Rear crossmember replacement

[Tbaumer]

Thought I would just clean up & seal the rear crossmember, but it didn't make sense with the extent of the rust holes, thinning & flaking metal separation. I'm not ready for the commitment of going "ALL IN" on a complete chassis yet. Here is my existing crossmember:



New galvanized crossmember & step bumper waiting to go in:



Checked out a bunch of threads/videos & it appears to be straight forward. As this is a first for me, advise is always welcome & I'll try to keep a simple job simple.

 

[Uncle Douglas]

straight forward, drop tank, pull wiring harness back so it doesnt get cut.
Welding galv steel sucks. It fizzles like a sparkler.

 

[4RF RDS]

Be very cautious welding galvie, grind off where you want to weld and wear a filter particulate mask at all times. Galvie welding can off gas cyanide.

 

[1of40]

Be very cautious welding galvie, grind off where you want to weld and wear a filter particulate mask at all times. Galvie welding can off gas cyanide.

Absolutely no joke. A local shop let one of their employees to weld a galvy crossmember w/o proper protection and it put him in the hospital with perm lung damage.

 

[Tbaumer]

Thanks for the warning all! I remember my grandfather drinking buttermilk before welding galvanized metal.
No, even as a kid I didn't see how it could protect his lungs, but the old guys seemed to think so...

I'll grind off the zinc to bare metal, exhaust fan to ventilate & wear a mask before welding.

 

[mgreenspan]

Thanks for the warning all! I remember my grandfather drinking buttermilk before welding galvanized metal.
No, even as a kid I didn't see how it could protect his lungs, but the old guys seemed to think so...

I'll grind off the zinc to bare metal, exhaust fan to ventilate & wear a mask before welding.

Haha that sounds about as real as women not getting pregnant while breast feeding.

 

[jymmiejamz]

Haha that sounds about as real as women not getting pregnant while breast feeding.

There are enough Irish twins in my family to know that this is not true!

 

[Tbaumer]

Removed my spare wheel carrier.



Haven't dropped the tank out of the way yet. Pre-marked the chassis to get an idea of where I'll be cutting & found that the rear sway bar brackets will make me notch the new crossmember flanges a bit on the bottom to miss them. I'm also splitting the floor rails, so I'll be grinding the front welds & re-welding them to the new crossmember. If I would've thought about it, I probably could have found a rear crossmember with the floor rails attached .

 

[Tbaumer]

I was out of town this last weekend, so tonight I drained the tank, lowered the sway bar, removed the muffler & fuel tank. The inside of the tank looked really clean & rust free.



Even before clean up, I noticed stress cracks in the upper floor rail (pic #3) that will need to be addressed.

 

[BarryO]

Be very cautious welding galvie, grind off where you want to weld and wear a filter particulate mask at all times. Galvie welding can off gas cyanide.

^^^This. But any real welding shop would know this.

 

[Tbaumer]

Tank & support removed. Looks like a bit of rust between them that I'll address before they go back in.



Because it 's working & easy enough to drop the tank that I'm waiting to replace the fuel pump (remember this comment if it quits on the trail ).
Had to edit because of the fuel pump statement - I was looking at the rusty spill return elbow - it's a diesel.

 

[Tbaumer]

Had to cut off the screws to remove the rubber protectors. Disconnected the harness & pulled the wiring down through the grommet.

 

[Tbaumer]

The replacement crossmember does not have the indentation for trailer hook up, so I'll be deleting that section of wiring for now. Harness disconnected at the rear & pulled down.

 

[Tbaumer]

Used grinder & cutting wheel to separate the back leg of the floor rail, leaving tabs that can be welded to the new crossmember. Cutting wheel to cut off the rear body bolts.

 

[Tbaumer]

I was afraid the wiring would catch inside & wanted to see what it was routing through before I started pulling it back, so I used a heavy wire to push the harness out of the way & carefully cut off the rear crossmember.

 

[Napalm00]

Looks very solid there , should have zero issues welding it

 

[Tbaumer]

Started cleaning it up with a wire wheel. Think I'm going to take up the offer from a buddy of mine who has a portable sand blaster. Too many nooks that a wire wheel won't reach. Cleaned up the backing nut plates, so I can POR15 them.



Looks like I'm ordering a new tank, as the one I have is actually pitted through after clean up!

 

[Napalm00]

Maybe spray some prep and etch ?

 

[Tbaumer]

Maybe spray some prep and etch ?

That could work on the hard to reach places if I can't get a little blaster in there. You don't mean on the fuel tank, right? I think it's a goner.

 

[Napalm00]

Na tank is toast , they are cheap thankfully.