4x4lbs rear bumper install.....questions...

[CodyRx7]

Ok....so I'm starting into the frame cutoff portion of my rear bumper install...now I have a few questions/need advice on a few steps...

My sawzall cut through the frame fine for the main cut, and then I'll have to do the angle cut at the bottom towards that inner towing eye bolt.

I used the sawzall to cut through the welds on the top and bottom pretty cleanly.

Now for this inside weld...

What magical tool works best in this area?

 

[CodyRx7]

Question 2:

Luke's Gallery shows this picture with the receiver sitting about flush....so his definately slides through the hole in the bumper.

Mine doesn't fit through that hole. Either the receiver tube is too thick, or the square hole its supposed to fit into isn't big enough.

Since that crossbar is something I install myself...would or could I move it back just about 1/4" and have the receiver tube installed like this for a thicker weld? Or am I going to want to enlarge that opening a hair so I can fit the tube in flush?

 

[FirstToy]

how far off is it on the reciever?
maybe just need to grind down the edge a bit & scrape some paint off the hitch if it is close.

 

[CodyRx7]

It would only take a little bit of grinding to be able to push the receiver tube in...

BrianMacgeyver was over earlier and mentioned that it might be better to have it pushed back like in my picture to make a better/stronger weld instead of having it flush...

What say ye, 80 series forum?

 

[24HOURSOFNEVADA]

Ok....so I'm starting into the frame cutoff portion of my rear bumper install...now I have a few questions/need advice on a few steps...

My sawzall cut through the frame fine for the main cut, and then I'll have to do the angle cut at the bottom towards that inner towing eye bolt.

I used the sawzall to cut through the welds on the top and bottom pretty cleanly.

Now for this inside weld...

What magical tool works best in this area?

A 4" grinder.

 

[LC80Ducati996]

Question 2:

Luke's Gallery shows this picture with the receiver sitting about flush....so his definately slides through the hole in the bumper.

Mine doesn't fit through that hole. Either the receiver tube is too thick, or the square hole its supposed to fit into isn't big enough.

Since that crossbar is something I install myself...would or could I move it back just about 1/4" and have the receiver tube installed like this for a thicker weld? Or am I going to want to enlarge that opening a hair so I can fit the tube in flush?

If you weld it before the cross tube you can weld the back side of that joint too. Then you could more easly grind the outside weld there flush and make it look trick and smooth!

 

[CodyRx7]

Yay....welding is fun.

But welding with gas with wind around makes me want to punch babies!

I tried my 4.5" grinder for those inner welds....that was the most awkward can't really reach anything experience....

The long blade on the sawzall killed those welds pretty easily...barely anything left to grind off on those.

This is as much as I could accomplish by myself before it started getting dark.

 

[Tools R Us]

...
Now for this inside weld...
What magical tool works best in this area?

I used a big die grinder with a 3" cutoff wheel.

Question 2:

Luke's Gallery shows this picture with the receiver sitting about flush....so his definately slides through the hole in the bumper.

Mine doesn't fit through that hole. Either the receiver tube is too thick, or the square hole its supposed to fit into isn't big enough.

I used the same die grinder with a 3/8" burr to make the hole larger, or grind down the receiver so it fits. If you push it back, the crossbar to recovery hard points spacing will be messed up. Surprised that yours has that problem, Luke said he was going to make that hole larger last year.

 

[CodyRx7]

ahh yeah, I didn't even think about those recovery points being pushed back if I did that...thanks Kevin.

 

[619TOY]

I used a big die grinder with a 3" cutoff wheel.

That's what I used as well. I just cut a thin slice along the length of the weld and then "popped" it loose with a big prybar. After that I cleaned it up with a right angle die grinder and sanding disc.

I used the same die grinder with a 3/8" burr to make the hole larger, or grind down the receiver so it fits. If you push it back, the crossbar to recovery hard points spacing will be messed up. Surprised that yours has that problem, Luke said he was going to make that hole larger last year.

Same here as well. If you have the ability to tig weld this area, it may leave the upper surface a little flatter/smoother. I mig'd mine and it caused the top flat surface to warp a little.

Another thing to look out for, if you're concerned is the stop you will weld into the center/top for the swingouts. Mine hits the plastic cladding when the tailgate is down and there is weight on it. I believe this is only a problem for LX450's.

 

[LC80Ducati996]

Tack the reciver in in many places... Do a solid little tack in one spot and do diagonally across from it and tack again.. Get a bunch of those in with cooling inbetween. Then make a 1/4 bead in one spot then go as far a way from that and do another wiith a short cool off. So on. Slowly weld small sections across from the last until done. Heat cant build way up in just one area and warp it.

 

[CodyRx7]

Anyone else experience this with their bumper kit?

Where the holes are cut into the main shell for the recovery points...the recovery points can slide through the shell.....but on the bumper...they crash right into where the outer wings bolt to the inner frame...

Do I just grind out the holes larger toward the center so the recovery points can slide in?

Passenger side:

Driver's side:

 

[619TOY]

Yes, I too had to cut these slots out a little wider(I used my airsaw IIRC). See how much you're learning about fabrication?

Edit: Afterwards, I MIG'd in the gap and ground it flush. Then I did the the nice cosmetic weld which covered the filler weld. Nobody will be any the wiser.

 

[CodyRx7]

Yup.

I've learned that whoever measured the locations to cut these holes based it on the recovery points being flush with the inside of the frame rails...and forgot about the added thickness of the wings bolted on...


I have also learned that welding is not fun when trying to bridge a gap between the wings and main shell. Grinding down a welding "stalagtite" is well....crappy.

I thought I had a great idea too...

"maybe if I get a really coarse flapper wheel, it will grind away those boogers faster..."

All it did was turn a 24 grit wheel into a 2 grit wheel in like 8 seconds...

D'oh!

 

[Tools R Us]

...

All it did was turn a 24 grit wheel into a 2 grit wheel in like 8 seconds...

D'oh!

If you using them itty bitty wheels, just buy them by the the box!

 

[Tools R Us]

Anyone else experience this with their bumper kit?

Where the holes are cut into the main shell for the recovery points...the recovery points can slide through the shell.....but on the bumper...they crash right into where the outer wings bolt to the inner frame...

Do I just grind out the holes larger toward the center so the recovery points can slide in?

Passenger side:

Driver's side:

IIRC, I left the recovery point out and ran a bead, welding shell to the wing, down in that hole. Then put in the recovery point and welded it up, by welding in the hole first, it somewhat built up that area, needing much less weld to fill.

 

[Skillet]

I found that the best approach for this setup is to drive to grass valley and let Luke put it on.

 

[NorCalSam]

LOL

Jeb, you funny man

 

[locrwln1]

One of my recovery holes was off bad enough that I had to cut about 1/4" toward the center, move the arm over and weld the 1/4" part that I cut out, back in. Wasn't real happy about it being that far off...

Bumper is done and it works/looks great. I am not sure if I had Luke/Brian weld it up, if it would have fit with the hole being that far off. Maybe they have a jig that I didn't see and it would have shown the mis-alignment.

Jack

 

[CodyRx7]

Yeah see thats the funny thing about it.

I imagine these shells are all cut in batches using the same exact measurements...and the kits sold are the same pieces they put together themselves when they ship a bumper or install it at their shop.

If it is all the same shell measurements....there's no way the wings would bolt to the frame like they should if the bumper was already together with the recovery points installed.

Oh well...I learn more as I add to it.

I just picked up a new die grinder and some bits to fix the parts that need fixin'.