switchhoodrider

i am doing a swap on my 90 and i got an axle off of an 80 truck and i'm wondering

1) why does my axle have blue hubs instead of red hubs,

someone told me that it's lower geared but i had a hard time believing that

2) is it true that i can use rear stock springs instead front lift springs, cause i have an extra set

3) ihave the steering box and everything off the 80 , so i was wondering if i should do the box swap with everything or should i make my own high steer kit, cause i can't afford it

4) and any other little tips that anyone knows would be great, thanks guys

Elton

could be painted or there superwinch got any pics ?

switchhoodrider

no, i'll get some picks on there tomorrow though, thanks for the fast reply

switchhoodrider

but it's not just paint i know that cause i tryed chipping it off and it was prety tuff

d0ubledown

1: maybe blue is sfa hubs, and red is ifs hub? i know grey are taco hubs..

2: yes.

Elton

they look like this

Elvota

I realize some of this may sound a little condescending, and I am not trying to come across that way.

That said… seems like you may want to do a little more research on the SAS before you get too much further. You are going to need a few parts and if you are already worried about the cost of a high steer you may want to re-evaluate your budget

1: Not sure about why the hubs are blue, but they seem to be Aisin, which is very good. Hubs won’t effect the gearing though. You will need to verify that the front axle will match the rear in terms of your gear ratio or you will be in trouble when 4WD is engaged. I think you will find you need a new gear set for the front axle. Also remember that the ’80 axle is narrower than the ’90 rear… so you will need wheel spacers or other option to compensate.

2: Rears will work in the front, but you need a pretty thorough understanding of how they will effect your caster, pinion angle and axle placement (wheelbase) and make sure you make adjustments with your install to correct for these. Parts you have are free until they mess up the rest of your conversion and require extra costs to correct.

3: You want the IFS box from your ’90. Marlin and others make pitman arms and high steer kits for that box. Be sure your fab work is fully up to the task if you decide to design and make your own steering. Remember that you may not be the only one affected if your steering fails. Respect the safety of others.

4: Tips…. Get a complete SAS kit from Marlin or other source unless you have done a swap before. You’ll save money in the long run and end up with a quality well performing suspension. If you decide to just piece this whole thing together on your own I think you will find a lot of hidden expenses such as wheel spacers, new rotors for the IFS calipers, seal kit and bearing for front axle, brake lines…. you get the idea.

Have all structural welding done by a qualified, experienced fabricator. Maybe that is you, but any doubts spend the extra to have things done right.

A ’80 axle wont have much (as in none) of a truss from the factory, so I would be sure to have the housing gusseted before you start while everything is all apart.

Search “SAS” here or on the web for tons of info and be sure you fully understand the extent of the project. So many have been done it seems rather easy. Even though you won’t be reinventing the wheel following in others footsteps, you will still have a big job in front of you that you will want to do correctly.

I sound like an old man.

Robinhood150

Ditto everything that Elvota said.

You have a lot more research to do before you start down this road. The reason you need to search about this topic is that there is way too much info on sas's to post in one place.

bodo

I was always told blue hubs mean 4.10 gears I think I even read that in a magazine, but it's been along time and I'm not saying that is a fact. I do know the earlier trucks up to 83' had blue hubs. You can run 4.10 in the front and 4.11 in the back without hurting anything.

sschaefer3

Now for the old man who helped you.

1979-1980 had hubs marked ASCO, not Aisin. ASCO = Aisin Company.

You might also have aftermarket hubs. Superwinch, etc.

As for the steering box, you don't want to put that push pull box on your truck, you want to use the IFS box that is there and save up to buy the incredably cheap Trail Gear High Steer.

Yes stock rears will work on the front but they are not the same length as stock front leafs and you will have to adjust your hanger accordingly.

79 is the only year that has no truss, 80-83 have a truss that stops at the leaf srings, 84-85 go past, big deal.

Also What Elvis Said.

switchhoodrider

ok, thank you everyone expecially elvota, luckyily i was wheelin last night and ran into a guy thats dont 3 or four swaps and my dads been in the garage door business for 30 years so i'm gonna put a new garage door in his house and he is gonna help me with all the fab stuff, thanks

dcg9381

One thing that's critical to the SAS swap is to determine how much lift you're going to run. Once you do that, you can decide if you need to correct your pinion angle.

If you correct your pinion angle, you'll be messing up your castor which can result in "death wobble".

The right way to resolve it is to cut and rotate the axle ends, as well as remove and reweld the spring mounts. It's a @#$@#$ and it has to be done in a very precise manner.... If you've got a "low" SAS, you don't have to worry about it as much, although your pinion angle won't be optimal.

switchhoodrider

can't you shim the leafs, but i'm gonna do 4 to 5 inches, and whats this death wobble, where does it come from?



and i've decided to wait a few weeks and buy the high steer kit, cause it will be way worth i

switchhoodrider

also, can i get brake lines that match up to the old calipers or do i have to do the fj swap?

dcg9381

Figure out what castor is and why it's part of the allignment process.
IE - Castor sets the steering plane slightly up from horizontal.. It helps make the wheels "self center". Without it, steering becomes unstable and dangerous. Google pirate4x4 and "death wobble".

You CAN shim the leafs, absolutely.. If you shim the castor, make the pinion angle worse. Best case: vibrations in 4wd when turning that driveshaft. Worst case: driveshaft will bind up and you'll be SOL. I 2nd transfer case helps, as it decreases the angle to the pinion.