Radial tires rubbing

[meric42]

One of my '42 Sedan Delivery's has a 4" dropped axle and I have fitted 15" Mercury rims with Coker G78 classic radials. Now I cannot turn the steering to full lock without the tires contacting the spring shackles on both sides. Initially I thought the problem was caused by the reversed eye spring that also had four leaves removed causing the shackles to spread too wide. Last weekend I installed a stock 12 leaf front spring and whilst it has improved the clearance, at full lock the tires still contact the factory shackles. Any suggestions? Should I get a shorter main spring made and then how might that effect the suspension geometry?

[51 MERC-CT]

Perhaps you could use a solution that I used for a similar situation.
That is to determine how thick a shim would have to be when added to the limiting contact point to prevent unwanted contact. Then attach it with what ever method is appropriate.
Of course this increases the turning radius but I never really noticed it.

[TJ]

I suspect it is your wheels. If you have gone to 15's rather that the stock 16's you will have more offset to the inside. That puts the tire closer to the shackles.

[drolston]

Do not shorten the spring to the point where the shackles at rest are flatter than about 40 degrees. That will stiffen the ride.

At 45 degrees, the side load on the spring and spring perch is equal to the vertical load. At 30 degrees the side load is 1.73 times the vertical load. It gets worse fast. At 10 degrees it is 5.7 times higher. Bounce around a while on that and metal fatigue could break the spring perch, with catastrophic results.

[Mart]

Add a couple of washers under the steering lock stop nut. It is the kingpin nut and should be elongated/domed. I needed to make an oversize stop nut and made one from a 7/16-20 lugnut. I have a lathe so it was a simple job. You will limit the lock but as stated above, you might not notice.

Or fit skinnier/bigger diameter/stock wheels and tyres. Every time something gets modified there is a knock on to something else. the trick is to achieve what you want while limiting the knock ons as much as possible.

Mart.

[TomT/Williamsburg]

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You can drop your tire size to be skinnier and taller or you can use steel wheel spacers to push the tire out (and you may still need smaller tires). Either way, I would see if you can borrow different wheel and tire combos until you are satisfied then duplicate that for yourself.

IMHO, and please take no offense, I think the G78s are too big for up front. But, I am more of a hot rod guy who likes his bigs and littles ....

[Paul Bennett]

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Consider buying your WW tires from Calli Tire as they are cheaper than Coker and they are built on Hankook, a quality which IMHO is 2 grades above Coker.












.

[34PKUP]

Originally Posted by Paul Bennett

.



Consider buying your WW tires from Calli Tire as they are cheaper than Coker and they are built on Hankook, a quality which IMHO is 2 grades above Coker.












.

How long have you been using Coker tires and what after using Cali tires makes them 2 grades above Coker's?

[TomT/Williamsburg]

Few applicable 16" tire choices with Calli tires unless you want 70, 65, 60, or 55 series sizes. I know more sizes will be added I am sure - just wish we could know more about longevity, wear, and problem resolutions ....

[meric42]

Had a play with the front end yesterday and I cannot adjust the steering stops enough to get clearance for the shackle. I'm thinking that I will need to get the spring shortened? See pictures below and I'll look forward to your comments.

[rich b]

When you get a new main leaf made; consider going to 3/4" eyes, those and the smaller shackles will give you another bit of room.

[19Fordy]

When you had your axle "dropped" did you happen to measure to see if the distance between the king pin centerlines became smaller or larger?

[meric42]

Originally Posted by 19Fordy

When you had your axle "dropped" did you happen to measure to see if the distance between the king pin centerlines became smaller or larger?

The axle was in the car when I bought it so I will need to measure the king pin centres and do a comparison.

[TJ]

It still appears that your front wheels have too much offset to the inside. How wide are your front wheels and what is the offset to the inside? Compare that inside offset to the offset of a stock 16" wheel and I believe you will have your answer as to why you are hitting the shackles.

[meric42]

Originally Posted by TJ

It still appears that your front wheels have too much offset to the inside. How wide are your front wheels and what is the offset to the inside? Compare that inside offset to the offset of a stock 16" wheel and I believe you will have your answer as to why you are hitting the shackles.

They are stock 15" mercury rims. I don't have any 167" rims with tires on to compare at the moment but will check these in a couple of weeks when I have tires on wheels to work with.

Thanks.

[38bill]

Did the '42 axles originally have the leaf spring eyes outboard of the spring perches? The earlier ones are inboard.

[meric42]

Originally Posted by 38bill

Did the '42 axles originally have the leaf spring eyes outboard of the spring perches? The earlier ones are inboard.

That is something I need to research to be sure.

Thanks.

[Mart]

I'm not too familiar with your setup, but if the centre distance of the perches is the same as a 1940, for example, you might be able to use a spring from an earlier model that fits and reverses the angle of the shackles. In other words a narrower spring may be available, rather than having a new main leaf made. Of course, depending on what is available, having one made may be easier.

