tail light lens cracking

OK, maybe I'm losing my soft touch as I get older, but I just had the fourth, yes fourth tail light lens crack when trying to lightly tighten. If I don't get it snug it loosens, but cracks if I barely tighten it. I broke one NOS and three after market lens this summer. The fourth today trying to put a new one on for my trip. Can someone shed some light on what the hell I'm doing or an alternative method?

I've ended up using Loctite on all of the screws on the tail light, after cracking a couple lenses. Just tighten them enough to seat the lens into the bedding. The same goes for the screws on the housing.

First thought was loctite. But if lens is cracking in the area where the screw is tightened are you sure you have the right length screws? Maybe too long which might make it difficult to tighten or too short meaning limited thread engagement unless you over tighten.
I haven't had this problem so I must be lucky because I'm rarely right when it comes to maintenance. My method is to repair something by breaking it which teaches me, typically, what not to do. Than when finally done right I fix the other thing I broke while fixing the first thing.

britbike220 said:

If I don't get it snug it loosens, but cracks if I barely tighten it. I broke one NOS and three after market lens this summer. The fourth today trying to put a new one on for my trip. Can someone shed some light on what the hell I'm doing or an alternative method?

Click to expand...

Have you lost the two rubber "buffer" washers which fit inside between the lens and metal bracket?
With the rubber washers in place, it shouldn't be necessary to tighten the screws so much.






Amal pilot/throttle stop screw O-rings make good substitutes for those rubber washers and I suppose you could also fit them under the screw heads as well? (the internal rubber washers also stop the screws falling out!)