What common wear items near the chassis should be replaced during a frame off repair?

[DR650]

I'm planning on pulling the frame off to deal with rust and want to replace any common wear items attached to the chassis. I tried searching for threads but I think my question is to general. (If anyone knows any that could be helpful please link them, I'd be greatful to read them).

I've already given some thought to the components in the engine bay and I'm planning on opening up the transmission to see what kind of shape its in but what wear components are attached to/near to the chassis? (I know obviously break pads, tires and I guess some wiring just going off what I can see with my eyes.)

 

[DirtDonk]

Rear spring and shackle bushings.
Front radius arm bushings. Both the rear "donuts" at the end, and the C-bushings at the axle.
Trackbar bushings.
Steering stabilizer probably.

Regarding the spring bushings, most would say that the springs themselves are in fact wear items after this much time. Springs sag ("sack out") and leaf springs in particular can take a set where they wear on each other.
Shock absorbers for sure, unless they're relatively new.
Soft brake hoses. One front, one rear at the axles, and one each for the front brakes.
Body bushings/insulators/cushions. In other words, the rubber bits that sit on the frame mounts and insulate the body from the frame. AKA "body mounts" is what most call them.
Perhaps the radiator insulators. They get old, but it depends on what condition yours are in.

Since removing the body from the frame is essentially a full restoration, don't ignore all the other stuff that goes along with this type of project. You going to paint too? Or at least fix the rusty bits?

Paul

 

[SteveL]

Like paul said. any soft parts like bushings and body mounts. Also take a look at the 1" body liftfrom wh. It's just a taller body mount and that extra inch of clearance comes in handy working under the bronco

 

[DR650]

Rear spring and shackle bushings.
Front radius arm bushings. Both the rear "donuts" at the end, and the C-bushings at the axle.
Trackbar bushings.
Steering stabilizer probably.

Regarding the spring bushings, most would say that the springs themselves are in fact wear items after this much time. Springs sag ("sack out") and leaf springs in particular can take a set where they wear on each other.
Shock absorbers for sure, unless they're relatively new.
Soft brake hoses. One front, one rear at the axles, and one each for the front brakes.
Body bushings/insulators/cushions. In other words, the rubber bits that sit on the frame mounts and insulate the body from the frame. AKA "body mounts" is what most call them.
Perhaps the radiator insulators. They get old, but it depends on what condition yours are in.

Thanks Paul, that's exactly the information I was looking for!

Since removing the body from the frame is essentially a full restoration, don't ignore all the other stuff that goes along with this type of project. You going to paint too? Or at least fix the rusty bits?


Paul

I am, at least the frame and the underside of the body. Still haven't decided about the rest of the body. I'm planning on having the chassis hot dipped in zinc once it's cleaned up and then covering it in a coat of steel-it for which I hope will result in double layered rust protection.

This guy says I shouldn’t paint my frame but should use rubberized undercoating on it.
Forum link: https://classicbroncos.com/forums/t...g-the-body-off-the-frame.321400/#post-3512105
The product he reccomends: https://www.rustoleum.com/product-c...-bed-and-undercoating/rubberized-undercoating

Steve83:
“And no matter what prep you do; paint (of any brand or type) is the wrong material to use on the frame. Paint CAUSES rust, when it gets scratched & chipped, and then holds water/salt against the steel. That's true even of brand new frames with paint or powdercoat professionally/industrially applied before assembly. The correct material is rubberized undercoating, which can't crack or chip. It's also cheaper, quicker, & easier to touch up if it ever needs it.”


I feel like what he says about paint might apply to standard paint but I would imagine the steel-it product is less sucetible to chipping given it's design is specfically to protect from rust and I also read it "goes on super thick" which strikes me intuitivly as meaning its likely strong and durable. For that reason I'm leaning towards using black steel-it paint to cover the zinc coating (and I think the black frames look really good).

The product: https://steel-it.com/products/polyurethane-aerosol

I don't really understand the merits of rubberized undercoating versus other materiels. I still haven't decided what to cover the bottom of the body with though steel-it is appealing since rust prevention is super importnat to me. That said I want quite and insulation so I think theres probably materiels that can do both of those and shield against rust so maybe that's where the rubberized undercoating comes in. I've read about guys using multiple layers of different materiels so maybe that's what I'll end up doing.

 

[DirtDonk]

It’s good to have a lot of knowledge ahead of time. But have you even received the bronco yet? You might have to add or change things before you get started once you get it in hand.

Regarding paint, powder coat, or rubberized, undercoating, they all work. I used undercoating on mine and it works great. I have to touch it up with paint or more undercoat every few years, but no troubles.
Lots of people paint theirs and that works great too. Steve is technically correct regarding rust growth from moisture intrusion under hard coatings. But if they’re done right they’re chance of that “can be” pretty far down the road. However, considering the general shape of yours, given the pictures we have seen, I wouldn’t make a decision until you start cleaning it up.
I wouldn’t necessarily use paint, unless you have all of the rust removed. One of the rust converting paints would be a different story, however.
Powder coater would buy necessity sandblast the entire thing before coating. Otherwise, as he said, rust would simply continue to grow under the crust of coating. And still might if they don’t prep and heat it properly.
But let’s wait and see what you get.

