Jacking 3.0 sc on rear trailing arms

[3.0schotrod]

Here's a good one for some heated debate

Can I jack up one wheel of 3.0 sc (to change a wheel for example) by using the 'cup' of my floor jack to sit right at the lowest point of the trailing arm, kind of where it has a lot of meat, near the hub, there looks to be say a 1" hole there on the aluminum trailing arm, where the cup of the floor jack would nicely cup the area there. Ive always wondered this, and more importantly, wondered why not, if its not a good idea.

[porsche930dude]

i usually jack it on the shock because the jack isnt narrow enough to grab the low spot. But the little honda scissor jack i use in my car for emergencies I welded a nub on top to go into that hole and not slide off. that way i dont have to lift the car off the suspension at all. It works great. that way it only takes like 1" of actual lifting to get the tire off the ground. I sometimes use it even at home. Perfectly safe

[Flat6pac]

I prefer to go on the cover of the torsion bar, no crawling under the car at ground level
4 10mm bolts and the heavy cover definitely will hold the quarter up
Bruce

[3.0schotrod]

Thanks to both of you. I like the idea of the welded nut for fitting in the hole, I might even be able to make an adapter that fits in place of the cup of my floor jack, as that pad on it comes out, something with a short post that fits in that hole for safety. I also like the scissor jack idea if im out on the road and I have a tire problem on the rear.

Ive often wondered if that torsion bar cover will hold a corner also so thats also good to know.

(going off at a tangent every couple of years I take out the lowest bolt of that cover and squirt in a bit of rust preventing fluid , then replace).

Its feels way less stressful to just lift one rear wheel an inch than have the whole side of the car up, and I can then place a jack stand on the torsion bar cover, or on the tube that carries the torsion bar, or maybe the sway bar mounting point/and or the jacking point itself.

I might even do this method if im doing brakes also for example.

Thanks again.

[Mahler9th]

Depending on the jack and/or jack stand, it can be hard to lift by the trailing arm and then use a jack stand under the tbar cover-- may not be enough space on the floor.

I have had my '74 for about 19 years. My use case is racing and I jack up the car and use jack stands a lot. Usually I just get the whole car up.. takes just a few minutes. When I do this I use the factory jack points.

If I want the rear up I just use the engine. Never had an issue with that on my '75 or the 993 cab I owned. for the '75, I used to place one jack stand each under the tbar covers, but I no longer have those so I use the factory locations on the chassis

[3.0schotrod]

Thanks Mahler9th.

Thanks for the info, yes I just had a trial run with my floor jack around that hole on the trailing arm, fits nice around that area, nearly got the tire off the floor just to see how it went. I think you may be right about further support on the body once the tire is in the air, will have to see what the best option is, but good to know I can do this if I want to do a quick job or just check things. But as we all know, just a quick check can turn into a bigger job.

[Mahler9th]

To be clear... I have 935-style spring plates. So I use the reinforced areas on the chassis for jack stands in the rear.

Again, my use case is racing, and I do all of my own work except for engine building and ring and pinion set up. So my car is up and down a lot.

I do not have a lift-- has not been an issue.

[porsche930dude]

When i jack at the shock and just need to service the brakes or whatever without going under I jam a piece of wood under the floor jack to brace up so it doesnt sink. Like a short piece of 4x4 standing upright

[pmax]

Is that with or without the engine dropped ?

I have only done the former.

[3.0schotrod]

Thanks everyone for your inputs, it will be useful to know how to do this in the future, and its easier to do this IMHO rather than have the whole side of the car up in the air.

[911pcars]

Under the control arm where the lower shock mount attaches. That's a direct support path at that corner of the car. Better if your floor jack (or equivalent) has a cupped lift plate to avoid slippage.

Sherwood

[BK911]

Depends on what you're doing.
Quick lift to change a wheel?
Under the trailing arm is easiest.
Long term lift to fix something?
IMO lift by engine then jack stands at torsion bar covers.
Or if messing with torsion bars, jack stands at car rear lifting points on chassis.

[emcon5]

Why not use the jacking point on the side of the car? It lifts the whole side of the car easily. Stick a jack pad in the hole and jack it up.

One of these: https://www.pelicanparts.com/More_Info/106641030M230.htm?pn=10-6641-030-M230

[unclebilly]

Ummm... jack on the engine?

Been doing it for years.