted the five wheel nuts to protect the studs.

Then I let the hub lay outwards so that the tips of the wheel nuts rested on the floor, or in my case, the deck of the four post hoist. I had to jack the car up a little to ensure that all five wheel nuts were contacting the deck of the hoist. Then I grabbed a five foot length of steel pipe (actually an old torsion bar) and slipped it between the wheel nuts and allowed the other end to contact the leg of the hoist. My tension wrench is a 1/2" drive that goes to 300 ft/lbs, and with the bar against the studs stopping the hub from turning, it was tough, but straight forward to get some serious bloody tension onto that nut. Having the hub lay over so that the wheel nuts contacted the hoist deck also made it very comfortable to work on the tensioning as everything was captive and laying flat.

As it's 1.25am here, I'll post a pic of my home made nut tool tomorrow. Best sneak into the cot now and try not to wake the Mrs!

It looks like you have wear at the inner bearing also.

I Googled info on the product and it will be interesting to see how long it will last in your application. One would think the force applied to it would be incredible. Did you wrap something around it during the curing process?

Mike

quote:

Originally posted by forestg:
It looks like you have wear at the inner bearing also.

Even though it looks that way, the measurements were perfect to the centre of the shaft. Only the bottom was worn (or the outer).

When you put it on Mike, it gets real sticky so I wrapped it in clingwrap and then was able to squeeze it on much better and then used a little roller to push it in really firm. Then off with the cling wrap and into the oven.

Mike, seems it's called a different name over there.

Loctite ® Fixmaster ® Metal Magic Steel

It's a steel epoxy in stick form

I've repaired quite a few stub axles and a few others have, as well. Unless that epoxy product is something very new, I'd be surprised if it lasts thru the warm up drive. The ball bearing manufacturers specify a 0.0005" press fit to keep the soft axles from being indented by the much harder bearing races. As Larry said, the loads are truely incredible and there's heating involved in controlling 300 horsepower going tyhru a drive system. When I weld up damaged axles, I use Stellite C- a nickel/cobalt rod thats used for hard-facing. It can't be single-pointed on a lathe; it musth be ground to size with a tool-post grinder. Other owners reweld the mild steel axles, turn them slightly undersized and have the axle hard-chrome plated, then finish ground. Both methods work.
The two big points: use METAL- as tough and as hard as you can find, and finish the axle to a 'medium' press-fit. You cannot estimate the right diameter either- you need a 4-decimal micrometer and you need to take the measurement at room temperature as steel grows enough with heat to foul up the measurements. Finally, stock '71-up factory axles WILL break in heavy use with big tires, always at the point where the axle flange transitions to the bearing surface. Aftermarket axles and the 'offshore' replacements now being sold are much stronger in this area.

Bosswrench, do you think that the new crop of Wilkinson axles would be okay for my future use considering the wide wheels I'm running?

The temp fix was just that, a temp fix. Nothing worse than getting a new car and then not being able to drive it for weeks whilst awaiting parts or researching parts. Hopefully it holds for a few miles, at least to get me through the roadworthy checks and Ozzie registration.

Admittedly the true GT5 cars had a stepped axle with larger outer bearing, but lots of people are running wide wheels on GP4 and GT5 conversions. You should be fine with new aftermarket axles, what probably happened is someone replaced the wheel bearings with an already own axle. Also be sure to replace the chamfered outer thrust washer as that can cause premature failure on an otherwise new axle and bearings too.

Julian

quote:

Originally posted by Bosswrench:

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.

Can I ask for some clarification on an issue here.

An owner in Oz recently purchased a WIlkinson axle for his failed rear LHS. When delivered it measures 39.99mm

When I removed my axle to temporarily repair the damage, it measured 40.04mm

0.05mm is quite a lot and it has me concerned. The Oz owner does not now need the new Wilkinson axle and I can buy it from him and have it in a day or two, but why would a brand new axle from Wilkinson be slightly smaller in the shaft size that the one already in my car.

If the bearing is a true 40.00mm inner, then it will not need to be press fitted to slide onto a 39.99mm shaft.

I need to rekindle this thread as I currently have the rear axles out of the car.

My temporary repair looks perfect after 300 miles and considering that I machined it to 40.04mm and it's endured a press fit of the new bearings, I'm actually very suprised that it held up as well as it did.

I've read over and over this thread and many others pertaining to the rear axles but I'm still in a quandary.

My axles appear to be original. They are hollow axles with the centre bore being approximately 19.5mm and on the very tip of the threaded end are stamped D and S indicating left hand and right hand threaded.

They measure as follows:

D axle (passenger side USA)
- spline end 39.87mm
- centre 39.98mm
- outer end 39.96mm
This indicates that I have some inner wear and less outer wear and that the centre is probably a factory spec as it is under size to the bearing inner.

S axle (drivers side USA)
- spline end 39.95mm
-centre 39.99mm
- outer end is badly worn and down to 39.75mm

Obviously the drivers side outer bearing has damaged the shaft badly, and the inner drivers side is showing slight wear, yet overall the centre measurement tends to indicate that these axles may be original (slightly undersize) factory items as evidenced by the center measurements being in the 39.98 / 39.99 range.

If these are original, then it's certainly time to change them but here lies the root of the quandry.

I'm more than happy to run the Wilkinson axle with the double size outer bearing and shortened centre spacer, but can anyone confirm that these axles are perfectly manufactured to 40.03/40.04mm with no taper to them. I'd like to run a 2 thou interference fit, and given the 335's on the back, I reckon it's prudent to go with the double width outer bearing if you guys think it's a good thing.

Is there any hub modification required to fit the Wilkinson double bearing axles?

Really stuck here.

Car is in a million bits, axles are on the bench and I need to order new ones but I haven't been able to get any clarification at all that any of the new crop of axles actually measures the 40.04mm required to give me 2 thou of press clearance on the new axles.

I wrote to Wilkinsons last Friday and still nothing.