Why aluminum bolts?

[MSCH]

Welcome to the subtle joys of MB ownership. It's designed to make you feel better about your tranny service.

actually, that MB is designed to so you give up and take it to an authorized Teutonic Anallyretentive Level service provider and have it
serviced/ repaired by a technician named Hans along with his trainee named Fritz, both who spent a 4 year apprenticeship in Friedrichshaven or Stuttgart learning to change oil and torque drain plugs.

 

[Vercingetorix]

Porsche uses aluminum oil drain plugs. Every gram counts.

 

[Trav]

The only reason I can think of is not so much weight but the case or parts may be made of a magnesium alloy, aluminum is less reactive than steel in magnesium alloys. I would think using the Magnesium is the weight saving. I don't care for aluminum bolts in general.

 

[eljefino]

Magnesium is arguably easier to cast vs aluminum, maybe Mercedes has a reason.

You'll recall the first non-steel wheels were "Mags" back in the day.

 

[loneryder]

Save weight?

 

[paulo57509]

Think of how many bolts the bolt factory has to ship to the MB transmission assembly factory, year after year after year....

Aluminum bolts are lighter per truckload (trainload?). Ultimately, you're paying for the freight. MB is being nice to you by passing along the savings.

/s

 

[another Todd]

The only thing I can think of is the topic of dissimilar metals.

Alum bolts into alum cases makes for less concern than steel bolts galling or otherwise fouling the case threads.

Except that we have been using steel bolts in aluminum transmission cases for what, 80 years with no problems I have ever heard of.

 

[Exhaustgases]

They likely have many excuses why they use them, no one mentioned expansion rates.
I think its just a great way to sell more bolts, an Al bolt will likely not take more than half the torque that a steel bolt will. Zinc coating? That was not done much in the old days, more like a phosphate type coating or?
The use of Al bolts makes me think of the wire insulation that got heat cracked and fell off, or the tasty stuff that mice and rats love to eat.