Axle Reinforcement and Heat Sheild

Jim Agnew's information on his Axle Heat shields & reinforcement.

You should be able to picture it with the following descriptions.HEAT SHIELD on outboard side of gear leg.
It keeps the radiated heat from reaching the gear leg

It is made of polished stainless steel .030 thick and is 3 3/4" wide x 4 1/2" high. It is centered on the axle (at an angle that matches the gear leg) and the bottom rests on top of the axle mounting flange. It is spaced away from the gear leg by two thick #3 washers (or 4 thin ones) and has two #8 x 1" sheet metal screws at the bottom located so they will have adequate thickness of the gear leg for the screws. You must pilot drill for the screws or they will break when you try to tighten them. The top is held by a centered AN4 bolt and two washers that goes through the gear leg and the reinforcing plate on the inside of the gear leg. the space between the SS plate and the gear leg is small, however air passing between the gear and plate carries the heat away.

GEAR LEG Reinforcement

on inside of gear leg (this plate replaces the small rectangular aluminum plate that the four axle bolts go through)

Mine is made of .125" 6061-T6 aluminum plate with the rough dimensions of 3 1/4" wide top tapering to 2 1/4" wide bottom ( actually it is cut to match the width and shape of the gear leg) by 7" high. It is drilled for the 4 axle attach bolts at the bottom (the bottom of the plate should extend to the very bottom of the gear leg) and at the top center for the AN4 through bolt that holds the SS heat shield top center. Obviously the plate is at an angle that allows it to match the gear leg. The real fun is to bend the plate to match the curve of the inside of the gear leg. Sand the gear leg where the plate will be out to the edges of the gear so microglass will stick and rough sand the inside of the backing plate. You want the backing plate to sit flat if possible where the axle bolts come through.

MOUNTING THE PLATES - the fun begin

The axle is put in place and the 4 axle bolts pushed through the gear leg and the new reinforcing backing plate and the same with the upper bolt (you may need some washers). Before you put the backing plate in place a lot of thick microGLASS on the gear leg where the plate will go place the plate on the bolts and torque the axle bolts first, then tighten the top bolt until the plate is pulled in and against the gear leg at the top bolt. At this point you should have squeezed out a lot of Microglass so use a stick to pack the plate solid between the leg and the outer edges of the plate. The idea is to have a solid backing of the reinforcing plate. Don't forget to wax the bolts if you ever expect them to come out again. Leave the assembly overnight to harden.

The next day remove the top bolt and insert it through the SS plate heat shield, then two washers on the inside of the plate. Push the bolt through the gear leg, line up the bottom of the plate and use the predrilled lower holes to mark and drill the gear leg for the sheet metal SS screws. Screw in the screws to form the threads and then remove the heat shield and top plate. Next insert the sheet metal screws wit two washers each and put some silicone on the screws to prevent the washers from falling off. Do the same with the top bolt. Now, place a large bead of silicone on the inside of the shield between the sheet metal screws and across the top of the plate above and in line with the bolt. Put the plate in place and tighten the sheet metal screws and then tighten the top bolt. You are now done. The silicone locks the sheet metal screws in place and also acts as a vibration dampener so the plate doesn't vibrate from the air flow etc.

Jim