Happijac new vs old?

[HMS_Beagle]

I have electric Happijacs, possibly 4600 (numbers are illegible) that are complaining. I could:

1) remove, clean and relube

2) replace the legs with 4220 or 4820 legs

3) replace the whole setup with 4820 legs and new controller

Happijac/Lippert do not publish much detail on these jacks, for example why the 4220 is rated lower than the 4820: tube strength? acme screw pitch? something else?

Obivously the cheapest is #1, provided they can be cleaned up. I think they may be the ball screw version (at least on the front) which are often too far gone to fix. Also the tubes on the old style jacks are somewhat - flexible - and so going to the new jacks has some appeal.

What I don't know is, will the old motors and controller drive 4820 legs? they have upgraded both and used to say (can't find it anymore) that the 4820 required too much current for the old controller. I'm not near their capacity (pretty evenly distributed at <1000 lbs each) so they might work fine.

Does anyone have an informed opinion about the old vs new legs, old vs new (vertical) motors, old vs new control? Anybody done this upgrade? New legs are about $1750 for the set, whole setup is $2750 with new motors and controller.

[egarant]

Yes it is too bad they won't sell or even repair the older motors. I spoke with Tyler the "guy in the basement" that used to repair the older motors. He told me the older ones are easy to re-build and asked management to continue the repair service, but was shot down, they want to sell the new ones that as you already know entail a new circuit board and possible upgraded wiring to the jack plugs.

[Dodgemahal]

I bought a replacement motor from Etrailer. To rebuild and replace one at a time as I found the time. And have an extra just in case. They were back ordered for about three months. It finally showed up. I had canceled another order after waiting for months the year before from another company. I don't have a very high opinion of Lippert so far. You may be stuck ordering and waiting. It seems just about everything is out of stock now. Or grossly overpriced. I guess welcome to 2022.:(

[daily_double]

I contacted them, they don't have any.

[Oregun]

HMS Beagle wrote:
You can often find the head motors on Ebay.

I've replaced the back jacks now too, with the same result. They run about the same speed and work the motor just as hard.

I got one here -> https://pantherrvproducts.com

[HMS_Beagle]

You can often find the head motors on Ebay.

I've replaced the back jacks now too, with the same result. They run about the same speed and work the motor just as hard.

[daily_double]

I need a jack head motor, just 1. Does anybody know where to get one? part # 182515.

[Joe417]

That is good info to know. Nice to have someone prove the fit without speculation.

I wonder why Happijac/Lippert wouldn't confirm the jack as a replacement.

Thanks..

[HMS_Beagle]

OK, to finish this out:

I bought four new 4820 jacks. The new jacks work fine as a replacement for the 4500 and 4150 jacks. Motors fit on top, all the holes in the same place, etc. The new ones are about 3 inches longer than the old. They have zinc plated lower tubes and a dust scraper on the leg.

The literature and some magazine reports say they are much stronger, however the tube size and wall thickness are the same as the old, and they weigh the same (26 lbs). Therefore they cannot be much stronger or stiffer than the old ones if at all. The upper tube being a few inches longer will add a little but not much.

Mounting one on one side of the front, I tested the new alongside the old one still on the other side. There was no significant difference in current drawn by the motors, when both of them are activated they run about the same speed with the same sound. This strongly implies that the torque required is similar. Given that the old ones were ball screw and the new ones Acme screw, the old ones should be easier operating. But another difference is the new ones have a roller thrust washer while the old ones have a plain greased washer. The two primary sources of friction are the nut and the thrust washer contributing about equally. The old one with low friction ball screw but high friction thrust washer seem to behave about the same as the new one with high friction Acme screw and low friction roller thrust washer. That makes the new ones better in my opinion since the Acme screw is more robust and less affected by dirt. In addition, though I did not disassemble them to confirm, the new ones reportedly allow easy removal of the Acme nut for cleaning, greasing, or replacement while the old ball nuts are pretty much not serviceable.

So to summarize the new ones aren't stronger, don't operate much easier, but are probably longer lived and certainly more serviceable. They can be used as a replacement for the old without changing the motors or controller.

[HMS_Beagle]

Yet sadly, no alternative.

[54suds]

junk then /junk now

[HMS_Beagle]

I believe the incompatibility has only to do with the overload protection mechanism. The old jacks have a ball clutch the slips in the event of overload. The new jacks do not. The old controller board has no overload protection beyond the fuse and depends on the ball clutch. The new controller board has current sensing overload protection, it will shut off the motor if the current indicates it is stalled.

This really only comes into play when you run the jacks fully collapsed or fully extended. You can provide your own overload protection by lifting your thumb from the button. The motors are quite audible in operation and it is very easy to hear when they begin to load up.

There are numerous vendors selling the new jack legs with the old style motors attached, HappiJac has a part number for the package, so clearly they fit. Some note that you need the new controller board but I believe that is due to the overload protection scheme. On at least some sites, the clearance required for the new motors is 8 1/2 inches above the top mounting hole. This seems accurate given the quoted dimensions of the motor.

The new controller board will also supply 25 amps (there are 25 amp fuses on each output) while mine (I checked last night) has 20 amp fuses. In addition, the new controller board specifies 8 ga wire while the old one specifies 10 ga. The 4800 jack is Acme screw while the 4600 were ball screw jacks. The ball screw requires less motor torque, at least until they get dirty. I think the increase current might be needed for a 4800 jack operated near its 2800 lbs load limit. Just swapping the board though, may not be enough, you will get significant voltage drop though 10 ga wire at 25 amps. Replacing the wiring to the controller and jacks is likely a more difficult and costly job than replacing the jacks and motors.

[bigfootgrey]

I spoke with Happi jac yesterday. They told me the old style motors are obsolete and no longer being produced. They also told me the new motors will not work on my 4800 jacks but e trailer says they will but with the new control board. I tried to purchase a couple of old style motors but couldn’t find them anywhere. If and when one of my motors fail I hope to be able to buy a new board and new motors but use my existing jacks. I also need to check the clearance of the cab over to the new motor. Happi jac says you need 9 1/2 “ clearance from top of the jack. Good luck to us all

[HMS_Beagle]

Thanks, good info. I think an advantage of the newer jacks is they have a galvanized leg, so a little more rust resistant. Supposed to be a stronger leg too.

The Acme screw jacks could be upgraded later with a stainless steel screw. The material is readily available and really not that expensive (maybe ~ $150/jack). Might be the ticket for salt covered roads.

[Glacier_D]

Hey,

I replaced two of my 4800 jacks with the newer 4820s, still using the old motors so it appears you may not need the new style motors. At least I haven't yet. I'll be replacing the other two jacks this spring, salt on the mountain passes here in Washington state did a number on them. They still worked, just the inner tubes were heavy rusted.