Wheel bolt thread engagement
Thread Starter
Newbie
Joined: Feb 2017
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Mercedes C204 C180 Blue Eff 2012
Wheel bolt thread engagement
Hi guys
I have standard oem 18' Mercedes alloys and I have just fitted 15mm spacers at the rear and I need a bit of a confidence boost on the length of the bolts I have used.
The originals have 27 mm of thread and engage with 6.5 turns. I have bought new 40mm bolts which engage very slightly under 6 turns (say 5.8 turns).
Do youse think this will be ok or not or am I being a bit paranoid?
Cheers
I have standard oem 18' Mercedes alloys and I have just fitted 15mm spacers at the rear and I need a bit of a confidence boost on the length of the bolts I have used.
The originals have 27 mm of thread and engage with 6.5 turns. I have bought new 40mm bolts which engage very slightly under 6 turns (say 5.8 turns).
Do youse think this will be ok or not or am I being a bit paranoid?
Cheers
MBWorld Fanatic!
Joined: Jan 2004
Posts: 5,939
Likes: 178
From: Seattle WA
99 E320
when you write that it engages at 6 vs 6.5 turns, I'm assuming you mean that
it is torqued to specs at those turns. I don't believe that is a valid measure if
that is the case.
if you take your OE wheels and OE lug bolts and torque to spec, you will see
that it protrudes into the hub and out the back side (side near car's centerline)
by X". the safest is to replicate that same depth...but with the new spacer
installed. this likely means new/longer lug bolts.
another way would be to measure your original OE bolt sized for the OE wheel
and simply add the thickness of the spacer to the bolt and order this new size.
using too long a bolt and it may protrude out the back severely enough to
negatively impact the function of the parking brake
it is torqued to specs at those turns. I don't believe that is a valid measure if
that is the case.
if you take your OE wheels and OE lug bolts and torque to spec, you will see
that it protrudes into the hub and out the back side (side near car's centerline)
by X". the safest is to replicate that same depth...but with the new spacer
installed. this likely means new/longer lug bolts.
another way would be to measure your original OE bolt sized for the OE wheel
and simply add the thickness of the spacer to the bolt and order this new size.
using too long a bolt and it may protrude out the back severely enough to
negatively impact the function of the parking brake
Thread Starter
Newbie
Joined: Feb 2017
Posts: 8
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Mercedes C204 C180 Blue Eff 2012
No the 6 vs 6.5 turns is just hand tight, in both cases they turn an extra say 10-20% once they are torqued up.
I was was aiming for a 42mm length bolt but I have had real trouble in actually finding any in the correct spec. The closest I could get was 40mm which is what is installed now. I'm just not sure if it is safe as they are.
The car feels perfect absolutely no vibration what so ever with them as they are
I was was aiming for a 42mm length bolt but I have had real trouble in actually finding any in the correct spec. The closest I could get was 40mm which is what is installed now. I'm just not sure if it is safe as they are.
The car feels perfect absolutely no vibration what so ever with them as they are
Member
Joined: Mar 2017
Posts: 101
Likes: 8
From: Australia
2003 SL500
Buy a 45 and cut it down to length.
When you look at the pitch of the thread they are a 1.25mm thread which means a thread is 1.25mm in length so it follows that a half turn from 6.5 to 6 is .625 mm
peter
When you look at the pitch of the thread they are a 1.25mm thread which means a thread is 1.25mm in length so it follows that a half turn from 6.5 to 6 is .625 mm
peter
