Running board truss rod adjustment

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
User avatar

Topic author
Steve Jelf
Posts: 7237
Joined: Fri Jan 04, 2019 9:37 pm
First Name: Steve
Last Name: Jelf
* REQUIRED* Type and Year of Model Ts owned: 1923 touring and a few projects
Location: Parkerfield, Kansas
Board Member Since: 2007
Contact:

Running board truss rod adjustment

Post by Steve Jelf » Tue Nov 01, 2022 5:35 pm

IMG_0069 copy.JPG
I'm pretty sure this is wrong.



IMG_0070 copy.JPG
The Bible doesn't cover this. How should the rods be adjusted? I assume this rod is bowed because of the weight on the running boards (gas cans, spare tires, tool box, etc. Should I try to straighten it?
The inevitable often happens.
1915 Runabout
1923 Touring


Bruce Compton
Posts: 665
Joined: Thu Jan 10, 2019 11:23 am
First Name: Bruce
Last Name: Compton
* REQUIRED* Type and Year of Model Ts owned: 1921 Coupe, 1925 Coupe
Location: Kemptville

Re: Running board truss rod adjustment

Post by Bruce Compton » Tue Nov 01, 2022 6:46 pm

Steve: Once the straightness is compromised they are pretty much just a decoration. They are virtually impossible to compress (bend) when kept straight but easy to bend as soon as a curve is established. On my '15 both were bent so I removed them, heated and bent the actual running board supports to get the boards level and the spent some time getting both connecting bars dead nuts straight. Even the slightest suggestion of a bend will soon develop into a bigger one and you're back where you started.


TXGOAT2
Posts: 7391
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
Board Member Since: 2021

Re: Running board truss rod adjustment

Post by TXGOAT2 » Tue Nov 01, 2022 7:34 pm

If you can get them really straight, try slipping a length of pipe just large enough to go over the rods and just long enough to fit tightly between each bracket, and leave the inner nuts off and tighten the outer nuts to put tension on the rod and compression on the pipe.

User avatar

Topic author
Steve Jelf
Posts: 7237
Joined: Fri Jan 04, 2019 9:37 pm
First Name: Steve
Last Name: Jelf
* REQUIRED* Type and Year of Model Ts owned: 1923 touring and a few projects
Location: Parkerfield, Kansas
Board Member Since: 2007
Contact:

Re: Running board truss rod adjustment

Post by Steve Jelf » Tue Nov 01, 2022 9:54 pm

...leave the inner nuts off and tighten the outer nuts to put tension on the rod and compression on the pipe.

It looks to me like you would want the inner nut pushing out against running board sag, and that outer nuts pushing in would help to cause the sag, not counteract it.
The inevitable often happens.
1915 Runabout
1923 Touring


John kuehn
Posts: 4433
Joined: Sun Jan 06, 2019 8:00 pm
First Name: John
Last Name: Kuehn
* REQUIRED* Type and Year of Model Ts owned: 19 Roadster, 21 Touring, 24 Coupe
Location: Texas

Re: Running board truss rod adjustment

Post by John kuehn » Tue Nov 01, 2022 10:27 pm

Maybe that’s why Ford started using the channel type a little later on. I don’t think the later type would give or bend like that. Did it just recently do that? You probably would have noticed it when you had the engine out.


Bruce Compton
Posts: 665
Joined: Thu Jan 10, 2019 11:23 am
First Name: Bruce
Last Name: Compton
* REQUIRED* Type and Year of Model Ts owned: 1921 Coupe, 1925 Coupe
Location: Kemptville

Re: Running board truss rod adjustment

Post by Bruce Compton » Tue Nov 01, 2022 10:39 pm

Steve; Read Pat's post again. Assuming you have the running boards level (not sagging) , "The "pipe" or tubing should be a tight fit between the running board brackets (with the inner nuts left off)", and the outer nuts tightened up to squeeze everything together. It's a lot more difficult to bend or compress a cylinder than a rod as well. Great idea.


John kuehn
Posts: 4433
Joined: Sun Jan 06, 2019 8:00 pm
First Name: John
Last Name: Kuehn
* REQUIRED* Type and Year of Model Ts owned: 19 Roadster, 21 Touring, 24 Coupe
Location: Texas

Re: Running board truss rod adjustment

Post by John kuehn » Wed Nov 02, 2022 9:51 am

Here is an earlier post about the running board brackets playing a big part with the truss rods and possibly being bent or causing other issues. https://www.mtfca.com/discus/messages/5 ... 1232556698


TXGOAT2
Posts: 7391
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
Board Member Since: 2021

Re: Running board truss rod adjustment

Post by TXGOAT2 » Wed Nov 02, 2022 10:32 am

Here's my guess on the early running board mounts and braces: Originally, the running board irons where shaped and attached to the frame with some uptilt on the outboard ends. When the car was assembled, the running board stay rods were installed and the outer nuts tightened so as to pull the running board brackets into proper alignment, which put considerable tension on the stay rods and some in the frame rails. This tension helped keep everything tight and aligned, and pre-loaded the running boards to prevent undue flexing under loads. With extended hard use, the various parts became distorted and tension was lost, allowing the stay rods to bow under load. (Or the nuts were allowed to get loose, which defeated the design)


TXGOAT2
Posts: 7391
Joined: Sun Feb 14, 2021 10:08 pm
First Name: Pat
Last Name: McNallen
* REQUIRED* Type and Year of Model Ts owned: 1926-7 roadster
Location: Graham, Texas
Board Member Since: 2021

Re: Running board truss rod adjustment

Post by TXGOAT2 » Wed Nov 02, 2022 10:34 am

The brackets being forged steel, used ones could be re-shaped to restore the original shape and function. I'm pretty sure the stay rods were intended to be under tension.

Post Reply Previous topicNext topic