unik5
Registered Member
ok cool thats exactly what I needed to know
So I do have the correct caliper brackets now I just have to wait until I have time to take everything apart again
CK5
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8lug swap completed
- Thread starter unik5
- Start date
ok cool thats exactly what I needed to know
So I do have the correct caliper brackets now I just have to wait until I have time to take everything apart again
ok cool thats exactly what I needed to know
So I do have the correct caliper brackets now I just have to wait until I have time to take everything apart again
You only have the correct caliper bracket if once you have the hub/rotor assembly on and the caliper will actually bolt back in place. The rotor for a 3/4 ton is larger in diameter than a 1/2 ton so the caliper bracket is different since it has to push the caliper further out by an 1/8" otherwise the caliper would hit the rotor and you wouldn't be able to bolt it to the bracket.
unik5
Registered Member
Are there different styles of caliper brackets or is it this bracket for the half ton and this bracket for the 3/4 ton type thing.
1/2 ton whats on my truck now
3/4 ton what i picked up
1/2 ton whats on my truck now
3/4 ton what i picked up
There are both of those styles for both 1/2 and 3/4 ton. Lay one bracket on top of the other and make sure that one mounts the caliper further outboard than the other (that would be the 3/4 ton bracket).
Well, not sure what I have anymore lol. My D44 8 lug, which supposedly came from the same truck my 3/4 ton 14bff did, uses the top pictured caliper bracket.
only diffrence is dia of the bracket to match the bigger rotor of the 3/4 ton.
the solid heavy stamped steel or the half stamped steel/tin cover is no diffrent to each other . only thay were cutting costs and droped half the steel and used tin to make up the rest.
and just cause that axle was under the truck dosnt mean it was correct for the truck. tons of guys swap axles and then years later sell it and not tell the new owners or can even tell its been swaped out.
the solid heavy stamped steel or the half stamped steel/tin cover is no diffrent to each other . only thay were cutting costs and droped half the steel and used tin to make up the rest.
and just cause that axle was under the truck dosnt mean it was correct for the truck. tons of guys swap axles and then years later sell it and not tell the new owners or can even tell its been swaped out.
unik5
Registered Member
while im at it, could the problem possibly be in the hubs? Are there differences in years or anything like that, any way to tell what i have? The new bearing part numbers matched up with my old ones so I know I have the correct spindle size,,, I havent compared caliper bracket sizes (i will in a few hours) yet but I figured Id throw that out there too so I can check.
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unik5
Registered Member
Sorry i dont know how to quote from another thread but i did find this by esteban86k5
GM has two different types of axles: the "first design" and the "second design". For those who dont know the difference, the "first" goes from 73-76. The "second" goes from 77 to 91. Some differences are:
1. Backing plates are ALL diffferent. Both 1/2 and 3/4 ton for both designs are NOT the same thing. 3/4 tons are larger diameter than the 1/2 tons. There are currently 6 different types of backing plates. The 1/2 ton has the 73-76, 77-80, and 81-91. 3/4 ton is the same years, but only bigger around.
2. Bearing hub and rotors are different. There are 4 types. 73-76 use a smaller wheel bearing on both the 1/2 and 3/4 ton. The 1/2 ton bearing hub is an internal drive. 3/4 tons were available in both the internal and external drives. 77 and newer bearing hubs are the same size wheel bearing. 1/2 and 3/4 tons are all internal drives. The differences in the rotor diameter is the fact that the 3/4 tons are larger around than the 1/2 tons. This is why the backing plates are larger around than the 1/2 tons. If you use a 1/2 ton backing plate on a 3/4 ton rotor, the caliper will NOT even align up with the bolts. If the 1/2 ton rotor is used with the 3/4 ton backing plates, the caliper will NOT have enough pad contact with the rotor.
3. Spindles. 73-76 are one type only. They are "first design" small bearings. 1/2 and 3/4 ton spindles are interchangable. 77-91 spindles are "second design" and all interchangable between 1/2 and 3/4 tons. You cannot use a first design spindle with a second design bearing hub & rotor. The hub will wobble in place. If the second design spindle is used with a first design bearing hub, the hub will not even go on at all.
