Front hubs and spindles

[Joe911]

I am developing an older CF chassis (1975 Titan Mk9) and am working on improving the front end. I have identified my stub axles as Spitfire (2 and 3/8" long measured from the top of the tapered seat at the rear bearing flat). I am interested in whether I can use the Triumph GT6 stub axle which is 2 and 13/16" long from the top of the taper.

1) Can anyone confirm for me that I need the GT6 hub/wheel bearings with the GT6 spindle or can I use GT6 wheel bearings and the Spitfire hubs.

2) Another possibility is to use the aluminum front hub from the Crossle 25-32F. Does anyone know which spindle/wheel bearings are used on the CF Crossle? My endpoint is floating rotors but I need to get the hub/spindle sorted out first.

[Brian]

If I was doing this I'd be looking at getting rid of the whole stub-axle/live hub design and going to a double row cartridge bearing type setup per the modern cars.


As I recall the GT-6 setup requires GT-6 bearings and hubs, which could of course be aluminium. I don't know the the taper into the upright is the same on Spit and GT-6 spindles. if you want floating discs why not just get some discs and top hats compatible with what you have? What is the actual thing you are trying to fix with the bigger stub axles?

Brian

[Joe911]

If I was doing this I'd be looking at getting rid of the whole stub-axle/live hub design and going to a double row cartridge bearing type setup per the modern cars.

As I recall the GT-6 setup requires GT-6 bearings and hubs, which could of course be aluminium. I don't know the the taper into the upright is the same on Spit and GT-6 spindles. if you want floating discs why not just get some discs and top hats compatible with what you have? What is the actual thing you are trying to fix with the bigger stub axles?

Brian

I do have the desire to be somewhat true to the period. I also wonder whether the control arm attachments/upright arrangement would need to be redesigned and is beyond my skill level.

So you are saying the the GT6 hubs were aluminium? I have been told that the GT6 spindle can be used on the Spitfire upright. There is a guy (Performance Research Industries) that sells a kit with HD spindles and aluminium hubs, but is not planning on making more hubs any time soon.

Goal - reduce flex. In my region I am running in FF and stickier tires and spindle flex may be contrubuting to pad knock back that I am experiencing. Plus I want to lose some weight and if the spindle upgrade is needed for the lighter hubs, this is the second reason. Once I am set on the hub, I will do the brake upgrade.

[Brian]

Stock Triumph used steel hubs for everything. Aftermaket Aluminium hubs are common, and if you are making the change and need to buy hubs anyway, why not make the upgrade? Dave Bean has them, I recall. Lot's of Fords came with them, including my Lola (haven't totally checked, but I think they are compatible with one or other of the Triumph spindles.) FWIW I have Spitfire type spindles on a sports racer from 1972, and they are OK with Atlantic rubber - not great, but OK.

I have often thought that adding inner spacers to stabilise the bearings would add a ton of stiffness to a Triumph spindle. You would machine the spacer so that correct preload occured when say 60 ft-lbs of torque on the bearing nut was applied. Common for many types of taper-roller bearing setups.


Brian

[jimf42]

What did you end up doing? We just bought a Titan Mk9 ...and since ours is a project...

[Larry]

I'd stick with off-the-shelf front uprights. They were excellent in early Formula Fords. Even better, they were cheap and plentiful! You can find good used spindles for $100 or less.

Larry Oliver
International Racing Products

[jimf42]

Thanks...just thought I would check...

[Joe911]

I ended up buying aluminum hubs for a Spitfire from a vendor in England and machining them down to the thickness to match the steel versions that were OE for the Mk9. It was part of my development and reducing the weight by 60 lbs.

The uprights are fabricated and not adapted Spitfire uprights like a Crossle. The spindles are Spitfire. If you do need to have new uprights fabricated, I need a new left side. I do have a spare right side and could provide a bent left side if needed.

[jimf42]

once we get into ours further, we will decide what we need... at this point, my friend has to clear out two customer cars so we can begin disassembly. I will be interested to hear how the alloy spindles work out... I think when we were considering a Turner MkIII project, we saw those alloy spindles online somewhere.

[Michael Edick]

to go one further, is there anyone out there that makes a nice aftermarket spindle for the old style FF Triumph uprights?

I'm hesitant to put original ones in, cuz my LF spindle just broke...

[stephen wilson]

I've never heard of problems w/ the Triumph spindles breaking. Was it the actual spindle pin, or the upright casting? Any pictures of the failure?
Steve

[provamo]

funny how many Formula One and early Can-Am type cars of that period used these pieces and now guys driving around with one-hundred horsepower cars are crying that they are not sufficient for their requirements.......... LOL.......... just saying

[JHaydon]

I've never heard of problems w/ the Triumph spindles breaking. Was it the actual spindle pin, or the upright casting? Any pictures of the failure?
Steve

If you check out the Car & Driver Tech section of Victory Lane magazine, a few years ago they ran an article about fatigue failure of Triumph front uprights. It's in the July 2003 issue, but I think I've seen it in other issues as well -- it's an important thing to know!

