1972 C30 dually drop spindle install HELP!!

[Junkpyl]

Hi all, I've looked around but cannot seem to find a definitive answer.
I just started installing my drop spindles from Bell Tech this morning and all is going well until I noticed the brake caliper mount is very different. The spindles are listed as 75-91 and they dropped right onto my ball joints with no issue. haven't gotten to mounting the rotor yet and hope there are no surprises there as well.

These new spindles seem to need a separate mount cradle for the caliper that is not in my possession.

I bought them used but in like new condition.

Anyone know what I'm up against?

[kwmech]

What part number did you get? Should have been 3500

[Junkpyl]

They are. Trying to upload picture from my phone but won't cooperate.

[Junkpyl]

Here are two pix. the caliper mounts are different.

[Junkpyl]

Looking online, I find a different caliper that is JB8 style? requires a cradle type mount that bolts to the caliper. I'm assuming this is what I need for these drop spindles. Anyone know if that style will work with my rotor or do I need to upgrade that as well??

[65standard]

Chevy has two different caliper, one single piston, and one dual piston. They also have two different rotors. Looks like your new spindles are for the bigger brakes. Dual piston calipers with the thicker 1 1/4" rotors. You will most likely need new caliper and rotors that go with those spindles.

[65standard]

Oh, and the brakes hoses are different between the two calipers.

[Junkpyl]

I'll explore that avenue as well, thank you.

The spindles are for 75-91 according to the part number on them. My original rotors and ball joints fit as they should. The caliper is the only difference.

[kwmech]

Those are not 1 ton calipers, they are 3/4 ton. Even the 1 ton is has a single piston caliper. AND as stated, you will need different hoses.



Are you sure it is a real 1 ton truck? Or something somebody put a dually rear end under.

[Junkpyl]

All original 1972 C30 dually with 12' flatbed.

[truckzilla]

Did you ever find the right caliper that fits those dropped spindles? I'm having the same problem and the guys at Belltech were of no help. One even told me that the Bel-3500 was not intended to be used in a dually application. Strange how so many places advertise these spindles for duallys but they used what is called a clip on caliper.

[Junkpyl]

Yes, its the JB8 code calipers. They are the clip style and the trouble I had was with some castings that I got from the local auto parts store had an issue. They had material added and then machined the surface and it was a poor job. I went to NAPA and bought a set and they went on but if you aren't familiar with them, they can be a little tricky. As far as the spindle not fitting, I had no problem. They bolted right on to my ball joints with no issue. My truck is a 72 but I have no idea if the control arms had ever been swapped out with later model ones, I do not believe they have been. I sourced later model dually rotors as mine were pretty worn and the new ones had a good 1/4" of meat on them and were off a truck with the JB8 brakes. got them turned and put new bearings in and they slid right on. I have not driven the truck but around the block because it still needs other work but it does stop real good from 25 mph now
I hope this helps. Shoot me a message if you have any other questions, I'd be happy to lend a hand.

[Junkpyl]

[SCOTI]

Originally Posted by Junkpyl

Attachment 1433441

Junkpyl...

Check the center bore of your wheels & compare it to the hub. Those look like 99-later wheels which have a larger bore vs 71-98 trucks. Might be an issue you haven't realized w/the limited drive time.

[Junkpyl]

Good eye on that one. I have had them on it for a while and did notice a little wobble at certain speeds. I've figured out I need hub centric rings to take up the slack just haven't gotten them yet.