Downey
SILVER Star
All pretty good post, and pretty good reasoning, but possibly any type of mounting has an up side and a down side??? Here's what we know, and what we do about it:
(a) The stock 6 cyl. bellhousing is very thick, would qualify as a scatter shield for racing. The stock GM bellhousings (cast iron or aluminum) are thin egg shells.
(b) The stock Landcruiser transfer-case is a side-thruster, always trying to spin around in a circle behind the tranny.
(c) During the early days of Chevotas everyone was mounted at the GM bellhousing, with the tranny and transfer non-supported. It was not uncommon to crack 1 or 2 bellhousings per year.
Theory was that if the bellhousing cracked fore and aft (starting at a bolt hole), the crack was from torque twisting (i.e. transfer trying to spin around in a circle). If the crack were from side to side (around the circumference), the crack was from the non-supported long span (golden gate bridge) between motor mounts.
(d) Since all the cracks were occuring fore and aft, it was determined the best way to prevent the torque twisting was to grab the back side of the transfer (at the center of torque twisting) and lock it into the frame---thus the invention of the transfer-case crossmember. Once we produced these crossmembers, cracked bellhousings came to such a screeching hault that this was the proof that the theory was correct.
(e) The other theory that we dealt with was that each piece of a set of items that are tightly bolted together (long span, golden gate bridge) has all of it's own original strength, PLUS the strength and support of it's neighbor, each piece literally becoming stronger than itself. The torque twisting thus became a bigger problem than the long span.
You guys get this figured out any way you want, but I think Downey will continue to build transfer-case crossmembers.
Now, regarding the rear tubular crossmember behind the transfer-case, it is a torque tube that is designed to keep your hot rivited frame as straight as possible (after twisting off road trips). This subject came up once before(or more), I commented in support of not removing it, zillions of y'all jumped on my case, so do what ever you gosh dang please with your very important crossmember.
(a) The stock 6 cyl. bellhousing is very thick, would qualify as a scatter shield for racing. The stock GM bellhousings (cast iron or aluminum) are thin egg shells.
(b) The stock Landcruiser transfer-case is a side-thruster, always trying to spin around in a circle behind the tranny.
(c) During the early days of Chevotas everyone was mounted at the GM bellhousing, with the tranny and transfer non-supported. It was not uncommon to crack 1 or 2 bellhousings per year.
Theory was that if the bellhousing cracked fore and aft (starting at a bolt hole), the crack was from torque twisting (i.e. transfer trying to spin around in a circle). If the crack were from side to side (around the circumference), the crack was from the non-supported long span (golden gate bridge) between motor mounts.
(d) Since all the cracks were occuring fore and aft, it was determined the best way to prevent the torque twisting was to grab the back side of the transfer (at the center of torque twisting) and lock it into the frame---thus the invention of the transfer-case crossmember. Once we produced these crossmembers, cracked bellhousings came to such a screeching hault that this was the proof that the theory was correct.
(e) The other theory that we dealt with was that each piece of a set of items that are tightly bolted together (long span, golden gate bridge) has all of it's own original strength, PLUS the strength and support of it's neighbor, each piece literally becoming stronger than itself. The torque twisting thus became a bigger problem than the long span.
You guys get this figured out any way you want, but I think Downey will continue to build transfer-case crossmembers.
Now, regarding the rear tubular crossmember behind the transfer-case, it is a torque tube that is designed to keep your hot rivited frame as straight as possible (after twisting off road trips). This subject came up once before(or more), I commented in support of not removing it, zillions of y'all jumped on my case, so do what ever you gosh dang please with your very important crossmember.
