Kalspeed

Hi, was wondering if anyone has a preference or experience of the quality of the bulb housings from Bosch and/or Hella.

I recently installed the E-code Bosch units on my 928 and today I noticed one of them suddenly developed a crack in them. The H4 bulb I use are standard Hella H4/9003 60/55W bulbs. Had the housing maybe 3 weeks.

Could mis-handling from the vendor have created a hairline crack, perhaps? or some other factor? Weather has been normal here, seems strange suddenly one crack appears after about 10 minutes of use.

Thanks

WallyP

Was there uneven pressure from the installation?

Dave928S

^^ What Wally said.

Cracks developing in glass unexpectedly often emanate from an unnoticed small chip, crack or other defect that was present before installation, and only needs minor mechanical or heat stress to cause them to run. Unless you find an obvious installation issue that caused a crack to start, you might never know.

Kalspeed

I was careful when I installed them, they were packed well when I received them, perhaps I'll never know what actually caused the crack

Alan

Hella or Bosch are both fine brands - I'd go with whatever you have on the other side... I suspect you will never know what caused the failure - but if they arrived in good shape well packed you don't have much of a case against the supplier. Just bad luck maybe..

Alan

Kalspeed

Both sides are the Bosch, I did contact the vendor and they requested I send them photos.

I also had , in both lens, a strange swirl impression identical to each side, which was only visible when the lights were on. Pics below. A manufacturing defect maybe, some kind of compound which caused a crack?

Passenger side with crack circled.



Driver side