Technical Milling a Torq Thrust

A little background:

The car in my avatar had un-named composite 5 spoke wheels, 14x6 / 15x6 forever. It was my uncles; he passed and I wound up with the car. When I got it back on the road, I found out the hard way that the wheels were less than true. Took all four to a wheel shop (sans tires) to have them checked, and they all had various issues. Couldn't find anyone reasonably local to straighten them, so I had to buy new wheels.

I wound up with American Racing 15x5 and 15x7's. (15x6 was not an option / not offered in what I wanted). Not the end of the world, but the rears are a touch too wide; tires kiss the inner lip of the fender at the top of the arch on occasion, as in a big bounce / dip in the road. Skinnier tire wouldn't look right. There was only one backspace offered, so I kinda got what I got.

My question is this: Has anyone ever milled down the backside of the bolt circle to tuck in the wheel, effectively increasing the backspacing? If so, how much is "safe"? My concern is there being too little material left to safely keep the wheel on (too thin at the lug area). These take conical lugs vs. shank.

Thoughts?

 

I think you should be able to have a machinist mill some off. The machine nits should have an idea as to how much. I know it has been done.

 

How much do you need to remove because there is is more than one way to skin a cat?

 

It might be possible but I'd never feel comfortable riding on them and you would probably need to take too much off anyway if they rub now. You might have to narrow the rear end.

 

I'm an First Gen American 5 spoke nut. I have them on 3 cars soon to be 4 and back space is often an issue. In my personal opinion to gain be it 1/2" or 3" I would never cut on the wheel. I have always narrowed the axle housing to get the rear done and on 2 occasions have narrowed the front A arms. That also has its limits but just saying.

 

If it only touches when you go over a large bump , sometimes .

roll the fender .


I know of a few place here in Toronto that will loan this tool out with a deposit .


I’ve also done it myself with a baseball bat or other round stock between the tire and fender .


Just push the inner lip up and ba k over itself for a bit more clearance , Clarence .

 

IF - The new gen wheels were offered in a 6" wide, this thread wouldn't be needed. The rear is a 9" out of a '69 Cougar. It's been in there forever, so not really wanting to go through all that for 2".

Ideally I'd like to have the "original" wheels straightened and trued, but...?

Attached is what I've got, and the finger indicated where everything wants to share real estate. Yes, it's in the air, but the rear is on jack stands, so that is ride height. Plenty of clearance 95% of the time, but just enough to kiss. It actually was one of two reasons that made me fail NSRA safety inspection; the other being a double throttle return spring.

 

Last year, I purchased a set o 15x6 American Torq thrust wheels from Summit.

 

What I see there is plenty space between tire and fender opening for normal travel as you said. I'd look into a different fix. What's stopping you from installing a rubber bump stop that makes contact with the housing 1/4" before the Tire gets to the Fender? Wouldn't that end your rubbing issue? Why does it look like the Fender isn't bolted completely in place? Looks like more than a 1/4" gap there.

 

No problem machining it in my mind as long as you do not get too thin below the seat of the nut. Most wheels blanks start off with plenty of extra meat and then are machined to the correct BS at the factory.

Make sure it itls running true in the lathe or sitting flat on the mill. We did a set of lightweight drag wheels for an OT early 'Vette at work once. Had to be really careful about how they were clamped so they didn't get bent. Lots and lots of high speed passes on those with no problems.

 

How old/new/soft are the rear shocks? Maybe a slightly stiffer rear spring with some new good, or adjustable on the bump side shocks..?
Or maybe air shocks with some air in them..
Wont affect ride quality..

my vote is to try that if you definately dont want to narrow the rear, which would be MY “done right” first option..

 

Rear fender in the pic is tight to the body; not the best pic so it looks like it's hanging. Bump stop may be the answer; not sure if there even is one there; never looked.

I looked last light for 15x6 in the wheel design I have; not offered. When I bought the current set in '19, I called to see if I could get a 6" - no dice. I think polished D spokes were offered; not what I wanted.

Rear suspension is a CE kit installed in the early 80s, with overall not a boat load of miles. It rides nice; not bouncy or lose.

 

How about a pic of the backside of the wheel center, and a measurement of the thickness?

 

yes I had 3/8 cut off the back of aluminums wheel. that is not a lot & has never gave me any concern

 

Have you thought about narrowing the rear end 1/2” per side? The housing shouldn’t cost too much and you may get by with the existing axles just cut off. You may have enough splines. That’s what I’d look into

 

I have heard of people doing just that and it worked out just fine. I'd say this is your best option if you are staying with your present wheels. Pull an axle out and see how much of the spline you are presently using, that'll tell you what you can afford to chop off. Either that or buy a set of polished wheels in the correct width/offset then sandblast the centers.

 

Hello,
We had custom wide rear steel wheels made for our next level of slicks on our 1940 Willys Coupe. They were in the long range plan my brother had, but they stayed under a canvas tarp in our backyard garage for the time being. But, we had wide Halibrand Mags already in the warehouse in Los Angeles ready for pickup. We were going to make mild rear wheel cut outs to fit the larger/wider mags and new M&H slicks also sitting in the same warehouse.

