Tell Me I'm OK - Front Axle Rebuild and SST for Centering Knuckle

[4Cruisers]

Well, I think I screwed up (slightly?) right off the bat this afternoon. The first thing I did was to install the new Marlin Crawler inner axle seals in the axle housing. Then I came in the house to read in the FSM the procedure for centering the knuckle and determining the total shim thickness for proper bearing preload. Well, the first step in that procedure is to remove the inner axle seals - duh! The knuckle centering tool has to be inserted into the housing and that can't be done with the seal in there.

I read through all of the extensive service documentation and receipts from the previous (original) owner, and it turns out the inner axle seals were replaced at one time, at Sauter Toyota in Santa Fe. I'm assuming the seals were replaced after pulling the axle shafts, without the steering arm, lower bearing cap, or knuckle needing to be removed. There is no evidence that the front axle was ever rebuilt beyond this. If that's the case, the upper and lower shims I removed (and kept track of their location ) should be how they came from the factory. I'm thinking I'm OK to reassemble the axle using the existing shims in their original locations. I should be able to confirm I'm OK when I measure the knuckle bearing preload. And by using Marlin's upgraded seals, I should be good w.r.t. keeping the gear oil from mixing with the knuckle grease over time.

Am I being overly concerned about this, or should I forge ahead?

 

[POTATO LAUNCHER]

Unless you are changing outer knuckles I wouldn't see an issue John. If everything except normal wear parts are as taken apart you should be fine.

 

[4Cruisers]

Thanks, that's what I was thinking.

I guess I won't be able to use the SST until I build the upgraded front axle, basically from individual mini-truck and Land Cruiser parts, for my '76 FJ40. For that project, I have no idea as to what shims were where or what the total shim thickness was.

 

[OSS]

I'm thinking I'm OK to reassemble the axle using the existing shims in their original locations.

Yes you are. That's how you're supposed to do it. The only time the centering tool is needed with new races & bearings is when the original shims are lost or mixed up or a new knuckle is installed on the axle housing.

 

[2mountainfish]

X2 on what they said. I was glad I read some of the forums before I did my rebuild, or I might have not kept track of the shims.

 

[Spook50]

Honestly after my experience I would get the tool. My knuckles were misaligned even when using the same shims in the same locations, which caused the oil seals to leak and contaminate the grease in the knuckle and wheels bearings, which ended up causing a NASTY death wobble around 40 MPH. I've rebuilt since then, using my feeler gauges and micrometer to best guess a centered position for the knuckles and also used the Marlin Crawler HD oil seals. It's been two years since that, and my passenger side leaked again causing the grease to again get contaminated. Sooooooo probably next summer I'll be doing yet another knuckle rebuild and this time I'll be using the SST to make damn sure I get it spot on correct.

 

[4Cruisers]

Looking back at all of the Toyota dealership service records it looks like the inner axle seals were last replaced (OEM seals) in early January '99, along with the front knuckle seal assemblies (felt, rubber, etc.). Mileage was 99,796. The front knuckle seal assemblies were replaced again (OEM seals) in early June '02, but the inner axle seals were not replaced. Mileage was 127,126. I'm not too surprised that both sides were leaking grease and oil across the inner axle seals, with the last seal replacement almost 18 years and 64,682 miles ago.

The only thing I noticed that was out of the ordinary, especially since both times a dealership replaced the knuckle seal assemblies, was the fact that the washers at the steering arm and lower bearing cap were mismatched, the plate washers are supposed to be at the knuckle arms and the split washers are supposed to be at the lower bearing caps. Mine were mixed and matched on both sides. That's what got me to thinking about the knuckle bearing shim thicknesses and locations.

I'm going to finish up the axle reassembly using the shims as I found them, and will periodically check the differential fluid consistency over the years to look for inner axle seal failures.

I appreciate all of the responses.

 

[60Works]

I'd be tempted to move forward with the install. If you kept track of the shims and they weren't changed since the factory install, they should be OK. It's a risk but not one that will leave you stranded. It's just a job that no one wants to do more than once. Which shims were where? Were they the same on each side?

If the shims vary from the original factory setting, the axle may have been bent. The small neck next to the ball is vulnerable.

 

[too tall]

Honestly after my experience I would get the tool. My knuckles were misaligned even when using the same shims in the same locations, which caused the oil seals to leak and contaminate the grease in the knuckle and wheels bearings, which ended up causing a NASTY death wobble around 40 MPH. I've rebuilt since then, using my feeler gauges and micrometer to best guess a centered position for the knuckles and also used the Marlin Crawler HD oil seals. It's been two years since that, and my passenger side leaked again causing the grease to again get contaminated. Sooooooo probably next summer I'll be doing yet another knuckle rebuild and this time I'll be using the SST to make damn sure I get it spot on correct.

