Spindle differences early chevy vs late bronco

[Id4jea]

After scouring the threads for days (this is a great forum btw) I can't find out if I can use a spindle from am 83 bronco (6bolt) instead of the hard to find 72-76 small bearing chevy for a disc brake swap on a 73 bronco. Maybe the spindle won't fit the axle of my 73?

I have the backing plates and calipers from a 77 K10 (the spindle was large bore) and hub/rotor from an 83 bronco which of course would work great on the 83spindle.

 

[broncnaz]

Welcome
the gm disc brake spindle and the bronco drum brake spindle are very similar. I think the GM spindle is about 3/16" longer than the EB spindle. Some people use a 3/16" spacer behind a EB spindle with a GM conversion. You can also have the big bearing GM spindle machined down the inner bearing is lager just machine it down to the EB inner bearing size.
The 83 ford spindle will not work at all. bolt pattern is wrong 5 instead of 6 and the part of the spindle that goes into the knuckle is way longer. Not sure on any lenght differances but overall it would take way to much work to make one work.

 

[Id4jea]

Thanks for taking the time to reply! The hubs I got off the 83 bronco were mounted on a 6 bolt spindle which left thinking I could use it. It makes sense that it would be longer the an early chevy though or else everyone would be looking for those as well..

Looks like I will try the 77 calipers/backing plates I have and buy some spindles from one of the 66-77 bronco shops. I've been driving with drums for 25 years, have a power booster ready to go, so might as well do it right.

 

[Pa PITT]

The Spindles need to be 1974 chevy 4x4 1/2 ton truck or Blazer or Submarine ..
.. And also I think that model, I really think it's like 73&1/2 ...74.. and part of 75.. FOR THE Spindle you need .. I did use some of the Big one that we turned down.. I think the no on the bearing are A45 & A37 with a 4250S SEAL. and a SBK1 SEAL KIT .D52 brake pads and the calipers are off the same chevy 4x4 along with the caliper brake hose .74 Stuff.
...THE backing plates from the 1974 are cast iron but the later model ones will still work but they only have a cast Iron frame with a tin plate for the dust cover . Some people have even ground off the tin plate an just let the dust fly.

 

[Ranchtruck]

The 83 spindles were off a TTB truck right? The issue with those is they don't have the step sticking out of the back of them for the brake backing plate. So the spindle doesn't have any part actually centering it in the knuckle if you use it with a backing plate.

I remember looking at those spindles myself and I'm pretty sure that's the reason I didn't use them.
I did use the rotors and hubs off a similar year ttb truck though.

 

[Id4jea]

Ok. I will plan on using the rotors and hubs off of the TTB 83 bronco. Caliper plates off of the 77 k10 pickup are solid, one piece iron and calipers looked ok. I will try to turn the spindles down (gives me an excuse to use my late grandfathers lathe). And I will give another look at the 83 spindles to see the differences you were talking about. I will post some pictures if I find anything of interest. The local yard here, LKQ, charges almost as much for their caliper+core as the new parts store so it may not be worth pulling those unless you enjoy it and have the time. rotors with hubs were cheaper than just pulling the hubs.

 

[Pa PITT]

Sorry but what does TTB stand for.. I think the hubs and rotor ass. I bought were from Ford 80 up to 86 or so .. I stole mine as Auto Zone was going to stop handling them . So I think I only had to give 24.00 each and I think the NO was 2492

 

[broncnaz]

Sorry but what does TTB stand for.. I think the hubs and rotor ass. I bought were from Ford 80 up to 86 or so .. I stole mine as Auto Zone was going to stop handling them . So I think I only had to give 24.00 each and I think the NO was 2492

TTB= twin traction beam basically what ford went to for a front axle on all the 80's up f150's and broncos

 

[Id4jea]

Just curious, found some pictures of an 83 spindle. I already know the bearings journals should be the same as the 72-75 chevy but from the earlier post by ranchtruck the flange probably won't work to center the caliper plate. If I get the parts together I will try to take a picture because I want to see how different they are and learn something.

http://www.supermotors.net/registry/media/728442