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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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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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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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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Kidoo
Chicoutimi, Québec, Canada
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Joined: 03/27/2004
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I did spray antirust oil inside of the Outside tube and inside of the inner tube. I made a bit of a mess but it should stop rust a bit.
I will take them apart next year and see how it is. Once you get use to do it, it takes maybe 1 hour to remove, apart, rebuit, install.
Monaco Cayman 34 2003, Cummins 300HP
Bigfoot 2008, 10.4, F350, 2006, Diesel 6.0, Black, 4x4, long box, Air lift, Rancho 9000, Rear sway bar.
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tdium
Barrie,Ontario, Canada
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Joined: 05/25/2004
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Some odds and sods:
I have used 4 coats of ZEP wax for my inner tubes. Made a horrible mistake coating them with light oil.
I believe there is a probability of capillary action working moisture up the inner tube from the ground. One of my 2002 vintage 4150's had rusted inside the outer tune and outside the inner tube quite badly. Could be the weather here in Ontario.
Just working on my first teardown of a 4150...all because of the generous sharing of knowledge here on this forum. Thanks all.
Tdium
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Kidoo
Chicoutimi, Québec, Canada
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Joined: 03/27/2004
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No did not contact Hjac, I removed one washer. They are thrust washers and normaly only one washer is needed on each side of the bearing.
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bigfootford
Fair Oaks, California
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Joined: 12/03/2002
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Kidoo wrote:Just received the top assembly. One word of caution, the pin would not go in the top hole when trying to assemble the new unit. I took it appart, where the spring meet the two parts clutch, and there was TWO washers on one side of the bearing, very small washer but the pin would not go, took it off and no problem.
Did you contact Hjac to let them know about the issue?
I would be interested why they had 2 washers.
Did you just remove 1 washer?
Jim
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Kidoo
Chicoutimi, Québec, Canada
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Joined: 03/27/2004
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Just received the top assembly. One word of caution, the pin would not go in the top hole when trying to assemble the new unit. I took it appart, where the spring meet the two parts clutch, and there was TWO washers on one side of the bearing, very small washer but the pin would not go, took it off and no problem.
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Kidoo
Chicoutimi, Québec, Canada
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Joined: 03/27/2004
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Yes, one of the front jack really started to bind. The bearing was all torn and the Clutch/brake spring was broken. There was also one the pin in the connector that was bent, probably near to brake apart. One thing that really made it worst, probably what caused the binding, the o ring below the shaft connector was all destroyed to small pieces and some of those pieces got chaught in between the shaft and the recirculating ball screw that is in the inner tube.
This part is made of many little balls, I hope it will eventually all clear from the screw shaft. The other side is really smooth, not binding at all.
The rear 4150 jacks uses the ACME block instead of ball screw and the shaft is made a bit different with smooth groove, the front jack screw is a much smoother shaft.
I also took a look at the other outer tube today and 2 were also bent a little, not much, but I gave it a few wack to make them as straight as possible.
I ordered an upper assembly from Happijack because I cannot find the Clutch / Wrap spring. I will also buy some TC1018 thrust bearings and thrust washer and replace them on all jacks. I think these bearings should be cleaned at least every two years and relube and the o ring check to make sure they do not get destroyed, in all 4 of my shaft, the o ring where broken.
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