I think MidFifty is talking about the little pieces of rubber on the eyes of the dogbone. I bought some once only to find my ends were too wallowed out to use them. They looked pretty shaky anyway. That's when I bought the solid ones. The solid ones have the rubber and metal sleeve molded into the solid arms.

 

Thanks for the reply and I hope I'm not coming off as argumentative at all in this thread. Certainly not my intent.

On the midfifty add they specific list the part number for the bushing and say it's not needed.

I understand in the scheme of things that the $100 difference is pretty minimal. I'm more just trying to understand the engineering and why option B will not do the same job as option A.

It may come down that I order the simple Heim joints and the Midfifty design and compare the two options and return the one that does not work.

 

Not taken as being argumentative at all. That's the greatness of FTE. There are pleanty of ideas and answers that help us understand our ole trucks.
To really rev this thread up; I always wanted to install a small shock in place of the dogbone to cushion the cab a bit but just never got around to figuring them out.

 

Challenge accepted.

 

I had never looked at them on their site. I didn't realize it said that bumper wasn't needed. But it also says if you use them, glue them in.

The picture I posted was just a crop of the first picture you posted. If you look really close, the bumper is there.

However, the second picture you posted, (blue cab) it is not.

I can picture in my mind how the rigidity of the cab and the distance between the front mounts should keep things centered. But I can also see a lot of shear force on the front mount bolts, and their holes.

My concern isn't daily driving. It's that one in a thousand chance you have to drive over or through something you normally wouldn't. Would the cab return to center/level, or not? Or would it contact the frame and damage it?

Maybe the secret is the poly bushings in the adjustable mounts, instead of rubber. Perhaps that restricts movement enough to prevent the cab from contacting the frame when extremely torqued. Maybe that's what eliminates the need for the bumpers, not the shape of the arm itself.

Argumentative? Heck no! You've raised a good point. This is a good thread.

 

Cool thanks!

I guess I don't really see how the cab can really move to side to side and not be centered at all times with these adjustable mounts.

If the mounts are connected to two fixed points on each side and do not expand or contract then how can there be movement.

For instance. To allow the for the left rear corner to go up that means the right rear would have to go down. This is not possible.

If the right rear corner of the cab was to move left that means mounting arm would need to extend and the left rear corner mount would need to compress.

So what am I to thinking of how these work? I'm not seeing how the stock arms allow for movement of the cab?

 

I think you guys are confusing your bumpers and bushings. They are not referring to the bushing installed in the end of the adjustable arm but the arm bumpers that are normally installed above the dog bones. Probably need to be glued in when using the adjustable type because they do no hold them in place as the stock ones do. I think this is what EffieTrucker is alluding to in his post.


Search Results - Mid Fifty F-100 Parts

 

The more I look at it, the more I think you're right. It looks like the rigidity of the cab would always force everything back to center/level, as long as the frame returns to it's normal plane.

In the below example, you're looking from the back. The right front tire has rolled up onto something tall. The twist of the frame has lifted the right front corner of the cab, bringing the right rear up with it. This pushes the left side down. But when the frame returns to level, the back of the cab should follow as well. Like you said, the arms being equal, level would equal centered.

But, this assumes the front mounts are in good enough shape and accurate enough to hold the cab in exactly the right place. If the cab were slightly to one side or the other, or if one side was slightly forward or back from the other, the cab would be trying to force the back into the same condition as the example below. This would put extra force on one front cab mount or the other.

That said: In an extreme flex condition, like the one in the example, the bumpers would actually prevent the back of the cab from "floating" and transmit some of the flex into the structure of the cab.

Climbing out of the pile of crap I typed above, I would say yes. The arms you suggest should work, as long as the front cab mounts are in the right position.

I really should stop thinking "out loud" with my keyboard.

 

Then again:

I forgot how modified your frame is. Flex probably won't be as much of an issue for you as with most of the others.

So....my previous post applies to everyone else. Except the part about it working for you as long as the front mounts are accurate.

 

Effie that is exactly what I was looking for! I also now understand better why Ford originally used this arched type dogbone. It was specifically done this way to build in the flex. To allow the frame to flex and not transfer that flex into the cab distorting it. This make perfect sense.

Given that the new adjustable arms are using the predicable and usable flex of the threaded rod to allow for this twist.

The pure heim join that I posted would most likely not allow for this type of flex and may cause more distortion in the cab itself.

You are correct that my frame has been fully boxed and now has full independent front and rear suspension. So this may be less of a risk for me specifically.

So the answer to the thread is most likely yes the cheaper heim joints would work. But likely at a cost to transferred flex in the cab if you have a standard C channel frame.

 

Excellent information in this thread. Thanks guys


Keep in mind that the original dog bones are rebuildable. I was looking into replacing the ones in my 49 which uses the old stamped steel design. All that is offered is the 53-56 style dog bone as a replacement. Once I looked at the mount more closely I realized that you could replace the bushings in the ends. I was able to fix the cab mounts for less than $20. Here is a link to what I did;
https://www.ford-trucks.com/forums/1...t-rebuild.html


Bobby

 

Ok so I did some research on this and what I've found is that it is possible and there are a few options to do this. Small shocks that may be able to handle the load. The issues is there is no real way for me to calculate easily what shock rate is needed. To week of a shock and the cab would settle to much. With that I would have to know exactly how much that shock would settle under normal load vs passenger load. And with that having only one driver would settle only the driver side.

If you did to stiff of a shock then you would really be taking out the purpose of having the shocks at all. As it would cause the ride to be very rigid with little cusion.

I'm not saying it's impossible. But more that it would take a lot more time and money to get this right than I have.

Not one to give up easily though. I'm going to keep this in mind for after my truck is on the road and running. I'll happily buy a few options here and there to test them out in the garage with the idea of returning them if they don't work. But this is more reason for me to use the hime joint option. To save money for something like this.

 

Sounds like you have kind of talked yourself out of the adjustable mounts from Midfifty but for what its worth they told me that a lot of guys will only buy one adjustable and leave the stock one on the other side and that offers plenty of adjustment to get the cab level if needed.

 

That's good info thanks HighDesert!

I was never sold on the Midifty. What I was looking for was should I take the chance of wasting time and money in buying the adjustable heim joints and then just having to end up buying the Midfity ones.

What more came from this is that I'm going to wait till I'm ready to mount the cab again and then buy the heim joints.

What I have been doing is buying what I need for my next step in the project at the beginning of the previous step. This way i have the parts on hand well in advance and not having to be held up on back order things. But doing this has caused a few times where I've not been able to return some things because I've ended up having them past the companies return policy.

 

Too bad AXRACER isn't watching the site anymore. He always had pretty good insite on shocks, frames & designs.

I wonder if you could tell the shock manufacturer the weight of the rear of the cab if they could enlighten us on what to use? Have to keep in mind the fuel tank is in the back of the cab on 56s. Then if you changed your bucket seats