Rear crossmember replacement.

Whilst stuffing the 'tank back in my lwb at the weekend I noticed that the rear crossmember looked knacked.
Theres substantial rust blisters in the centre (hidden by the tank), and both 45 degree sections that lead to the corners of the vehicle have patches where you could shove a 'driver through.
I'm expecting this to be a mot man failiure, and I'm gonna order a newun regardless, but wait untill the test as I'm sure theres gonna be a bunch of other stuff.
Has anyone replaced one of these and what did you do and how much of a ballache was it?

not done a LWB but several SWB.

cut it off before you unbolt the body, supporting body carefully before cutting, tack it back on once bolted up to rear body which is the alignment nicely sorted, then remove rear body & weld it up properly.

having seen what you've been up recently to it should be a walk in the park.

That sounds like a good idea, and positioning is going to be a lot better like that.
Taking off the rear tub was something I didnt want to do, maily cause I havent got the room.
I spose I could cut the old one out and tack the new one in one day, then remove the tub and weld up the next, without driving the landy of course.
Do you think I could fold down the windscreen, open the doors, unbolt then jack up the tub with the roof on just enough to gain access, or am I being silly.
Wheres the best place to go for one of these, I've never got body bits for landys before, other vehicles yes, and quality varies from naff to excellent.

yeah I reckon you could, don't jack it up too far though. you might want to loosen the sills if they're still fitted.

always got mine from paddocks ... they at least look the right shape.

hi i have just done the one on my 109 i have done plenty on swb but this was a whole differnt story the 109 chassies has a dip in it unlike a swb so i had to modify the new crossmember (i got the one with the extensions on ) but the only sell a swb one

do u need a replacment fuel tank ?

Supporting the body? Why? Would it twist if not? Mine didnt.

I would personally take the body off first, check this rear end of the chassis...it might end up being a rear quarter rather than just the crossmember by the time you have got back to good metal! When I did the rear 1/4 on mine measured everything before, cut and then a few tack welds jsut enough to hold it, then the body back on to make sure that everything was still aligned.

rustyrhinos said:

Supporting the body? Why? Would it twist if not? Mine didnt

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not twist, but can sag if the steel under-tub support cross members have rotted ... which they often have. it's easier to bung some bits of wood under it while it's in position than jack it back into place afterwards.

Now you got me confused, do I need to support everything before I hack the member off, or use a jack to get everything inline before snotting back on.
I didnt know the 109 was diffo to the 88, mines a 109.
Sounding to be a pants job.
The rear floor on mine unbolts, this gives fairly good access all round the rear xmember.
I've been looking at photos of rear xmembers with extensions and 1/4 chassis, they both look similar, on closer inspection looks like the rear xmember with extensions has a 'u' shape extension that fits over the end of the chassis rails and welds on, because of the 'u' section the bottom is open so the original springs hangers are retained, whereas the quarter chassis has a full box section extension, still looks as though it fits over the end of the original chassis rails, but this time the original spring mounts are ground off and the ones on the quarter chassis are used instead.
This sound correct?, is it a much more difficult job doing the quarter rather than the xmember?, I'm thinking I'd rather do the quarter and know its gonna be right, or rethink the whole job and start with a vehicle that isnt fecked.

gotter be said it IS a pants job.
you could take a punt on it not dropping ... just undo the rear body bolts and see if it does drop. make sure all the rubber pads are still in place under the body first though. if it does drop you just have to support it back so the holes line up again.
I tend to buy just the crossmember and make up any new bits of chassis that are required out of sheet metal, but having a set of bench shears helps immeasurably.

if your floor unbolts there's probably no need to lift the body at all, provided you can get to the top of the chassis rails to weld up the join.

Only do the rear 1/4 if it actually needs it. No point in replacing good metal IMHO...but I would personally take the body off anyway so you can properley inspect it.

The 1/4 chassis...on mine it, as you said, has the spring hangers on it. And the one I had was designed to slide over the top of the original chassis. Measure how long the rear 1/4 is...mark where that will but up to your chassis...bear in mind you will need a little extra chassis for it to slide over - make another measurement there then lob it off. Slide new 1/4 over, tack in place, check body fitment, if OK, weld it proper, not forgetting some fish plates.

For the hell of it, my rear chassis 1/4 replacement....

Grotty...


Marking up...first line where the new 1/4 will but up to, the second where to lob it off...


Lobbed...


trial body fit:


Weld in place (then fishplates, not pictured):


Sorted...

Thanks rusty, thats very usefull info, and you managed that with a suitcase welder.
I'd be happy to do that, if only I had somewhere to put the tub, I could store the roof maybe but not both, without a load of fannying juggling around and putting the 2 together in the front garden, which would risk a divorce, odd seeing as its her landy.
Right then I'll pull the floor up and have a good look maybe post up some pics.
My rear xmember looks worse than yours rusty, a fair bit worse, theres 4" blisters on the bottom section, holes in the 45 degree corner pieces, and where the towbracket fits theres evidence of the previous owner having distorted the member while towing with it being weakened by corrosion, new member req I think.

hi this is what happend to my 109 with a swb rear x memeber.

Thanks matt, very informative, I like this forum.
The more I look the worse it gets, both here and on the vehicle.
My chassis is a patchwork quilt, there are loads of patches welded on, from the seats back there must be 20.
And I realised today that I'd not get a 1/4 chassis to fit as the 88 has the leafs mounted inboard whereas the lwb has them outboard, then looking at the last pic the chassis rails are also bigger on the lwb, I knew that but didnt think of it, doh.
Turning into real pants innit.
I had a look today and there are a few patches around the rear spring mounts, overall apart from that the longitudanal chassis sections rear from the spring mounts isnt all that bad visually, so a modded rear x might have to do, that might change of course once grinder and chassis meet.
Please no suggestions for a new chassis, I'm calling the breakers before that happens.

dr pepper said:

My chassis is a patchwork quilt, there are loads of patches welded on, from the seats back there must be 20.

Click to expand...

sounds fairly standard! I think I can match that.
Is this the same landy you've been squeezing the 300 into?

Well thats good I spose no diffo to the norm, a monocoque this bad would be scrap.
Yep its the same bus that has the 300tdi and deffy axles.
Land rovers are like any other project vehicle wise I've done the more work you do, the more work you find.
Mines gonna look like matts when its done then, as I take it lwb rears are not available, depending on how things look I might have to make a temp jig welded to the chassis and bolts onto the old member through a couple of holes, then lob the old one off and bolt the new one on to the jig, weld up then grind off the jig.
Matt, were the chassis rails on yours the right width for the swb rear, did the extensions slide over the rails once you'd doctored the height, or did you have to widen them as well, that chassis looks mint compared to mine.

hi the swb chassies is the same width. the cross memeber was from paddocks,
i left the body on and cut the old one off then offerd the new one up and found i had to run the grinder down the tops of the extensions so i had a flab on top the mounted it up and bolted the 10 bolts in and welded down the sides, then removed the body.
once that is done make the top fit the best way like i did and just but a plate in the bottom. hope that helps

Yep thanks, gonna see if it can be done wit tub on.
Paddocks and others claim that the rear memver with extensions will fit either the swb or the lwb, spose it can fit the lwb, looks like a fair bit of adaptation required.
I really didnt want to remove the tub, its looking more and more like I need to, borrox.