I have a small pile of these that were going on my last XJ (axles and driveline), but when I got them and felt how stiff they were they went in the misc parts bin. I don't see anyway they'll work unless they're already very hot and pliable. I've heard there's one or two brands that're very soft, but the ones I bought from PSC aren't useable in my opinion.
I was interested in this and had posted a thread on it awhile back. What I found was that the bellows are not really big enough to make much differnce. If the temp goes up 50 degrees, the volume of air goes up something like 10 percent. The volume of those bellows is so small as to be of no use.
Some people will say they never had a problem running them. That is because some seals can Eccept some pressure. In the old days, many gearboxes just had a pipe plug with no vent and worked fine to.
A forum community dedicated to custom off-road vehicle owners and enthusiasts. Come join the discussion about trail reports, builds, performance, modifications, classifieds, troubleshooting, fabrication, drivetrain, and more!