Hex head vs regular 6 side bolts? - Page 2 - PeachParts Mercedes-Benz Forum

t walgamuth · #16 01-31-2021, 11:57 AM

When all parameters are considered it is very rare for MB to put in something that is not well though through. When I find something that makes no sense to me I have learned to back off and think more about it.

speednjay · #17 01-31-2021, 11:57 AM

I’ve switched out a lot of the Allen head bolts I’ve stripped out with 6point bolts. Mercedes used some really soft metals for the Allen heads, pretty much a guarantee that a stuck bolt will get rounded out

t walgamuth · #18 01-31-2021, 01:46 PM

They usually round out because the recessed socket has not been cleaned and you are only able to get half the depth into the socket, thus you are applying twice the design amount per square inch.

tangofox007 · #19 01-31-2021, 01:53 PM

Quote:

Originally Posted by t walgamuth

When all parameters are considered it is very rare for MB to put in something that is not well though through.

Anyone who continued to use internal hex fasteners after Torx fasteners were introduced probably won't win any awards for thinking things through.

t walgamuth · #20 01-31-2021, 04:01 PM

Quote:

Originally Posted by tangofox007

Anyone who continued to use internal hex fasteners after Torx fasteners were introduced probably won't win any awards for thinking things through.

Do you know their reason for doing so?

speednjay · #21 01-31-2021, 05:35 PM

Quote:

Originally Posted by t walgamuth

They usually round out because the recessed socket has not been cleaned and you are twisting twice the design amount per square inch.

No because when they built the car the engine was out on the bench. When the engine is in the bay you can’t always get the correct Angles on a hex bolt..and also after 30 years they’re always seized up. They used a very mild steel for the bolts for whatever reason

tdoublenastywitit · #22 01-31-2021, 05:54 PM

Quote:

Originally Posted by t walgamuth

They usually round out because the recessed socket has not been cleaned and you are twisting twice the design amount per square inch.

what's your method for cleaning them? because ur right if you can get your allen bit all the way down to the bottom they typically don't slip.

Mike D · #23 01-31-2021, 07:31 PM

Carb cleaner and compressed air. Use a good quality hex bit. Those Harbor Freight/Amazon "specials" just won't cut it.

As Tom mentioned, make sure the ends are square/flush. Don't even try it with one of the "ball end" style.

tdoublenastywitit · #24 02-01-2021, 11:05 AM

I have this little addictiion to carb and brake cleaner where as soon as I pull it out to clean a couple bolts or something I end up seeing something else that's dirty getting side tracked and proceed to spray the whole $7 bottle on a small 1'x1' area.

Then I'm out of cleaner by the time I get back on track with the bolts haha!!

I guess knuckling up and taking it do a detailer to do a underbody and engine bay cleaning could solve this problem

t walgamuth · #25 02-01-2021, 01:58 PM

Quote:

Originally Posted by Mike D

Carb cleaner and compressed air. Use a good quality hex bit. Those Harbor Freight/Amazon "specials" just won't cut it.

As Tom mentioned, make sure the ends are square/flush. Don't even try it with one of the "ball end" style.

I also have a very small straight screwdriver that I use to loosen the debris in the hex, then spray and blow.

t walgamuth · #26 02-01-2021, 02:01 PM

Quote:

Originally Posted by speednjay

No because when they built the car the engine was out on the bench. When the engine is in the bay you can’t always get the correct Angles on a hex bolt..and also after 30 years they’re always seized up. They used a very mild steel for the bolts for whatever reason

I heartily disagree on two things:
1. The bolts are very high quality in a benz and it is unusual in my experience to find one that is rounded off. I have always found it remarkable how few bolts break when being removed after decades of use.
2. Although it is sometimes a pain to get on the bolt or nut squarely it is always worth it to do so, even if it means buying a different socket or a universal joint.