80's chassis crack

[80's_delirious]

just found a small crack in the chassis rail beside steering box.
the crack is on the bottom corner of the rail about 40mm long,

do I just drill small hole each end to stop it cracking further and weld along the crack or should I plate over it?

where else are 80s prone to cracking?

[dumbdunce]

just found a small crack in the chassis rail beside steering box.
the crack is on the bottom corner of the rail about 40mm long,

do I just drill small hole each end to stop it cracking further and weld along the crack or should I plate over it?

where else are 80s prone to cracking?

this is probably the most common place for 80's to crack. it could also be the source of your creaking and groaning as the chassis twists more than its supposed to. I would remove the steering box and strip the grime and paint off the chassis around the steering box to see how far the cracks extend, it is not uncommon for them to go all the way around some of the crush tubes through the steering box mountings.

to plate or not to plate depends somewhat on the severity of the problem and whether or not it is possible to reach all of the crack(s) adequately with the welder. if you can reach all the welds, drill and weld. if you can't, drill and weld what you can, then grind flat and plate over. plate it thin if you need to plate it; excessively rigid reinforcing will just cause the chassis to crack again in another spot, usually right next to the reinforcement.

cheers

DD

[80's_delirious]

cheers DD

seems to be just one small crack, though will check thoroughly. I knew there is pros and cons with plating, you reckon its better not to if possible?

Dave

[dumbdunce]

yes better not to plate if you can stop drill and weld the whole crack, if you plate it you have a short, rigid section of chassis so the normal flexation of the chassis will eventually cause it to fail somewhere else.

[mud4b]

yep as dumbdunce said, it is common as hell.
also check your panhard mount as it cracks too.

cheers mark

[T-rex]

i'll putting a 5" lift on my 80 this weekend, what should i do to prevent this cracking or just wait till it happens.
any help appreciated.
Thanks Troy

[rezpkt]

steering box cracks/stress is almost a guaranteed problem on the 80 i hear.

hijack: i have also found a crack on engine mount bracket off chassis, how to go about this one?

As I am only just learning welding and although i'm confident with my welds not sure how to approach this one and giving it a good penetrated/non-contaminated weld given it's circumstance.

Good heat?

[80's_delirious]

steering box cracks/stress is almost a guaranteed problem on the 80 i hear.

hijack: i have also found a crack on engine mount bracket off chassis, how to go about this one?

As I am only just learning welding and although i'm confident with my welds not sure how to approach this one and giving it a good penetrated/non-contaminated weld given it's circumstance.

Good heat?

do you mean the bracket that is bolted to the engine? if its this I reckon spend the time to remove it so you can clean it up and weld it in a comfy position.

If your talking about the bracket thats part of the chassis, might be worth removing parts around the area if access is no good. clean it up as good as you can and grind or scrape off paint where you need to weld. if the area is really greasy might be worth grinding out the crack a little bit with a thin cutting disc

disclaimer: Im a chippy, definitely not a pro welder, but this works well for me. some of the crew here might have different tips

When I have to weld something critical I do some test welds with scrap of same thickness to make sure penetration is good first. adjust your settings until you get a good weld on cold bits of scrap.
If the crack/weld is vertical I start at the bottom and weld upwards, about 10mm at a time. weld pool will want to run downwards, welding from bottom up means if the weld pool runs it runs to where you have already welded and wont cover where you are trying to weld, so you should still get good penetration. by welding in short bursts with only a few seconds pause between welds ( im assuming you have a mig) it allows weld pool to cool slightly without the steel around it cooling out completely
doing vertical welds sux!! if at all possible move the part so you dont have to weld vertically (bit hard with a car chassis) practice a couple of vertical welds with scrap.
be careful where you lay under the chassis while you weld it otherwise. . . . burnies

[T-rex]

Has anyone got a picture of how they plated their chassis and is it wise to fully weld the crush tubes on the steering box?
Thanks
Troy

[Shifta]

If you are going to weld the chassis, DISCONNECT THE BATTERY and clamp the earth as close to the weld area as possible.

[T-rex]

Too late i have a crack in between the steering box and panhard mount running parrallel with the chassis.this truck has only had 31" on it and still has a crack. so should i just weld it up and keep an eye on in it? bit worried about running 36" centerpedes on flipped rims.
any thoughts.
Troy

[80's_delirious]

yes better not to plate if you can stop drill and weld the whole crack, if you plate it you have a short, rigid section of chassis so the normal flexation of the chassis will eventually cause it to fail somewhere else.

use a small drill bit about 2-3mm, drill a hole through the chassis at the very end of the crack at each end. the idea is that the round hole relieves the stress and should stop the crack traveling further. learnt this trick with cracked alloy dirtbike rims worked a treat with them.

after drilling holes weld along the crack. I think the weld should be stopped just short of the holes you drill.

Ill be keeping an eye on mine, I think its not uncommon for cracks to re-occur beside welds