Bleugoat
Platter, OK
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Joined: 11/17/2010
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Many thanks for this thread.
Mine were in bad shape and I discovered a broken cinch spring in one upper unit. I will be ordering parts from Happijac as soon as I get back from Colorado.
2003 Dodge 3/4 T Cummins
2005 Outfitter Apex 8
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devildog1971
Rome
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Joined: 12/07/2003
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It can be a messy job
2019 Northern Lite 10-2 EXCDSE Dry Bath 2007 G M C dually crew cab and 2018 Harley Davidson Limited Low
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bigblue1978
Knoxville, TN
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Joined: 02/20/2014
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Great post. If the swivel at the bottom of the acme thread is badly rusted, the black tube will torque twist. This will cause the paint scraping because of corner to corner rubbing. This will also cause lots of groaning and grinding and popping noises. I lubricated my 4150 with 90 weight hypoid oil. with the black tube secured in the vertical position, I extended the screw as far as possible and then poured the oil(a few drops) onto the nylon nut and let it drain down. This takes several hours. I repeated this several times. Working the acme thread rod up and down, it eventually was loose enough to turn with only my thumb and forefinger. After everything is loose, grease the whole rod.
The nylon nut can fail and become stripped. The steel safety nut should prevent catastrophic failure. Similar nylon nuts are used in adjustable hospital beds and they do fail. The nylon nut can be replaced, but you will need advanced machining skills. For all that is at stake, replace the whole jack instead. A new jack is cheap insurance.(Oil the new jack with the hypoid oil.)
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bigfootford
Fair Oaks, California
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Joined: 12/03/2002
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bigblue1978 wrote:Great post. If the swivel at the bottom of the acme thread is badly rusted, the black tube will torque twist. This will cause the paint scraping because of corner to corner rubbing. This will also cause lots of groaning and grinding and popping noises. I lubricated my 4150 with 90 weight hypoid oil. with the black tube secured in the vertical position, I extended the screw as far as possible and then poured the oil(a few drops) onto the nylon nut and let it drain down. This takes several hours. I repeated this several times. Working the acme thread rod up and down, it eventually was loose enough to turn with only my thumb and forefinger. After everything is loose, grease the whole rod.
The nylon nut can fail and become stripped. The steel safety nut should prevent catastrophic failure. Similar nylon nuts are used in adjustable hospital beds and they do fail. The nylon nut can be replaced, but you will need advanced machining skills. For all that is at stake, replace the whole jack instead. A new jack is cheap insurance.(Oil the new jack with the hypoid oil.)
Welcome to rv.net Bigblue1978, I'm impressed that you know all about these pesky jacks having only joined RV.net TODAY....
Been through exactly what you described except that I had the jack on the bench and apart. I used WD-40 to loosen the acme nut, running it up and down on the threaded shaft with a drill attached to the TOP end... Took a while but finally the nut moved freely. Greased it with boat axle grease.
Jim
2000 2500 9.6 Bigfoot,94 F250, Vision 19.5, Mich 245/70XDS2's, Bilstein shocks, air bags/pump, EU2000, PD 9260,Lifeline 100ah, 200W. solar, Morningstar Sunsaver 15A/ display panel, Trimetric, Delorme/laptop, Holux gps rec,led lights, Wave-3 heat.
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bigblue1978
Knoxville, TN
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Thanks, Bigfootford. I didn't know the proper terminology. The swivel to which I refer is perhaps called a centering block. It is internal to the black tube and is attached to the bottom of the acme screw. one of the members used a band saw to cut the black tube apart and the picture of this part shows excessive rust. I only intended to explain how I delivered hypoid oil to this part. My jack was binding, but from what I could see everything appeared to be well lubed. I did what I could to lube that which I could not see and now the problem is solved. I will try to be more accurate in the future and also to have pictures and illustrations as well.
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mjkruid
Madison, Ne.
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Joined: 07/05/2014
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I found this topic while searching for happijac maintenance. This is the best information I've found anywhere. Thank you for posting this!
I have happijac 4500's, 14 years old. I purchased this camper this spring and the jacks are in dire need of service. I have 2 completed and they work great. My problem with the remaining 2 is that I am unable to pull out the manual socket. I have removed the C clip and the sprocket is loose on the inside but the socket will not come out. I have tried everything I can think of short of welding in a coupler nut and using a slide hammer. The drawback to this is the socket will be ruined.
Any thoughts would sure be appreciated.
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sleepy
Oak Ridge,Tennessee
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Joined: 04/07/2003
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This is very good post... thanks for taking the time to capture the repait with detailed pictures.
I mighty be able to help with one of the simplier problems... rust!
Ijanet and I have spent a lot of time on The Gulf of Mexico Beaches over the last few year.
My jacks (Atwood) have a fine red rust hear and there all over them...
I was in my local Home Depot to get some stain for a home project... Ed, the paint department expert asked if there'd be anything elso.
I told him about the rust... asked if he had any ideas.
He suggested CLR, CLR
a product called Calcium, Lime, Rust
It was less than $6.00... I thought what the heck... I'll try it.
When I got home I used a scotch brite pad and the CLR on my jacks... hoping to get enough of the rust off to paint them...
Within a few minutes they were as clean and brilliant white as they were when I bought the camper new.
I will still paint the jacks with a thick, RustOleum paint... using a very small roller (that costs about $3.00 and comes with a roller pan.
Thanks again
Sleepy
2003 Lance 1161,/slideout/AGM batteries/255W Solar/propane generator/Sat dish/2 Fantastic Fans/AC/winter pkg
AirFoil, Trimetric, LED lights, Platcat vent heat
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magic43
Brookhaven, Ms.
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Joined: 07/28/2004
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Wow, it is good to see this thread again. I believe that it once was a "sticky".
Since I disassembled, removed the skimmed paint, and properly lubricated my jacks (in August, 2012) I have had absolutely no problems. This thread was a lifesaver.
magic43
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carrnutt
Tampa Bay Area, Florida
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Definitely a life saver. Well money saver, anyways. After performing this maintenance, my jacks all work great. I still have one that's going to need to be replaced, but working for now, as opposed to replacing all four. Thanks again!!!
2014 Cougar 31SQB
1993 Dodge D350 Cummins
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bigfootford
Fair Oaks, California
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magic43 wrote:Wow, it is good to see this thread again. I believe that it once was a "sticky".
Still is a sticky...
Truck camper university, scroll down to jacks
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25966285.cfm
Jim
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