Looking for a better method of centering the steering knuckles?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Got it! So with the factory tool it would be spot on because you're scribing to the steering axis. With the other methods discussed here a correction for the one degree over the distance from steering axis to face of target would be needed. Hey! What if the face of the target was extended out to the steering axis?
 
There is the same problem for the OEM tool, but since they are scribing the line on a bolt that does through the bearings, there isn't much offset from the steering center line. One way would be to extend the target, but it is also simple to calculate the offset by simple trigonometry and apply a correction factor to the measurement.
 
Ah! I didn't think about the bolt radius But like you say it's a small amount. Boy! What ever route I go when I do my knuckle job I'll have a much better understanding of the centering. Thanks.
 
If the distance from the steering CL to the seal target is 100 mm, then the 1 degree camber line would hit the target 1.7 mm high. , which is .065 inch. That is a lot of error and it is not mentioned or compensated for in the Pirate tool. That is because the guy assumed that the bore axis was in line. He was not a front end alignment guy.
 
Hi All
Reading this thread makes me ask the question Were do you buy the Toyota genuine Tool?
I have asked Toyota Australia but have been told not available to any one other than dealers.
Any ideas?
Cheers Peter


...via IH8MUD app
 
Pin_Head said:
If the distance from the steering CL to the seal target is 100 mm, then the 1 degree camber line would hit the target 1.7 mm high. , which is .065 inch. That is a lot of error and it is not mentioned or compensated for in the Pirate tool. That is because the guy assumed that the bore axis was in line. He was not a front end alignment guy.
Click to expand...

I get your math, and here is what I have concluded after rebuilding a lot of these axles: if there is in fact a 0.065" difference in the inner axle shaft @ the center-line of the trunion, it is not enough to cause a leak. Furthermore, when aligning the axle, there is a 'sweet spot' where the spindle will gracefully slide onto the knuckle. While there is some minor room that the spindle needs to compress, making any adjustments up or down makes the spindle improperly align. This, mathematically is a margin of 0.04", because the smallest shim is 0.02", allowing for alignment within a 0.04" margin.

While I'm not one to usually disagree- on solid axle alignment, 0.065" is nothing, expectantly over any kind of distance.
 
I don't know how much misalignment the seals will tolerate, but if they can take .065 then that is pretty easy to work with. The point is that it can't hurt them to be more perfectly aligned, so you might as well take the geometry into account and use the .065 inch correction factor when estimating the shim thickness. Like you said, the minimum shim size is .020, so it isn't rocket science.
 
Pin_Head said:
The 1 degree misalignment comes from the +1 camber setting. The outside end of the birfield is pointing down by 1 degree from the axle shaft and the intersection is at the center line of the steering axis. It is built in to the axle housing and knuckle assembly.
Click to expand...

I'm confused about this.... I had always thought the shims were there to ensure correct centering of the axle and had nothing to do with caster as the shims are of equal thickness from front to back and adjusted the axle up and down in the axle housing. So would it be correct that adjusting the shims on the top or bottom could (in some small way) correct caster angle problems?

On a similar note, why are shims needed? From that I mean why is there variation in the axle position from the factory? Do all solid axle front end vehicles all use shims like the land cruiser/mini trucks?

As you can tell, I'm pretty ignorant about all of this but I just like to ask questions.

Thanks for any info.

best, ty
:beer:
 
Yes, the shims are only to center the axle WRT the seal.
They have nothing to do with caster.
The camber built into the knuckle assembly only effects the ability to measure the centering accurately.
80 series axles no longer use shims to center the axle, apparently because the manufacturing tolerances are better.
 
I've read many times that the alignment is basically to center the axle and seal. It seems to me that more importantly is to center the axle in the bushing that resides in the housing. Am I off here?
 
Lots of good info here. I ended up having a machinist at work duplicate the pirate tool. Once I finally get around to finishing out my disc-brake swap I plan on using it to center the axle since I can't seem to get the SST over here...

-Geoff

P1030540.webp

P1030541.webp
 
You must log in or register to reply here.

Share this page

Back
Top Bottom