Front jack point fabrication

Z4C_er · Post by **Z4C_er** » Thu Sep 24, 2020 9:13 am

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:

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And this is Liam's:

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

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60mm:

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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?

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Thoughts anyone?

MrPT · Post by **MrPT** » Thu Sep 24, 2020 9:23 am

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 · Post by **Z4C_er** » Thu Sep 24, 2020 9:56 am

MrPT wrote: ↑Thu Sep 24, 2020 9:23 am 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 · Post by **AveZ4coop** » Thu Sep 24, 2020 10:43 am

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 · Post by **Z4C_er** » Thu Sep 24, 2020 10:46 am

AveZ4coop wrote: ↑Thu Sep 24, 2020 10:43 am 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 · Post by **Z4C_er** » Thu Sep 24, 2020 10:52 am

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

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AveZ4coop · Post by **AveZ4coop** » Thu Sep 24, 2020 6:06 pm

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 · Post by **Old-Duckman** » Thu Sep 24, 2020 6:19 pm

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 · Post by **patriot66** » Thu Sep 24, 2020 6:56 pm

The Reinforcement Plate 51717028433 is box section all around its perimeter on the reverse (upper) side.

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

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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 · Post by **Z4C_er** » Thu Sep 24, 2020 7:55 pm

patriot66 wrote: ↑Thu Sep 24, 2020 6:56 pm 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?

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Z4C_er · Post by **Z4C_er** » Thu Sep 24, 2020 7:56 pm

Old-Duckman wrote: ↑Thu Sep 24, 2020 6:19 pm 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.

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kis · Post by **kis** » Thu Sep 24, 2020 9:20 pm

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 · Post by **Z4C_er** » Sun Oct 04, 2020 10:13 am

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 · Post by **mac27040** » Sun Oct 04, 2020 11:23 am

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

G600 · Post by **G600** » Sun Oct 04, 2020 11:47 am

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

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