68/70Vette
Well-known member
I recently received my new diff. It's a 10 bolt, with Tom's 30/31 (?) spline inner axles, tuned polished differential case, etc. (The inner and outer half axles have different spline counts so I just forget if the inner is a 30 or 31.)
To install a diff on a bare frame seems like a piece of cake. If you do it by yourself, with no helper and you have no upper arm strength at all, it gets to be a challenge. I can relatively easily lift a 100 pound transmission. You grab the input shaft and the tail housing and lift it up like a dumb bell. No problem. However, the diff is about the size of a bowling ball and weighs about 95 pounds. It's very small size makes it almost impossible for me to handle. I have no problem man-handling a 300 pound Corvette frame, but a 95 pound differential was a problem for me.
I placed the differential on a mechanics creeper (the 4 wheeled thing you lay on your back and scoot around under the car.) I positioned the diff underneath it's cross member and hoisted up the frame with a jack. The diff to crossmember bolts are 7/16 X14 X1 and 1/4 inch. I used 7/16X14 x 6 inch bolts....with the diff on the creeper and the frame up in the air.
I took a lot of moving around, etc, and after about 15 minutes, I got one of the 6 inch bolts into the diff cover. In not too much more time I got a second 6 inch bolt in..and successively easy all four bolts in. With all 6 inch bolts in, I jacked up the frame more, removed the creeper, and placed some wood blocks under the diff, then I dropped the frame so the 6 inch bolts caused the diff to mount up exactly with the diff crossmember and then I easily replaced the 6 inch bolts with the 1 1/2 inch bolts.
As for the differential nose bracket bushings, I wasn't really sure how they went together. So I went out and looked at my 70 and quickly saw how they are assembled. Sooo.....the diff is in!!
Thanks to Mike Deyer for the differential (and trailing arms). (Tracdogg2). Mike did some extra machining on Tom's parts to reduce some tolerances even more. The differential was painted by Mike in a grey color I preferred and also he added a drain plug to the differential casting. Draining lubricant will now be easy if I ever have to do that.
Next, I have to add the trailing arms, axles, strut rods, and spring. I have everything except the spring (I still can't make up my mind as to whether to get a plain mono spring, or the dual mount.) Also I have to add the tranny to the frame. I have a TKO 600 5 speed in a box ready to go. The differential is a 3.73 and with the TKO 600 0.64 fifth gear, this should be a good freeway ratio. I currently have a Richmond 5 speed mounted on the frame. I decided to replace it since it is only rated at 450 foot pounds of torque. I was going to have the differential built to a 3.08:1 gears until I found out about the limited torque rating of the Richmond. So I decided to have the diff built as a 3.73 and replace the Richmond with a TKO. Working with all this stuff on the frame is certainly a little bit easier!!!!
Sitting on the frame is a Keith Black Aluminum BB with Brodix heads. The block has a Keith Black crankshaft but no rods, pistons, etc. I have a 454 placemaker flywheel and a McLeod dual disk clutch with a stock GM aluminum bell housing. The frame also has a completely assembled front suspension, SS brake lines, aluminum calipers, SS gas lines, and a new gas tank. I hope I can get this thing finished before being forced into retirement!! I think I'm way past the 1/2 point so chances of finishing are relatively good.
To install a diff on a bare frame seems like a piece of cake. If you do it by yourself, with no helper and you have no upper arm strength at all, it gets to be a challenge. I can relatively easily lift a 100 pound transmission. You grab the input shaft and the tail housing and lift it up like a dumb bell. No problem. However, the diff is about the size of a bowling ball and weighs about 95 pounds. It's very small size makes it almost impossible for me to handle. I have no problem man-handling a 300 pound Corvette frame, but a 95 pound differential was a problem for me.
I placed the differential on a mechanics creeper (the 4 wheeled thing you lay on your back and scoot around under the car.) I positioned the diff underneath it's cross member and hoisted up the frame with a jack. The diff to crossmember bolts are 7/16 X14 X1 and 1/4 inch. I used 7/16X14 x 6 inch bolts....with the diff on the creeper and the frame up in the air.
I took a lot of moving around, etc, and after about 15 minutes, I got one of the 6 inch bolts into the diff cover. In not too much more time I got a second 6 inch bolt in..and successively easy all four bolts in. With all 6 inch bolts in, I jacked up the frame more, removed the creeper, and placed some wood blocks under the diff, then I dropped the frame so the 6 inch bolts caused the diff to mount up exactly with the diff crossmember and then I easily replaced the 6 inch bolts with the 1 1/2 inch bolts.
As for the differential nose bracket bushings, I wasn't really sure how they went together. So I went out and looked at my 70 and quickly saw how they are assembled. Sooo.....the diff is in!!
Thanks to Mike Deyer for the differential (and trailing arms). (Tracdogg2). Mike did some extra machining on Tom's parts to reduce some tolerances even more. The differential was painted by Mike in a grey color I preferred and also he added a drain plug to the differential casting. Draining lubricant will now be easy if I ever have to do that.
Next, I have to add the trailing arms, axles, strut rods, and spring. I have everything except the spring (I still can't make up my mind as to whether to get a plain mono spring, or the dual mount.) Also I have to add the tranny to the frame. I have a TKO 600 5 speed in a box ready to go. The differential is a 3.73 and with the TKO 600 0.64 fifth gear, this should be a good freeway ratio. I currently have a Richmond 5 speed mounted on the frame. I decided to replace it since it is only rated at 450 foot pounds of torque. I was going to have the differential built to a 3.08:1 gears until I found out about the limited torque rating of the Richmond. So I decided to have the diff built as a 3.73 and replace the Richmond with a TKO. Working with all this stuff on the frame is certainly a little bit easier!!!!
Sitting on the frame is a Keith Black Aluminum BB with Brodix heads. The block has a Keith Black crankshaft but no rods, pistons, etc. I have a 454 placemaker flywheel and a McLeod dual disk clutch with a stock GM aluminum bell housing. The frame also has a completely assembled front suspension, SS brake lines, aluminum calipers, SS gas lines, and a new gas tank. I hope I can get this thing finished before being forced into retirement!! I think I'm way past the 1/2 point so chances of finishing are relatively good.
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:lol: