Toy Knuckle alignment tool...

MIG'DHORSE · Apr 9, 2008

how necessary is this tool? i understand it's part of "building it right" ...but do i need this? I'm building up a front end right now and i've pondered this possible problem. thanks in advance!:awesomework:

Turtle Bite · Apr 9, 2008

If you keep track of where the stock shims came from and put them back in the right spot you dont need it. I had parts from a bunch of different axles so I bought an used it, and the front seals lasted two years without leaking. Before it really was only a few trips.

skrause · Apr 9, 2008

Turtle Bite said:
If you keep track of where the stock shims came from and put them back in the right spot you dont need it

IF, and only if, you're also reusing the original arms... Put new arms on there and the trunion preload goes out the window.

MIG'DHORSE · Apr 10, 2008

hmmm... i see. well considering the fact that these are new bearings, knuckles and arms, ill be needing this i guess. damnit. thanks, guys.:beer:

JThompson · Apr 10, 2008

Thanks for asking this question. I have been wondering about the necessity of this tool for a while now...

I am just lucky, I guess. I took an old rusty axle, tore it down, bought all new shims, put high steer arms on it, and after about a year, still no leaks. I was really afraid of this problem, and I must have missed it somehow.

And, yes, I do have gear oil in there!!

84Toyota4x4 · Apr 10, 2008

I heard a rumor that the lower shims were mostly for alignment, the uppers for preload. I ended up using the same lower shims, and just changed the top ones to get the preload right, and it ended up working out for me also.

~T.J.

Mock Knight · Apr 14, 2008

MIG'DHORSE said:
how necessary is this tool? i understand it's part of "building it right" ...but do i need this? I'm building up a front end right now and i've pondered this possible problem. thanks in advance!:awesomework:

T-Lo I have a pull scale, remember you I used it when we put my front end back together.....

MIG'DHORSE · Apr 14, 2008

oh word.

wentz912 · Apr 20, 2008

so if a guy goes to crossover with new arms and the like, he HASto get the tool and set it up this way? What exactly will happen if he doesn't?

MIG'DHORSE · Apr 20, 2008

wentz912 said:
so if a guy goes to crossover with new arms and the like, he HASto get the tool and set it up this way? What exactly will happen if he doesn't?

his head will spontaneously combust.

MIG'DHORSE · Apr 20, 2008

nah i think he has a higher chance of worn tunion bearings early on.

Turtle Bite · Apr 21, 2008

skrause said:
IF, and only if, you're also reusing the original arms... Put new arms on there and the trunion preload goes out the window.

Huh I never thought of it that way but true. Hopefully the highsteer arms have pretty close tolerances though.

84Toyota4x4 said:
I heard a rumor that the lower shims were mostly for alignment, the uppers for preload. I ended up using the same lower shims, and just changed the top ones to get the preload right, and it ended up working out for me also.

~T.J.

Nope, both top and bottom affect preload and alignment equally. If you take all your bottom shims out you lose your preload, take the top shims out and the knuckle moves up.

64FJ40 · Apr 21, 2008

MIG'DHORSE said:
nah i think he has a higher chance of worn tunion bearings early on.

The alignment tool has nothing to do with the trunion bearings. The shims are used to set the bearing preload, which is the only thing that affects the trunion bearings.

The alignment tool is used to correctly position the knuckle housing vertically and the only reason for this is for the longevity of the inner axle seal. If the knuckle (and, hence, the birfield) are too high or too low, there will be "excessive" wear on the seal since the inner axle will not be exactly centered.

I put quotes around the "excessive" because in all reality, most of us end up rebuilding our front axles on an interval that more than makes up for the shortened lifespan of the seal. IIRC, Marlin is selling a super-duper seal now that further improves the longevity as well.

Somewhere I have a scanned copy of an article on an alternate method of alignment using a dial indicator and measuring at reference points from the front face of the knuckle, but I'd have to look on my home computer.

My take is that if you split the shims half-and-half (top and bottom), 99% of rigs will work just fine and you'll never know or care if it's correctly centered. I will go through the extra effort on the wife's LX450 just because it's full-time 4wd, but for a part-time (or trail only) rig there's no point in dropping an extra $100 or spending the extra time required.

Trailtoy1993 · Apr 22, 2008

skrause said:
IF, and only if, you're also reusing the original arms... Put new arms on there and the trunion preload goes out the window.

No ****, I found that out on the 82 this weekend!!!!:redneck:

64FJ40 · Apr 23, 2008

Found the article about the homebrew setup - pics below. Save them and zoom in. BTW, the SST is on backorder right now from OTC-SPX. End of May ETA.

MIG'DHORSE · Apr 23, 2008

thanks, fj40 for the tech. nice work!:awesomework:

Pook · Apr 24, 2008

Brian at Diamond Axle told me that if your knuckle balls are straight (mine where since they where new housings) you can get it damn close with a stock thick shim bottom and a two aftermarket thick shims top.

He said they've uses the SST many times on straight housings and pretty much all came out the same.

Change just the top shims for the preload.