Another leaf spring question

[SomeRandomDude]

My leaf spring saga continues. I just finished pulling the old springs and found a pretty rusted area on the front side of the driver's side frame where the bolts for the hanger come through like so:

The other side isn't bad:

This is the same spot after some "percussive maintenance" to break most of the loose stuff off...

The hanger kit I purchased came with a reinforcing plate that will mount against this side - effectively sandwiching the damaged portion between 2 plates of new steel. Here's the plate:

In your opinion will the new hardware/plates be good enough or should I have a welder come out and repair this spot?

 

[72bluNblu]

That’s toast. Multiple layers of that outrigger/spring mount need to be replaced. That reinforcement plate is for adding strength to that area on cars with no rust at all.

 

[Wvbuzzmaster]

I am going to suggest this… run it. I know it looks bad, but on my Duster the spring hanger mounting location on the driver side looks exactly as yours and I too bought reinforcement plates that I didn’t use because of it. Just use washers under the nuts or the original washer intergrated nuts if they are decent, that’s what I did 4 years ago when I installed new springs. I’m only running about 400 horsepower 340 and if you are not drag racing, just spirited driving, should be fine for many years, it took 50 years to look like that today… If you want it perfect you will not get on the road, and if you could see thru it or deflect it by hand… then it’s a hard no, but that will take several more years to be a problem but now you know about it so you can check it once in a while and when ready to dig into it, dig in, otherwise run it and enjoy the car for now.

 

[RustyRatRod]

That whole area is totally rotten and needs to be cut out and replaced.

 

[junkyardhero]

clean it up, POR that mess and ship it. it's only temporary till it ain't. or till like, ya wind up on your roof in the ditch cuz the whole mess done come apart.

that's a critical mounting point for the rear suspension and thereby the axle. disregarding the damage there is doing yourself and others on the road a disservice. it's dangerous. it's a safety issue. fix it right.

 

[SomeRandomDude]

Well @72bluNblu @RustyRatRod & @junkyardhero confirmed what I was thinking - I have a new mount on the way and I'm going to be visiting with a buddy who does fabrication work for a restoration shop to see if he'll help out with the welding.

On a related question - do you think it would be worth it to start working on peeling off all the undercoating on the car to look for any other bad spots while at it? I've visually inspected and knocked around on everything and the only spots that look questionable are this one and a couple of others around bolt holes. But I guess who knows what someone years ago coated over rather than repairing. I suppose I could spend the next week under the car cleaning everything up and have them fix whatever else is found at that point - I just don't look forward to spending that much time on a crawler - but it is what it is I suppose. What would you guys do?

 

[SomeRandomDude]

I am going to suggest this… run it. I know it looks bad, but on my Duster the spring hanger mounting location on the driver side looks exactly as yours and I too bought reinforcement plates that I didn’t use because of it. Just use washers under the nuts or the original washer intergrated nuts if they are decent, that’s what I did 4 years ago when I installed new springs. I’m only running about 400 horsepower 340 and if you are not drag racing, just spirited driving, should be fine for many years, it took 50 years to look like that today… If you want it perfect you will not get on the road, and if you could see thru it or deflect it by hand… then it’s a hard no, but that will take several more years to be a problem but now you know about it so you can check it once in a while and when ready to dig into it, dig in, otherwise run it and enjoy the car for now.

You know... normally I'm in the 'send it' crowd - I just cant talk myself into it with this one though. I'm sure it'd be fine for a bit but on the off chance it wasn't the risk would be too high. Gotta love these old cars!

 

[Demonracer]

I think I would get the undercoating off and see just how soft the metal is. That way you can make an intelligent decision as to how far you want to take it to make it safe. Just "my" thought on it.

 

[RustyRatRod]

Well @72bluNblu @RustyRatRod & @junkyardhero confirmed what I was thinking - I have a new mount on the way and I'm going to be visiting with a buddy who does fabrication work for a restoration shop to see if he'll help out with the welding.

On a related question - do you think it would be worth it to start working on peeling off all the undercoating on the car to look for any other bad spots while at it? I've visually inspected and knocked around on everything and the only spots that look questionable are this one and a couple of others around bolt holes. But I guess who knows what someone years ago coated over rather than repairing. I suppose I could spend the next week under the car cleaning everything up and have them fix whatever else is found at that point - I just don't look forward to spending that much time on a crawler - but it is what it is I suppose. What would you guys do?

Glad you're going to fix it the right way.....but word of warning. "That type" of metal rot is worse than actual rust.....even though it is rust. When metal rusts on the level that you can see the different layers, it's gone. And I mean GONE. So, be prepared for the damage to extend further than the actual reinforced leaf spring mount area. I hate telling you that, but it's the God's truth. But good luck with it and it CAN be fixed!

 

[72bluNblu]

I would definitely do a thorough check on the rest of the car and chassis, how much undercoating you remove is up to you. That kind of rust is usually not isolated to one spot, and if it’s that bad in one spot then there’s a really good chance that it’s that bad or worse at other locations too. With rust there’s always more than what you see at first.

As RRR said, it’s just about impossible to repair sections at locations where there’s rust like that between the layers, you just can’t weld to it without pulling in all the oxidation. Obviously I’m not looking at it in person, but I would not be surprised if repairing that mount includes sectioning both the frame rail and rocker, at the least. That corner with the mount is a complex joint with overlaps of a lot of different pieces, and it’s a major structural component for the chassis because it ties the frame rail, rocker, spring mount, and floor together and serves as the base for the quarter structure and C pillar.

 

[H22A4]

Good call replacing that entire section! If you were only to use those reinforcing plates, you might as well also make sure the car has 10+yr old tires on it too. Total disaster waiting to happen.

 

[SomeRandomDude]

I would definitely do a thorough check on the rest of the car and chassis, how much undercoating you remove is up to you. That kind of rust is usually not isolated to one spot, and if it’s that bad in one spot then there’s a really good chance that it’s that bad or worse at other locations too. With rust there’s always more than what you see at first.

As RRR said, it’s just about impossible to repair sections at locations where there’s rust like that between the layers, you just can’t weld to it without pulling in all the oxidation. Obviously I’m not looking at it in person, but I would not be surprised if repairing that mount includes sectioning both the frame rail and rocker, at the least. That corner with the mount is a complex joint with overlaps of a lot of different pieces, and it’s a major structural component for the chassis because it ties the frame rail, rocker, spring mount, and floor together and serves as the base for the quarter structure and C pillar.

After speaking with the guy who owns the restoration shop I'm going to bolt this together for the (slow and careful) 2-mile drive to his shop. He'll get it on the lift and do a full inspection so we can make a call on what needs addressing and how. They do a lot of work on cars from the 40s through 70s and are apparently pretty familiar with this type of repair. Fingers crossed that this rabbit hole doesn't go too deep...

 

[SIX225]

How are the actual frame rails? Have you considered moving the springs inboard?

 

[SomeRandomDude]

How are the actual frame rails? Have you considered moving the springs inboard?

I wouldn't say they look terrible - but not great either. I'll drop some pictures below - but either way, I'd prefer leaving the mounts where they are and fixing it properly.
Here's a couple other shots I have on my phone:

 

[SomeRandomDude]

The Mopar Gods reeeeally want this mount to be rusty.... Noticed a few paint bubbles on the new part - rubbed a finger across them and found a surprise underneath!