Wheel hubs & bearings
While putting the calipers and rotors back on the car I noticed some play with the driver side wheel bearing. Synching it down with an axle helped, however, the outer bearing race kept popping out when the axle wasn’t connected. This to be expected (to some degree), however, given that I didn’t know how old the bearings were, I decided I’d replace them while everything was still in pieces.
So last week I removed the carbon ducts and jumped over to my press to pull everything apart. Much to my surprise I discovered that the front bearings were not using the OE (wax style) grease. While the first picture below looks pretty bad, realize that the grease being used is Redline CV-2 (hence the red/brown color). After some head scratching I recalled that one of the original sponsors Mark had was Redline, and that he may have some more information on the bearings and setup. After some back and forth communications I found out that the front and rear hubs/bearings were likely pieces Mark installed back in 2003, shortly before he sold the car. Apparently (and as some us are very familiar with), the OE wheel bearings fail on a pretty consistent basis, especially when you track the car. Typically the rears fail first but fronts aren’t far off. For the most part, the bearings fail due to the extreme side load and heat they’re subjected to, especially in the rear and especially with sticky tires and large rear anti-roll bars. Mark said he’d typically get 10hrs or so off a set before having to replace them, and for the most part, he’d replace them after race.
For the most part, rebuilding the OE bearings with special high-temp and high-pressure grease helps prolong the life and decreases the risk of sudden failure during endurance events. Amazingly, the bearings and hubs on the car were at least 12yrs old, however, based on the history during that time, most of the abuse came from some HPDE events and lots of storage. Also I didn’t mentioned it before, but I was able to identify the hubs as being the original parts (during Mark’s ownership) as they still had custom high-speed wheel studs pressed into them. After some additional inspection, I opted to replace everything (new NTN rear hub/bearing assemblies , new front Koyo bearings, new front NTN hubs, and new custom made wheels studs on four corners). Additionally, everything would be fully disassembled, “blue printed”, and reassembled with new Redline CV-2 grease. The pictures below show you some before and after results, however a few things are still outstanding (for example the wheel studs are on special order from Europe, thanks Mark).
Original front wheel bearing:
Disassembled (new) front wheel bearings:
(notice how little grease comes out of the bearings, approx 5-8g)
(new out of the Koyo box)
(OE grease removed, Redline added)
Disassembled (new) rear hubs/bearings:
(OE grease removed, <5g)
(OE grease removed, 10g worth)