Installing a Lift in the Garage, will this type of lift work?

[joshuaho96]

1 minute ago, soviet_merlin said:

Hah, I was going to post a picture of one as a joke. You are ruining your point by picking the most ludicrous EV there is. Surely even the states aren't bonkers enough to see them as a regular occurrence. I'd also love to see someone put one of those on jack stands. Or maybe not, it sounds stupid and possibly dangerous. They are humongous.

True, but it’s also not unusual for people to own and drive HD diesel or gas trucks which actually have comparable ground pressure.

[GTSBoy]

Why is there a lot of carry on about the pinch welds? You do not jack on the pinch welds. You jack on the jacking points, that just happen to be located at the pinch welds. The jack doesn't touch the pinch weld. The jack touches the jacking point either side of the pinch weld.

If you're lifting at the jacking points with anything other than the original jack, you simply have to make sure that you pick up on the jacking points, not on the pinch weld. I always struggle with understanding people's apparent lack of understanding on this point.

[joshuaho96]

49 minutes ago, GTSBoy said:

Why is there a lot of carry on about the pinch welds? You do not jack on the pinch welds. You jack on the jacking points, that just happen to be located at the pinch welds. The jack doesn't touch the pinch weld. The jack touches the jacking point either side of the pinch weld.

If you're lifting at the jacking points with anything other than the original jack, you simply have to make sure that you pick up on the jacking points, not on the pinch weld. I always struggle with understanding people's apparent lack of understanding on this point.

¯\_(ツ)_/¯

It's not that complicated but I still see a lot of cars with severely damaged pinch welds.

[Shoota_77]

I'll never jack from my sills be that at the jacking point or not.  The diff from the back or the subframe from the front.  I lift my  car on the hoist from the chassis rails which I'm comfortable with as the hoist pads span across the whole width of the rail meaning the force travels through the vertical sections of the rails.  My chassis rails are dented from previous owners and their mechanics using smaller jack/hoist pads however....

I use the subframe at the back same as the person in the picture is pointing to (not my finger....) -

I'm contemplating making a steel jacking point that uses the existing threaded holes in the chassis and the rear subframe mounting point something like this-

There is a step in it which complicates it a bit but would make me feel a little safer if I ever took my car to a tyre fitter or something.

 

[GTSBoy]

Why not use the jacking point? Designed to carry the load. All the other mentioned points are not. The subframe is not intended to carry concentrated load from the top of a jack/stand. The diff bushes are not meant to carry that load either (not that stops me from jacking under the diff if I need to - I just don't like it because I'm an engineer who can picture what it is doing to the bushes in mind as I do it). The subframe mounting points being index fingered above are also not really meant to carry point loads from a jack or stand, and you would have to obtain or make an adapter to fit there to avoid causing damage - same as you need for the jacking points to avoid rolling the seam.

There is really no safe place on the subframe to put a chassis stand. The best spots available are the lower inner suspension arm pivots, as they are strong and intended to carry the vertical load, and a jack stand will go there without too much risk of wanting to fall off. Well, narrow headed domestic jack stands will anyway. Big heavy workshop stands not so much. And the lower arm pivots are not always convenient either.

The jacking points are ideal for supporting the car on stands because they are mostly completely out of the way of just about anything you want to do under the car with very little risk of the car falling off - provided you have the right adapter on the top of the stand.

[kevboost7]

I went under the car last night and realized that my pinch welds/sills are completely f**ked. They are all bent and folded over. Can i still use those points? just the metal area next to the pinch welds? 

And can those pinch welds be fixed by bending them back?

[Murray_Calavera]

7 hours ago, kevboost7 said:

I went under the car last night and realized that my pinch welds/sills are completely f**ked. They are all bent and folded over. Can i still use those points? just the metal area next to the pinch welds? 

And can those pinch welds be fixed by bending them back?

I'd watch a couple of youtube videos of people bending the pinch welds back. It won't be perfect so at least you'll have an idea about what level of repair you can expect and what tooling is involved. 

[joshuaho96]

10 hours ago, kevboost7 said:

I went under the car last night and realized that my pinch welds/sills are completely f**ked. They are all bent and folded over. Can i still use those points? just the metal area next to the pinch welds? 

And can those pinch welds be fixed by bending them back?

Bending them back is possible but it will work harden the metal guaranteed. To avoid that you need to anneal with heat but that's a can of worms involving heat treatment and all of that fun stuff. The problem with completely bent/folded sills is that even if you don't bend them back they almost certainly will have lost strength because it starts rusting easily. Theoretically the correct way to fix this is to reconstruct the sill like so: https://blog.garage-yoshida.net/archives/1926

The other "correct" way is to drill out/cut the old welds for the sills and replace them with a new OEM assembly but those are long discontinued unfortunately.

I have folded over the pinch welds on my LS400 learning the lessons I'm talking about now (never buy a Powerbuilt U-jack, those things are garbage) but in my case the fold wasn't too bad so I just used some pliers to bend it back and call it a day. You may not be so lucky.

[Ben C34]

Won't work harden dude.

[joshuaho96]

2 hours ago, Ben C34 said:

Won't work harden dude.

Either way, just bending it back once may be good enough but I certainly wouldn't want to find out what happens with repeated bending.