 

[Broncobowsher]

Anything rubber
Check all bolt holes for damage.
Track bar and steering box for cracks.

 

[DR650]

It’s good to have a lot of knowledge ahead of time. But have you even received the bronco yet? You might have to add or change things before you get started once you get it in hand.

Fair point, I just recieved it today! The rust on the bottom of the doors is much worse than it looked in the photos but the floorpans, underside of the body and the engine bay are all in good shape.

https://cdn.discordapp.com/attachments/571983014096273409/1153544300173459486/20230918_185339.jpg

I wouldn’t necessarily use paint, unless you have all of the rust removed. One of the rust converting paints would be a different story, however.
Powder coater would buy necessity sandblast the entire thing before coating. Otherwise, as he said, rust would simply continue to grow under the crust of coating. And still might if they don’t prep and heat it properly.
But let’s wait and see what you get.

Right now I'm thinking it's gonna be a full, down-to-the-metal frame off restoration. I want to clean up the rust and then cover everything in a protective coating so hopefully I never need to pull the frame off again.

 

[cdj7k]

Mine had a rust hole behind the rear shock mount

 

[DR650]

Mine had a rust hole behind the rear shock mount

How did you address it?

 

[cdj7k]

Cut it out and patched it. We replaced the mounts so had easy access. just another place to look Since you are playing the game. You should be able to tell without cutting the mounts off.

 

[DR650]

Cut it out and patched it. We replaced the mounts so had easy access. just another place to look Since you are playing the game. You should be able to tell without cutting the mounts off.

OK much apppreciated!

 

[DirtDonk]

I hear what you’re saying, and it’s a noble goal.
The way you’re planning, it should never need anything again other than some paint touchup.
But think about this too. These things are never going to live like they used to. Sitting out in the field, or under a shed in the snow at a cabin, or out on a ranch with a snow plow on it.
So rust in the future is really a non-issue anyway. If you plan to keep it covered, or in a garage, rust-through won’t be an issue.
Heck, even if you leave it in bare metal, it’ll probably only have time to surface rust!
OK so that’s probably an exaggeration, but you get the point.
Simple preparation’s and coatings can likely produce long lasting results. In the neighborhood of the next 50 years.

Now, if you live near the coast, or plan to leave it at a second house on the beach, or plan to drive it in the winter on salted roads, none of that counts, at all bets are off!

 

[73azbronco]

I'd say good prep and two stage paint. My OEM painted frame had no rust on it after 40 years when I bought it. I also prepped and zinc chromated inside of frame to prevent problems there using Eastwood frame paint. I live in Az so YMMV in Wisconsin. Pretty sure a rubberized coating here would not go well in the heat. I would avoid powdercoat, as everything I have powdercoated later needed modding.

Just don't park it by side of house and let weeds or grass grow up and touch the frame.

 

[DR650]

I hear what you’re saying, and it’s a noble goal.
The way you’re planning, it should never need anything again other than some paint touchup.
But think about this too. These things are never going to live like they used to. Sitting out in the field, or under a shed in the snow at a cabin, or out on a ranch with a snow plow on it.
So rust in the future is really a non-issue anyway. If you plan to keep it covered, or in a garage, rust-through won’t be an issue.

I can't believe I never thought of that before! Of course how rusted out they are has a lot to do with how they are stored and we are likely to treat ours very differently than most owners.

Heck, even if you leave it in bare metal, it’ll probably only have time to surface rust!
OK so that’s probably an exaggeration, but you get the point.
Simple preparation’s and coatings can likely produce long lasting results. In the neighborhood of the next 50 years.

Now, if you live near the coast, or plan to leave it at a second house on the beach, or plan to drive it in the winter on salted roads, none of that counts, at all bets are off!

I guess I just don't want to have to worry about it. I'd like to be able to get it dirty and not wash it immediatly. Even then, I doubt It'll be that bad. I live in SoCal so I think the climate is on my side. I'm gonna find out how much a hot zinc dip costs and if it's not too expensive I'll probably still do it just for my own satisfaction

On a different note, I'd like to get your persepctive on roll cages. I just finished reading through this whole thread on cages and a few others. It's given me a lot to think about. One user supported his cage from the frame like this and I think I'd like to do something similar. What was brought a lot in that thread I linked was lateral stablity. One user posted this photo of a cage with poor lateral support. No one suggested how to achieve good lateral strength without putting x bars infront of the rear seats and I wonder if you know of any designs that do this?

I don't want to be a perfectionist, I just want to check the big boxes and leave the rest to chance. At the moment I'm leaning towards a cage like this. I feel like your pretty knowledgeble and I wanted to know your opinion on what a pretty good cage setup for light to moderate wheeling and daily driving looks like.

Edit: I just read your post about cages in this thread which was quite helpful.

 

[ssray]

I'm gonna find out how much a hot zinc dip costs and if it's not too expensive I'll probably still do it just for my own satisfaction

You may already realize it, but that will make it rough to do any welding on it after the fact so best to figure out anything you may want to do to the frame before. You also need good ventilation as the fumes can make you sick. Supposedly not permanent but not fun.