Front jack point fabrication

[Z4C_er]

Hi all, Does anyone here have a lathe and a bit of spare time? I was going to make a front jack point for my own car (like Liam's) but then thought there may be others that could benefit as well. This is the Z4M one:

And this is Liam's:

It could be a nice little earner for someone. I looked up the prices of nylon, and they're pretty reasonable:
50mm:

60mm:

I'm guessing from a 250mm piece you could get 5 or 6 out of it? Then a 10mm countersunk bolt (stainless?) to finish it off?

Thoughts anyone?

 

[MrPT]

Nice idea. I guess this might turn out to be a question of how many people are willing to take a hole saw to their front reinforcement plate.

 

[Z4C_er]

Nice idea. I guess this might turn out to be a question of how many people are willing to take a hole saw to their front reinforcement plate.

Yes, indeed. If it went ahead then a threaded marker bolt could be included to mark the hole location. I didn't look though Liam's post in detail, but did he add any reinforcement or has he suffered any loss of stiffness? Maybe I'll have a look now.

 

[AveZ4coop]

Liam has only drilled a holesaw hole in the aluminium under tray, not the sub frame. The M10 threaded hole should have no effect on stiffness.

 

[Z4C_er]

Liam has only drilled a holesaw hole in the aluminium under tray, not the sub frame. The M10 threaded hole should have no effect on stiffness.

Thanks for the clarification!

 

[Z4C_er]

Interesting, on the part there is already a hole. Does this correspond with the M10 hole in the member behind?

 

[AveZ4coop]

Certainly a good marker for getting the hole in the correct place. Also, looking at the photo above you can see other mounting holes larger than 10mm on each side of the jacking point, so that is a good indication that stiffness will not be affected at all.

 

[Old-Duckman]

Wouldn't you think the M part and bolt are available from BMW? Would be a lot easier to just order one, drill the hole in the splash shield and mount it in the existing threaded hole.

 

[patriot66]

The Reinforcement Plate 51717028433 is box section all around its perimeter on the reverse (upper) side.
You will need to use a hole saw right through both sides, circled in red.
I've had this plate off my car a couple of times and it is very lightweight, the aluminium is very thin. You could literally bend it over your knee without too much effort. Its strength must be in tension and compression longitudinally. Personally I wouldn't be making any more holes in it than it has already got, especially big ones

 

[Z4C_er]

You will need to use a hole saw right through both sides, circled in red.

That's where I'm a little confuzzed. If the hole in the lower panel corresponds with the M10 hole in the member, and if the upper panel sits against the member, then I should be able to cut a (dia 50) hole in the lower panel and a dia 11 hole in the upper panel and the lifting pad would sit against the upper panel, and sandwich it against the member. Yes?

 

[Z4C_er]

Wouldn't you think the M part and bolt are available from BMW? Would be a lot easier to just order one, drill the hole in the splash shield and mount it in the existing threaded hole.

Possibly. Good call. It's part of the panel, looks to be riveted on. Which also suggests that the top panel sits against the member.

 

[kis]

If you look on the forum services section, there was someone offering cnc jacking points, so would be similar for this. Maybe take a look?

Nice idea though. Will follow with interest

 

[Z4C_er]

When I had my car serviced on Thursday, I had a look through the oil drain panel and saw that yes, indeed, the upper panel sits hard against the member. So, my diagram above is correct, and all that needs to be done is drill the larger diameter hole in the lower panel and frankly glue a puck into the hole (if you don't want to drill through the upper panel). Something like sikaflex would be fine.

 

[mac27040]

isn't the location a long way under the car so you wouldn't be able to get a jack to it

 

[G600]

I've got a a low entry ally jack which reaches it fine, the rectangle in the non M is the same shape as the BMW jacking pad and it's shown as a lifting point in TIS

 

[Z4C_er]

I've got a a low entry ally jack which reaches it fine, the rectangle in the non M is the same shape as the BMW jacking pad and it's shown as a lifting point in TIS

It's a strange one. I won't argue with you or BMW, but there is empty space above that marked/stamped location. The fact that it's marked out in a rectangle suggests it's the place to jack from, but it's thin ally and as mentioned, just an air gap above it. I'd rather jack to something substantial and I'm also aware that panel is pretty critical in the stiffness of the front end. I mean, even the bolts are 'torqued to yield'.
Even if I jammed something into the cavity, I'd be happier, but I like the idea of an easily identifiable location visible from the side of the underbody (ie when you're wheeling a jack under).

 

[Z4C_er]

So Steve at 9designs made me up a proto pad - in BMW blue no less! 68 dia x 32 thick. Should just protrude out from the jacking feature nicely.

In the next few weeks I am going to holesaw my lower panel and pop this pad in with some JB weld. I'll let you know how it goes!

 

[kis]

In the next few weeks I am going to holesaw my lower panel and pop this pad in with some JB weld. I'll let you know how it goes!

andd??

 

[BumpyZ4]

The pre-existing hole on the back side of the tray does line up with the hole in the subframe. Here's my install of the jack point. You do need a VERY long jack to reach it.

 

[Liam22]

Neat job!

I recently re-made mine, final dimensions were 50mm diameter by 30mm tall. M10 bolt picks up an *existing* threaded hole in the cross-member.

I find it very useful for getting the car high up in the air on truck stands, but less useful for simple wheel-off jobs.