Ok, just putting on winter tires and it appears that ONE of the bolts on a 5 bolt pattern front wheel won't go in.

Closer examination reveals that the bolt hole is stripped.

Question is:

* Right now it's hanging on by 4 bolts out of 5. Seems pretty secure. Is this ok?

* Can I rethread the bolt hole ? If so, what tool do I need to rethread it? (Specifics please on the size/spec of the die/tap!)

This is on the ML...

Thanks for any advice.

Go back to the last place that had anything to do with your tires and complain. It needs a new hub.

__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

The W163 (ML's) have a 14MM wheel lug bolt that require 100ftlbs of torque. For safety I would have the hub replaced.

There isn't enough material for a heli-coil to work properly, however a Time-sert might hold. 14MM x 1.5 thread

A new hub lists for $50. you also will need a new front wheel bearing( $61.) as it will be damaged when the hub is removed.

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I have a snap-on tap 14mm x 1.5
Could I not try just rethreading this bolt hole?
It doesn't look terribly messed up - it just looks like a few threads inside got stripped right at the beginning part. I understand any advice is taken at my risk and absolve anyone of any liability!

If you're gonna try to run a tap to clean the buggered threads, I would suggest trying to run the tap from the inside out. That way you have the good threads to guide the tap and clean the buggered ones true. If it is only the first couple as you claim, you might end up OK.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Mike, I noticed the car you have on your profile. Do you have an pictures of it you can share on line?

Which car? Pictures of both the 560 and the 4.5 abound in the many pages on this site. There is a nice glamour shot of the 4.5 in the DIY section, in the sub-frame mount article.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Ok, can you provide any pointers on how to run it inside out?
Thanks

I would expect the hub will have to be pulled so you could start the tap from the back side of the hub. Are we talking a front hub or a rear hub?

I don't know anything about the ML, but expect there to be a difference between front and rear, hopefully someone can guide you further.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Mike is right on. If it's just the first bit, running it through from the inside out is the solution.

__________________
1982 Mercedes-Benz 300CD
1982 Mercedes-Benz 240D - stick

Ah, but here's the rub: If you're going to have to remove the hub to run the tap through it, then are you are going to have to replace the bearings, as previously stated, as they get buggered up when removing the hub? If so, you might as well replace the hub and not bother trying the tap.

I'd suggest you go ahead and use your tap from the outside, with LOTS of cutting fluid and great care. If you end up punching out the first couple threads, not that big of a deal as long as your bolt finds clean threads further in without future cross-threading. Hardened steel has lots of strength, you'll just be losing some margin on that bolt.

Bottom line, I suggest cleaning up the threads with the hub on the car first, just make sure you get every last bit of metal fluff out of the threads afterwards and again, use lots of cutting fluid (oil). The true test of whether this effort is OK is when you put the wheel bolt back in and you can acheive 100 ft. lb torque without stripping. If it strips, then just take a deep breath, let it out, then bite the bullet and purchase a new hub and bearing and consider it a noble effort.

Also, I really would raise holy hell with the last place that touched your wheels....there is absolutely no excuse for stripped wheel bolts and hubs.

Good luck

__________________
On the plains of hesitation bleach the bones of countless millions who at the dawn of victory, sat down to wait, and waiting -- died

I don't see why you would ruin the bearings when you pull the hub ,I would just replace the rear seal clean out the old grease and repack them if they look OK I'm sure that going from the back would be best but I have done them from the front with no problems,just go easy and line the tap up straight
.............
William Rogers...........

I'll try out your suggestions this wknd and let you know how it works out. I will torque the bolt 100lbft and if I can torque it and then remove it and then retorque it, I will know it worked.

If it doesn't, i will bite the bullet and have it replaced...

Thanks everyone!

if you are going to go through the trouble of taking the hub off to run the tap from the back, id just replace the hub. its not worth the risk.

__________________
Current Stable:
1994 S500 v140, 210k miles, white with grey.

Former Mercedes in the Stable:
1983 300CD Turbo diesel 515k mi sold (rumor has it, that it has 750k miles on it now)
1984 300CD Turbo Diesel 150 k mi sold
1982 300D Turbo Diesel 225 sold
1987 300D Turbo Diesel 255k mi sold
1988 300 CE AMG Hammer 15k mi sold
1986 "300E" Amg Hammer 88k mi sold (it was really a 200, not even an E (124.020)
1992 500E 156k mi sold
etc.

Ok,
I have an update. First of all, thanks to everyone for their thoughts.

I took a Snap on 14x1.5 tap and slowly wound it all the way into the hole and then wound it out by hand.

I then put the new wheel bolt in by hand.
Torqued it with a torque wrench.
It torqued up perfect.

Then I removed it, and then put it in again with the torque wrench.

Absolutely tight.

Perfect.

My SA guesses that it was really was just the remnants of a stripped bolt that was stuck in the threads of the hole - instead of the hole's threads actually being stripped.

So the tap cleaned the threads well enough that the new bolt went in cleanly.

I am so glad I didn't have to replace the hub!!