Rear quick lift pickup points?

[mikey]

Hey guys,
Looking for confirmation that the proposed lifting method below is sound and does not risk damage to the gearbox casing long term. The car is a Lola T91/50. When I acquired the car, it had this simple aluminum block attached to two lower points on the rear of the gearbox and used a female receiver bolted to a standard floor jack to interface and pick it up:


my challenge is that a standard floor jack does not roll easily on various surfaces so I'd like to change the interface to fit a steerable quick-jack like MK makes (I had one for my PFM) with a rotating T-bar like this:


Here is a paper cutout mock-up of what would be 1/4" aluminum plates:
(I can add additional cross tubes to prevent the plates from spreading also)


But I just want to be sure if anyone knows - are the lower two pickup points sufficient for a rear quick jack lift? On my PFM the interface was built into the longer rear wing uprights that tied into more of the gearbox structure.

Here is the Lola box with no attachments so you can see the two bosses. They are drilled for NAS1103 bolts.


Appreciate your input!

Cheers,
Mike

[David Ferguson]

Could you make the car side a ball, and the quick jack a circular pocket (like an inverted tag trailer hitch)?

I certainly think that looks like a suitable lift point for the rear of the car.

[tlracer]

Given that the existing mounting points are adequate for the pin-socket jack connection, it should be fine for your proposal. Personally I would try to keep the 'horns' as short as possible to minimise any increase in leverage/moment on the mounts. That would also keep the whole assembly as stiff as possible too.

[mikey]

Thanks guys. Based on that input I had took another look and was able to move the pick up arch forward about another 0.3 inches. Overall now the center of the pick up arch is only 5/8 inch aft of the center of the cross bolts. And I’m 1/2” further forward than the center of the old pickup stub. So the lever force arm length when lifting is about half what it used to be.

[Fred Michael]

That location should work fine. You might want to put a cross bar between the two plates to stiffen the assembly up a bit.