Steering knuckle centering gauge
- Thread starter kvhnry
- Start date
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4Cruisers
SILVER Star
Here's my stab at it - the tool ensures your axle shaft is centered in the housing and the oil seal. The knuckle housing caps, top and bottom, have shims/shim packs. Using the tool you can determine the right shim thicknesses to center things up. It's all explained in the FSMs.
Ah ok, So if i was just doing a rebuild could i just use the existing shims or is the tool required each time the hub is disassembled?
Also, what is the disadvantage/problem if its setup incorrectly?
I think from memory i checked the preload using a spring gauge and it was within specified range.
EDIT - And i am in too if the price is reasonable.
Also, what is the disadvantage/problem if its setup incorrectly?
I think from memory i checked the preload using a spring gauge and it was within specified range.
EDIT - And i am in too if the price is reasonable.
4Cruisers
SILVER Star
When I built a front disc brake axle for my '71 FJ40 that's what I did - just used the existing shims from the mini-truck donor in the same locations - I haven't noticed a problem. However, I recall seeing other posts where that approach didn't result in proper centering.
Montie Thomas
Cruiser42
The Steering knuckle gauge arrived yesterday. Hopefully the axle seal, bearings etc install goes well. I'll post an update when complete.
2fpower
SILVER Star
I don't know the answer here, but this is my thought.... the axles can be out of center and you would not really know it. The issue is the inner oil seal. If you aren't centered, then run the risk of wearing the seal on one side, and eventually leading to premature failure. Gear oil in your birfs and soup for everyone.
yes that's how I understand it too. if you are sure they were set up properly before you take them apart you can resume them if you keep the shims in the right orientation. (top on top and bottom on bottom of course). for me I'm building a new to me axle so can't trust the shims that I have with the old knuckles so I want to make sure they are centered properly. I dont like rebuilding knuckles very often because it's such a messy job. I want my inner seal to last as long as possible.
Montie Thomas
Cruiser42
I'm not sure if someone else had been into the axles / knuckles before me so I wanted to have the tool on hand just to check and to check bearing preload. If things aren't right I can then correct them. Hopefully I can just reuse the original shim setup.
Montie Thomas
Cruiser42
Another way to avoid premature axle seal failure, even if the axle is slightly off center / bent, is use Marlin Crawler axle seals. Very forgiving.
4Cruisers
SILVER Star
Thanks for the reminder - I'll definitely get some for my next axle build.
Montie Thomas
Cruiser42
I understand that the newer alignment tool version is to enable work on drum too. Someone correct me if I'm wrong.
DTSkyCop
SILVER Star
I would be interested if "The Price is Right!!!" 
That's the concept. If you measured your brass bushing ID, one of us could confirm the fit...
The adapter is added to fit the axle housing where the inner seal goes and is removed to fit the bushing in the spindle.
I just put mine to use and I have a couple of suggestions if these go into production that would make them work better. First off of the long bolt and the cylinders with the flats could be keyed it would make it easier to align the flats to measure. As it is now the cylinders turn with the nut and bolt making it a bit of a pain to get it all lined up. Also the plug that fits in the spindle bushing could fit a bit tighter. Even with new bushings it leaves too much play. In this pic you can see the extremes of the play on a relatively new bushing in the spindle. It's the top line. The fir to the housing is better than the fit to the spindle bushing.
I recommend new bushings if yours have seen some miles. I went with an average of the 2 more or less. The other thing is that the tool will not get you super perfect accuracy any way because there is now way to accurately measure the lines on the shaft. The best way I found was to use the back side of the dial calipers that are used for internal diameters. That way it is easier to see if your lined up. It also helps to have calipers with the thumb adjuster to
take this measurement. Anyway it gets you close enough to keep the bushing from wearing weird as well as keep the seal from leaking.
Pete
I just put mine to use and I have a couple of suggestions if these go into production that would make them work better. First off of the long bolt and the cylinders with the flats could be keyed it would make it easier to align the flats to measure. As it is now the cylinders turn with the nut and bolt making it a bit of a pain to get it all lined up. Also the plug that fits in the spindle bushing could fit a bit tighter. Even with new bushings it leaves too much play. In this pic you can see the extremes of the play on a relatively new bushing in the spindle. It's the top line. The fir to the housing is better than the fit to the spindle bushing.
I recommend new bushings if yours have seen some miles. I went with an average of the 2 more or less. The other thing is that the tool will not get you super perfect accuracy any way because there is now way to accurately measure the lines on the shaft. The best way I found was to use the back side of the dial calipers that are used for internal diameters. That way it is easier to see if your lined up. It also helps to have calipers with the thumb adjuster to
take this measurement. Anyway it gets you close enough to keep the bushing from wearing weird as well as keep the seal from leaking.
Pete
2fpower
SILVER Star
I agree with the play that exists with the centering gauge when you put it in both sides. I typically coat it with heavy grease hoping it is centered, however, I could see a slot cut into it that would allow you to put different width O rings to make up for any gap differential.
Any update on the reproduction of the tool?
Cheers
Cheers
It's down the pipeline a bit but we (Cruiser Outfitters) have been working on a low-cost replacement for the SST to offer along with our growing tool offerings. We've got a sample that we're tweaking and might need another revision or two to nail it but it's on the radar.
