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Here's one for you:

I started pulling apart the right side steering knuckle on my A1. The first thing I noticed was what looked like 90wt on the inside of hub; this is after removing drive flange, but prior to removing any bearings.

After removing bearings (bearings and cups are fine), drum/hub and spindle, I get down to the steering knuckle housing and axle shaft. Now by this time, I expected to see 90wt all over the place, especially puddling in the grease-filled cavity of the knuckle. But no 90wt, just grease. I had figured that if I had 90 wt visible after only removing drive flange, that it would be all over further into the knuckle as well.

I popped off the knuckle (kingpin bearings and races are fine) and pulled the axle shaft out. There is no sign of 90 wt anywhere in steering knuckle or axle tube.

So now I'm wondering where the 90wt came from as I had assumed that the inboard oil seal at the diff was allowing oil past and into the tube with the eventual destination the hub. I'm left with two answers:

1. the oil did come through the diff seal, but it was a long time ago (jeep has not been used much for years)

2. the grease in the bearings/knuckle is old and suffering from oil separation. The grease was very old- hardened in the knuckle in areas (typical lack of TLC by PO)

The amount of (what looked like) 90wt at the hub was minimal- it didn't drip out or anything, but it looks like it was enough to get onto the brake linings. Left side seems to be fine- dry over there and has same old grease.

Any ideas?

Don't consider this an answer from an expert, but it sounds like oil separation to me. I have seen this once before.

Randy

Randy, the other time you saw it, was the grease dried out and hardened in some places? The spinning of the ujoint in the knuckle kept some of the grease pliable- enough to preserve the joint, but the grease on the walls of the knuckle was, as I said, very dry. So dry that I had to chip some of it out. Who knows when it was last cleaned out and re-packed.

I realize that changing out the inner oil seal is the ultimate answer; but I'd be interested in others' experiences.

Hi Dago, I apologize in advance for digressing to another vehicle but it may help explain what I think you are talking about.

The old Series Land Rovers are built very similar to jeeps in some areas of the vehicle design. The axles are one of them. The official Land Rover maintenace manuals call for grease to be pumped into the knuckle housing. In theory it works but some people have found over the years that the upper bearing in the knuckle doesn't get enough lubrication and as an off the record repair put gear oil in with the grease to hopefully lubricate that bearing. It is so common there are DIY formula's available to get the best ratio of oil to grease. I have worked on a few jeeps where this was done too.

Does it work? The manufacturers typically say no, but the long time owners usually say yes. I am undecided but suspect it is unnecessary with good maintenace. I stick to the TM's and have had no problems.

I recall reading recently on a thread- this forum or another one- not sure, about making up a "knuckle pudding" or something along those lines. I believe it was a combination of 90wt and grease.

But I'm inclined to not think that was it. The one thing about the grease in the knuckle is how dried out it is. If anyone ever put 90wt in there, it was a long time ago.

I hate to say it, but it wouldn't surprise me that the knuckles have not seen fresh grease since the last non-civilian owner. That puts it at at least 17 years. And prior to that, a university owned it (U of Idaho) and who knows if they even knew the knuckles had to be greased! So, it's old stuff, for sure. All the same, all the bearings (wheel and knuckle) have survived fine and the ujoint had sufficient gease to survive.

I'll still replace the inner seals.

John

It was very similar to what you described. Only about 3 tablespoons of liquid 90wt. The M38 had set for two years prior to my purchase. It was driven about 20 miles before we tore it down. Lots of very dry grease.

As is usually the case the scheduled periodic maintenance these old jeeps require has all to often been ignored. Depending on type of operation and annual mileage the knuckles must be opened up at least evry 12,000 miles and in some cases as often as every 6,000 miles to clean and repack the pivot (king pin) bearings. The knuckle pudding game is the old wive's tale of jeep maintenance. The pivot bearings need the cling power of the #1 or #2 chassis lube. Also keep in mind they do not sit there and spin for mile and miles. They actually rotate only a few degrees in each direction causing heavy wear in one small segment of the bearing's circumference. For this reason they need a periodic cleaning and inspection for roughness due to the uneven wear pattern. The Bendix and Zeppa joints benefit more with a good hand packing of the #1 or #2 chassis lube. The late cardon joints get no benefit from any of the lubes since they are prelubed and sealed. The extra grease pumped in is really there to keep water out and help keep the grease in the joints and lower temps. In temperate to warm climates the #1 & #2 chassis lubes are ok. In far northern climates you can tell when that #1 or #2 grease is cold because you can almost come to a stop without the brakes at 0 deg F. Of course the use of lockout hubs precludes that issue up north. If you spend a lot of time up north 4 wheeling at 0 deg F and lower then it might improve the drag issue by using a 600 to 800 weight heavy gear oil like the old Ford non-hypoid rear axle lube during the winter or year round if it doesn't leak past your seal too much in the summer.

So the bottom line here is not so much what concoction you fill the hub with but more importantly how often you open clean and inspect then properly re-lube the bearings and joint.

Thanks for all the replies.

It does sound like what twojeeps describes. PO bought the jeep in '93 with 29000 on the odometer, sold it to me last month with 32000. 3000 miles in 17 yrs and virtually none of that in the last 10 yrs (maybe 500 miles). Grease is who-knows-how-old.

Thanks for the rundown on lubing, Wes. I'd heard of the 600wt, etc approach. I'm plenty content with cleaning out the knuckles on schedule, so the jeep will get the TLC. I do plan on putting a set of dualmatics on the front, so I'm not too worried about temps here, even though I live within sight of Canada. I do have a question, though: when I flat tow the jeep, keeping speed to 55 or less, does the regular chassis lube work fine in the bearings?

The #1 or #2 chassis lube that is packed into the joint and bearings by hand will do the job no matter which way you turn the axles. The glob of lube jammed into the ball just keeps the water out and provides the rolling resistance in cold weather. Of greater concern would be the turning of the transfer output gears and shaft with out a lot of gear oil help. On long distance flat tows, say over 300 miles, then neither axle should be allowed to turn the transfer. This means either lock out hubs or disconnecting drive shafts. The rear axle can be converted to a full floater and can then use lock outs also (expensive) Or just converted to full floater and pull the rear axles on long tows and throw two home made covers over the tubes. Years ago it was popular to fabricate a wheel adapter with a built in bearing/hub so the rear two wheels are removed, the adapter is bolted to the wheel lugs and then the wheel is re-installed on the adapter and voila free wheeling rear wheels for long tows.