Welding to an axle.

[mumad]

Hi all, about to remodel the rear suspension on my mu.

Was having a look and the plates that the springs pull upto on the axles are cracked and shagged in general, so i wanna weld some new ones on.

What should i do?? drain the oil out, and pull out the axles, bearings etc, or can i do it with everything in place??

Also should this really be done by a certified welder??

All comments and help appereciated, Thanks, john.

[tristanp]

if your welding on your axel tubes you really should get someone who knows what they are doing. if its not done right (preheating / right rods etc) the steel will crack beside where you have welded.

[mumad]

Oh ,so its not as simple as just stiching them on with the mig or gp arc rods then??

[wopass]

if your a half decent welder and confident you can do it, grab a hand full of amps and burn some rods arc it with 77's they are good for everything and anything ... i wouldnt worry about stripping it down personally but... i work on a 36yr old cruiser so

[tristanp]

id at least use low halogen rods and preheat (so its warm to touch)
sqirting with the mig will work , but it will create a weak point on the side between the spring and the axel, you could also throw in a gusset ot two to help spread the load with 1/4" plate

[mumad]

I think i might try to pull the whole thing apart, and check the bearings and seals whist i'm stuffing around with it, the gussets sound like a good idea, thanks tristanp, the plate will be hard up against the bottom and will be sort of like a channel about 120mm long that will have holes in the sides so that it kind of wraps around the axle, basically a heavy dutie version of whats there.

Thanks for the help guys, anyone got a good idea of doing it another way???

[eatenfuller]

low hydrogen rods i think tristanp ment and using low hydrogen rods is overkill and why an arc??????????and why pre heat cumon were not hard faccing a d11n cat shovel are we?????

mudmad, just strip the diff all seals out etc and just mig it but id be using a machine around 200 amps plus

[SupraLux]

Yep, theres no tin cans in the rear axle of a MU Why pre-heat and use special rods tho? The axle tube is probably just mild steel tube. I accept that you MAY get a weak spot beside the weld, but the early MU spring pads are virtually only tacked on from memory anyway. Just don't go mad, get good penetration, and watch the inner seal with the heat. (Inner seals are about $17 each, just replace em).

Good time to do a spring-over I'd say, and I have a set of those 50mm lifted Isuzu springs here too if you are still keen to swap them.

Steve

[mumad]

Thanks guys, i thought it would be pretty simple. i have a 350 to 400 amp mig i can use at work so the amps arn't a problem, and yeah, the factory ones are just tacked on, its the actual plate that is cracked, not the welds, so there is enough weld on there.

thanks steve, you have got me thinking, what benifits would a sring over give me??

Would i have to get it all certified?? the way i'm gonna do it means the garage won't even notice it so certification is not a worry.
Say i got a set of springs then i would only need them to be standard height, and it would give me more clearance under the axle, but the diff is there anyways, but as i don't need the extra height i could go a lighter spring pack which would give me more flex.

I only want about a 2 inch lift anyways, 3" at the max so how much would a spring over give me???

Would i need to space the gear/transfer box down a bit?? or should ui go a set of falcon springs??
Dam you, steve, you have given me so many questions now, i hope you can answer them!!!

Thanks very much for the offer steve, but I have a cheap set of springs lined up from my mate who works at repco, am buying a set of efs ones off trademe for a guy too so i will be able to look at them when they arrive.

[SupraLux]

thanks steve, you have got me thinking, what benifits would a sring over give me??

First - you get rid of the underhanging rubbish. Have a look at this, although I'm guessing you have already seen it.
http://www.4x4wire.com/isuzu/tech/SOA/

Now the lift: Well, lets say the centreline of the axle is at point A above the ground, and you move the axle from on top of the pack to below it. The tube is around 3" across, and add 1/2" for the spring plate. If we then say the spring pack is 1" thick, moving the axle below the pack moves the centreline down 1.5" + .5" + 1" + .5" + 1.5" (half the tube dia + spring pad + spring thickness + new spring pad + half the tube again) = 5" lift approx. In reality with your existing springs that will be more like a 3-4" lift over factory - something you can balance in the front by tweaking the torsion bars and with a balljoint flip, and bumpstop trim.

Would i have to get it all certified?? the way i'm gonna do it means the garage won't even notice it so certification is not a worry.
Say i got a set of springs then i would only need them to be standard height, and it would give me more clearance under the axle, but the diff is there anyways, but as i don't need the extra height i could go a lighter spring pack which would give me more flex.

Yes, it will need cert - you'll also need to remount the shocks after the spring over, which means you can fit longer ones to fully utilise those folding shackles you made. GQ rear poo-troll ones would be a good choice for length and they have the same mounts as MU's.

I only want about a 2 inch lift anyways, 3" at the max so how much would a spring over give me???

Leave it as-is then... This will lift it 3-4" approx.

Would i need to space the gear/transfer box down a bit?? or should ui go a set of falcon springs??
Dam you, steve, you have given me so many questions now, i hope you can answer them!!!

Well, I'd probably leave the coon springs out of the equation due to their length and flatness, I'm not sure the would suit the MU. I looked at fitting them, but decided to just go with lifted standard Isuzu ones. I'd also not bother spacing the T/C - just drive it and see how it goes - if it needs it do it.

Hope this is answering the questions .

Steve

[mumad]

Thanks steve, i knew you would be an expert about this. Yeah, i looked at that article, it kinda put me off, i really don't want that much lift, so i'm just gonna buy some cheap springs from repco and set up the back eend with them for a start off, and i'm gonna mount the shocks the way they are in that article, since i have to weld to the axle anyways.

So thanks very much for your advice and wisdom, i'll put up some photos when its all done

[tristanp]

thanks eatenfuller for the correction, im pretty hard on my gear, so i like to make things as strong as poss