Weling Spring Perches

[Stinky]

On my '86 2wd Nissan PU, I want to change the axle ratio and the easiest way to do it is change the axle. I have an axle from a 4x4 PU...totally dif, but it is slightly beefier and is 10% lower.

The spring perches are totally dif.

Not a big deal, or is it.

My friends say that the perches need to be very precisely welded on....that they have to be welded on just so. I'm thinking that it ain't no big deal, just put them on and weld them on w/a weld that is similar in size and etc as the factory weld (say 1/8" 7018 or a MIG).

BTW, I am gonna tack it w/my 110V Flux core and the take it to a shop for the final beads.

I am not talking about alignment of the perches. I am talking about the metallurgical bond that is used to affix the perches to the axle.

What do you think?

[Auto Affair]

On my '86 2wd Nissan PU, I want to change the axle ratio and the easiest way to do it is change the axle. I have an axle from a 4x4 PU...totally dif, but it is slightly beefier and is 10% lower.

The spring perches are totally dif.

Not a big deal, or is it.

My friends say that the perches need to be very precisely welded on....that they have to be welded on just so. I'm thinking that it ain't no big deal, just put them on and weld them on w/a weld that is similar in size and etc as the factory weld (say 1/8" 7018 or a MIG).

BTW, I am gonna tack it w/my 110V Flux core and the take it to a shop for the final beads.

I am not talking about alignment of the perches. I am talking about the metallurgical bond that is used to affix the perches to the axle.

What do you think?

I find your verbiage a bit difficult to follow. I suppose it is the younger set's shortened or condensed version of language? Does your term "dif" mean different, or differential in that you mention a rear drive axle in a rear wheel drive vehicle? How do you mean "10% lower". I don't see much how the physical height would be a factor; or do you mean gearset ratio for final drive reduction?

Regardless, if you are wanting to swap rear axles just cut the existing spring perch pads off the axle you wish to use and replace with a set marketed by Summit Racing or Jeg's which are readily available. Clean up the axle tubes where the new perches are to mount and slide the axle under the truck, (I'm assuming the old axle is already removed). Place the axle in close to the proper location, loosely set the new spring perches onto the axle tubes, lower the truck down to rest the leaf springs onto the perches, loosely install new "U" bolts, lower some truck weight onto the new rear axle, align the universal joint and pinion angles to what is required, lower the rest of the trucks weight onto the spring perches, snug up the "U" bolts and tack weld the spring perches into place. Now, remove the axle from the truck again and have the new perches solidly welded if you are not confident in you ability to safely install these and reassemble.

It really is not rocket science to do what you want but the pinion and driveline angle must be correct for the driveline or it's components will have a very short lifespan. You will also have to correct for speedometer inaccuracy due to the gearset ratio being different.

Both the axle tubes, and the replacement spring perches are of mild steel. You will no special material to do the work. Can't count on five hands the number of times I've done this building dirt track cars and working on semi trucks. Just ensure you have good jack stands, and USE THEM!!

[MAC702]

I've never done spring perches with anything more precise than a tape measure, and it's just steel. Weld it.

[Stinky]

Well, I think that I am gonna weld it w/my 110 fluxcore.* I don't doubt my ability, I doubted the processes ability.

But, I hear that the housing is only about 1/8" thick.* I've welded a ton of things that thick...including a flying machine (sand-rail).

Thanks for the tips.

AutoAffair...I'm over 50.

Dif=Different, as in, "What's the dif"?

As a side point, the shock brackets bolt on, they are the bottom bracket for the U-bolts.