Knuckle Centering Tool Use help

[Brice Noonan]

Hello,

I've got a Trail-Tailor KCT I'm trying to use. A few questions.
1) Instructions suggest it is necessary to remove the birf oil seal. However it seems the 'plug' of the tool (which marks the rod) fits inside the seal perfectly. Remove or don't? (seal only has 20 miles on it).

2) Measurement A (photo from instructions below). This illustration is not clear (calipers and spread of "A" lines are not measuring the same thing). The only YouTube video I have seen does not clearly show (and frustratingly obscures view with his forearm). Any insight as to what points in the photo below are to be used for measurement of A? Looks like it could either be 1-6 or 2-5. Any help?

.

 

[hobbes]

Coolerman has a write up in the FAQs.

Steering knuckle centering tool instructions (FAQ)

OK I thought I would post some pics here of this procedure with the tool. Fellow Bluegrass Cruiser member bought the special shim determining tool and invited me to help him do the procedure. Pic 1: Install the scriber part of the tool inside the axle housing then mount the rod assembly...

forum.ih8mud.com

 

[Brice Noonan]

Ahhh! That write up is super helpful! Unfortunately he forgot to take the photo of measurement A I’m wondering about.
From his description it sounds like from 2-5 in my photo (those otherwise useless ledges on the top and bottom of the tool). Can anyone confirm?

 

[smokeater]

That would make sense and account for the cutout on the shoulder to accommodate the caliper. I thought I read something in that thread the other night where someone mentioned or referenced the missing picture. I'll look and report back.

 

[smokeater]

The missing pictures were not the correct reference to measurement "A." After reading a few more posts, #36 gets into some of the differences found in aftermarket tools, which is not important to this conversation, but he mentions in the last paragraph of the post about measurement "A" correlating to your distance 2-5. Would you agree?

 

[Brice Noonan]

Ive gone through that thread, which thankfully gets into some hefty detail. You are correct that is not the right missing photo. I think I agree and will move forward with measurements but hold off on install until tomorrow in case someone else weighs in. Thanks!

 

[ArizonaFJ]

Woo-hoo! I get to be the first to post a solid, been-there-done-it answer. 2-5 is correct. I just did this a couple weeks ago and also had to search Mud for some help.

 

[Brice Noonan]

Thanks ArizonaFJ!

 

[Brice Noonan]

EDIT: So it turns out it matters which direction you insert the bolt into the knuckle. Sorry, but keeping this here to help others that do the same. If you measure 0 for D, flip the tool around inside the knuckle. Doh.

OK, another issue that I am now facing: Measurement D (between the 2 score lines) is essentially zero. See photo of scribed lines. I can't even differentiate one from the other. Any suggestions? Should I just move forward with D=0?
(NOTE: A sharpie paint pen works for marking the tool and comes off if cleaned quickly with mineral spirits)

 

[ArizonaFJ]

I'll bet you're doing the same thing we did and swapping position of the arm the spring scale attaches to. IE, it's under the head of the "bolt" when you measure the axle housing but then under the nut when you measure the knuckle, or vice versa. The arm must be under the nut each time. Putting it under the head moves the bolt in relation to the center of the axle housing/knuckle. You're not the first to make this mistake (nor was I), it was a quick search to find someone else who had, and solved, the same problem.

 

[pbgbottle]

i always found the tool to be very generic i could measure a million times and depending how i set it up i got a different reading every time . not sure what i did in the end ,, i know i bought Toyota oem shims ,super nice compared to the cheap ones you get int the knuckle kits , and I used the marlin heavy duty seal been leak free for about 8 years , i was always under the impression that that tool was going to set me up with a precise or exact tolerance setup , but there was nothing precision about it, i measured a million times before bolting it all back together , i guess it worked as no leaks yet to date ...

 

[Brice Noonan]

Hi @ArizonaFJ,

Interesting. No, what I was doing was sticking this bolt into the knuckle from the wrong side. Sticking it in from the right side allowed me to measure a distance (nearly 4mm), if I put it in from the other direction the lines matched up perfectly (=wrong; as in the photo above).

When mounting on the knuckle, the spring scale arm is not used at all, right (see below; this photo also shows the same scribe line that was made on axle, but now inserted the other direction).

I'll bet you're doing the same thing we did and swapping position of the arm the spring scale attaches to. IE, it's under the head of the "bolt" when you measure the axle housing but then under the nut when you measure the knuckle, or vice versa. The arm must be under the nut each time. Putting it under the head moves the bolt in relation to the center of the axle housing/knuckle. You're not the first to make this mistake (nor was I), it was a quick search to find someone else who had, and solved, the same problem.

 

[Brice Noonan]

Here is the photo of setup on axle end where I took measurement "A". When taking measurement "B" on the knuckle itself (the shim seats) the KCT is not used at all.

 

[ArizonaFJ]

Hmm, makes me wonder why we had the spring scale arm mounted when measuring the knuckle. Probably beer, or lack there of. We had to do this twice actually. The first weekend was during "dry March". Our measurements didn't make any sense. We tried again the next weekend, drank beer and everything went perfectly. Lesson learned.

 

[Brice Noonan]

Hah, yeah, perhaps the 2nd time you didn’t mount the arm? Inclusion of the arm under the nut would definitely throw off the distance between the two scribed lines, making the distance smaller. Glad it worked out in the end.

 

[hobbes]

I’ll be doing this soon for the first time. What do you mean by “right side” versus “wrong side”? It’s not clear to me. Thanks...

 

[Brice Noonan]

Yeah, I realized that wasn’t particularly clear when I wrote it. Sorry.
Basically, when you make the first mark, and then go to the knuckle to make the second one, make sure you insert the ‘bolt’ through the bottom of the knuckle (in the same bottom-up orientation as when taking measurement “A”).
I had made the first mark with the bolt inserted bottom-up on the axle end, then top-down on the knuckle. That does not work. Was easy for me to mix up because with the knuckle on the bench, top and bottom were not obvious to me.

 

[hobbes]

Ok. That makes some sense. You have to keep the orientation the same for both measurements. Thanks.