If the steering lock is acceptable, at the point before rubbing starts, you can use oversize lock stop nuts to set the angle. (I used modified lug nuts on my roadster). You must allow for clearance, though as things may give a bit if cornering at or near full lock and either hitting a bump or using hard acceleration.

You could also investigate using some thin wheel spacers and longer studs.

Basically the problem has been caused by using a dropped axle, 15" wheels and wide tyres. There may also be an influence from using f100 brakes (not sure about that, are they f100 or lincolns?). Seeking a narrower spring is the most logical way to go.

Mart.

[Ggmac]

Originally Posted by meric42

That is something I need to research to be sure.

Thanks.

I think you need to measure for a new spring , your new axle is likely not the same width as your old . I think you shackle angle is in the wrong direction , meaning it should be inboard and angling 45 from down to up right to the perch . I hope you can picture what I'm saying . If you have a speedway catalog it'll give a good how yo on this subject

[51 MERC-CT]

Sure looks like someone has installed a spring made for a different application.
(too long)



This is a drop axle setup showing the correct spring orientation.

[mrtexas]

Looks to me like the lowered axle is the problem. And 15 vs 16 wheels does not help as well and makes the problem worse. When the axle is bent up it definitely shortens the width of the axle vs stock. I'd get a new single leaf spring myself a couple inches shorter and use/shorten a couple more to solve the problem easily. Surely shortening the spring so that the angle with respect to vertical is inbound vs outbound wouldn't change the ride stiffness much? This place can make you the spring https://www.eatondetroitspring.com/l...SAAEgLBKfD_BwE . I used them to make lowered rear leaf springs for my 49 hot rod not requiring lowering blocks. Now postage to Kiwi Island is another thing.

Here is my 41 with front discs, stock 16 inch wheels and non lowered axle. I have lots of room while the discs move the wheels out very little, maybe 3/4 inch total.

[Tinker]

Most drop axles also shorten track length to clear fenders. More drop more reduction.


Everything effects something. just a thought.


.

[19Fordy]

meric42:
Give Posie a call after analyzing this info. Maybe they can help.
http://www.posiesrodsandcustoms.com/...35_48_springs/
Here's a photo of 40 Ford with Posie 39 inch 2040 reversed eye spring, 4 in. dropped axle that is 3/4 in. narrower than stock, Perch bolt centerline distance is 38 1/2 - same as stock 40 axle. dropped steering arms and Posie shackles. Wheels are early Ford pick up 15 in x 5 1/2 in with 4 in. back space. Tires are 5:60 x15. Because the car is so low in the front the axle bump stops almost touch the axle. Shackles are at 45 degree angle. The shackle pin centerlines are 1 1/2 in apart. Spring is 2 in. wide.
I don't know if the 42 front suspension is a lot different from a 40 but, I hope this helps a little bit.

[Bored&Stroked]

I'm with 19Fordy and others . . . spring is too long for the application (why, I don't know). You want the shackle angle more like what is shown above in 19Fordy's post. The guys at Posie's are easy to deal with - they should be able to hook you up. I'd clean and rebuild the spring while you're at it and get the smaller spring/shackle size as mentioned by others.

[flatjack9]

Ditto on the above 2 posts. I have 15" Merc wheels on my 39 with 195 78 R15 tires with no problems. My spring with reversed eyes hangs with the lower ends of the shackles inboard.

[19Fordy]

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meric42, I looked in the BIG GREEN BOOK and I can't find any specific listing for what front spring fits a 1942 Ford sedan delivery. It does show an 11 leaf front spring for a 1940 ford sedan delivery. Sedan delivery is not even listed. Are you sure you have the correct OEM spring? Do you know the Model number and wheelbase of the sedan delivery? Is it considered as a special vehicle?

[rustythumb]

the shackle angle on meric's car is correct for '42-'48. the problem is narrower dropped axle + wheels with more back space. narrower spring might be the best fix.

[Ggmac]

Originally Posted by meric42

Had a play with the front end yesterday and I cannot adjust the steering stops enough to get clearance for the shackle. I'm thinking that I will need to get the spring shortened? See pictures below and I'll look forward to your comments.

Did you split your wishbone ? If not than the angle couldnt move just the axle is narrower. It just hit me , it does look opposite to all other set ups but it could only change if you split your bones or heated and bent your spring perches .

[Jack E/NJ]

rustythumb>>>the shackle angle on meric's car is correct for '42-'48. the problem is narrower dropped axle + wheels with more back space. narrower spring might be the best fix.>>>

Don't know about the angle but the spring shackles are different for 42-48. 21a-5468 vs. 11a-5468 Jack E/NJ

[19Fordy]

Here's a great thread on Ford axles.
https://www.jalopyjournal.com/forum/...d-axles.55439/

Here's 1942 dropped axle that Speedway sells. Maybe the measurement data will be helpful.
https://www.ebay.ca/itm/Magnum-Axle-...1:pf:0&vxp=mtr