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Back Panels Cracking


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My 110 CSW is used as an overland vehicle. Last year it did 25,000 miles in Australia with about 20,000 miles on non sealed roads.

As an overland vehicle it carries a lot of weight. It has been back in the UK for a couple of months. Last week I noticed a crack on the offside rear panel. This I decided was due to the weight of the spare wheel carrier and decided that a purpose built bracket would help to support the lower bracket.

At the weekend set out a RTV and midday notice a crack had developed on the nearside.

The rear winch is set well back into the rear cross member and we had to cut out the first 50mm of the floor.

Some photos showing the damage

Rear of the 110

IMG_9622.jpg

Crack on offside

IMG_9623.jpg

Crack on nearside

IMG_9624.jpg

Suggestions to solve this problem most welcome

Regards

Brendan

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Is it just on the outer panel or has it spread inside as well ?

Is there any buckling that might suggest it's being caused by the weight above it or is it just that there's a bit of movement there and it's down to the panel vibrating ?

Difficult to tell from a photo, you should have told us all at the trial and you'd have got a different answer from everyone there :)

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To me it looks like the body isn't as stiff as the crossmember or vice versa - from the buckling of the panel there's been movement, and enough to crack the skin. You're getting a stress concentration at that body corner. Your options are to reduce the forces seen by the body (less weight on the roof!) or to better integrate the crossmember and body side. I'd suggest a spreader plate behind the panel (behind the number plate) with a number of rivets (1" pitch in a square matrix pattern?) and maybe the same to the wing skin too - that'll carry the forces up behind the panel and into the hardtop above, rather than using just the two bolts on the crossmember's tab as at present.

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you can see at both cracks the body has 'bulged out',

this means there must have been some considerable and sustained compressive force going vertically down on the whole back body and this has resulted in the bulges. You can see the bulge starts at the 90deg bend at each door bottom - which coincidentally happens to be at exactly the mid point between the rear crossmember to body tabs and where the floor meets the vertical parts of the wheel box. There is a reason they dont use right angles in aircraft and boats for this very reason, as cracks like to appear at stress points on sharp angles! You should know that Brendan.... :P

If the back body is heavily laden and going over lots of bumps - then the floor will try to sink! Obviously its supported by the rear crossmember tabs and the tub mounts underneath, but the main load point of the rear floor and the weight carried on the wheel boxes all join at that right angle at the door corners - which also happens be the points furthest away from any support brackets! Whats the odds on betting that simillar cracks or deformation has happened under the tub where it attaches to the tub mounts further forward as well.

post-2947-1239092900_thumb.jpg

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Brendan,

have you gone through your loads of pictures to see if this is a recent problem or one that has been developing over a longer period of time?

Looks to me that your overloaded, but the question is where? The rear tub or the roof rack??

Todd.

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The problem has become apparent only very recently. Have altered the rear suspension after the vehicle returned from Australia as the shocks were shot to put it mildly. Noticed the offside crack on Thursday and the nearside crack appeared mid day Saturday half way through setting out a trial.

I do not use a roof rack on overland trips. There is a lightweight wire cage fitted at roof level inside the rear which carries light stuff, say 20 kg max.

Will get the 110 on a lift and ensure a thorough inspection in the near future. Will report back on what is found.

Have people seen this sort of problem before?

Regards

Brendan

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had the same problem with my first 110. the bulkhead behind the seats was removed by the previous owner which i believe reduced the torsional rigidity(ooh listen to me with me fancy words :P ) which led to lots of flex. mine looked exactly like that and all i did was sell the vehicle ;) ..... dunno wether your bulkhead was removed

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had the same problem with my first 110. the bulkhead behind the seats was removed by the previous owner which i believe reduced the torsional rigidity(ooh listen to me with me fancy words :P ) which led to lots of flex. mine looked exactly like that and all i did was sell the vehicle ;) ..... dunno wether your bulkhead was removed

My defender has 784,000 kms and alot of that well oaded and on rough roads and I too have cracks in the rear panels but without the bulging. Just beneath the fog light and reverse lights are two pieces of metal that join the rear X-member to the panels - on my Defender the cracks appeard around these leading to them becomming pointless/useless so I added some more rivets and bolts near to them which seems to have stabalized things alittle.

A chassis will over time develop some flex and the difference in flexability between body and chassis is I believe the cause of the body cracking which because it is box shaped is less flexible than the ladder chassis.

Check that all the body to chassis support and joins are intact.

The buckling, as noted by others, seems to indicate compression either from a heavy roof load (and you say there is none) or possibly a loose or non existent post/roof joint leaving the roof supported by the rear panels ? I found that the beams joined to the posts behind the doors were not properly tightened and of the 2 bolts on each side there was only 1 (must have been a friday afternoon or monday morning build and the assembly from new was with only half of the number of bolts needed !!!!)

You say that your suspension was shot - possibly the repeated, over time, supression of the springs as far as the bump stop could cause this buckling as it would be similar to repeatedly striking down on that joint with a hammer the weight of everything above the joint !!

Keep us posted on your findings

Adam

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The chassis was replaced about 2 1/2 years ago due to an 'over enthusiastic' ditch crossing at about 50 mph due to pilot error.

Currently in the Iberian Penisula in the Disco so can not examine the 110 further at the moment. Will certainly keep forum informed of future findings and corrective action taken.

Regards

Brendan

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