Mercedes-Benz Forum banner

101 - 108 of 108 Posts

·
Registered
1985 500sel and 500sec 2012 E63 1989 Porsche 911
Joined
·
5,266 Posts
do you think these welds will significantly unbalance the wheel when mounted on tires....and require more weights to get back balanced
 

·
Premium Member
87 Euro500HVSEC. 88 Euro 560HVSEC. 89 Euro 560HVSEL
Joined
·
4,266 Posts
Not really as the extra weld head left is in the centre bore - but i will have the rim spun on a top end balancer without the tire just to confirm.

In need i could easily have a counter weight stuck into the bore hole on the opposite side to the weld as a very simple fix but i don't think that is necessary

However I will take that centre bolted up into a rim - to my Rim Shop when it opens again after the x-mas break and get it spun up to test it without a tyre on it but that will only show if the actual barrel is not dead straight or perfectly round.
The centre bore spins much slower than the barrel and is locked in by the surrounding 5 lug bolts firmly to the hub

Where balancing is more sensitive is in how it spins up on the actual outer barrel and also the weight of a tire valve versus the hole in the barrel for accepting the tire valve but the main issue is whether rim spins true

Adding a tire is where the whole balancing science comes into it as a tire is such a large heavy item with so much room for error in manufacture and the tire spins so much faster compared to the centre hole bore of a rim.

Refer previous page for detailed pics of final repair
 

·
SuperModerator
1986/1990 W126
Joined
·
13,762 Posts
Are we without the official technical info from AMG?

I approached Lorinser for the stuff on my LO wheels and they dug out the old documents to send me the info. Very cool of them actually. I don't suppose AMG is so helpful though.
 

·
Outstanding Contributor
450slc5.0cab 280sl5sp 280se4.5 500se+500slAMG +250seStkW108 350sl4spdX3 500secEuro
Joined
·
22,330 Posts
Digging up bones here, but I believe that many center cap bores get cracked due to wheel balancer comes getting stuffed into the the wheel on the outside. MB wheels are designed to take a load on the rear center bore, but the face is just cosmetic meant to hold nothing more than a center cap. The proper way to press these more delicate faces up against the spring loaded cone to get the flat back of the wheel on the balancer is to use a “pressure cup nut” which presses on the face of the wheel near the lug bolt holes rather than loading up only the center cap ring with a cone. I wonder if all these threads about cracks that all seem to originate at the face (not necessarily the lug hole) aren’t from over torquing lug bolts, but actually from over torquing the wheel on the tire balancers using a cone instead of a pressure cup nut.
Just a thought.
 

·
Premium Member
87 Euro500HVSEC. 88 Euro 560HVSEC. 89 Euro 560HVSEL
Joined
·
4,266 Posts
Could be a contributing factor - yes you are correct the rear of the full face solid centre (the hub mount where all the meat is ) takes all the load and the lug bolt hole seats fix the wheel to the hub and the hubcentric bore hole at the rear handles the weight. The solid forged centre is a good thing versus an open spoked wheel for handling the torque forces. The crack if it ever occurs is only in the front face half of the lug hole/bore wall where the metal is at its thinnest and not into the rear of the hub where the metal is thick.
I have never heard of an AMG wheel failing ( i drove around with a cracked rear wheel for some yrs on my white coupe as a test and it never got any worse)
 

·
Registered
SL 280 1993, 560 SEC 1988
Joined
·
72 Posts
Could be a contributing factor - yes you are correct the rear of the full face solid centre (the hub mount where all the meat is ) takes all the load and the lug bolt hole seats fix the wheel to the hub and the hubcentric bore hole at the rear handles the weight. The solid forged centre is a good thing versus an open spoked wheel for handling the torque forces. The crack if it ever occurs is only in the front face half of the lug hole/bore wall where the metal is at its thinnest and not into the rear of the hub where the metal is thick.
I have never heard of an AMG wheel failing ( i drove around with a cracked rear wheel for some yrs on my white coupe as a test and it never got any worse)
That means one shouldn't be afraid of driving cracked 3P Amg rims as the wheels are strong enough not to crash even being used in "cracked" condition, right?
 

·
Premium Member
87 Euro500HVSEC. 88 Euro 560HVSEC. 89 Euro 560HVSEL
Joined
·
4,266 Posts
It is your own choice and i am just quoting my own experience in testing a cracked rear rim over aproximately a two year period to see if it got any worse - which it didn't.
These are solid face centres. The crack happens usually in the top half of the lug hole and can be repaired by a professional tig welder. There is a lot of meat in those centres compared to an open spoke modern rim design which are only cast rims anyway versus a forged solid centre. The bore takes all the load and the lug nuts just hold the rim in place to the hub and prevent the rim from spinning on the hub. If there is mutliple cracks then no don't mount the rim.
 
101 - 108 of 108 Posts
Top