Rear Gear Lube - Synthetic Or Conventional?

[Rory McNeil]

Originally Posted by Eman

Shockproof doesn't make any sense to me. thick as mud and it's claim to fame is it clings, so does axle grease! Might be great in a roundy round car where the rear gets very hot. I want thin oil that flows all of the time.

I have to assume that you have not used the light or heavy Shockproof gear oils offered by Redline. It is not at all thick, I`d guess it flows like a 30W engine oil, and it definatly does cling. A couple of years ago, I pulled the cover of my Mustangs 8.8" rearend after sitting all winter, and the top of the casting was still wet with oil. Both my cars are 4 speeds, and I use the Redline light shock in the Jericos, and the heavy shock oil in the diffs. My 10.0-9.9 ET bracket car has a Dana 60, and and has been a stick car for 15 years now, the gears always look like new. I think some gear ratios are more likely to break than others, especially when you get into lower ratios. I`ve been racing my Mustang for 13 years now, the same set of 4.88s still look fine, but I have broke 2 sets of 5.14s, which have 1 less tooth on the pinion than the 4,88s do, From what I have seen with 8 3/4 MoPars is that with the steeper ratios, the teeth on the ring gear get quite shallow, which can`t be good for strength.