The vintage guys call it a Triumph Herald upright, but the article notes that the same basic design was used on GT-6 and Spitfire. The design has a big stud out the bottom, a long L-shaped upper portion with a hole for a ball joint, and a central bore for a stub axle (of which there were 2 versions, calling for one or another set of bearings). The lower stud goes into a brass-bushed trunion -- as the article says, "high-centered... between antiquity and modernity, Standard Triumph engineers compensated for the nice ball joint by giving us a vestige of king pins at the other end."

The trouble is threefold: Lateral loads create a bending force against the stud; the start of the thread is a sharp stress riser (of course they are cut instead of rolled); AND that last thread is just outside the trunion. Looking at a photo of a failed unit, the stud appears to also be hollow! When you consider (a) we're using much stickier tires now than when these uprights were new, (b) we seem to bounce off of curbing a lot more often these days, and (c) many of these uprights are approaching 40 years old, it's no wonder they're breaking!

Recommendations in the article include:
Crack checks, a minimum of once a year. Check for corrosion and pitting as well (water collects in the trunion).
Turn down the diameter of the unthreaded portion to the same diameter as the thread root, with a large radius tool.
Ensure the upright does not bottom out in the trunion at extreme steering lock, and that there is no torque load on the stud.
Check that the A-arms' inner axes (at the chassis) are parallel, and that the upper ball joint is precisely centered over the hole in the upright throughout the range of suspension travel (to minimize bending stresses). Don't try to adjust caster with these uprights! The trunion limits the range of motion to only 2 axes; trying to change the caster introduces a 3rd axis, which puts a bending force on the stud.
Modify the upright to accept a rod end or ball joint, eliminating the stud and trunion.

One more, based on something the FV guys do: If the stud is actually hollow, you may be able to ream the bore to a precise size and then install an aircraft bolt inside it. I don't know how much practical strength this would really add, but it might be better than nothing.

[Michael Edick]

funny how many Formula One and early Can-Am type cars of that period used these pieces and now guys driving around with one-hundred horsepower cars are crying that they are ninsufficient for their requiirements.......... LOL.......... just saying

I know your statement above was meant to be a bit of tongue in cheek, but I'm having a hard time not telling you to go "f" yourself when luckily my spindle broke on the slowest corner of the track (T4, top of the hill at Willow Springs) when it could have broken on me thru the flat out in 3rd gear T2 or even worse, the flat out in 4th T8/9...once the wheel ripped loose and took the caliper with it, my front brakes were gone, which left me with a long throw before the rear brakes came on...had all this happened to me at turn 8/9 going 130+, my car could have been written off, and put me in the hospital...so pardon me for not taking your comment in the spirit for which it was meant...to me, this is deadly serious...just saying.

[stephen wilson]

Thanks for the explanation. Hopefully it's not a problem with my RF78, since it doesn't utilize the original trunnion. It has a replacement lower stud welded on to receive a spherical bearing in the lower A-arm.

Mike,
It looks like you had a different type of failure, and the stub axle broke outboard of the inner bearing? The picture is a bit small to be sure, but that seems to be an unusual place for a failure. What car is this on, a FF or FSV?

[Brian]

Michael, with all respect to your situation and the failure you experienced, F1 cars used the Herald upright up to around 1964, Formula B cars right up to the late 1960's, and I have a 1972 sports racer that uses the same stub axles (in a proprietary aluminium upright) with 10" wide Formula Atlantic rubber and 180 hp. It's a fairly stout design, and yeah, they do fail every once in a while although I have never seen an outright break of the stub axle before. The upright usually breaks just below the ball joint, or the where the lower threaded stub is machined.

Doug Learned at Fast Forward makes a nice little upright for D sports racers that has almost the same geometry as a herald upright and could be adapted with a little ingenuity. It has a dual ball bearing cartridge and pressed in hub, like the modern cars do. Going to the GT6 stub axles and hubs would be an upgrade, as would machining up a solid spacer to set the bearing pre-load, and magnafluxing the parts every off-season might become part of your routine.

Brian

[Michael Edick]

Mike,
It looks like you had a different type of failure, and the stub axle broke outboard of the inner bearing? The picture is a bit small to be sure, but that seems to be an unusual place for a failure. What car is this on, a FF or FSV?

it's a 1976 LeGrand Mk 21 FF...

several of the FF regular guys were indeed scratching their heads as to how and why it broke like it did...once I get into doing a post mortem on it, and post the photos on this thread, I hope it'll bring some things to light.

