Solid axle rebuild

[2ndGenToyotaFan]

I'm going to start rebuilding a spare axle for my dad's 84 mini, but I wanted to ask about the replacing of the steering knuckle bearings and shims and what is the way to do it without all the SST's.... As far as preload and centering is concerned.... I have the FSM on it, but dont' feel like spending $$$ on the SST's....

Thanks for any tips. And I'll take lots of pics as usual!

Edit: It's fine to reuse the shims that are in the knuckles as long as there is not excess play to begin with. Just make sure you keep them where they started; Driver top/bottom, and Passenger top/bottom.....

 

[WristPin]

you can use a fish scale to test preload.

 

[2ndGenToyotaFan]

So do people usually just reuse the shims that are there, even when installing new bearings? If preload needs adjustment, should the shims be changed equally between the top and bottom, or one or the other?

Edit: The shims on the lower bearing cap set the center line for the axle, the shims on top set the bearing pre-load.

 

[Full_M3tal]

So do people usually just reuse the shims that are there, even when installing new bearings? If preload needs adjustment, should the shims be changed equally between the top and bottom, or one or the other?

Kinda... Use The New Ones That Come With The Rebuild Kit. But Use The Same Size As Your Old Ones. Then When You Get It All Together, Don't Fill The Nuckle With Greese. Until You Have The Preload Right. Meaning You Might Need Some More Shims, Or You Might Need To Take Out One.


On Mine I Put The Same Size Shims In. And Tried To Turn It Will Just My Hand And It Was To Tight. So I added Some More Shims Until It Was Nice And Smooth. But Not To Smooth. I Did Not Have A Prelod Scale. I Just Did It By Feel. And I Have Not Had Problem With It Since.


I Hope This Helps


Thanks Cameron

 

[RVBtruck]

Using the original shims is always a good starting point. Always a chance of change from original, but it will be close. the pinion should turn smoothly by hand, and definitely not "free spin". They aren't too picky but it needs be close. I haven't used a fish scale, although I would assume it should work.

good luck

 

[KY854RUN]

Originally Posted by 2ndGenToyotaFan
should the shims be changed equally between the top and bottom, or one or the other?

The bottom shims ONLY center the knuckle in the housing.

Your top shims set your preload

 

[2ndGenToyotaFan]

Thanks for the tips, I spent today tearing it apart.... 8 hours including pulling the axle out of the parts truck and getting everything cleaned up pretty good. I should have some pics tomorrow night.

 

[KY854RUN]

Yes, you want the shim thickness to be equal, top and bottom.

Jerod,

I was wrong in my post above. I had been given incorrect information. The shims can end up having a different thickness top to bottom. Read the FSM carefully. If you label each shim for the location where it came off and match the thickness of the new shim to the old ones then you should be good.

Here is the post by Shipwreck in the 40-55 tech section that set me straight.

Originally Posted by 67azcruizr
Kevin, the bottom shims ONLY center the knuckle in the housing.

Your top shims set your preload

consequently you could have different shim(s) thickness on top and bottom

This is exactly right!

There is alot of misinformation in this post. For anyone who has never used the SST and doesn't quite understand how it is used look here:

http://www.ih8mud.com/tech/knuckle-c...ering-tool.pdf

The tool allows you to measure the difference between your bearing seats and outer knuckle to determine the total amount of shims needed to set knuckle preload. It then measures the difference between inner axle centerline and spindle centerline to determine the amount of shims needed to center the two.

Using the fish scale only helps you set knuckle bearing preload. It does nothing to help you center the axle and spindle.

Bottom line - As mentioned above, keep track of your current shims and replace the same thickness shims in the same locations when you service the knuckle and you will probably be golden. If you have had a history of bushing wear, leaking inner axle seals, or you don't trust the previous owner's work, then borrow the SST and center the knuckle.

 

[2ndGenToyotaFan]

I edited it so you look like the smart guy, Kevin! No misinformation here! Hehehe

 

[KY854RUN]

Thanks!

 

[2ndGenToyotaFan]

Alright!