[kevboost7]

On 11/3/2022 at 9:43 PM, joshuaho96 said:

Bending them back is possible but it will work harden the metal guaranteed. To avoid that you need to anneal with heat but that's a can of worms involving heat treatment and all of that fun stuff. The problem with completely bent/folded sills is that even if you don't bend them back they almost certainly will have lost strength because it starts rusting easily. Theoretically the correct way to fix this is to reconstruct the sill like so: https://blog.garage-yoshida.net/archives/1926

The other "correct" way is to drill out/cut the old welds for the sills and replace them with a new OEM assembly but those are long discontinued unfortunately.

I have folded over the pinch welds on my LS400 learning the lessons I'm talking about now (never buy a Powerbuilt U-jack, those things are garbage) but in my case the fold wasn't too bad so I just used some pliers to bend it back and call it a day. You may not be so lucky.

I just looked up a powerbuilt u-jack, in theory that seems like a great tool cause it'll save you time and hassle of having to put the jackstand on. Why do you say its bad?

[Murray_Calavera]

7 hours ago, kevboost7 said:

I just looked up a powerbuilt u-jack, in theory that seems like a great tool cause it'll save you time and hassle of having to put the jackstand on. Why do you say its bad?

You might be interested in having a look at these - 

https://rennstand.com/

https://jackpointjackstands.com/

[GTSBoy]

Both of those are porn. I worry about the multi-piece construction of the Rennstand. I see a few ways for that to go wrong on people. And I ponder if you can only make the other one work with certain trolley jacks. But they are both the realisation of idle ponderings I have done myself when staring at the shitful combination of things I have to hold my car up over the years.

[joshuaho96]

11 hours ago, kevboost7 said:

I just looked up a powerbuilt u-jack, in theory that seems like a great tool cause it'll save you time and hassle of having to put the jackstand on. Why do you say its bad?

The jack is garbage. There's no control when releasing the jack so it crashes down hard on the jack stands. My 60 USD Harbor Freight chinesium jack is better in that regard. The design of the saddle is also awful. It doesn't engage the pinch weld properly so it's still going to crush it. The whole thing is a huge finger crushing hazard because you have to manipulate the jack stand to get it into the cutout.

22 minutes ago, GTSBoy said:

Both of those are porn. I worry about the multi-piece construction of the Rennstand. I see a few ways for that to go wrong on people. And I ponder if you can only make the other one work with certain trolley jacks. But they are both the realisation of idle ponderings I have done myself when staring at the shitful combination of things I have to hold my car up over the years.

I agree the jackpoint stand looks a lot better but they're all super expensive and are really only necessary for cars where the engineers shrugged and decided there was no need to put in a factory-approved central floor jack point. The F80 M3 is one of those cars where I'm genuinely debating whether I should buy a set because the logical rear jack point (rear diff) has fins running all along the bottom and the lower control arm mount works but is still annoying.

[GTSBoy]

1 hour ago, joshuaho96 said:

are really only necessary for cars where the engineers shrugged and decided there was no need to put in a factory-approved central floor jack point.

What, like most cars, including our Skylines? We jack up on the diff, but we probably shouldn't. The front crossmember is really not designed for jacking. It has no crush resistance, slippery rounder profile. Everything that should scream "do not jack here".

[joshuaho96]

1 hour ago, GTSBoy said:

What, like most cars, including our Skylines? We jack up on the diff, but we probably shouldn't. The front crossmember is really not designed for jacking. It has no crush resistance, slippery rounder profile. Everything that should scream "do not jack here".

As far as I can tell the front crossmember and rear diff under the main case is explicitly designated as the floor jack point. I use a rubber pad and try to make sure the car isn't loaded with a bunch of random garbage. As far as I can tell it works fine. If it's listed in the factory service manual presumably they've done some math and made sure there's an adequate safety factor. The F80 M3 rear diff is truly impossible to put a floor jack on:

[Shoota_77]

3 hours ago, GTSBoy said:

What, like most cars, including our Skylines? We jack up on the diff, but we probably shouldn't. The front crossmember is really not designed for jacking. It has no crush resistance, slippery rounder profile. Everything that should scream "do not jack here".

We clearly differ greatly on this matter. In my opinion the diff is a perfectly good location to jack from as is the front crossmember.

At the end of the day each to their own and for me my car will NEVER get jacked by the sills. 

[BK]

On 06/11/2022 at 6:32 PM, Shoota_77 said:

We clearly differ greatly on this matter. In my opinion the diff is a perfectly good location to jack from as is the front crossmember.

At the end of the day each to their own and for me my car will NEVER get jacked by the sills. 

I'm pretty much in agreement here. With a floor jack it's the front crossmember marked with an X, or the rear crossmember near the diff, but not the actual diff housing. I mean the housing is strong enough, you just dont need to. Then jack stands on crossmember mounting points - I stay away from any sill or body area.

[r32-25t]

No sense of adventure I just Jack it up from the sump and the rear bumper bar and put the stands under the foot wells in the floor pan 

[GTSBoy]

12 minutes ago, r32-25t said:

No sense of adventure I just Jack it up from the sump and the rear bumper bar and put the stands under the foot wells in the floor pan 

Do you use inverted speaker carpet spikes on top of the jack stands? (asking for a friend).