Homebrew jack bar for lifting M5 - The Unofficial BMW M5 Messageboard (m5board.com)

tbalon · 5th August 2007, 04:24

After reading posts on how to properly jack the rear end of my M5
I decided to do something completely different. I had a shop make
me a jack bar that spans between the two chassis lift pads and has
a center lift point. I balance this on my low profile floor jack, line
it up and lift the entire back end of the car using the factory jack
points.

I've attached some photo's so you can see what I did. Please note
that the vice grips you see in the photos are simply there to keep
the bar from slipping off the floor jack while I'm sliding it around
under the car to get it into position.

Once the car is up and level, I can easily place jack stands under
the bar. I leave the floor jack in place to be extra safe. Cost to
build this was about $100.00. It has to be very strong and be
arced a bit so that it does not touch any part of the suspension when
under load.

Tom

SeattleM5 · 5th August 2007, 04:26

Cool idea.

Snowbeast · 5th August 2007, 07:44

I wish I would have had that today - would have made my work much easier. Nice work!

ard · 5th August 2007, 08:07

Yikes

What if that bar rolls???!??!

Looks like the only thing holding it to the jack is a vicegrip. The aspect ratio of the height above the jack looks like 2:1... 2" wide on the jack and 4" from the jack saddle to the lift points. This makes me nervous.

Great idea, but you need to ensure it cannot rolls as weight shifts. Weld it to the jack, or weld a round pin on the bar that replaces the saddle on the jack.

If that rolls the jack be supporting the car by, what, the driveline, exhaust and floorboard?

A

Salty · 5th August 2007, 10:24

Quote:

Originally Posted by ard

Yikes

What if that bar rolls???!??!

Looks like the only thing holding it to the jack is a vicegrip. The aspect ratio of the height above the jack looks like 2:1... 2" wide on the jack and 4" from the jack saddle to the lift points. This makes me nervous.

Great idea, but you need to ensure it cannot rolls as weight shifts. Weld it to the jack, or weld a round pin on the bar that replaces the saddle on the jack.

If that rolls the jack be supporting the car by, what, the driveline, exhaust and floorboard?

A

Good feedback Ard, but...

If he places jack stands under the bar, directly beneah the jack pads & short welded risers on the bar, it should be virtually impossible to roll shouldn't it? The bar is cradled in the jack stand saddle.
The pictures show jack stands placed outboard of the risers.

The only (small) potential for "rolling" would be when lifting the car and I would have thought that the rollers on the floor jack would take up those forces.

Regarding the vice grips comment, it looks like the centre section of the bar is wider than the floor jack pad, so there should be no potential for rolling.

Cool idea. I might build a couple of these too.
Those Ivy League folks in Ithaca have larger brains, I am told.
Salty.

Sebring NL · 5th August 2007, 14:04

Well

How much does that alloy jack take? I have been looking into those and can't find one that fits the bill.

about the bar, seems OK if you would make a cradle on the jack for it..

On the other hand, you could buy one of those flat floor mounted "sanding" hoist for anything short of 2K, which I would do if I had your garage!

Put the hoist on the left, leave the space in the right for jack action!

Wout

tbalon · 5th August 2007, 17:18

There is a circular pad about 4" that fits the floor jack. The reason
for the vice grips was to keep the bar from sliding off the jack while
I as pushing on it to get it into place. It would not really be possible
for the bar to "roll".

The pads mate perfectly to the chassis mount points and fit in the
plastic cups. One is welded to the bar the other is adjustable.

I've attached a few more pics so you can see it better. The idea is
to get he car up and level then put the floor jacks under. Once it's
on the jack stands, it solid.

Tom

Quote:

Originally Posted by ard

Yikes

What if that bar rolls???!??!

Looks like the only thing holding it to the jack is a vicegrip. The aspect ratio of the height above the jack looks like 2:1... 2" wide on the jack and 4" from the jack saddle to the lift points. This makes me nervous.

Great idea, but you need to ensure it cannot rolls as weight shifts. Weld it to the jack, or weld a round pin on the bar that replaces the saddle on the jack.

If that rolls the jack be supporting the car by, what, the driveline, exhaust and floorboard?

A

tbalon · 5th August 2007, 17:31

It's rated for 3000 lbs. The entire car is 3450 lbs. This was the jack
recommended for lifting the front of the car from the center jack
point. I found it on the list and ordered it from Harbor Freight.

Quote:

Originally Posted by Sebring NL

Well

How much does that alloy jack take? I have been looking into those and can't find one that fits the bill.

about the bar, seems OK if you would make a cradle on the jack for it..

On the other hand, you could buy one of those flat floor mounted "sanding" hoist for anything short of 2K, which I would do if I had your garage!

Put the hoist on the left, leave the space in the right for jack action!

Wout

Evil One · 6th August 2007, 01:42

Top idea mate! I like lateral thinking like that, well done!

M5CCIE · 6th August 2007, 02:32

Nice idea! What kind of shop made this? Maybe they can do a Group Buy and build a few for us although shipping maybe an issue? Also, the last picture where the car is on the ramps at the front and the bar is supporting the rear is scary for me. Since there is no way to apply the front brakes, it looks possible to me that the car can roll back while jacking up the rear?