Technical Model a with 39 transmission wishbone mounts?

Hi guys, is it just me ? Looks scary to me, if i hit the brakes the whole weight of the car is on this two tiney bolts? How did you fix this problem? Because of the law in switzerland i can’t split the bones


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Are you running a torque tube?

 

Should be adequate. I see you have grade 8 bolts.

 

Id run it without a second thought.

 

I seem to remember in someone’s build thread, where they fabricated a full width cradle, welded in to each rail.

 

that wishbone was designed to absorb bump impact but also when you are going 60mph and stomp the brakes the wheels want to stop and the car doesn't... lots of stress when you have to lock them up...
I see you are bolting through the bell housing bolt holes,
IMO they are not that strong... science guys to the front...

 

I agree with you, I would make a mount that spreads across the frame.

 

On a model A the transmission is the wishbone mount so its not that far removed from what was there. Fuck it if your not comfortable with it change it. Can't enjoy a car you dont have faith in.

 

i made my own mount. similar to what you show, except i went further up the bell housing so i could get 2 bolts on each side. its a tight fit that needs to ground to fit the shape pretty close to get 4 bolts, and have it sit nice and flush on the trans bolt surface

 

Thank you guys, guess i make a whole cross member

 

Back then I ran a flattie" with '39 trans & juice brakes. My "Freeway Flyer" going to work in L.A..

 

I put a Vern Tardel 32 cross member in my Model a chassis. It includes the wish bone mount. Check it out.

 

I'm running a 39 trans in my Model A with a torque tube and a similar wishbone mount from Clings, no problems.

 

I guess i have no space because of my whole brake set up

 

Need springs on those bolts so the ball can float lightly . Going by memory I thought I drilled a third hole for a third bolt

I try to check my AV8

 

Yep your missy the center third bolt

 

when you are braking the wishbone force at the ball is going up towards the transmission. I would think if you could modify the bolt on support such that it rests against the bottom of the transmission would improve the mounting. To carry it further if you extended the mounting brack to the rear and added a couple of additional mounting points at the rear of the transmission (rear torque tube / u joint bracket?) you would eliminate the bending that can occur with the current mount, since you have a bending moment occurring from the flange of the transmission to the centre of the wishbone ball.

 

Street is neat....shows a picture on how your mount should be installed ! The grade 8 bolt UP through the bottom of bell is strong/clean install. Your problem at this time, is that you have to MARK HOLE location now while you have adaptor properly located.
Then trans has to be removed to place thru bolt once hole is drilled. I use a self locking nut withred locktite and cotter ...if you like.
You may have to shim adaptor with a Large washer to level !
There is one other way that this can be done. If picture comes thru, it will show a trans with adaptor WELDED and BRAZED in place.
I have this frankentrans now. It has ‘32 rear mount; ‘39 gears; 3” fork and adaptor welded. Good ole American genuity !
Dont know what case is ? NUMBER: 68-7222 ?

 

Tune in Guys: 51... has it and Street... nailed it with a picture. Such brackets have been around for ages with bolts from two angles. Quite common to find the hole through the bottom of the trans already drilled. Home brew brackets may not have the third bolt without a clue. Good Luck: Fred A

 

Like 51 mercules, I used the Clings setup in my '29 with a '38 transmission. No problem!

 

You’re missing the third bolt for that bracket.
See pic.
Ken

 

As @4bangerbob mentioned, as you brake, the wishbone yoke is pressed up into the transmission.
At no point is the whole weight of the car on that point. The weight is carried by the front and rear springs and weight is transmitted to the axle and tires.
On a Model A setup, the wishbone ball is captured by two bolts and a cup into the bottom of the transmission. Doesn't look much different here.

 

Well, then, that changes everything!

 

I've ran that adapter on two different cars, a flathead V8 A and a banger powered A with a V8 trans and had no problems at all. Everything is real solid, there is no real strain on the rear of the wishbone especially if you use the stock springs on the ball clamp.

 

i have a crossmember which probably will solve your problem. it is a original 32 k member without the legs and was installed in a model a. and i also live in switzerland


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Unfortunately the wishbone would not reach

 

@Gasolinedeniz

One other factor here, the substantial length of the wishbone acts as a long lever to dampen and control any axle rotation forces created by the brakes. Ford designed it with that in mind. The wishbone also controls axle movement created by unequal forces applied to the front wheels, such a bumps and chuckholes. But, again, the lever effect is up to the task in anything less than a serious collision.

Given the mass of the engine and trans, and the design of their mounting points, IMO, a wishbone mount such as you have pictured should be quite adequate so long as it is carefully fabricated to attach securely.

Ray

 

If you apply only the front brakes, the rear radius rods are in compression as the the frame keeps the rear axle from continuing to move down the road by itself.

If you apply only the rear brakes, the rear radius rods are in tension as the rear axle tries to dragy the frame to a halt.

If you apply front and rear brakes, the force on the rear radius-rod ball cup is the sum of the tension and compression on the radius rods - which could even be zero.

Of what value is this analysis to choosing the right bolt set-up for this guy's radius rods? Probably none, but I thought it was interesting.

 

thought the same