8" Truck Rally's on a 67

[jons70]

I don't know if I'm posting in the right place, but I have a problem with trying to put 15x8 truck rally's on the rear of my 67 C10. Someone has converted my truck to front disc brakes and 5x5 wheel lugs. The front appears to be a kit from LMC Truck using the 71-72 style 5 bolt discs. The rear however has been modified. It appears that someone has removed the rear axles from the diff and has had the original 6 bolt holes welded up, then re-drilled with new holes to suite the 5x5 bolt pattern. They appear to have used new drums also off of a newer truck. My problem is the center hub on the end of the axle shaft is larger than the center hole on my 15x8 truck rally's. The wheel will not fit up tight to the brake drum. Just a rough measurement with a tape measure shows me the hub on the truck is approximately 3 1/16" and the rally wheel appears to only be 3". The other issue is that the wheel is in too far compared to front, so I need to use a wheel spacer to correct this. Using a wheel spacer may also correct my problem with the hub diameter. If I get one that fits my rally wheel correctly I could always have a machine shop machine out the bore on the spacer to match the hub on the truck. I guess what I'm getting at is, has anyone come across the same problem? If so what was the solution?

Thanks
Jon

[N2TRUX]

Welcome to the forum jons70. Lets see if anyone can answer this...Anyone?

[Clyde65]

Welcome! have you thought about a spacer?

https://www.rsracing.com/rscatalog/a...hl-spacers.asp

[smashingchuck]

I have no idea why you are having this problem, if it were my truck i would pull the axles and have the centers turned down.

[jons70]

Thanks for the responses. I will have to measure the hub on the end of the axle and compare it to the rim. I measured the rim centre today and it's 3.063in or 77.81mm. Like I said before I'll likely have to use a wheel spacer to bring the wheel out to match the look of the front and to keep the tire from rubbing on the inside of the wheelhouse. The only problem I see with most of these spacers is that they are just a flat piece of billet aluminum with no hub centric to support the centre of the wheel. They rely on the wheel studs themselves to centre the wheel and support the weight of the truck. I'm probably worrying for nothing, but the centre hub is what is designed to take most the load, not the studs. I figured someone on here has put these 8" truck rally's on their truck and likely ran into the same problem.

[jons70]

Originally Posted by smashingchuck

I have no idea why you are having this problem, if it were my truck i would pull the axles and have the centers turned down.

The problem with doing this is that the drums will not be able to centre themselves on the hub because the hub would be smaller than the centre hole in the drum. The drum is designed to fit tight over the hub centric of the axle to centre itself so you don't have a mad brake pulse or a balance issue. This is all part of my confusion, I can't for the life of me figure out why the rally's wont fit. If the drums are what I think they are, than the centre hole has to be the same size as a newer 5 lug truck because that's what they appear to have come off of. This is the problem when you get something that someone else has messed with and you don't know what they've done.

[lolife99]

IF it was mine,...
I would buy a set of 71-72 brake drums and some aftermarket 5-lug axles and be done.
Everything would fit like it should and no spacer required.
The rear wheels are sucked in,... because you have the narrower rearend housing.
71-72 rearends are 1-1/2 inch wider. (total)
Maybe a cheaper solution would be to swap to a 71-72 rearend.

All of this is just my opinion.

[jons70]

Originally Posted by lolife99

IF it was mine,...
I would buy a set of 71-72 brake drums and some aftermarket 5-lug axles and be done.
Everything would fit like it should and no spacer required.
The rear wheels are sucked in,... because you have the narrower rearend housing.
71-72 rearends are 1-1/2 inch wider. (total)
Maybe a cheaper solution would be to swap to a 71-72 rearend.

All of this is just my opinion.

I don't really want to get into changing the whole rear axle to a 71-72. Mine is in perfect condition, it's been totally rebuilt, sandblasted and repainted when the truck had it's frame off done. I also like to keep it because it's the original numbers matching 12 bolt 3.73 posi. I have found out that my wheel track is 63.1in on the front and 61.1in on the rear, which makes sense about the 71-72 axle being 1 1/2" wider like you say. Theoretically if I use a 1" spacer on the rear and have a machine shop machine out the centre to the diameter of the hub centric on the end of the axle, everything should be fine. Spacers are only about $65/pair. Not my first choice, but defiantly the easiest and most inexpensive way to go.

[lolife99]

Sounds like you have it figured out.
Post up some pics when you get it all together.