Centralising Wheel on spinner

[Strobe]

I just took my wheels off to clean the other day and after knocking them back up found giving repetitive clunking particularily on lifting the throttle. I took the rear wheels off and this time ensured lifted the wheel slightly to centralise the wheel on the spinner prior to knocking them up. The noise has been eradicated. I guess you the moral is that you cannot hope that the spinner will centralise the wheel and that spinners are sensitive to being eccentric.......
Anyone have this experience?

 

[Graham T]

Stephen,

The spinner is not there to centralize the wheel only. The drive pins should locate them accurately and the spinner then tighten the wheel to the hub and pins. I suggest that you check that your drive pins are all located in the flange tightly and measure them accurately for matching radius from hub centre.

Are there any chatter marks on pins or in locating holes in rims ?

 

[Strobe]

comprendi!
I have been down this path before when I first put the spacer on the flange. I did have some aches before finally getting the pins fully tightened, I did check the lock nuts were equadistant. My point was that there it is abosultely critical to ensure centralisation of the wheel around the spinner threat prior to tightening things up........
Thanks for your insight!

 

[Russ Noble]

We found when we clocked our new wheels on a CNC mill that the pin drive holes were up to .4 mm out of position. Probably meant that only one pin was ever going to be doing the driving! We bored out the pin holes on the correct PCD so that everything was true and made our pins to suit. When we machined our axles we also located our wheel centre on the axle. We have diametrical clearances of 0.1 mm on the centres and 0.2mm on the pins. Thus the centres locate the wheels, the pins do the rotational thing, and all the spinner does is hold the wheel on. As a matter of reference we measured up a mates T400 Lola F5000 and the wheels are only located by the pins and they run 0.3 mm diametrical clearance. Everything is so spindly and light on those things! Some people think my car will be light, you should see these 5000's

Cheers

 

[Phil]

Steve
Russ makes a most important point....the wheel should register on the adapter or snout, and be reasonably free of runout. I can tell you that my wheels will mount and be centered without the pins..they just wont lock to the adapter. Also, I would be interested in seeing what means you have to lock your spinner or nut to the wheel mount. I am using the Porsche style clips that engage a groove in the wheel nut, if the wheel is improperly mounted the clip will not engage the nut...a sure sign that something is wrong.
Cheers
Phil

 

[Malcolm]

My thought is that the flat rear face of the wheel should butt up to the flat face of the spindle. If those two surfaces mate up then the spinner should just be simply holding it there. Someone once tried to convince me that the tapers on the spindle and spinner co-locate the wheel all by themselves but I don't go for that. From what is written above I am not sure whether this point of mine is totally relelvant though!

 

[Julian West]

Interesting thread, thx for starting it Stephen!

Surely the purpose of the 'drive pegs' is to 'drive' (& help to locate) the wheel, whilst the taper on the hub face & spinner serve to centralise the wheel?

If this is not the case what purpose do the tapers serve?

Someone once reccomended to me that wheels should 'matched' to the hubs & spinners with valve grinding paste... seems sensible to me, anyone got any opinions??

 

[Russ Noble]

I agree with 91740GT. The tapers on the spinner only hold the wheel on.

Have you noticed the clearance on the threads? They are usually a very loose fit.I think this is so you can get them on and off easily when everything is covered in dirt and grime. Not a close enough fit for accurate wheel centering. Julian, I think lapping-in the wheel and spinner tapers is a totally wasted effort! The tapers will hold the wheel better than a flat face but they certainly won't centralise it. As Malcolm also said the wheels are centred by the pins. Bearing in mind the clearance on the threads, the tapers will just lock the wheel up where it has been located by the pins.

Personally, I don't like ANY wheels where the wheel studs or drive pins take all the weight so I have chosen to have my wheel centres register on the axles as has Phil. We can do that because we are building our own, otherwise you are stuck with what your wheels and hubs are supplied with. As a matter of interest the afore mentioned T400 had no wheel centre register and it worked OK for Lola, so I don't think you guys should worry so long as all the machining is accurate.
Cheers

 

[Strobe]

Stephen,

The spinner is not there to centralize the wheel only. The drive pins should locate them accurately and the spinner then tighten the wheel to the hub and pins. I suggest that you check that your drive pins are all located in the flange tightly and measure them accurately for matching radius from hub centre.

Are there any chatter marks on pins or in locating holes in rims ?

To be honest this is a good point, I had some trouble on ensuring that the nuts were tight pulling the space and hub assembly together. As a consequence I did suffer from differential radial distances of the pins through elbow grease.

I really only adjusted these distances by eye and ease of mounting the wheel. I probably need to check the tolerances as suggested.

Quite possibly I have incomplete drive from all the pins!

When mounting the wheel do people turn the wheel against the driving edge of the pins prior to locking the spinner? Does it matter?

Steve

 

[Russ Noble]

When mounting the wheel do people turn the wheel against the driving edge of the pins prior to locking the spinner? Does it matter?

Steve

Which driving edge? Power on or brakes?

I don't see any F1 teams going to that trouble. Honestly if you've got discernible movement there you've got a wear problem or a machining problem.

Cheers

 

[Russ Noble]

Deleted double post

 

[Strobe]

Which driving edge? Power on or brakes?

