Harbor Freight Jack - Heads up
 

Here is a thread from the BMW forum. The jack failure has to do with the protrusions on the lifting plate. Someone had the weight of the car on one of these points and it snapped. Reading the thread further suggested using a larger pad, piece of wood or even an actual hockey puck.

Roscoe

Here is is:

#6. Re: Harbor Freight lightweight jack failure - from Neil MallerTopDate: Wed, 21 Aug 2002 12:21:50 -0500
From: Neil Maller
Subject: Re: Harbor Freight lightweight jack failure

on 8/21/02 9:51 AM, Steve Lilley wrote:

> I just received my $189 jack yesterday. I'm pretty sure problems
> like the one described below can be avoided with only a couple
> dollars worth of material...
>
> Since the vertical fingers are slightly higher than the rubber pad,
> they carry all the weight when jacking a flat area of the car. In
> order to avoid this, I remove the rubber pad entirely and replace
> it with a 3/8" or 1/2" thick piece of wood cut into a circle. (I'm
> not sure what kind of wood it is, but it's really hard. Maybe oak
> or cherry?) Now the lifting load is always carried by the center
> of the jack pad, not the fingers on the edge. All the fingers do
> now is keep the wood circle in place.
>
>> I wondered how long these things would last. Ours is less than
>> 2 weeks old. Part of the weight of the car was resting on one of
>> the four vertical "fingers" surrounding the rubber pad. The
>> finger broke clear off taking about 20% of the circular aluminum
>> pad with it..

Most steel jacks have these fingers, presumably as a safety feature to
prevent a car's underside from sliding off the jack saddle.

However I think that's a design flaw for any aluminum jack. It's easy to see
how the jack could be positioned such that much of the car's weight was
being carried on one finger. Not only would this put a lot of force on the
finger, but it would also apply a large bending moment to the central mount.
Aluminum isn't that strong a material, and unless the saddle were made very
massive it would be at risk of breakage.

The other racing jacks I've seen either have a heavy continuous rim around
the saddle, or just have a couple of small notches. Both approaches strike
me as stronger then the HF jack design. However if the HF saddle is
positioned squarely on the E36 lifting puck, or otherwise on a flat surface,
then I think risk of breakage would probably be eliminated.

Roscoe,
I think the jack was not being used properly. This is not an all around shop jack,but really a nice lightweight jack for use at the track. The Verticle fingers are designed for keeping the lifting pad from sliding out from under it's lift point. I don't beleive they were designed to carry the weight of the lift. That's what heavy steel shop jacks are for.
I am sure the $1000.00 Nascar jacks are built much stronger.

Just my .02

Cranky

Cranky,

Yeah, I know, but just thought I'd give a heads up so the guys are aware of a potential problem if you jack up the car on one of those 'fingers.'

Roscoe

Here is a picture:

http://www.harborfreight.com/cpi/pho...7299/47246.gif

Jeff , the box it comes in says made in China. If someone buys this and thinks they are getting a top quality racing jack they are fooling themselves. I have one and for what I use it for it works perfect. Changing tires at the track.
BTW where do you think those nice Eagle rods and Cranks come from?

If we remove all the China made parts from all our American made cars, I don't think anybody woud be able to use their cars today.

Again my .02

Cranky

Moderator Note
 

This is the All Racing Talk forum.
The thread is about a racing jack with a potential problem.

(The political discussion portion of this thread has been moved to the lounge.)

Thanks
Ron
Club Cobra Moderator

Ron,
You are right, if people don't like where a racing jack is made. Don't buy one.

Cranky

I don't care what jack you use or what material it is made of--the center pad (wood, etc) is what should be holding the weight if it is to a flat surface. The gaps between fingers are to allow you to jack to a channel jack point to keep it from sliding. Obviously, folks using steel jacks wrong and having the fingers carry the load might not have a failure because of the strength of the metal--but arruminum dictates you use it correctly. The rubber pad is really there to keep the wood from sliding around just like the fingers are. Wood is the best medium for the pad IMHO.

ROSCOE - - -

THANKS VERY MUCH FOR THE "HEADS-UP". SOME TIMES WE ALL GET IN A HURRY AND PERHAPS A LITTLE SLOPY WITH OUR TOOL HANDLING.

THE WORD TO THE WISE IS WELL TAKEN.

THANKS, AGAIN, AND Y'ALL HAVE AREALLY GREAT DAY,

BLACKJACK