VaSteve

It happened to me at the track and I found the cover inside the wheel. I found one of the guys that used the blue painter's tape as DE numbers and put a little of it on the lip of the cap. I pounded it back onto the car. That little bit of additional thickness held it in fine.

kurt M

Al hubs expand a lot. 951 hubs are stressed and fail too often as built so I am reluctant to hammer or drill on them. I take a good center punch and make 3 dimples in the cap flange from the inside This makes nice rounded bumps that are not sharp as when punched from the outside and dont gouge the hub when being installed and removed. Hold the punch and cap in one hand with the cap in your plam and some wood under the flange and give it a good hammer hit.

Chaos

I do both of Jerome951's tips

johntorg

Thanks to everyone, my new caps are arriving tomorrow. I'll try the centerpunch and glue approach together. I'm not usually a belt and suspenders guy, but losing the cap at the track is a PITA and it actually might hit another car. I guess, I'll add the small hole also.

Norm Swanberg

Mine have gotten loose, but were not lost. They were held in by the stock 951 wheel. I center punched the cap four times, 90 degrees apart. So far it has held.
Norm

johntorg

I just added a picture to the first post of some red stuff that really seemed to hold the cap in on the opposite side. Anyone know what it is?