Michael, with all respect to your situation and the failure you experienced, F1 cars used the Herald upright up to around 1964, Formula B cars right up to the late 1960's, and I have a 1972 sports racer that uses the same stub axles (in a proprietary aluminium upright) with 10" wide Formula Atlantic rubber and 180 hp. It's a fairly stout design, and yeah, they do fail every once in a while although I have never seen an outright break of the stub axle before. The upright usually breaks just below the ball joint, or the where the lower threaded stub is machined.

Doug Learned at Fast Forward makes a nice little upright for D sports racers that has almost the same geometry as a herald upright and could be adapted with a little ingenuity. It has a dual ball bearing cartridge and pressed in hub, like the modern cars do. Going to the GT6 stub axles and hubs would be an upgrade, as would machining up a solid spacer to set the bearing pre-load, and magnafluxing the parts every off-season might become part of your routine.

Brian

this was my first time out with the car...I bought it several months ago and went thru all the things that a person should go thru, like bolt check and visual inspection of the various bits and pieces, but a spindle failure?

as you say, it's a stout part that has been used thru the ages, and maybe that's what happened...it was just plain old, and who knows what kind of life it led before I got it.

needless to say, I need to replace the one that broke, and want to change out the one on the RH side as well.

so what do I do? buy some NOS spindles and consider them "good enough for an F1 car", or look for some super-duper spindles?

[stephen wilson]

IIRC, I bought a replacement stub axle from Dave Bean. As John mentioned, there are 2 different sizes, so you'd have to measure the old one. Could it have been damaged when you bought the car, say from a crash?

[DanW]

Mike,

Sent you a PM.

[carl correll]

Because you must have some bearing clearance for the taper rollers, this type of stub is subjected to bending loads unlike more modern designs using double row ball bearing cassette bearings. The ball bearings are clamped up tight on the stub so that there is not supposed to be any bending load. Any little stress riser, be it corrosion or a slight scoring of the stub will eventually fail. The failure site will show up under magnaflux long before it becomes an issue. Be sure that the radius of the inner bearing cone matches the radius of the stub, or that a chamfered washer is used between the bearing and stub radius. Magnaflux will save your bacon. The little tool marks left on turned parts like a spindle will give you a proper case of the willies.

[provamo]

sorry that my comments upset you....i would be ok with you telling me to go f myself

glad you survived your incident without harm to your person

the photos you posted reveal the severity of the situation you experienced

yes my posting was meant to be tongue-in-cheek so to speak

[jefftrue]

Uprights:
http://www.pamotorsport.com/for_sale/view.asp?id=34

Stub Axles:
http://www.pamotorsport.com/for_sale/view.asp?id=38

Steering Arms:
http://www.pamotorsport.com/for_sale/view.asp?id=37

[Michael Edick]

sorry that my comments upset you....i would be ok with you telling me to go f myself

glad you survived your incident without harm to your person

the photos you posted reveal the severity of the situation you experienced

yes my posting was meant to be tongue-in-cheek so to speak

I'm sorry that I got a bit tweaked by your comment...looking back, all my original post said was that I broke my spindle, so you could not have known that it happened while I was driving the car.

for the full effect, here's a photo of the car where it came to rest...and the wheel sitting there on the body? that's where it landed after it came off the car...

it slid down the side of the body (after hitting it HARD and breaking the fiberglass), then got launched when it hit the rear tire, and landed right beside my head...

most wheels leave the scene of the crime once they come off the car...mine decided to come after me.

[Jonathan Hirst]

Those spindles are essentially bulletproof, they never fail and anyone who checks them with any regularity likely has a compulsive disorder. Until they fail, and then you crack check them every year and become pedantic like a good CF owner should.

OK that's tongue in cheek but thankfully you didn't lose the car as a result and with a new spindle in both sides and the good advice already listed above, there is no need to have a repeat of this failure..

The LeGrand Mk 21 is a fantastic car. When I was about 18 (almost 20 years ago - ) I was racing Vintage FFords and my Dad and I stopped in Vero Beach FL at a company called Wirewheel. They usually sell British road and race cars and we were taking a side trip while we were on a family vacation. Amongst the old MG Midgets and Healey's there was an unloved old Mk 21. I poured over that car and had to ask what make it was. Although I haven't seen another one since you posted your pic, I have never forgotten that dart like body shape and side rads.

Get it fixed and get back out there.

Jonathan

[JHaydon]

Very sobering... "crack check front spindles" is definitely going on my winter to-do list!!

Amd so incredibly lucky, all things considered.

Please keep us posted on any findings. Tiga uprights are fabbed steel with a hollow spindle (larger OD) as the central piece, and I'd be grateful to know what to watch out for!

[Michael Edick]

Thanks Jonathan!