I don't see any F1 teams going to that trouble. Honestly if you've got discernible movement there you've got a wear problem or a machining problem.

Cheers

What is discernable movement? They arent rattling around if thats what you mean....they are not exactly an interference fit and dont need to be I assume! So getting back to the consistent radaii question, if there is no play between pin and recess hole then assuming you get the wheel mounted then pin radius seems fairly irrelevant!?

 

[Russ Noble]

What is discernable movement? They arent rattling around if thats what you mean....they are not exactly an interference fit and dont need to be I assume! So getting back to the consistent radaii question, if there is no play between pin and recess hole then assuming you get the wheel mounted then pin radius seems fairly irrelevant!?

If you haven't got a problem, I wouldn't worry about the movement. If you have got a problem then I would eliminate any movement by getting everything remachined and rematched!

Just my two cents.

Cheers

 

[Strobe]

Agreed Russ.........thanks for your words

 

[Julian West]

Sorry chaps, for the purposes of discussion only, I don't agree that the drive pegs centralise the wheel... I also disagree with my own earlier post (!) as I now don't believe the wheel is centred on the taper.....

Looking at the picture of my front hub, I'm conviced the wheel is centred by the straight part of the spindle (between the taper and the face of the hub).

I'm further convinced by this picture of an original hub (from Roy Snooks post http://www.gt40s.com/forum/gt40-parts-sale/13106-gt40-hubs.html) & altho the design is different to mine I belive the wheel would be centred by the shoulder inbetween the hub face and the radiused down section of the spindle.

If the wheel *was* centred on the drive pegs, surely they would have to be such a close fit in the wheel it would make it very difficult to get the wheel on and off??

WDYT?

 

Hi Guys,

If I can add my two cents worth.

Ideally there are three functions to consider when attaching a wheel to a hub.

Firstly the wheel should centralize accurately on the vehicle hub spindle. This should be achieved by locating the centre bore of the wheel onto the vehicle hub spindle - preferably with no more than 0.010" to 0.015" diametral clearance.

Secondly the function of the drive pins is to drive the wheel NOT to locate it. Ideally around 0.005" diametral clearance of the drive pin to the drive pin hole.

Thirdly the "Spinner" or locking nut should effectively clamp the wheel to the hub face. It should NOT be meant to locate the wheel and should be torqued adequately to prevent any movement between the wheel hub face and the vehicle hub.

On the other hand, if the design incorporates a taper on the vehicle hub spindle and a mating taper at the rear of the wheel centre bore and the wheel is a sloppy fit on the vehicle hub spindle then the "Spinner" taper will be centralizing the wheel as well as clamping it between the two tapers.

In this instance the wheel cannot be pull back against the vehicle hub face.

If this is the case, then it is sloppy design and not in step with current wheel engineering principals. Whoever has engineered it has tried to copy the old Rudge-Whitworth wire wheel hub design and tried to replace the function of the splines with drive pins.

 

[Russ Noble]

Soooo...... If you have 15 thou diametrical clearance on the centre and 5 on the pins, then the pins come into play before the centre so what is it that is actually locating the wheel!

Cheers

 

Hi Russ,

Yes, I guess the spindle to wheel tolerancing that I quoted was a little on the loose side but I was more intent on getting across the rationale behind the wheel location and attachment.

Neverless the tolerancing does need to be a little on the loose side to account for fitting of cold wheels to red hot hubs when wheels are changed during pit stops.

Cheers,
Kaydee

 

[Russ Noble]

Actually Kaydee, if you consider F1, or particularly A1GP, the problem seems to be getting the hot wheels off, not the cold ones on! Not sure why. Also I don't think either of these have centres to locate them (reduced unsprung weight) only the pins, but I could be wrong.

As I stated earlier I am running 0.1mm (0.004") on the centres and 0.2 (0.008") on the pins, thus the centres will locate the wheel. We're hoping the higher expansion rate of the aluminium will compensate for the hotter axle. Still six months away from finding out!

What is the basis for the clearance figures you mentioned? We're playing ours by ear, it's much easier to increase the clearances, if we have to, than it is to to decrease them.

Cheers

 

Hi Russ,

I don’t think that you will be too far away with your tolerances and I would certainly give them a try before changing anything.

The basis for my figures was an old and rusty memory and being too lazy to boot up the CAD system!
However, I’ve just checked through some of my old drawings and these are the dimensions and tolerances.

O.D. of spindle location diameter 76.0 mm. Locating bore in wheel 76.3 mm -0 +0.01

O.D. of drive pin 16.0 mm diam. Drive pin hole in wheel 16.1 mm -0 +0.01

These dimensions and tolerances are for 17” x 11” magnesium wheels as fitted to V8 SuperCars and were derived from feedback from various teams. If my memory serves me correctly these final figures were the result of being asked to open up the clearance on the wheel centre bore and reducing the clearance on the drive pin holes.

It is also interesting to note that the tightening torque used by the various teams for the centre lock nut varied from 450 ft/lbs to 1,000 ft/lbs. However, I believe that most of the teams are now using around the 600 to 800 ft/lb range as the wheel hub faces showed “fretting” at 450 ft/lbs and the 1,000 ft/lb was often difficult to undo if the rattle guns were not in top notch condition.

Hope this helps,

Cheers

Kaydee