For some reason I thought the hub service frequency was 48,000 km or every 3 years, which I have been roughly following.
However, the other information I have says to replace the "Steering Knuckle and chassis grease" every 12,000 km for Severe Condition Schedule and 24,000 km for Normal Condition Schedule". Is that correct - ?
I thought it was 100000klm service item or every 4 years.Less under severe conditions. As long as you dont have grease mixing with oil or oozing past the seals ,you dont have much to worry about.
It might be 24000 klms that you check or inspect it.
That would seem reasonable.
But in the maintenance table I have (a FSM scan pulled of the Mud board here) "Steering Knuckle and chassis grease" cell is says "R" rather than "I".
The chassis grease gets pushed out, therefore eventually replaced, but the steering knuckle you can look in the inspection hole - which would be "I" for inspection.
The steering knuckle grease only gets replaced, when the whole thing is dismantled, cleaned and re-greased ??.
Is it possible to add grease through the inspection hole? I just noticed mine, kinda like a coolant plug on the front/top of the knuckle. be nice to just pump some moly in there every now and again.
Is it possible to add grease through the inspection hole? I just noticed mine, kinda like a coolant plug on the front/top of the knuckle. be nice to just pump some moly in there every now and again.
I replaced the plugs with grease nipples. Also because of my extreme cold climate I add a few ounces of synthetic gear lube to the moly grease in the knuckles.
I replaced the plugs with grease nipples. Also because of my extreme cold climate I add a few ounces of synthetic gear lube to the moly grease in the knuckles.
I top mine up with grease through the half inch square headed plug on the top of the knuckle once or twice a year and wipe the knuckle off, it's been 4 years since I did the overhaul and everything still looks great... While maintence is important for obvious reasons these axles can take a ton of neglect, I've seen knuckles on trucks in horrendous shape still performing as they should...
As said earlier if you don't have diff fluid contaminating ur grease they're golden!
No, but a standard grease fitting screwed into the hole perfectly. I took out a plug and went to the NAPA parts store and bought two fittings to match the size of the plug.
I would suggest not putting a grease nipple on the steering knuckle, since pumping grease in there usually means that you're going to push it past the inner axle seal and into the differential housing - makes a big mess - or you're going to push it past the knuckle felts and to the outside. A few pumps through the plug once every few oil changes is all that is needed, and probably more than most people do.
And, make sure that if you're mixing greases, that they have the same base. Mixing grease bases can cause the grease to liquify and run out.
And as far as "service" goes - I run the grease for the life of the front axle service, which is typically 3 - 5 years depending on the use. If in wet conditions, get in there more often. I don't tend to top up the knuckle grease much if ever because I pack it about 3/4 full on my own truck, and there's little room for more.
If you play in the water a lot, you really want to get in there and service your bearings and knuckles more frequently. I hate running in water and especially watery mud... evil, destructive stuff.
I would suggest not putting a grease nipple on the steering knuckle, since pumping grease in there usually means that you're going to push it past the inner axle seal and into the differential housing - makes a big mess - or you're going to push it past the knuckle felts and to the outside. A few pumps through the plug once every few oil changes is all that is needed, and probably more than most people do. ...
That's all it gets, the grease nipples make it easier. A little grease coming out the knuckle seals is good. If they're dry it's a sign of potential problems.
John is correct. To much grease also fills up the FWH and hudrolecks them and stopes them engauing propley and damages them and also pushes grease out of the rearhub seal and onto the breakes
Getting back to the frequency of hub service question.
My last hub service was done in December 2009 exactly 40,000 km and 3 years ago. During that last service all new Koyo kingpin and wheel bearings were installed. My truck is a dedicated expedition truck - no daily driver use – used only for long bush and desert trips – mud, water crossings, dust and desert. The truck has heavy 60 OME springs and 315s on alloy rims – the alloy wheels save about 9 lbs per corner over steel wheels. I measued them.
Just did another hub service. After 40,000 km the lower and upper kingpin bearings were worn out - they were ovalized in the straight ahead position - the direction the wheels are in 95% of the time. The wheel bearings were also rusty and races marked. The outside wheel bearing grease was dirty and inside grease was as new. New Koyo bearing and Marlin inner axle seals went in.
To detect ovalized kingpin bearings – take off the wheel, disconnect steering linkage and brake line and slowly swing the hub back and forth in a full sweep– if the kingpin bearings are ovalized you will feel the hub indexing itself in the straight ahead position – they are ovalized and need to be replaced.
For heavy off-road use the amount of hub grease is not the big issue-- it’s the condition of the kingpin bearings from heavy pounding on the trail and the condition of the wheel bearings from moisture intrusion from water crossings and mud.
In future I will be doing the complete hub service and bearing change-out every 40,000 km – 3 years. Waiting for for inner axle seal to leak will not detect worn out or rusty bearings.
All the kingpin bearing failures I have seen have been due to lack of maintenance (dried out) and lack of replacement when worn. The bearing that was replaced would have gone a long way, but the problem was contributing to excessive play. Replacing the bearing with an aftermarket sleeve or shim or whatever - I don't think is the solution. Kingpin bearings are not that expensive.
The other major issue I have experienced on the trail is that more you depart from OEM parts the more difficult it is to get parts when far from home. Parts for the 40, 60 and 70 front axles are easy to get in North America.
The vast majority of king pin bearings failures we see are from contamination with water and dirt, and relating to this, a lack of grease sticking to the top bearing.
Other failures are from being run either too loose or too tight. Loose causes them to pound out, tight causes the bearings to wear and fail.
Next up is wheel bearings - running them too loose initially, allowing for play to develop, and then allowing them to be run loose over time is certainly a problem. Tightening wheel bearings that have been run loose for any length of time can lead to premature failures of the bearings.
Outright failures of wheel bearings in trail driven trucks can most commonly be attributed to water contamination. It is very uncommon for clean, dry (no water contamination), properly adjusted and lubricated wheel bearings to fail in mileages under about 80-100k km (or often more).
Tire size and weight can contribute to accelerated king pin bearing wear, and once they get loose it's game over in a hurry due to pounding.
Using a good grease with high surface adhesion is very key. We only use Moly Slip brand moly grease in front end work and have had excellent success with it.
Cheap greases and non-moly fortified greases are not a good idea at all in my experience.
Oh, and one more point, cheap king pin bearings - ie: bearings other than high quality parts such as Koyo or NTN with the correct taper, simply do not last as long as the proper parts.
Karter: note that your HZJ77 HP 8" front end uses the same KP bearings as the 80 series and not the earlier bearings found in the 40, 60, 70 series up to 08/1989.
Karter: note that your HZJ77 HP 8" front end uses the same KP bearings as the 80 series and not the earlier bearings found in the 40, 60, 70 series up to 08/1989.
