The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 55.2-59 4speed OD trans and original crossmember

dsraven · 06-21-2018, 03:12 PM

brace the frame side to side if you plan to do that because the frame could spring and that will have an effect on the front cab mounts which can have an effect on the door and fender fitment.
brace the frame around it side to side, cut it out, modify it to your needs, or build a new cross member to keep the frame width uniform in that area, bolt it back in. or box the frame for rigidity and hope it is enough or if you have some sort of independent front suspension cross member in front of the old trans cross member you may be able to remove the old cross member without any worries depending on how beefy and reinforced your new trans cross member is, does it tie the top and bottom frame rail together? it is a concern for the front cab mounts though when it gets removed. the front cab mounts sorta give the cab their position in relation to the rad support (like a teeter totter) so any movement in the area may have an effect on door gaps, door latch fitment and change after a hard bump etc so you may wanna keep it but modify it so it is a specific length between abutment points on each side and can be removed and installed for engine or trans work.
make sense?

06-21-2018, 03:12 PM	#2
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 7,835	Re: 4speed OD trans and original crossmember brace the frame side to side if you plan to do that because the frame could spring and that will have an effect on the front cab mounts which can have an effect on the door and fender fitment. brace the frame around it side to side, cut it out, modify it to your needs, or build a new cross member to keep the frame width uniform in that area, bolt it back in. or box the frame for rigidity and hope it is enough or if you have some sort of independent front suspension cross member in front of the old trans cross member you may be able to remove the old cross member without any worries depending on how beefy and reinforced your new trans cross member is, does it tie the top and bottom frame rail together? it is a concern for the front cab mounts though when it gets removed. the front cab mounts sorta give the cab their position in relation to the rad support (like a teeter totter) so any movement in the area may have an effect on door gaps, door latch fitment and change after a hard bump etc so you may wanna keep it but modify it so it is a specific length between abutment points on each side and can be removed and installed for engine or trans work. make sense?