I’ve been doing quite a bit of DIY work on a BMW an Audi recently. They’re a nightmare to work on but one thing I’ve noticed is all of the fasteners are like new, they all come undone and never round off or corrode. Anything Japanese I’ve worked on usually has zinc plated hex fasteners that start to corrode within a year or 2. Never had that with anything German, do they treat fasteners differently? Noticed all of the fasteners have that galvanised colour to them?
German cars better fasteners?
- Thread starter Diesegas
- Start date
Yes, even working on my FILs Jetta, the fasteners came out looking almost like new. Don’t exactly know which coating they have. Traditional zinc coatings have a shiny finish, these are dull grey. So perhaps galvanized zinc? Note sure but it definitely works.
edyvw
$50 site donor 2026
Anything that bolts etc. on German vehicles is not only better quality but oversized too.
My experience with VW is that the germans think they are such amazing engineers that they can figure out how to make everything out of plastic.
I've seen many VW and BMW fasteners that had chromate coatings. If the fastener looks yellowish or greenish it's chromate-coated. The thickest chromate coating will make a fastener look very dark or even black. The chromate coating makes the underlying zinc or zinc alloy coating last much longer. There could also be an additional phosphate coating between the zinc plating and the chromate coating. Phosphate coatings appear dull grey to black.
I worked at a mitsubishi/hyundai dealership. The hyundai fasteners were often rust-i-fused while the mitsubishi came out looking new (inside). The fasteners on my Alfa look new inside and out for the most part.
Kamax and Vibo make a majority of German fasteners. Many of them are one-time use and coated.
I absolutely hate those Allen bolts that are on many euro cars. They always round out.
Funny, I've not had that issue.
It is a shame that the quality of many of their plastics are not as good as the quality of their fasteners. Where I live some of it starts cracking, breaking, and turning to dust after just a few years.
Germans love their stretch bolts... and the Dacromet coating
then VW/Audi loves their triple square bolts....
Back to stretch bolts, owners are too cheap to replace them each time, as they feel the shop is nickel & diming them.
then VW/Audi loves their triple square bolts....
Back to stretch bolts, owners are too cheap to replace them each time, as they feel the shop is nickel & diming them.
After wrenching on German cars for a quarter century, I agree. The only exceptions that come to mind are the pinch bolts on Audis and the rear alignment bolts on bmws. Those require some fire. Oh, and exhaust flange bolts on bmws.
I've noticed the same thing. The underside of my wife's Outback is covered with rust on fasteners. But my E350, which is only 1 year newer, has almost no rust underneath. I'm not sure what coating is on the fasteners on the E350, but they always come loos with ease.
I haven't managed that yet on even my '81 Rabbit. I must be doing it wrong. I do however replace bolts that need to be replaced before they become problematic and I don't try to make do with SAE bits. I quite like triple square head bolts and bits. They tend to hold up better than Allen head bolts and bits.
While brittle plastic can be annoying, I've found I prefer working on German cars over American/Japanese living in the rust belt.
German = being careful with plastic bits
American/Japanese = break out the torch for every bolt
One reason I bought my Jeep Wrangler in California, it is rust free and a joy to work on compared to every other NorthEast Jeep I've owned.
In addition to one time use, stretch bolts, VW just loves triple square, allen style bolts. When I changed the clutch on a Vetta I had several years ago had to source a number of metric triple square allen sockets. They do hold the tool bit more securely making it almost impossible to strip, but as they are all one time use, I dont understand why those in lieu of normal allen head bolts.
Yes I agree, their plastic sucks, but the metal fasteners are - once you have the right tools - very durable.
Fact is 90% or more of the "one time use" fasteners are no such thing. Just looking at them you can see they are not stretch bolts and when measured against new are identical, there is no stretch area on the bolt, a nut will spine right down the threads with no binding.
On some VW models if you replaced ever bolt the say (one time use replace) on a clutch job there are over $200 worth at dealer retail.
I replace the clutch cover and flywheel bolts only, if the others are in good shape they go right back in.
Mercedes used to have a okay to reuse length on some of their bolts.
On some VW models if you replaced ever bolt the say (one time use replace) on a clutch job there are over $200 worth at dealer retail.
I replace the clutch cover and flywheel bolts only, if the others are in good shape they go right back in.
Mercedes used to have a okay to reuse length on some of their bolts.