Step one, Put the new knuckle bearing races in the freezer, overnight (I can't say this helps a lot, but I can say that putting them in was just hard enough, so I would not want to try without freezing them)

Then take everything apart! I fount a small cold chisel helped get the cone washers out. The only thing you need to watch is that you label and keep separate the upper and lower shims on both sides, for reasembly later. If you get them confused, there is a TEQ round emblem pressed into the upper part of the knuckle where the shim sits. This will usually leave a mark on the shim where it has rested. If you get them mixed up left to right, you may have to guess and check. Lucky for me all the shims were the same size, and much thicker than those included with the rebuild kit... whatever that means.

Step two, Clean...... then clean some more..... I found that a wire wheel on a drill helped a lot! I went through about 4-5 rolls of blue shop towels.

This axle is a little on the rough side, and I'm not doing a 100% super clean job on this, so with that said, here's what it will look like when you're ready to start putting stuff together:

 

[2ndGenToyotaFan]

Stick in the new oil seal.

Beat the new (frozen) bearing races in.

Slide on the felt, rubber, and metal rings.

 

[2ndGenToyotaFan]

Grease the new bearings, and stick the top bearing into it's race.

Partially install the lower bearing cap, so the bearing sits on the bottom of the knuckle, then install the knuckle by slipping the lower bearing into it's race and tip the top of the knuckle onto the upper bearing.

 

[2ndGenToyotaFan]

Tighten down the upper and lower bearing caps, do the next guy a favor and anti-seize the cone washers.

71 ft/lbs here

 

[2ndGenToyotaFan]

Bearings......

Test the pre-load with a pull spring, 6.6-13.2 lbs on the spring per side. Pull from the end of the steering arm. Mine were right at 13 with the shims that were on it originally.

 

[2ndGenToyotaFan]

Install the metal ring, rubber seal, and felt.

 

[2ndGenToyotaFan]

This is as far as I have got, about 11 hours so far, but I took the axle out of the truck.... You do not have to do that.... and yours may not be so dirty because this one has sat for 5-6 years....

Some of you may be thinking..... "Hey, how'd he check the bearing pre-load with the tie rod still on it?" Well, I checked the first side while I held the rod up, and it was right at 13. Then after the other side was installed, I checked them both together at around 26-27. Now you're thinking..."Dang, he's clever!"

 

[KY854RUN]

Jerod,

Excellent write up and photos!

Alright!

Step one, Put the new knuckle bearing races in the freezer, overnight (I can't say this helps a lot, but I can say that putting them in was just hard enough, so I would not want to try without freezing them)

Here is another way to freeze the races and this only takes about 15 to 20 minutes.

Get some dry ice, isopropyl alcohol (AKA, rubbing alcohol 70% by volume) and 8 oz styrofoam cups. Fill the styrofoam cup about half way, put the race in the cup and add the dry ice. Wait about 15 minute and then fish the race out of the cup, with something other than your fingers. The dry ice and alcohol mix is around minus 60 degrees Fahrenheit, so be careful. Then install the race before it warms up.

Freezing the races does help. In aviation manufacturing this is done a lot for, what is called, interference fit parts. But, in aviation we use liquid nitrogen.

 

[Red_Chili]

You using Mobil1 grease? I was unhappy with it. Separated. Went back to Valvoline Moly Di.

The preload matters, I dimpled some kingpin bearings due to slightly too much preload over time.

Marlin has some ROCKIN' new design inner axle seals he is selling. Get a pair and take a look! Should save some rebuilds due to inner seal leakage.

(Edit by 2ndGenToyotaFan) Here's the Marlin seals:

There is some web wisdom about not filling the knucks with grease. I would be concerned about doing that. Pack the birf well, fill the knuck per FSM specs. You are relying on that to lube the upper kingpin after all, as well as the birf.

 

[2ndGenToyotaFan]

Thanks for the tips Bill, this is now under my dad's truck which is a daily driver and only sees 4wd in the snow, maybe 100 miles a year? I'll keep an eye on the grease though.