Machining can be done, but no trust is to be taken with thinner specs than what was originally molded from the factory. Why weaken something that was designed to do what it was supposed to do on anyone's car. Thinning the depth makes is weaker in anyone's book and caution is to be taken.

Jnaki

If you are worried about what a well machined lip of your stock rear fender, looks like, look at others in the same style and build. Custom does not always have to be making something weaker. But, for the fender, a slight rounded or even if you have to add in a wider piece, it would be well worth it and still look relatively stock appearance for the overall look. IOHO

 

There are possible few ways to move the wheel in, since you donot want to cut housing down,
How thick is the flange on wheel? Maybe Remove axle see if a enough
room to Re Machine for bearing & wedding band so can be mover closer to Axle flange, the cut that amount off spline end,
then install backing plate on back side ,
So all moves closer to Pumpkin/differential
Just a thought ..
If you're determined there's other ways you just got to commit!!!

""E/T wheels can & will make a wheel with any Off set !!!
These are 7 inch wide with 1 inch back spacing made to look like 8 ish wide from front side , I have dragged race this set with over 600 hp over 100 mph in 1/8th & over 15,000 miles

 

With what you've decided you AREN'T willing to do, whether it's a money thing, a sentimental thing or (sorry) just being lazy, there isn't much left to do, most options have been offered.
As to the money part, one way or the other it's a fact of life, sometimes you just have to bite the bullet.
I think the bump stop suggestion is the quickest and cheapest first step with shocks and/or an anti-sway bar install if that doesn't remedy the problem.

 

Might not be the answer but if 95% of the time you don’t have a problem you might consider air shock absorbers to lift rear end of car slightly and/or stiffen suspension for less travel on bumps. Not as easy but possibly adding a leaf to springs would also lift rear slightly and stiffen suspension for less travel. If you really need 2 inches of clearance I don’t think there is any safe way of machining wheels.

 

^^^^^ if Op needs 1inch per wheel !!!
"""NO""" on milling wheel ,
Op needs to stiffen rear either shock , leaf or even 1/4 plate spacer,or bump stop like other said, Op mention it only happens when he hits a hard bump I run an 1-3/4 gap between tire in Fender lip,
In my area there's quite a few vehicle dealerships that have guys do wheel straightening on premises, their mobile new wheels are expensive but they're different alloy than the old stuff

 

I will throw out this tip just incase some reads this in the future. not a lot of clearance on front hubs and center caps if you run them up with an impact even loosely without grinding down the hub. you will crack the center cap I know this for sure

 

There is only one way to do it right, and thats to narrow your rear end. DON"T machine the back of the wheel, as no one here can honestly tell you that it won't ever break later on.
As some others have mentioned, narrowing the axle should be inexpensive to do. Don't need to buy any parts, just remove the rearend and narrow it 1/2" on each side. The axles may still fit ok but you can take a chop saw and remove a 1/2 inch if needed. Then you are done and done right.
It won't cost any more to narrow the rear than to narrow the wheels mounting surface. It takes a big lathe to turn a wheel.

 

Not knowing what the Front suspension is I'm cautious to recommend a rear sway bar. No doubt it may help but if it's a 3-spring system you may build in a new issue. Something I learned 25+ years ago on another 37 Ford. I had built a new Chassis for a fellow that took it home, installed the Body and preceded to build the car. One day I get a phone call and he tells me I installed the rear suspension crooked. Rear tires are not centered in Fender Opening and it don't sit level. I went to his place to eat Crow and decide what to do to correct things. A lot of time under it with a Tape measure and everything checks out spot on. No doubt about it, the Tires weren't centered in the openings and it looked like Crap. Upon very close measuring it was good Old Henery's built in problem. The openings in the fenders were not symmetrical Left to Right sides and if I remember correctly from corner of Running board to bottom front corner of opening 5/8" different from side to side and 1/2" bottom ledge to top center of opening side to side. Yes, I corrected that for him but it was all sheetmetal work, not chassis work. Lesson there was to be careful what you point fingers at.

 

If you're only rubbing on one side and the Body has been off the frame, I'd do some critical measuring to make sure it's centered on the Frame. Then measure from frame to outside of Fenders to make sure one isn't narrower that the other causing the issue.

 

I'd simply raise the rear slightly to help clear, and then buy a pair of polyurethane bump stops and add them to the frame rails above the axle to limit travel so the tires cannot contact the fender. I had this same issue with my pie crust slicks, and that's how I fixed it. I had to build a box tubing spacer to get the bump stops closer to the axle, but once I set them up I've never hit the tires, and rarely hit the bump stops.

 

^^^^ Like Pis -N-Broke said
Between Left & Right are not always same even when new on alot of older vehicles,, Measuring and measuring tac & tac before final welds & Ext !!

 

Another route-- since the fender has no paint on it, the opening could be re-radiused to a bigger dia. and honestly, I doubt anybody's eye would catch it as long as you are reasonable on the amount. A lot involved with cutting a rear end down and no mention of type/brand of the housing. Some brands use "C" clips to hold the axle in the diff. and those are harder to shorten than just whacking some of the spline off.
Back in the 70's we would just throw on some "HI-JACKERS", and call it good

 

Wheels can be narrowed. Try Eric Vaughan.

Or just let it rub on occasion, like I do.

Chris