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Topic: hubleaks and shocks and questions, oh my (Read 1022 times) previous topic - next topic

hubleaks and shocks and questions, oh my

My google fu is weak this morning and we have a trip coming up so here we go. I took a shakedown drive and found that there's a problem at the RF wheel. Inspection shows that the hub has water in it and has let gearlube out. I am going to replace the hub cover gasket and sight window and plug today, in the fond hope that this solves the problem. I cannot find any sign of oil leaking onto the inside sidewall, rotor, caliper, or wheel. All the oil streaks are on the outside wheel and sidewall. My question is, how wishfully am I thinking here? How the heck can a shotglass at least of water get in there under any circumstance? It just don't seem reasonable.

My other question is, a few years ago I adjusted the shocks. I thought rebound was too soft and somewhere I found the way to stiffen them up. I went too far. Backed them off. But now I think they are still too stiff and want to back them off more... and I can't remember for sure what the procedure is. Senior moment. Great.  So the red Konis on the early Unihomes, am I right in recalling that compression is not adjustable but rebound is, and you do this by squishing the shock all the way up and rotating the shock body > And if I want to soften rebound I rotate 'em counterclockwise? Thanks all.

Re: hubleaks and shocks and questions, oh my

Reply #1 –
Adjusting Koni shocks: http://www.konirv.com/adjustment.cfm

If you have driven any distance with that much water in the hub (assume fluid is milky) do not assume that the bearings/races are OK. 

Only way I know to get that much water in the hub is to submerge the hub in water!

What does the other wheel look like? Other signs of water intrusion?

Re: hubleaks and shocks and questions, oh my

Reply #2 –
Quote from: twobus –
My question is, how wishfully am I thinking here? How the heck can a shotglass at least of water get in there under any circumstance? It just don't seem reasonable.



Per one of our technician-members, if the seal isn't good and a hose gets a little "aggressive" when washing (such as with a pressure washer) that's one way water can get in. 

Front Wheel Beaing

Re: hubleaks and shocks and questions, oh my

Reply #3 –
It's had a hubcap dome over it, and it didn't leak last time it got driven. It is not a new problem though, I replaced the red rubber hubseal plug awhile back because it leaked. The LF hub is tight as a drum. No leaks at all. The gasket on the leaky side though, the one between the cover and the hub, doesn't really look all that great. I syuppose it could have a leak on one side that lets rainwater in.  Brett, it did get driven about 10 miles. I am going to jack that corner up and check for rough nunning or play. I hope I caught it in time. But I don't have high hopes. At least there's no sign of blueing or other heat damage. Thanks for the Koni link, I guess my memory wasn't as bad as I thought.

Re: hubleaks and shocks and questions, oh my

Reply #4 –
If those are the original shocks there's no way they still have the original dampening left, may be time for new ones.Would check
the bearing and race on the hub and have new ones on hand and do both at the same time.

Re: hubleaks and shocks and questions, oh my

Reply #5 –
Readjusted my red tops several times.  Better.

Replaced them with FSD's.  Different drive.  Dual circuit is necessary for the design.

Separate low and high speed circuits.

Re: hubleaks and shocks and questions, oh my

Reply #6 –
Quote from: John44 –
If those are the original shocks there's no way they still have the original dampening left, may be time for new ones.Would check
the bearing and race on the hub and have new ones on hand and do both at the same time.
That's what I thought too. Amazingly, when I did this adjust thing the first time, I was planning on replacing them. But when I tightened them up, the ride was so stiff that it was like I set it up in race mode. I backed them off halfway and I think they are still too stiff. They were at full soft , as Foretravel set them at when they installed them. I think I will try one or two turns harder than that and see how it goes.  That's of course right after I take a good hard look at those bearings... just bought new 2 of everything for the front side, and am gonna go lift that wheel and look at the bearings.

Re: hubleaks and shocks and questions, oh my

Reply #7 –
RE: Water in Hub,  My left front hub started dripping oily/water from the hub cap while sitting for several months. I removed the cap, plug, outer clear plastic oil well and replaced the gasket and red plug. drove it a few miles and the oil was milky again. The wheel in between the inner and outer bearing has an oil well, or depression where oil normally is held (reservoir),  but when water is introduced into that hub area the oil gets displaced, the oil floats out. My final fix was to remove the left front wheel, remove both inner and outer wheel bearings, along with the inner seal,  clean the inner wheel hub, (oil reservoir) replace the inner wheel seal, the bearings and races were O.K. , add new gear lube to the hub.  I believe the inner seal, ( inside of the wheel against the spindle),  is where the water was getting into my hub.....      ^.^d   

Re: hubleaks and shocks and questions, oh my

Reply #8 –
Quote from: Gerry Vicha –
I believe the inner seal, ( inside of the wheel against the spindle),  is where the water was getting into my hub.....      ^.^d
Gerry,

I'm not questioning your diagnosis - sounds logical to me.  What I don't understand is how water could make it's way past the inner seal and into the "oil reservoir".  I can't imagine a scenario that would cause that to happen.  Like Brett said, I would think the hub would need to be completely submerged in water...and even then it seems to me the seal would be pretty "water tight" under most circumstances.

