Need some technical help guys.

[jorgensensc]

Okay, so the saga continues with my friends C/30. Backstory: A Friends '72 C/30 flatbed needed new front brakes/rotors in a bad way. I didn't have time for it so I took it to a local shop to do the work. They have searched high and low, but can't seem to find the right rotors. They ordered all the rotors that are correct for a '72, but none of them fit. It appears that the truck has a set of '71 rotors on it (possibly leftovers from the previous year) which they say were a one year only production (which makes them pricey at 800.00 a set). I can't verify any of this as no one else seems to know any thing at all in this area.
Which brings me to the current question. After all of this I think the easiest thing to do would be to change over to the '72 front rotors/ calipers, etc. I am going to assume that the spindle will need to be changed also. Can anyone tell me if the spindles will interchange correctly with the ball joints? If so that might be the easiest thing to do. I just don't want to have to change out ball joints etc. Any input/ knowledge/ advice is greatly appreciated!!! Thanks!
Shawn

Moderators, please don't move this to the suspension forum. I need alot of eyes on this, and it just doesn't get the traffic in that sub forum. Thanks!
Shawn

[jorgensensc]

Okay, I think I finally figured it out (with the help of Rockauto's website, very user friendly!)

I found the ball joints on the c-30 are the same from 71-86
I found the bearings on a c-30 are the same from 71-86
I found the calipers on a c-30 are the same from 71-78
The only rotors that I found that look like the ones on here are from 74-86
So given the information above, it would lead me to believe that the spindles are the same from 71-at least 78 for a c-30 w/dual rear wheels. It seams that the rotors from 74- 86 will fit on a spindle from a 72. So I think that is what we have,72 ball joints, 72 spindles, 72 bearings, 72 calipers, and 74-86 rotors. Does this sound right to anyone else? they must have used the later rotors to push the chrome Budd wheels out, since the rotors for 72-73 look similar to regular rotors and the wheels would have been sunken in. Any ideas?
Shawn


This is the rotor for '72-73 (thin, looks regular):
This is the rotor for 74-86 (tall, what ours looks like):

[jorgensensc]

anyone have any input or experience with this?
Shawn

[Olden Days]

You wont like what I have to say, I have been through this. I also ordered every rotor listed from 2 different local parts places. they kept sending the 74 up rotor. The conclusion was the 71-73 rotors were the same but discontinued. the parts suppliers for some reason have there part #'s messed up for those years of dually style rotor. I checked like you that all the part #'s for ball joints bearings etc were the same to try the 74 up rotor but even if the rotor went on the spindle our calipers are different than 74 up c/30. You say they (calipers) are the same. Is this by looking at part numbers or physically looking at them? I had another 79 c30 to look at and the calipers were definatly different on what I was looking at. so the only way I saw would be to change to the 74 up spindles too. The possible problem with that is the parts book in 2 different store was wrong about the rotors so I didn't want to keep beating a dead horse and find out those part #'s were wrong too. What I did was to use the 71-72 C20 rotor which will work on that spindle because I already had some good ones and bought some dual wheel adapters so I could still run the correct wheel up front . next time around I would do a whole crossmember swap.

[jorgensensc]

Olden,
Were you using calipers for dual rear wheel c-30's? I did notice there are several types of calipers offered for the c-30. some go all the way up in years, others don't. so are you saying that there is a tall rotor that was available from 71-73? I haven't been able to find anything other than the short rotor. But then again I can't find a reference to in any parts books for any dual rear wheel applications for 71-73 trucks either, and I know they made them. The best I can figure is maybe the wheels didn't stick out as far in the front so they only used one type of rotor. If push comes to shove I will switch out the crossmember, or possibly just the spindle and rotors/calipers from a 74+ truck. what do you think?
Shawn

[Olden Days]

Yes I was using calipers (Mine was an original disc dual wheel truck but rotors were shot. original rotor was tall and looked simular to the 74 up dual style but some what smaller (thinner and not quite as big around.) the rotor part was the same size as the c/20 rotor and used the same calipers as the c/20. Switching out the spindles and calipers seem like it might work ,as I considered that myself. I just never took it that extra step to see if in fact it would.
I hope that wasnt too convoluted to understand,