Rusty rear frame rails repair question

[GTbird]

Has anyone on here fixed this much destruction without spending thousands of dollars?

 

[XR7-4.6]

That’s actually the rear frame rail/torque box structure, and the bracket attached is the subframe stabilizer bracket, it’s main purpose is actually just to make the IRS bushings double sheer, which is partly torque related but mostly for all other forces(cornering loads, braking bumping curbs etc.)

Having said that I hate to be the bearer of bad news but that kind of rust is pretty bad and it’s probably worse where you can’t see it. That’s not going to be a fix on the cheap without making it worse. I’d recommend finding a less rusty car and swapping the good stuff from that into it, it will be cheaper than even the cheapest repair there.

 

[Kenz]

That looks like terminally bad rot, is that the rear sub frame mount? Even if that spot can be fixed what shape is the rest of the chassis in? Check rear shock absorber mounts in the trunk, and look at the front shock towers under the hood. If they are in bad shape it's not worth repairing.

 

[GTbird]

The rest of the car isn't rotten from what I've seen. I didn't look under the carpet so I'll check it out, thanks.

 

[GTbird]

It's ok, I bought it knowing the whole drivetrain will fit in my crown Victoria which is from Washington and Utah so is super clean underneath.
The only bad part is now I've driven this platform and like it so have my eye on a 3.8 car for a grand close to me but I already have a van, truck and three sedans.
Everything works on this car: I'd hate to see it go to the scrapyard. I'd also hate to have the rear suspension fly off going down the road. When that shit lets go it's gonna be hairy.

 

[XR7-4.6]

It's ok, I bought it knowing the whole drivetrain will fit in my crown Victoria which is from Washington and Utah so is super clean underneath.
The only bad part is now I've driven this platform and like it so have my eye on a 3.8 car for a grand close to me but I already have a van, truck and three sedans.

Unless there’s water leaks 93-97 floor pans tend to hold up remarkably well, as they switched to galvanized stampings. The big issue is the rockers, torque boxes, front shock tower “finger” area(although that’s more ugly than structurally deficient) and the rear shock towers. There’s a lot of interlapping steel joints in these areas, sound deadening foam and points for water/salt entry that just eats this chassis alive.

If the 3.8 car is clean go for it. Depending on year it can be a direct swap using everything from your car, if not a few tweaks of the wiring will make it work

 

[GTbird]

The other areas where the rear end and suspension get supported look solid so I went for it. We'll see how long it all holds up!
The transmission pan looked really good today when I dropped it: barely any film on the inside and just fine particles on the magnet, so that's good news. Fresh fluid in the supercharger as well. Let the fun begin! Oh, yeah, back tires are super bald so I'd better do something about that.

 

[XR7-4.6]

back tires are super bald so I'd better do something about that.

Perpetual problem of mine

 

[Zep5.0]

Has anyone on here fixed this much destruction without spending thousands of dollars?

I can answer the first half of that question, affirmative...

 

[Kenz]

The shock tower on the Tbird I used to have eventually started separating. That is why I stopped driving it and sold it for scrap value. The car still looked surprisingly good on the outside but was rotting apart underneath.

I don't recall the rear subframe/mounts were too bad on it.

Reminds me of a coworker's expression he had for the rotten pickups still driving around on the roads up North... "they were one railroad track away from breaking in half"...

 

[GTbird]

I can answer the first half of that question, affirmative...View attachment 9178View attachment 9179

Is that a different car in each picture?

 

[Zep5.0]

Is that a different car in each picture?

Same car, many thousands spent. If you want to fix it you have to find a donor car, or get to forming metal. You can certainly drive it that way for a while, but it's on it's last leg.

 

[theterminator93]

Rust in your torque boxes are more progressed than mine, but it's more or less the same situation I'm in. Like Seth said, it can be fixed but the hard part will be finding someone who will do it, followed by finding the money to have them do it, then finally a donor car to hack up.

 

[Grog6]

Finding a southern car and shipping it would be cheaper.

 

[XR7-4.6]

The shock tower on the Tbird I used to have eventually started separating. That is why I stopped driving it and sold it for scrap value. The car still looked surprisingly good on the outside but was rotting apart underneath.

I don't recall the rear subframe/mounts were too bad on it.

Reminds me of a coworker's expression he had for the rotten pickups still driving around on the roads up North... "they were one railroad track away from breaking in half"...

View attachment 9177

The bigger problem when rotting is the frame rail to shock tower. There’s a structural component to the shock tower to that fender rail but it’s not quite as critical as it would appear compared to the former, I wouldn’t be afraid to drive the car with that, it’s just really really ugly!

 

[Kenz]

The brake lines are what scare me most on vehicles rusting out. Unless all the lines have been replaced, they are going to fail eventually. It can often happen at the worst of times.
Rusted brake lines like to explode from the pressure of a hard panic stop..... brake pedal goes to the floor

 

[jb351]

It can be repaired, it generally sucks though as if that part needs to be replaced there is likely significant rot elsewhere that will need fixing also.
Mine were not gone as far as that but were thin with very heavy pitting. What I ended up doing was cutting out the worst of it, sandblasting/POR15 what was left and then fabricated and welded in new sections over the old. I did this on both sides. The 2 pieces were welded together before installation.

 

[GTbird]

It can be repaired, it generally sucks though as if that part needs to be replaced there is likely significant rot elsewhere that will need fixing also.
Mine were not gone as far as that but were thin with very heavy pitting. What I ended up doing was cutting out the worst of it, sandblasting/POR15 what was left and then fabricated and welded in new sections over the old. I did this on both sides. The 2 pieces were welded together before installation.

That's what I'm talking about! Did a similar repair on a crown Victoria but nowhere near as nice on the prefab pieces.
The rest of GTbird is solid so eventually I'll get around to it. Gotta keep these old beauties rolling as longking as possible since the new cars aren't as good IMO.

 

[Generalee0527]

The brake lines are what scare me most on vehicles rusting out. Unless all the lines have been replaced, they are going to fail eventually. It can often happen at the worst of times.
Rusted brake lines like to explode from the pressure of a hard panic stop..... brake pedal goes to the floor

Or when you replace the master cylinder due to weak brakes and try to bleed the air out. I seem to recall it was a wall of brake fluid with every pump of pedal. This was a long time ago on a co-workers Monte Carlo. Wound up putting a pipe plug in the rear of distribution block and driving on fronts only.