288 GTO with knock-off wheel.... ever came loose?

I use a paint blotch on the wheel bolt and the trim ring. If the bolt moves, the paint blotch is broken apart where the bolt and trim ring meet.

 

They do up as the car is driven. It is more likely that the nut will be overtightened when you come to change the wheel in fact.
By all means, mark the nut and wheel with a paint mark; but it would be unlikely that you will have a problem if they are torqued correctly in the first place. The only drama I have with my F50 is the nuts being overtightened constantly. It can be a REAL drama getting them undone.

 

and yet, even when torqued correctly, there are still occasions when they can come loose in extreme use...

Scott, remember your F50 RF and LR came slightly loose at the Calder track day....

The F50 has nuts and washers with flat surfaces between nut and washer, whereas the TRossa and 288GTO have bolts with double taper.

Typically, they'll require about 25% more torque to crack them loose, than when they were done up. This is mostly stiction on the nut.

 

What I don't get is how the hell they move at all on an F50, given it has the cap bolted over the top of the nut to STOP it moving.

 

The cap doesn't work does it... that little 6mm bolt that hold the cap on is only in a slot, not a positive hole.

But yes, it IS weird, but it happens.

You can take wheels on and off a car that does no work, with no effort. yet, the more heat cycles they get, the more things change.

It's an age old problem, and still affects many new race cars.. A1GP teams have had a re-invent of the wheel nut already, F1 cars still have trouble from time to time too... especially since the wheels stay on for a whole race now.

Aren't Ferrari's fun!

 

That slot in the nut isn't terribly big and only there in the first place so that the bolt will find the hole on 2 splines of the hub (if that makes sense). Therefore the bolt should only move a very slight distance, not enough to make a difference either way.

In any event, a cental wheel bolt is a very silly thing to have on a road car IMO.

Fun, yes. Frustrating- YES

 

How much torque do you do up the F50 wheel bolts with?

 

Phil does it. There is a specified torque in the w/shop manual which is what is used; but I can't recall off the top of my head what it is.

 

I don't have my info near the pc, but it's engraved on the bar I use. I'll post it when I've looked.

 

It was something like 750Nm I think

 

750Nm?! No wonder you have difficulty undoing them.

The most we put on BMWs is 140Nm, and that's on the X5's and 7 series. Every other model is 120Nm (including the M3 and M5).

 

You can't compare torque on 5 stud wheels with torque on a single centre lock nut. I may well be wrong on the figure, my memory isn't what it used to be.

 

Ah right, completely different type of wheel on the F50 - forgot about that. I was thinking along the lines of 3x8, 360, 550, etc.

My bad!

 

Sorry, I Just can not believe that a spinner, or central Locking Nut could ever come loose under any driving condition except Maybe, Just maybe under severe constant hard braking of an already loose Spinner.
The reason they REVERSE the threads on the right side wheels is just proof that under any foward movement these nuts just secure even more by turning into the tighten up direction of the threads.
So Maybe an already loose nut could tend to spin the opposite direction of tightening on a series of 100mph to zero brake tests.
BTW...I use a 6 foot breaker bar and my 190lb. weieght to tighten all the spinners on my 512BBi

Really Now!

 

The TR wheel nut problem was a design flaw that was corrected on later hubs. KO should be checked often. They come off all the time for many reasons. I've seen many Cobra's where they're safety wired. When they loosen you only have a very short time to react.

 

I had a friend who lost one to the cost of 35K for a rear fender, 86 TR.

 

I've still never been able to explain why some cars have different thread directions..

eg, Aston martin have used LH threads on the LH side on some cars, while all Ferrari use LH threads on the right side.

And in V8 supercar racing, some teams use different theories than others. Some have different threads front and rear, some left and right... it's smoke and mirrors.

 

This was a common problem back in 85-85 when mechanics were not installing the wheels correctly in their haste. There was a great, well known, example at my local Ferrari dealership that ended up in lawsuit when the wheel came off within a mile of the dealership.

Anyway, the problem is that mechanics install the wheel and lightly torque the wheel. Then, drop the car, and finish tightening the wheel while the wheel is loaded. This is incorrect. You're supposed to tighten the wheel with the wheel still off the ground. A pain, yes, but it works. I've owned a 288 GTO for years. I drive it to work, I drive it at track, and never, not once, has the wheel fallen off. Also, once the dealership started following this procedure, they never had another early Testarossa wheel fall off either. The more common problem, as someone alluded to in another thread, is that with hard driving, the wheel nuts will actually tighten and are hard to get off if you don't properly prepare the threads. I know of one F40 where the dealer had to cut the nut off. Even a NASCAR air gun couldn't get it off.

What happens is that when you drop the car down, the nut may not really be seated properly on the stub axle and with the wheel, it sort of jams on the spindle and the torque wrench hits 325 lb-ft and everyone thinks things are honky-dory. In reality, the wheel nut never seated correctly between the wheel and spindle. So, once you start driving, the wheel falls off under load. This has a habit of ruining your whole day.

Everything I just said assumes you have an undamaged stub axle (spindle) and wheel nut. Nothing will work if these are damaged.

Steve