Well ok sports fans. It has come that time to upgrade the transfer case cause I am bored and let's face it. We all like mods. So going to swap in a Oshkosh 55000 from a HEMTT. I acquired this unit from Silversate55 a few months back. Impulse buy and I didn't even have to wait for the EUC to clear. Case is air operated to engage the front axle so the single air switch should suffice.
Ratios for this case are .98:1 High and 2.66:1 Low.
Transfer case dimensions: Width 17". Front to back 28". Top to bottom 30"
U Joints - 5-280X
Power rating : Can handle a C15 Kitty and 8V92 so the big cam I in its future should not hurt it.
Speed range : with the CAT 7155 and 16.00s - 76mph @ 2400rpms
As far as the regular 5 ton case. the Oshkosh 55000 is narrower by 6 inches. Longer by 5 inches and height is about 10 inches more
Installing it should be pretty straight forward. My transfer case was moved back 8 inches, and I continued to use companion flanges on my output on the transfer case on the E brake drum and on the jack shaft side I swapped on a companion flange and did away with the "mechanics" style joints. This is my benefit as by removing the companion flanges on each side and using just the spicer joints I gain 6 inches. a companion flange is 3" from center joint to mating face. So forward to backwards alignment should be the same. It will also lower my drive angle to only a few degrees down than a drastic down and to one side as it sits at the moment. My weak point at the moment of upgrade to a Big Cam will be the companion flanges and the transfer case.
Side to side install should not be an issue if I can locate some actual HEMTT brackets. If not I can always make my own. They bolt on the front and rear of the case on each side. So making 4 independent mounts should not be an issue either.
Height wise is going to be the problem. At 30" high the top of the case would be against the arch on the bed frame as it ran across and would be as low as the drivers step and fuel tank brackets. Simple enough would be to cut the bed and reinforce it. However I will probably canter the transfer case to drivers side on the lower part. This would make my front drive line angle almost straight and not have such a drastic turn around the CAT 7155. With the way the oil pump setup works on the 55000 it should not be a problem for the oil pickup. Also would help with the rear drive angle as to not be so inline with the rear axle.
This will be up and coming. I am doing some measurements on the mounts as I am having a hard time sourcing the HEMTT ones so will see what type of design I can come up with. More to come. I promise snow and cold weather won't hinder my progress.
Ratios for this case are .98:1 High and 2.66:1 Low.
Transfer case dimensions: Width 17". Front to back 28". Top to bottom 30"
U Joints - 5-280X
Power rating : Can handle a C15 Kitty and 8V92 so the big cam I in its future should not hurt it.
Speed range : with the CAT 7155 and 16.00s - 76mph @ 2400rpms
As far as the regular 5 ton case. the Oshkosh 55000 is narrower by 6 inches. Longer by 5 inches and height is about 10 inches more
Installing it should be pretty straight forward. My transfer case was moved back 8 inches, and I continued to use companion flanges on my output on the transfer case on the E brake drum and on the jack shaft side I swapped on a companion flange and did away with the "mechanics" style joints. This is my benefit as by removing the companion flanges on each side and using just the spicer joints I gain 6 inches. a companion flange is 3" from center joint to mating face. So forward to backwards alignment should be the same. It will also lower my drive angle to only a few degrees down than a drastic down and to one side as it sits at the moment. My weak point at the moment of upgrade to a Big Cam will be the companion flanges and the transfer case.
Side to side install should not be an issue if I can locate some actual HEMTT brackets. If not I can always make my own. They bolt on the front and rear of the case on each side. So making 4 independent mounts should not be an issue either.
Height wise is going to be the problem. At 30" high the top of the case would be against the arch on the bed frame as it ran across and would be as low as the drivers step and fuel tank brackets. Simple enough would be to cut the bed and reinforce it. However I will probably canter the transfer case to drivers side on the lower part. This would make my front drive line angle almost straight and not have such a drastic turn around the CAT 7155. With the way the oil pump setup works on the 55000 it should not be a problem for the oil pickup. Also would help with the rear drive angle as to not be so inline with the rear axle.
This will be up and coming. I am doing some measurements on the mounts as I am having a hard time sourcing the HEMTT ones so will see what type of design I can come up with. More to come. I promise snow and cold weather won't hinder my progress.
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