You should make sure to check to see if it your housing is bent. The centering sst will not keep that seal from leaking again if your housing is bent.

 

[4Cruisers]

I'd be tempted to move forward with the install. If you kept track of the shims and they weren't changed since the factory install, they should be OK. It's a risk but not one that will leave you stranded. It's just a job that no one wants to do more than once. Which shims were where? Were they the same on each side?

If the shims vary from the original factory setting, the axle may have been bent. The small neck next to the ball is vulnerable.

The vehicle has seen very little off-road use during its entire life, so the axle housing shouldn't be bent. The shims were the same on each side, one thick and one thin at the knuckle arm, one thick at the lower bearing cap.

I just came in from tightening down the top and bottom nuts on the right side, I'm heading back out now to torque the nuts to 71 ft-lbs and check the preload.

 

[4Cruisers]

New Koyo bearings and races, packed with Valvoline Palladium grease, shims as found, nuts torqued to 71 ft-lbs top and bottom - preload only 3 lb using a fish scale. So I need to reduce the shim thickness (equal amount top and bottom) slightly, correct?

 

[88Retired62]

I’d very much like to see a picture of this very Specialized Service Tool that centers our knuckles and appears indispensable when accomplishing a complete axle or standalone knuckle replacement. I’ve also been told that only a very knowledgeable or seasoned parts guy can access the tool. Can our skilled MUD vendors provide the part #, cost and photo?

On second thought, never mind, just discovered the Genuine Toyota eight part, gold plated, diamond encrusted tool on a Marlin site for $540; but have heart, it’s 50% off shipping charges! Just don’t show up to your SST rocket launch without your trusty Spring Loaded Fishing Tackle Tension Guage! Let’s pray there’s an acceptable facsimile at your local parts store?

 

[Spook50]

I’d very much like to see a picture of this very Specialized Service Tool that centers our knuckles and appears indispensable when accomplishing a complete axle or standalone knuckle replacement. I’ve also been told that only a very knowledgeable or seasoned parts guy can access the tool. Can our skilled MUD vendors provide the part #, cost and photo?

On second thought, never mind, just discovered the Genuine Toyota eight part, gold plated, diamond encrusted tool on a Marlin site for $540; but have heart, it’s 50% off shipping charges! Just don’t show up to your SST rocket launch without your trusty Spring Loaded Fishing Tackle Tension Guage! Let’s pray there’s an acceptable facsimile at your local parts store?

Yeah it's not cheap. I used to have a link to a company that sells a bunch of Toyota SSTs and they had it for about $400. Still not cheap, but a lot easier to swallow than $540.

 

[pistonpete]

Check this out, might help..

saw this on pirate,
734345-setting-up-knuckles-without-sst.html

 

[4Cruisers]

Well, at least I have an ample supply of various thickness shims. I pulled out the box with my older set of front axle rebuild parts and found at least 13 more shims of various thickeness, including quite a few OEM Toyota shims with the thickness indicated. Together with the 4 shims in the kit from Cruiser Oufitters, I should be able to dial in the preload to the middle of the Factory specs. I'll use my micrometer to measure and assemble some shim stacks to reduce the thicknesses a tad top and bottom and see what preload I come up with.

 

[pistonpete]

View attachment 1568778

 

[88Retired62]

Thanx, PistonPete...ain’t it a thing of Priceless Beauty!

 

[Spike Strip]

What was the condition of the removed seals? If they're not abnormally worn, you're prolly good to go.

 

[4Cruisers]

What was the condition of the removed seals? If they're not abnormally worn, you're prolly good to go.

Didn't look closely at the old seals, but there was an awful lot of mixing of differential fluid and knuckle grease going on, probably for a very long time. I hadn't been doing the normal amount of maintenance over the years given that it was always intended to be the donor vehicle for my '86 FJ60 build, knowing that I'd be cleaning/derusting/painting/rebuilding everything moving across from the donor to the recipient.

 

[4Cruisers]

Well, I got done to the point of being ready to reinstall the axle shafts/Birfield joints tomorrow morning. I started with the right side knuckle. I decided to first try using new OEM .50mm and .30mm shims stacked, both top and bottom, to replace the much thicker Factory shims (1.0mm). And I reinstalled the additional thinner Factory shim at the top. Torqued the nuts down and got to about 7 lbs preload. Substituted .20mm shims for the .30mm shims, retorqued the nuts, and got to 10 lbs preload, right in the middle of the Factory spec range, right where I wanted to be. Used the same shim stacks on the left side knuckle and also got 10 lbs preload. So I installed the knuckle seals to the back of the knuckles and called it quits for the day. I think it'll work out fine. Time will tell.