Last week my friends from the Estonian Ford Mustang Club told me about their upcoming event at a gokart racing circuit, lately used mostly by cars. I ofcourse joined them and on Saturday morning we were ready at the track to prepare ourselves for some laps with an instructor and then get going alone. I must say that it was an awesome experience and it gave me a lot of experience with the Corvette in regard of handling, stopping and recovery from loss of control. The Vette behaved nicely the whole time and I was just missing some good racing tires. In the front I currently have Road Hugger radials and they aren’t really made for track performance. Quite a bit of understeer with them.
Although everything was OK with the Corvette differential when I bought the car October 2008, I had it parked in the garage over the winter and when I began driving it last Spring, I noticed a very strange behaviour with the rear end. When cold, everything was fine, but when I began driving it and had driven for about 20 miles, it began making horrible noises when taking corners and giving gas at the same time. It also wanted to drag the inside wheel and the car was just vibrating terribly. I almost had the rear end rebuilt but I didn’t have time to mess with it and then I just thought I’ll do it over the winter. Browsing the Corvette Forums about a week ago about the similar issues people have had, I accidentally found a tip which suggested to try fully synthetic 75W-140 rear end oil instead of the usual 80W-90. They also said that it’s very important to add limited slip diff additive (one 4 oz. bottle) even if the oil is certified for LSD use. So I decided to give it a try and bought also a small bottle of Ford LSD additive which was told to be the same thing as GM additive, simply different branding.
Guess what – my rear end issues are GONE. It’s silk smooth, the lock seems to be working fine and I can drive hundreds of miles without any of the issues appearing which I had before. It’s just a pleasure to drive this car now. Again it’s a good proof that American cars are EASY to fix. I’ve fixed most of the issues on my cars in a similar manner. I don’t know if the oil solved the issue permanently, but at least this summer-autumn period will hopefully be OK to drive.