Trying to get the front end right on this banger powered 30 coupe. Was looking at 48" socal 4" dropped axel, early lincoln style brakes and 35 wires with 600-16 on the front. Unsplit bones. Is there any reason to narrow the front axel? Does anyone forsee any issues with this? I'm having a hard time trying to conceptualize it all with out all the parts in front of me. Thanks for any help.
With or without fenders? If you plan to run fenders, the narrow axle tucks the tires in tighter to avoid fender rubs.
I am running fenders. My understanding is the narrowed axel also narrows wishbone mount with seems like a potential problem.
Typically they do not. If they did, you would also need a narrower main leaf, or a entirely different front spring. If you are purchasing a dropped axle that has been dropped by a person (as in not made at a factory that way), keeping the stock width would require that the area involved in the drop be not just dropped, but also stretched quite a bit. Performing a drop-only on an axle would narrow it a lot, so some stretching is still required there, too, but not nearly as much. In any case, the section that is manipulated when dropping is between the spring perch boss, and the kingpin boss, so the center of the axle remains the same. Most importantly, where the wishbone attaches, the spring perch bosses, do not move. To add complication, there are manufactured axles out there that are narrower, but generally these are for vehicles built to fit them, and not the other way around.
You can see it here. Observe the red dots. The middle two are the same on both of the two top axles in the picture: If you look at what would be considered the outboard pairs of dots on the top two axles, those pairs are closer together on the dropped axle, than those of the undropped axle. That is where the axle is narrower. As has been mentioned, this is to move the wheel inboard, so that it is better centered in crown of the fender. If you don't do this, there is a chance that the tire can strike the fender lip on corners. Early Ford fenders do not hold up well to tire strike. My recommendation is to always go to a person that drops axles, rather than buying one. You can work with a craftsperson to make sure that you get exactly what you need. If buying retail, you will get exactly what they sell.
If you're using bolt on arms you need the So Cal deep drop arms. On a lowered model A with a banger, the tie rod needs to go below the wishbones.
You need to contact the axle vendor and confirm the perch width, no matter what the kingpin width is. If you want to use the stock wishbone the perch width needs to match.
Aloha Matthew Davis Since your question seems to be answered, Sorry for thread hijack. But is related issues. Staring at my front Ford 15 x7 rims with flat tires and thinking about the scrub point. My (lots of drop an sweetly priced on craigslist) axle score on a 31 phaeton. Looks to have lower shock mount hanging down below string 3/4+ Does this mean that I will have to use a 17 inch rim or bigger to be safe? Am I understanding this correctly? Is there a 'bolt on' way to fix this? I.E. move lower shock mount up. I know the king pin / turn stops aren’t in. I’m beginning to understand its pricing. At 51.5 across the kingpins the rims don’t fit under the fenders (wasn’t going to use fenders but), tires/rims hang out about an inch and a half. Does the wider 51.5 axle have a better turning radius then a say 48 inch axle? Or is that also dependent on rim width?
How did your axle get to be 51 1/2" inches at the king pins ? What is your c to c on your spring perches ? 1928 - 1936 Ford axles are 50 1/2" king pin to king pin and when dropped properly will be streched back to 50 1/2" or not streched to 48 1/2" ( most popular choice) 4" drop 1937 - 41 Ford axles are 48 1/2" and if used in a spring over the axle will be streched to maintain 48 1/2" and use a special spring to make up for the difference in spring perch lenght. I'm guessing that some one that didn't know what they were doing dropped your axle and welded up the ends to cover up their screwup. Craigslist special.
The aftermarket narrow axles are copied from original axles that were cut in the center, narrowed and welded back together and dropped. The spring perches are closer together. Some were done nice and some were done like a shetchy death trap crap. Someone decided to just make new axles to those dimensions- narrowed and dropped. The biggest reason for narrow axle is that changing brakes and wheels pushes the tires out and changes the Overall track width. Look at stock wheel mounting surface and stock wheel offset. So logically the answer getting it to fit again is to bring the king pins closer to each other.
It has a mono leaf (with reversed eyes) mocked up on it now and I’m not sure the spring affects scrub line, right?
The spring changes frame to axle distance. Not axle to ground. That blue axle looks pretty long in the drop portion.
Here’s a 36 stock and 36 dropped here’s another dropped axle under the 36. I can’t really positively ID the lower one, but it’s a lot prettier and uniform. Same C/C dimensions but a little less drop Here’s the layout to cut and narrow a factory axle. 36 dropped shows 4” total change from top spring thru change to top king pin
You're right on scrub line in relationship to the bottom of the spring perches but will in other area's such as pan and exhaust.
FYI, 48" is a narrowed axle. 50 1/2" is stock for a Model A You might check with these guys. I'm guessing that they're running 48" axle, 4" drop, 16" wires and 500-16 tires. https://bolingbrothers.com/model-a-frames/
Will the unsplit wishbone be an issue with the dropped axel. It's not something I've considered until just now and haven't been able to find enough info. It seems like it would want to pitch the axel forward. Does the I-beam flex enough or do I have to pie cut at the perch?
Looks more like someone built that axle similar to an Okie Adams axle. I would never worry about 2 flats; but if it bothers you, get rid of those street rod shock mounts and just weld a stud onto the axle like in the old days. 15x7 wheels are too wide for hot rod front tires. Sorry couldn't help it.
Mathew, you don’t want to bind these parts or force the spring into submission to get parts to fit. Every one is a bit different. First off you getting any stock wishbone to fit is a question since that axle is strange and may not have a common perch to perch dimension. Secondly, the lowering of the axle alone might not appear to mess with the angle of other parts but it does. The new rake changes the caster. If you want all bolt on parts your wishbone ball would need to be mounted inconveniently low to maintain the castor needed. D
Understood, so is there a preferred method of correction? To me the pie cut at the axel end seems to make more sense that bending it at the ball. Either of these is going to lengthen it by some small amount, enough to cause another problem? Also, how is the pie cut determined so that the caster is correct when reassembled? Does anyone have a link to a build thread of someone doing this?
You will need to mock up the chassis at final ride height and rake before you can know how much to piecut the wishbone. It’s very common to piecut wishbones to correct the caster. You will need a gauge that shows the angle to determine the amount needed. They are available at many places. Piecutting won’t lengthen the wishbone. But buying an axle with a non-stock perch distance will mess with your length.
When setting this up; use the actual size wheels and tires, front & rear that you will be using; otherwise it won't be right when you do install them.
This has been covered here on the HAMB and in about every build here. Irontrap and other Youtube hotrod build channels show it as well. You just have to study it a bit and compare and contrast perspectives. No one way and no step by step tutorial. That's hotrodding. You should have no problem finding plenty of examples. D
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