Sure Grip unit feels much better than Eaton TruTrac did..
I recently replaced the differential in my 8 3/4 with a blueprinted Sure Grip unit from Doctor Diff. I was getting a high speed 95+ vibration and the passenger side Green Stripe bearings were getting noisy after a few thousand miles. The driveline was smooth until I exceed 95 mph, and then a significant vibration would start and increase in intensity as speed went well into the triple digits. It didn't make for a reassuring feeling while it happened.
According to Cass aka Doctor Diff, the TruTrac's have an design issue that doesn't stabilize the splined components that the axles fit into allowing them to move around inside the TruTrac carrier. He says it's the only differential that he has seen designed with no provision to set that clearance inside the unit. He spoke with them about it, and hears similar vibration and early wheel bearing wear stories all the time from all over the world. I was able to grab my rear wheel with the car jacked up at the 3 & 9 O'clock points and shift the wheel back-and-forth like it was turning left or right slightly.
I've yet to get on a track to see if the high speed vibration is gone, but I did immediately notice how much more solidly the car hooks up on launch. I knew right away why they called the unit a Sure Grip. It feels exactly like that, where as the True Trac never gave the feeling of solidly hooking up. It worked, but it just felt different. Sure Grip feels exactly like it's name implies. Mopar is awesome!
I recently replaced the differential in my 8 3/4 with a blueprinted Sure Grip unit from Doctor Diff. I was getting a high speed 95+ vibration and the passenger side Green Stripe bearings were getting noisy after a few thousand miles. The driveline was smooth until I exceed 95 mph, and then a significant vibration would start and increase in intensity as speed went well into the triple digits. It didn't make for a reassuring feeling while it happened.
According to Cass aka Doctor Diff, the TruTrac's have an design issue that doesn't stabilize the splined components that the axles fit into allowing them to move around inside the TruTrac carrier. He says it's the only differential that he has seen designed with no provision to set that clearance inside the unit. He spoke with them about it, and hears similar vibration and early wheel bearing wear stories all the time from all over the world. I was able to grab my rear wheel with the car jacked up at the 3 & 9 O'clock points and shift the wheel back-and-forth like it was turning left or right slightly.
I've yet to get on a track to see if the high speed vibration is gone, but I did immediately notice how much more solidly the car hooks up on launch. I knew right away why they called the unit a Sure Grip. It feels exactly like that, where as the True Trac never gave the feeling of solidly hooking up. It worked, but it just felt different. Sure Grip feels exactly like it's name implies. Mopar is awesome!
