King Pin Bearings and Knuckle seals

How to do it - the rough guide
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King Pin Bearings and Knuckle seals

Post by Alan » Fri Apr 29, 2011 1:17 am

My Jeep developed the fabled 'death wobble' problem about 12 months before I stripped it down. Before I stripped it, I had changed tie rod ends, Steering relay and adjusted and lubed everything I could in an attempt to get rid of it. I finally gave up and fitted a steering damper. This worked a treat but simply hid the problem. During the 'try and find it' stage, I had checked for play in the kingpins but found non because of the knuckle seal and fibre washer successfully hiding the problem. When I removed the bearings they turned out to be completely worn out.

This is them, you can clearly see the pitting and worst of all the wear grooves that the rollers sat in.
bearing cup fubar.jpg
Its my opinion that well over 50% of our Jeeps that are still on the road will have this kind of wear and as such you need to do something about it.
This is how to do it. It is amazingly easy to do.

Parts you will need,
New bearings - 11590 and 11520. You will need 4 sets, 2 sets for each knuckle. As Land Rover copied large parts of the original Jeep, part number 606666 for land rovers is the same bearing ;)
New seal kit - From Jeeparts ( see suppliers in alternative parts) Ask for a Knuckle seal kit. REMEMBER THEY ARE NOT A MAHINDRA PARTS SUPPLIER.
Shim pack - From Jeeparts
I did mine with the axle completely off the vehicle but it can be done with it still in place. You need to jack the vehicle up and support the axle on axle stands.

First remove the wheels and then remove the brakes completely from the hub.
Remove the tie rods complete from the hubs (see removal tool)
Remove the drive flange or free wheeling hub and then remove the circlip at the end of the drive shaft.
Undo the wheel bearings using the correct box spanner and remove the hub.
Now remove the stub axle bolts so you can remove the stub axle. With this removed, you can now slide the half shaft out of the axle. Its not necessary to remove the half shaft but it makes it easier with it out of the way.
Now remove the bolts from the seal clamps and remove the felt seal and the rubber knuckle seal.

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Re: King Pin Bearings and Knuckle seals

Post by Alan » Fri Apr 29, 2011 11:49 pm

With The seals removed you can now remove the kingpin clamps. Only one side needs removing to release the assembly. But loosen the other side to make removing it easier when its on the bench ready for cleaning. Take note of the shims on one side of the clamps. The shimmed clamp should be the top clamp when the axle is fitted to the Jeep.
This is the assembly on the bench, you can see the bearing race located on the kingpin clamp for reference. Give all the parts (except the old bearings obviously) a good clean and inspect for damage. Take care when cleaning the shims, some of them are very thin.
With the assembly removed from the axle, access to the bearing cups in the knuckle is easy. Using a drift, knock the old bearing cups out of the axle and give the whole thing a good clean. Make sure you remove all the old gunge and debris from the knuckle face that the seal slides over. Emery cloth is your best friend for this job.
Now we can start fitting the new parts and then set the bearing preload.

First of all slide the new fibre seal over the knuckle and slide it up the axle out of the way. If you don't do this now it wont go on because it wont go over the assembly. Once that's done, fit the new bearing cups into the knuckle. Tap them in using a hammer going round the cup in a circular motion. Its fully located when the sound changes as you hit it. The sound as its going in, but not seated, is a dull clunking noise which changes to a more solid 'ding' when the cup reaches the locating collar.
Next fit the bottom clamp into the assembly, tighten the bolts and locate the new bearing race on to the Kingpin. Give the race a good daubing of grease. Next daub the other race with grease and 'glue' it in to the knuckle at the top. Locate the assembly in to the bottom bearing cup first and then align the top bearing with the top kingpin clamp and slide it in.
This is where it becomes a trial and error excercise. What you are now trying to do is set the bearing preload with the shims. The manual states that the assembly should move with 12 - 16 lbs of pressure on it. This is tested using a spring balance (fishing scales) without the seals being fitted. Adding shims reduces the pressure on the bearing so taking them away increases the pressure. I got it somewhere near by putting too many shims in and removing them until there was no play. This resulted in a preload of about 2 pounds. So I removed one shim at a time and checked it until the correct reading was obtained. Both mine were set at 14lbs, as you can see :grin:

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Re: King Pin Bearings and Knuckle seals

Post by Alan » Sat Apr 30, 2011 5:15 pm

Now the new bearings are fitted and the preload is set we can fit the new knuckle seals.
The kit contains 2 sets of these.
The rubber seal needs to be split so you can get it onto the axle. Some kits come with the split already there and some do not (mine didn't). If yours needs the split cutting, its easy to do with a sharp stanley knife. The steel band in the seal is not a complete circle, just locate the gap and cut through. Its clearly visible here.
rubber seal.jpg
To get it on the axle, prise the split open sideways to a coil / spring shape to get it over the axle tube. Dont just pull it straight open as you will bend the steel insert and render the seal useless.
The RIGHT way
The WRONG way
Next thing to do is put all the bolts through the new steel plates and push them through the felt seal. Make sure the cut profiles are lined up and the lip on the steel clamp plates point out from the seals. The reason for this little sub assembly is to hold everything together and in line ready for bolting up to the knuckle. (a free tip from me ;) )

With all the seals now ready to be bolted up, smear the face of the knuckle with grease and pull the rubber seal into position, making sure the split is at the top by the shimmed kingpin clamp. The rubber seal should have the steel band facing the knuckle and the lip on the seal on the outside edge facing the felt seal.

Now pull the felt seal up and spin all the bolts in. Torque them up and check everything is tight. You will find the knuckles very stiff to move now. This is perfectly normal and will free up quickly as the felt seal beds in.
Now re-attach the steering tie rods and fit new split pins to the castle nuts. ('R' clips are perfectly acceptable to the MOT man).
Slide your half shafts back in, being careful as they go past the oil seals at the diff. I gave mine a light coating of grease to help them slide over the seal.
Re-fit the stub axle and re-assemble the rest of the hub.

Now we come to the knuckle lubrication. This has been the subject of much debate here and elsewhere on different forums. I will quote what it says in the manual and you can make your own decision whether you go for that or go for the 'tried and tested homebrews' that are out there.

The manual states -
manual lube.jpg
Thats it, your bearings are replaced and new seals fitted. All lubed up and ready to go again. :good: