With the car down for the trans swap.... I thought it would be a good time to inspect the rear end gears. The DSS rear end conversion uses a Strange 9” gear set in a aluminum carrier. When it comes to the choice of ring and pinion gears for these, you have to decide whether you want to go with a hardened “street” gear that is somewhat power limited, or the “Pro” gear that by comparison... is not. The street pinion is a rather puny 28 spline that is said to not be up to the task with what I’m doing. So.... I made the decision to go with the 35 spline Pro in a 3.40 ratio to work with the T400. The downside (there’s always gotta be a downside) is they are soft. The steel is soft. They are engineered to absorb the shock that they will see on launch with a high hp drag car. They are “not for street use”. I’m thinking.... yeah but you can still drive them in the street. What’s the worst that can happen? They will wear out faster. The question is... how much faster? I’ve been told that if you do any prolonged driving (like on the highway) they will get hot and wreak the gears within a matter of minutes. Others have suggested maybe 150 miles of street use and they’ll need to be replaced. Strange says.... 15 to 300 passes on the quarter mile... “depending”. That’s a big help. So between engine break-in time, dyno time (40 mile round trip freeway drive to get there and back), data logging miles on the street and last but not least.... those long hot 1/2 mile pulls at over 180 mph. I figured we should take a look see at what was going on in there. There was a lot of metal in the oil so there’s definitely some wear going on. But the gears.... look ok to me! What the hell 😂. I have another complete 3rd member with the same 3.40 gear coming next week and we’ll be using that for our first round of testing on the track. That will give us a chance to evaluate that ratio and change to another gear if we think it would be better. In the mean time I’ll see if I can find somebody who is actually experienced at judging the wear on these gears to get a legit opinion. I have right at 400 miles on them. They are not loose feeling as far as lash goes and I’m thinking that with fresh oil every 400 miles they could go another three times that. I’m also thinking that I’ll be getting experienced at changing out 3rd members on the floor of my garage. Lots of stinky gear oil. 😝
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