Tips on replacing rear crossmember?

[Rich Lambert]

The rear crossmember for my Series II arrived from RN this week. It's the one with the 16" extensions. Has anyone done this repair? Any tips?

[leafsprung]

best advice is that the extensions are not welded on the same way the factory ones are. If you simply weld the extensions over the original frame it will be in the wrong place vertically.

[SafeAirOne]

best advice is that the extensions are not welded on the same way the factory ones are. If you simply weld the extensions over the original frame it will be in the wrong place vertically.


That might explain the tub alignment issues I'm having with my 5-door-to-3-door tub swap...a PO-installed replacement crossmember was giving me trouble with its horizontal and vertical position.

Now for my tip: Take the tub off to weld the replacement crossmenber on. Don't be an idiot and cut two holes in the floor of the tub to weld the top of the extensions to the chassis like one of my rover's POs did.:mad:

[Rich Lambert]

Tub's off.
http://granitehead.smugmug.com/Trucks/1958-Land-Rover/Power-wash/692356141_sGDcq-M.jpg

Maybe I need to make some kind of alignment jig. Thanks for the tips!

[SafeAirOne]

Tub's off. Maybe I need to make some kind of alignment jig.

You read my mind..As a matter of fact, that's what I just recommended on your post in the G&R forum.

[Tim Smith]

I just did this on my truck. Took about four hours including playing about and eating dinner. I took pictures but haven't had the time to post them yet. It's a straight forward job.

Make sure you keep the wiring well clear when you are cutting and welding. I also did it without moving the tub any. After you get the sides welded nice and strong and are sure it all aligns correctly, you can lift the tub and finish welding the top.

Any questions in particular?

[Terrys]

I've done 3 of these in the past year. I can tell you that the present replacement Xmember is a piece of tin compared to the original. You will find out when the bushings start sliding out off their tubes when you start to draw up the spring bolts.
Push as much slack of your wiring back into the old xmember, take your sawzall and cut down halfway. Pull the sawzall out, pull the harness up tight, and slide the sawzall blade back in and finish your cut. Tape about 6' of heavy wire (#8) to the harness, and feed it through the new extensions and out the hole. Use this to pull the harness out once you have the new xmember in place.

Too bad you've already taken the tub off, because to start locating the new one, you simply chop the old one off about 1" ahead of the last body support, slide the new one on, and bolt a few of the 10 tab bolts in, Then tack the center of the vertical edges of the extensions.
At this point you can take the tub off if you wantm and finish up your welding. The cleanest weld will be with a Mig, and mixed gas (CO2/Argon) but straight CO2 is OK. If you're good, you can do it with stick, 3/32 6013, though I have used 7018. Once you have done all 4 tabs (the bottom one is done last) transversely, go back with your grinder and grind the longitudnal joint of where each tab meets the next one (the corners) and weld that joint too. I say grind it because you want to join the extensions to the old frame fore and aft, not just the edge where the tab ends.
The absolute best way to align the new one is with the tub and roof still in place because you know the length and elevation are right. Since you've already taken the tub off, you can measure it to the tabs on the front edge and lay out the new ones, but you'll never be certain you have the elevation correct with out a long straightedge. Having done it thisway, I'd stick the tub back on, slip a few bolts back into the old Xmember, and shim up the body to the old body supports (there's usually a gap there ) then cut the old one off, slide the new one in and tack it good. Then remove the tub. Chopping holes in the floor is kinda blacksmith.
As for the spring bushings in the new crossmember, you're going to need to put something like a large flatwasher in between each end and the shackle, because the bushings are such a loose fit they start sliding from side to side in no time, with a pretty annoying noise.
I'd also strongly suggest you rust protect with whatever makes you happy, as the new crossmember is Very much thinner gauge than the old one, with all the same desighned in moisture traps.