GM has two different types of axles: the "first design" and the "second design". For those who dont know the difference, the "first" goes from 73-76. The "second" goes from 77 to 91. Some differences are:
1. Backing plates are ALL diffferent. Both 1/2 and 3/4 ton for both designs are NOT the same thing. 3/4 tons are larger diameter than the 1/2 tons. There are currently 6 different types of backing plates. The 1/2 ton has the 73-76, 77-80, and 81-91. 3/4 ton is the same years, but only bigger around.
2. Bearing hub and rotors are different. There are 4 types. 73-76 use a smaller wheel bearing on both the 1/2 and 3/4 ton. The 1/2 ton bearing hub is an internal drive. 3/4 tons were available in both the internal and external drives. 77 and newer bearing hubs are the same size wheel bearing. 1/2 and 3/4 tons are all internal drives. The differences in the rotor diameter is the fact that the 3/4 tons are larger around than the 1/2 tons. This is why the backing plates are larger around than the 1/2 tons. If you use a 1/2 ton backing plate on a 3/4 ton rotor, the caliper will NOT even align up with the bolts. If the 1/2 ton rotor is used with the 3/4 ton backing plates, the caliper will NOT have enough pad contact with the rotor.
3. Spindles. 73-76 are one type only. They are "first design" small bearings. 1/2 and 3/4 ton spindles are interchangable. 77-91 spindles are "second design" and all interchangable between 1/2 and 3/4 tons. You cannot use a first design spindle with a second design bearing hub & rotor. The hub will wobble in place. If the second design spindle is used with a first design bearing hub, the hub will not even go on at all.
unik5
Registered Member
The caliper bolt holes clear the rotor it looks
KansasTwister
1/2 ton status
Got it together? Sweet!
unik5
Registered Member
No
it still grinds i have a video but i dont know how to post it
it still grinds i have a video but i dont know how to post it
KansasTwister
1/2 ton status
still hitting on the bolts?
unik5
Registered Member
Yupp i matched my hubs with some other 85 k20 hubs and theyr the same..
RollinKaos
1/2 ton status
Just a question could it be a difference in the years ? I know that there are different rotor thicknesses on different years of 2wd drive trucks. Is it possible that the rotor is the wrong thickness for the hub?
2wd stuff dont fit 4wd stuff 
also same thickness rotors just 5/8" bigger dia like we have said before in here.
and you need to pull the wheel seal and check fitment of inner bearing to race and hand check the bearing to spindle and take pics and post up for us to verify correct parts.
also same thickness rotors just 5/8" bigger dia like we have said before in here.
and you need to pull the wheel seal and check fitment of inner bearing to race and hand check the bearing to spindle and take pics and post up for us to verify correct parts.
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KansasTwister
1/2 ton status
on my half ton stuff you can't put the race in to deep because there is a stop. i would assume 3/4 would be same way
2wd stuff dont fit 4wd stuff
also same thickness rotors just 1" bigger dia like we have said before in here.
and you need to pull the wheel seal and check fitment of inner bearing to race and hand check the bearing to spindle and take pics and post up for us to verify correct parts.
The diameter difference is .625" (5/8"). The 1/2 ton stuff is 11 7/8" diameter and the 3/4 ton stuff is 12 1/2" diameter.
RollinKaos
1/2 ton status
OK , I wasnt clear on that LOL. What I was asking is since he has 2 different yrs of hubs could that be the problem. I was referencing that GM had a 1 1/4 " and 1" rotors on the 2wd trucks.I know the 2wd stuff will not fit the 4wd hub. I was just asking if there was a change in rotor thickness between the years is all.
unik5
Registered Member
on the race the hub has that lip that it sits on so i know its not too far down.
but I should have time to work on it again before this weekend since class ends monday so i'll mess with it some more and take some more pictures yada yada yada
but I should have time to work on it again before this weekend since class ends monday so i'll mess with it some more and take some more pictures yada yada yada
on the race the hub has that lip that it sits on so i know its not too far down.
but I should have time to work on it again before this weekend since class ends monday so i'll mess with it some more and take some more pictures yada yada yada
If it was me, i would have pulled the whole axle off the donor axle.
Good time to do new Bj's, and then you know it all fits together.