As to the "pressure washer" theory - this might be a common practice with the "trucker" crowd, but how many of us regularly blast the the front hub assembly with high pressure steam/water?  Like Jay said, during wash jobs it is normally protected by a chrome cap.

I don't know...obviously water DOES get in there...but how it does it...?

Re: hubleaks and shocks and questions, oh my

Reply #9 –
Just as an FYI the fleet I worked for changed all wheel bearing lubricant to a synthetic grease. Drain the gear oil, repack the bearings with synthetic (red) grease, replace the seals, install a yellow fill plug using silicone sealant on the hub cover.
We were very religious about setting bearing preload, too. Never had a bearing failure or a hub leak if this process was done correctly. Thousands of OTR and city delivery units done this way.
We also used synthetic lubes in manual transmissions an differentials. All good for 500K miles.

We used Mobil product but the are several other good products out there.

Steve

Re: hubleaks and shocks and questions, oh my

Reply #10 –
I was as baffled as anyone else, as to how the water got into the hub. I do know that after the new seal was in place, the problem was resolved....

Re: hubleaks and shocks and questions, oh my

Reply #11 –
The inner seal is mainly to keep oil in. Possibly when going through puddles the cooling effect pulled water in when the hub was cooled.

Re: hubleaks and shocks and questions, oh my

Reply #12 –
When a coach is parked for an extended length of time and  there is a lot of rain sometimes the moon hubcap fills with water and with water sitting there it enters the hub through the red plug. You can fix that by drilling a small hole in the chrome hub cap 90 degrees apart and then it can't hold water in it

Re: hubleaks and shocks and questions, oh my

Reply #13 –
SteveB did you preload the wheel bearings or leave them .001-.005 loose?

Re: hubleaks and shocks and questions, oh my

Reply #14 –
Yes, torque the retaining nut to 50 ft lbs, back off one turn, retorque nut to 10 ft lbs then back off 1/8  of a turn and check end play for .001" to .005" with a dial indicator.
Rotate hub/rotor whilst applying torque.
If you have to align the retaining nut with the locking device always loosen slightly. Do not tighten.

Here's a YouTube video that explains it very well: Proper Tapered Roller Bearing Installation in the Hub Assembly - YouTube

Of course this only applies to tapered roller bearings.

Hope this helps

Re: hubleaks and shocks and questions, oh my

Reply #15 –
Thanks SteveB.  I have gone great lengths to research and test this.

The legal .001-.005 allows a small amount of a dead spot.

Had my coach done with an actual preload.  No .001-.005 at all. 

Done by my x Foretravel 20 year chassis mechanic.

Zero dead spot.  Small pressure on edge of wheel to maintain lane position.

Identical setup but now at one side .001 and the other .003.

Small dead spot.  Coach self steers I think because of the .Michelin directional siping on the steer tires.

But if you need to correct your line in the lane it requires a conscious movement of the wheel to get to where your path is altered.

Subtle thing.  More noticeable in windy conditions.  Coach was almost immune from wind wander and opposing truck traffic with a real preload but now moves a bit. Not much but it is different.

If you had driven this setup both ways you would defintely notice.

Enough I am probably going to pay my old buddy mechanic to retighten my front hubs with a slight preload.

Not recommending anyone do anything that they feel uncomfortable with.

Vincent has done hundreds of rv's this way with perfect results and my Foretravel customers loved and noticed the difference.

Original unihomes had a steering wander problem. We retimed countless steering columns to orientate the steering columns to different clock points to try to correct wandering.

Foretravel finally made a support kit to brace the column that my buddy installed.

Dozens of them.  Part of the fix was the wheel bearing adjustment.

Otherwise the wander was accentuated by the steering column flexing and the universal joints clocking in relation to each other.

Drove us crazy in early unihomes

Re: hubleaks and shocks and questions, oh my

Reply #16 –
What is the opinion on using the newer Pro-torque nuts?I'm assuming the above is being done with the older style?
Will be changing a seal soon so that's why I'm asking.

Re: hubleaks and shocks and questions, oh my

Reply #17 –
I think the pro torque requires a hub change?  And then results in the legally verifiable play

Re: hubleaks and shocks and questions, oh my

Reply #18 –
From what I read you can use either one the pro torque being newer.
 

Re: hubleaks and shocks and questions, oh my

Reply #19 –
Pro torque nuts are really just a different locking mechanism they don't change bearing preload specs.