closed knuckle question

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May 2, 2012 | 09:46 AM

lowrider50

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closed knuckle question

I've got a 75 F-250 with the closed knuckle axle. I Just installed new wiper seals and added 140 wt. to check for leaks. After 2 days alot of it leaked back out which I didn't expect. I thought mabey a few drops but not that much. I know some say to mix the gear oil with grease to thicken it up but Iwas thinking of packing the kingpin bearings and the axle u-joint with grease and don't put in any grease or oil. It seems to me like this would be good for a few years. Has anybody else heard of this or done it? If so what were the results

May 2, 2012 | 10:06 AM

Blackfoot Big Block

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From: Park City, Utah

My supposition is the spherical part of the knuckle has a bunch of pits/ rust, etc and thus not a smooth surface for the new wiper seals to maintain contact with.

If that is the case you would need to get those surfaces smooth for the wiper seals to work properly.

But honestly and this isn't meant to be rude, the closed knuckle, low pinion, drum brake stock Dana 44 axle on a 1975 F-250 is not very desirable.

If the wallet allows it I'd start looking for at least an open knuckle disc brake Dana 44 axle (1976-1977.5) or a high pinion Dana 44 (better still: 1977.5-1979) or the best would be a high pinion, disc brake Dana 60 (in some 1978-1979 trucks. (Rare and expensive))

May 2, 2012 | 10:26 AM

montana_highboy

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From: Big Sky Country

I echo everything Blackfoot said, his assessment is spot on, if you're going to continue to run a closed knuckle axle with pitted/rusted "*****" the best you can do is pump in a slurry mix of 50/50 chassis grease and 140w gear lube.

May 2, 2012 | 10:44 AM

85lebaront2

Old School Hot Rodder

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From: Exmore, VA

The other item I have run into on the closed knuckle is wear in the king pin bearings. They are shimmed to proper clearance and if they are loose, it will wipe out the seals very quickly. I did a 73 a number of years ago for a guy who couldn't keep oil in his, the ***** were a little rusted with some small pits. His biggest problem was the "shop" that redid his front end threw the shims away. I was able to make enough shims to fix it and while I was doing that, another guy wire brushed, sanded and polished the ***** as well as possible. When we finished, after a month, the right side was a little wet, but not dripping, left side just damp enough to keep from hurting the seals.

May 2, 2012 | 11:33 AM

lowrider50

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The ***** on this truck were actually in good shape. a little pitted but no dings or gouges. After the oil was added I havent driven the truck. It leaked out just sitting for 2 days. I agree it would be better to change the axle but money is tight now. I guess the best and easiest for now is to mix the 140 wt. with grease.

May 2, 2012 | 12:07 PM

montana_highboy

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From: Big Sky Country

Quote:

Originally Posted by lowrider50

The ***** on this truck were actually in good shape. a little pitted but no dings or gouges. After the oil was added I havent driven the truck. It leaked out just sitting for 2 days.

I'm not questioning your mechanical abilities but did you install the wiper seals correctly?

i.e. soaking the felt seals in oil prior to installation, cutting the felt seals on a bias and positioning the cut atop the knuckle with some sealant at the cut,

positioning the split in the rubber seal so it's not directly over the cut in the felt seal but still atop the knuckle and applying some sealant at the split,

installing the retaining plates so the seams are horizontal and not vertical,

lastly, and probably most importantly, just wrenching down on the bolts until they're "snug" as to not distort the felt seals and/or warp the retaining plates.