Cracked chassis on my D2

[Redback]

Well while out last weekend on a track at Wheeny creek, i had a noise from under the car, when we inpected it we notice a crack in the chassis, this noise is a clicking sound and we feel that it's the crack that is causing it.

The crack is where the bumpstop bolt on passenger side rear.

This post is to warn you and to check your chassis, as apparently this is a common problem with the D2 according to B Davies, he said it normally happens in the front and not the rear.









Baz.

[walker]

Some impressive cracks there.  :lol:

Unfortunately it is a problem and quite a few of the guys have already had to weld up cracks. The other place it often cracks is around the engine mounts.

[Slunnie]

Gday Baz, Do you know why it cracked, such as from an bodily, bumpstop or shock absorber impact or something that propogated from stress raiser like a weld or something?

[Slunnie]

Adam, is that a general problem or notable in the TD5 or v8?

[walker]

I have seen it on 2 others, they were both V8's

[Slunnie]

It really sounds worthwhile checking these parts, especially if they get used a bit.

[LRTD5]

The early D2's had a lot of problems with cracks arounf the steering box - I had mine welded up.  I'd not heard of cracks at the rear. Those look ugly.  When it stops raining I'll check mine

Cheers

David

[Redback]

Gday Baz, Do you know why it cracked, such as from an bodily, bumpstop or shock absorber impact or something that propogated from stress raiser like a weld or something?

Not really, i have hit some bloody big holes when travelling, one in particular on the road to the Dig Tree, and some pretty bumpy stuff in the Simpson from corner of the Rig Rd & The French Line through to Dalhousie.

What i'm annoyed about the most is that i didn't notice it when i took the bumpstops off when i did the springs :evil:  :evil:

As some may know i'm pretty hard on my D2 and i'm kinda thinkin that this along with the outback touring with a 1.3t trailer on behind and fully loaded in the rear of the Disco, has colmenated in the crack, also having bent the 2 crossmembers :evil:  :roll:  that too could have contribruted to the crack.

Baz.

[ianswalkingthedog]

Hi Baz,

Sorry about the cracks, but they can be easily repaired. The comment I would make is that it appears as if the crack has resulted from either an over loading of the vehicle, too high a tow hitch load, or you have hit the bump stop a number of times very heavily or a combination of all of these. The reason I say this is because from your pictures it appears as if the sides of the chassis box have bowed outwards and the two butt ends of the crack on the lower face are slightly curved upwards. This is similar to what hapens when you overload a box beam with a single load point. Imagine taking a square section tube and bending it over a brick. The face contacting the brick will curve upwards and the sides will bow outwards. Now if you were to do this a large number of times it would eventually fatigue and a crack appear. Of course once the crack starts if will fail progressively faster.

While this will not help you fix the problem it might be something for you to consider if the future.

[LRTD5]

I remember Mike warning once against getting the car up on a 2 point hoist when fully loaded

[Slunnie]

Hmmm. I also wonder what effect some good snatching has on this? I would have though it would introduce greater forces than towing or bumping around while laden.

[Redback]

Hmmm. I also wonder what effect some good snatching has on this? I would have though it would introduce greater forces than towing or bumping around while laden.

I've only snatched some twice so i think maybe Ian could be right, on our Simpson trip we were loaded up and on other trips too we have had a bit of weight in there and have bottomed out when the trailer has been on.

But since the new springs have been in it has been better with no bottoming out, with the trailer i will have to work out how to reduce the weight over the hitch, which is around 120kg, not really alot but when combined with the load in the back of the car could be a bit of a problem.

Baz.

[ianswalkingthedog]

Slunnie,

If you think about the direction of the loads applied during snatches it would suggest that the chassis would be pulled apart. The pictures tend to suggest that the chassis has been bent.

[Redback]

Well it's fixed $496 the other chassis rail had impact bludge like the
the cracked side, as discused it was felt that it was from impact the
bumpstops, also another crack was found this one was the front engine
mount.

It never ends.

Baz.

[Slunnie]

Slunnie,

If you think about the direction of the loads applied during snatches it would suggest that the chassis would be pulled apart. The pictures tend to suggest that the chassis has been bent.

Gday Ian, you're absolutely correct. After a reread I realised that that made perfect sence. It must have put one hell of a force through the chassis!

I guess I was considering some heavy snatching I'd done, and was thinking that surely the ball weight + load of a bouncing disco wouldn't be the equal of good hard snatches, but in hind sight when looking at the damage and considering the bending moment that had been introduced over the bumpstop area, that towing offroad will work the chassis very very hard, and possibly a lot harder than a linear snatch. Those springs in it now should help a fair bit to prevent further bending by absorbing a lot more of the shock though.