I will most certainly get this thing fixed and get back out there, and feel good about all the great feedback that came about from this thread!

this would be a good time for a shout out to Apex Speed as well!

my history with the LeGrand goes back even further than yours, as I worked for Red fresh out of high school (mumble) years ago and worked on the short wheelbase Mk27.

[Brian]

I still say a useful upgrade would be to machine up a spacer from steel and use it to set the bearing preload. That would at least double the strength in bending of the stub axle and make the assembly a ton stronger. You could make it in two parts, and make up some shims that were say .098, .100, .102 to make the preload adjustable. This is exactly how taper roller bearings in rear hubs and on big racecars are set up. You would set the preload, and tighten the nut to say 75 ft lbs and the spacer stack would effectively double up the stub axle with support.

Aside from the fact that I've never seen one of these fail and they are adequately stiff for a lot of applications already, I have no idea why this isn't a common upgrade. Aside from added unsprung weight, i guess.

Brian

[Brian]

I still say a useful upgrade would be to machine up a spacer from steel and use it to set the bearing preload. That would at least double the strength in bending of the stub axle and make the assembly a ton stronger. You could make it in two parts, and make up some shims that were say .098, .100, .102 to make the preload adjustable. This is exactly how taper roller bearings in rear hubs and on big racecars are set up. You would set the preload, and tighten the nut to say 75 ft lbs and the spacer stack would effectively double up the stub axle with support.

Aside from the fact that I've never seen one of these fail and they are adequately stiff for a lot of applications already, I have no idea why this isn't a common upgrade. Aside from added unsprung weight, i guess.

Brian

[JHaydon]

Dumb question (I'm sure it's in the Carroll Smith books), but does the ID of the spacer(s) have to be close to the OD of the spindle? Or does it just need to be reasonably close and no larger than the ODs of the bearing cones?

[carl correll]

It 's going to be the diameter if the inner race of the bearing cone. Basically a tube. If the uprights are maintained there should be no need of a preload spacer on these little cars. Just remember how old the parts are and treat them accordingly.

[Wayne Lee]

Hi Jim,

I'm not sure You understood what other's were meaning while discussing Alloy Hubs etc. You seemed to think that materials use in Hubs also icluded it being used for Spindles.

"Quote"
"I will be interested to hear how the alloy spindles work out... I think when we were considering a Turner MkIII project, we saw those alloy spindles online somewhere."

Of course there are no such things as Aluminum Spindles and never will be. I'm sorry if you just had the nomenclature "Spindles" in mind while thinking Hubs or Uprights while replying. I just wanted to make sure you didn't waste much time looking or waiting for feedback on their usage.

Good Luck,
Cheers,
Wayne Lee
Douglas, MA
wayne@sportsracer.com

[jimf42]

No, I realize that they were talking about hubs...aluminum is totally unsuited to spindle use.

[Michael Edick]

Got the spindles apart and cleaned up, and here's what a stub axle failure looks like close up.

The machine work on this stub axle is such that you can see and feel the grooves made be the lathe tool...they're small, but between all those little stress risers and the age of the part, and the application, it was just a matter of time.

The RH stub axle has an almost polished look to it, but it's getting replaced as well.

[LFFR]

[FONT=Times New Roman]Without any dimensions or other information, it looks to me like you have a large spindle (GT6) that has been turned down to accept a small spindle (Herald) hub & outboard bearing. In that process someone has put a wicked step change in the spindle and consequently really bad stress risers. If you have a small spindle hub, your outboard bearing number should be--- Cone 03062 / Cup 03162. The inboard bearing on the small spindle hub should be ---Cone 07100-S / Cup 07210-X. I don’t have the inboard/outboard bearing numbers s for the large spindle at my fingertips. I’ll have to dig them up.[/FONT]
[FONT=Times New Roman][/FONT]
[FONT=Times New Roman]The stock Triumph shaft should look like this [/FONT][FONT=Times New Roman]http://www.leechapmanracing.com/images/axle_chromemoly.gif[ [/FONT][FONT=Times New Roman]either small shaft or large shaft. No step changes in the spindle at the inboard bearing [/FONT]
[FONT=Times New Roman][/FONT]
[FONT=Times New Roman]Are both sides of the car the same? If they are, you have a very scary situation. [/FONT]
[FONT=Times New Roman]John Mihalich, Jr.[/FONT]

[john hennessy]

i know this is an old thread, but i am at this moment in time looking at some triumph spindles and uprights,

i need information on how to convert the trunion into a spherical bearing,

do they turn down the trunion thread to what would be 5/8" and put a 5/8" fine thread on the end, or do they sleeve the trunion with a chrome moly sleeve?

this, i feel is important because with a trunion, you can't adjust caster, it is what it is.