Something inside the wheel
Discussion
I just had my 996 TT fitted with new Pilot Sports and one of the rear was wheels was not letting the tyre shop off easy – it just would not balance. First the guys thought the machine is broken. Then tried another machine, same thing. Then took off the tyre again, thinking maybe something was inside the tyre. No luck. It turns out, there’s something moving around inside one of the hollow spokes. When the wheel was turned on the balancing machine, you could here something that was like aluminium particles sliding around the spoke. I have no idea how the wheel has been balanced before, I just got the car less than a month ago.
I was wondering, if something like this has happened to someone before and if so, how was it fixed. Our current plan is to drill a hole, get the stuff out and then weld it back shut. Any objections why this would not work?
By looking on eBay, the twists are not that rare, so if all else fails, I probably need to get a "new" one, but I’d resort to that a the last option, as you’ll never know the condition of used items, especially if ordered from an unknown source.
I was wondering, if something like this has happened to someone before and if so, how was it fixed. Our current plan is to drill a hole, get the stuff out and then weld it back shut. Any objections why this would not work?
By looking on eBay, the twists are not that rare, so if all else fails, I probably need to get a "new" one, but I’d resort to that a the last option, as you’ll never know the condition of used items, especially if ordered from an unknown source.
Not an expert on the later cars; you say there are plenty of replacement wheels available. You may know this but not all are the same. Check they match the wheels you already have as I believe there are a number of non Porsche out there and weigh more than the originals. Good luck with the 'repair' or replacement.
steve singh said:
I'm not an expert, but the sound of drilling an alloy doesn't sound great.
Can you see an entry point for these bits inside the spoke?
You sure it's not water or corrosion?
There’s no entry point – I believe it could be a factory defect. Could be that at some point a piece of aluminium has become loose and when the car is driven, dislodges more of be scratching the spoke from inside. That’s of course just a theory.Can you see an entry point for these bits inside the spoke?
You sure it's not water or corrosion?
Why doesn’t the drilling sound good? I’m not an expert myself as well, that’s why the original post
Steve32 said:
Not an expert on the later cars; you say there are plenty of replacement wheels available. You may know this but not all are the same. Check they match the wheels you already have as I believe there are a number of non Porsche out there and weigh more than the originals. Good luck with the 'repair' or replacement.
Yes of course, the part number must match, wasn’t planning on getting a replica.hellraiser said:
steve singh said:
I'm not an expert, but the sound of drilling an alloy doesn't sound great.
Can you see an entry point for these bits inside the spoke?
You sure it's not water or corrosion?
There’s no entry point – I believe it could be a factory defect. Could be that at some point a piece of aluminium has become loose and when the car is driven, dislodges more of be scratching the spoke from inside. That’s of course just a theory.Can you see an entry point for these bits inside the spoke?
You sure it's not water or corrosion?
Why doesn’t the drilling sound good? I’m not an expert myself as well, that’s why the original post
I'm not technical enough to know if this is the case or not.
Do not drill and reweld the spoke.Scrap the wheel and buy a new one. The wheels go though a heat treatment process that gives specific physical characteristics that will be affected by the welding. I manufacture aluminium castings so have a good understanding of what you can get away with I would buy a new wheel. Watch ebay as there have been some very unsuitable New replica road wheels sold that are wrong material and not even xrayed
Edited by Redarress on Saturday 3rd August 13:48
Here's an idea. Drill a small hole at the rear of the offending spoke. Say 8mm nominal. Fill the spoke with expanding foam. This will lock down the loose ally particles so that the wheel can then be balanced. The foam is quite light, too. I would not weld anything however, not worth it, the foam can expand out of the hole and then be shaved off flush. Welding means repainting etc etc.
As for the viability of repairing and welding, where I am at the moment I have seen alloys with bits taken out of them that have been repaired with new metal, it's done every day.
As for the viability of repairing and welding, where I am at the moment I have seen alloys with bits taken out of them that have been repaired with new metal, it's done every day.
I doubt you will see weld repairs to the spokes of a aluminium wheel. On the rim yes but the spoke has an enormous amount of rotational forces to deal with. This is a high performance car we are talking about. Wheel fail at high speed could be catastrophic. I know nothing about most things I do know about aluminium wheels and I would worry that if there is something moving inside the spoke the strength of the wheel could be already weakened. OP I am back in the UK next week I could happily get the wheel xrayed for you
Do not scrap the wheel until you try this first... If it's a genuine hollow spoke wheel remove the valve (unique to the 993 tt and 996 tt hollow spoke wheels) and see if you can shake the material out the valve hole. It's possible that the wheels were bead blasted at some point and the shop didn't seal the valve hole properly.
Here's an image of the wheel's construction
Here's an image of the wheel's construction
Probably some casting flashing that has come loose.
Porsche says no wheel repairs that involve welding or machining.
So, if there's no way to get the loose piece of material out of the wheel without drilling or cutting a hole in any part of the wheel I'd say the wheel has to be scrapped.
Also, I was taught when discarding something like a wheel or a bolt (main bearing bolt, rod bolts, etc.) because they were no longer usable but having no obvious signs of this to make it clear the item was no longer usable. For bolts I'd take a hammer and smash the threads so someone would not spot the bolts in the trash and pick them out and place them back on the work bench.
So you might consider having wheel rendered obviously unusable so it doesn't end up on eBay for sale...
Porsche says no wheel repairs that involve welding or machining.
So, if there's no way to get the loose piece of material out of the wheel without drilling or cutting a hole in any part of the wheel I'd say the wheel has to be scrapped.
Also, I was taught when discarding something like a wheel or a bolt (main bearing bolt, rod bolts, etc.) because they were no longer usable but having no obvious signs of this to make it clear the item was no longer usable. For bolts I'd take a hammer and smash the threads so someone would not spot the bolts in the trash and pick them out and place them back on the work bench.
So you might consider having wheel rendered obviously unusable so it doesn't end up on eBay for sale...
phelix said:
Do not scrap the wheel until you try this first... If it's a genuine hollow spoke wheel remove the valve (unique to the 993 tt and 996 tt hollow spoke wheels) and see if you can shake the material out the valve hole. It's possible that the wheels were bead blasted at some point and the shop didn't seal the valve hole properly.
Here's an image of the wheel's construction
This.......if the wheel has been refurbed in the past and the valve not sealed the blast media ends up in the spokes.Here's an image of the wheel's construction
hellraiser said:
Got the wheel stuff sorted. Great tip about the valve hole being connected to the hollow. There was a lot of black "sand" inside the wheel, got it all out and wheel balanced without any issues.
Looked like this:
Sandals? Are you sure it's not a 993? Looked like this:
Sorry, apologies - I hadn't noticed they were being worn without socks - as you were then
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