The Stovebolt Site Forums The Shop Area Driveline Redrilling 6 bolt hub to 5 bolt

Have a 37 w/stock 6 bolt front hubs. Would like to convert from the 16" to 15" wheels with 5 bolt 4 3/4 inch circle. Can the existing hubs and drums be redrilled to accomodate 15" rims? Can't afford a front end change out right yet. Thanks in advance for comments

I don't think you have enough area between the bearing retainer on the hub to use a smaller bolt pattern. I did however have the rear axle flanges drilled for 4 3/4 on my 56 to match the front disc conversion. What you might try is the front hubs & drums from a 49-54 car, which are 5 lug. I know they can be used on AD & TF trucks. Not sure about earlier trucks.
Fred

I have been considering having the rear axles drilled and wondered if someone had done this before. I already snagged the front hubs for 5 bolt but was not sure if making the rear match would require custom axles or what. Did you use care drums after re-drilling the axles for the new pattern? I just can't see re-drilling the drums as they would have more torsional stress in my way of thinking.

I did have the drums re-drilled. It is also necessary to machine the center of the outer axle flange as the center hole on the 5 lug wheel is smaller. It has been working well for over 10 years.
Fred

Not a good idea. Save up the money, do it right.

Your truck will thank you.

So are you saying no to drilling axles or just the brake drums?

A little background on my truck. My dad bought it in the 60s and I have had it since the 70s. Dad put a set of E/T torque-thrust style wheels on it and they have been all I have ever known the truck to have. I know I have Tim cringing as he is more of a "purist" than I am but I want to keep the wheels. They have been on with a set of 6 bolt to 5 bolt adapters all these years and I want to do it right. I bought the car front hubs and drums but the rears will be a little tougher as I want to keep the torque tube rear end. I thought I could probably weld and re-drill the axles and assumed at this point the car drums would be a direct replacement. I am looking for advice or experience from someone who has crossed this bridge before.

If you have rear drums with 75 years of service, I'd look at replacing them rather than re-drilling. You can try the car drum after you get the axles machined. New drums are ~$30 at Rock Auto.

But I've not done this, only speculating.

regards,
Leon

My thought is that the face of the drum has the weight of the truck on it as the brake shoes lock the outside of the drum. It seems to me that there would be a great deal of force trying to spin the middle out of the drum face. I just think the extra holes in the drum might not be the best idea. My question was on the axles. Are they up to re-drilling?

this is what I did on the front of my truck....find a set of 51-53 chevy belair backing plates and hubs and drums and take off the old huck brakes and backing plates and put the 51-53 backing plates on your axle the hubs and drums will fit right on you're spindles with new roller type bearings and not only will you have 5 lug but also you'll be updating you're brakes to bendix brakes...(modern brakes) I did it to my 46 1/2 ton and have no problems at all, and its easy to do... dont waste time and money on trying to drill...it never works right... on the rear you might be able to find an early 50's chevy car with the torque tube set up and just buy the rear with the 5 lug already in it then just do whatever modifications you need to install it...any driveshaft shop can help with that

I didn't think I would have to defend doing a simple operation that is safe, efficient, and fairly inexpensive. Yes you probably could use car drums but would have to further machine the hub to fit the center hole. If you look at the quality of the Chinese made parts out there I would prefer to use a good and serviceable old part. The drum is centered by a hub flange and studs. Everything is held in place by lug nuts and the wheel the same as stock. It is no more at risk of spinning out and breaking than a stock drum. The machine shop that did the work on the axles and drums specialized in off road vehicles. He does them on a regular basis and has had no problems. Off road stuff certainly gets more severe use than one of these trucks. I guess you could go to Currie and have some new axles made. I'm sure they could accommodate you.
Fred

I am not trying to make anyone defend themselves. This is the input that I wanted. I have seen race axles that looked like swiss cheese. They have a thicker flange and I wasn't really worried about that. I did have big question about the drums. Hence the question.

I gave my reasons for concern and just wanted to hear both sides so I could weigh the info for myself.

Thank you