Post by Pontiac1976 on Oct 12, 2021 22:27:18 GMT -5
If you have Square body truck with standard brake (2 ") 12bolt 8.7/8 5x5 blot pattern system. And you want change to HD brakes (2 3/4") 12bolt 8.7/8 5x5 blot pattern system. You will have to find a diff from a Diesel or Heavy 1/2, Big 10 truck or any C/K 10 to 20 truck with the HD (2 3/4" shoes) 11-5/32 drums OPTION.( This is the fastest easy way if it is a working running set up. You should still check the brakes to see how good they are.) But it your using your diff you need the hardware to hold the Backing Plates from one of the (2 3/4") HD diff list above.( If the hard ware for the brakes is in nice shape springs, leavers, wheel cylinders take them. You have to re-move the axes to get the Backing Plates off. Re-move the diff cover take out the pin bolt slide out the main pin( just move the gear enough to do this do not rotate gears more than around 3-1/2” -4 4” in one or the other way when the pin out( if it a Posi you do not have to be careful of the spider gears). Press inward on the axes clip will show them self or fall out do for both side. Pull out the axes trying to keep centered if your try to save good axes seals. If there leaking look wore or there 2-3yr I would re-place the seals with new one’s
The Square body truck with a big brake (2 3/4") system.
What I ended up going with was replacing the brakes, from backing plate to drum, with a set of smaller 2" wide 12 bolt 8-7/8” 5x5 drums 11”off a 73-80+ mostly but if the 12 bolt diff option ordered.)
It should be easier to find a 12bolt 5x5 pattern w/standard brakes 11” drums w/2” shoes than it is to find one w/HD brakes wide 11-5/32” drums w/2-3/4” shoes. ( Backing Plates are the hard parts find as they do not sell them anymore.
Once you find a set not to badly most times you may want to get the wear pad re-weld to build up the pads file smooth
To like factory spec. to use them without biding) ** This 60’s old trick to save money back in the day, that can work more now days because you cannot order backing Plates anymore.
The Square body truck with a big brake (2 3/4") system.
What I ended up going with was replacing the brakes, from backing plate to drum, with a set of smaller 2" wide 12 bolt 8-7/8” 5x5 drums 11”off a 73-80+ mostly but if the 12 bolt diff option ordered.)
It should be easier to find a 12bolt 5x5 pattern w/standard brakes 11” drums w/2” shoes than it is to find one w/HD brakes wide 11-5/32” drums w/2-3/4” shoes. ( Backing Plates are the hard parts find as they do not sell them anymore.
Once you find a set not to badly most times you may want to get the wear pad re-weld to build up the pads file smooth
To like factory spec. to use them without biding) ** This 60’s old trick to save money back in the day, that can work more now days because you cannot order backing Plates anymore.