Eplebnista

I have a two post lift in my garage and my 928 spends a lot of time in the air for various reasons. This is ok except when I am diddling with the suspension and things need to be done at ride height. The usual solution is to drive the car until it settles but that takes time and since my garage floor is very stout I had the idea that I might put anchors in the floor and use ratchet straps to pull the car down to ride height when it is on the floor and either do my diddling or wait overnight depending what needs to be diddled.

I have a dim recollection that there was some reference in the WSM or in some past thread that this was a legitimate approach to settling and am posting in the hopes that this rekindles the dim recollections of others or generates meaningful feedback.

Thanks

drooman

It works... we would use ***ratchet straps*** to over compress the suspension, release, bounce, then align. Section 44-2

you can also drive the tires onto a steel bar and use that as your pull down.

FredR

The kind of lift where the platform rises with the car sat on it is perfect for such but on a two post lift such does not seem possible

Bulvot

I do it anytime I do an alignment. Attached is an excerpt from the WSM with the Porsche instructions. Below is a photo of how I do it on my four post lift.

You don't need to pull the rear down, but you do need to pull the front down if the rear is raised. It's pretty easy, just make sure that you pull it down the same amount on both sides.

drooman

the drive onto the steel bar method works but its a pain to get under there and do it. What about using axle stands under the tires while lifted? just make sure you have a way for the wheels to camber out under compression. Maybe you could modify some axle stands with some casters and a tire platform... I use some alignment tables I bought at a swap meet years ago.

I'm pretty they sure instructions in the work shop manual assume you have skid plates.

FredR

I would have thought the entire point of the procedure is to drive on, pull down, tighten everything and then drive off to the alignment rig wherever it may be.

drooman

I don't think that was what the OP was aiming for... ? or is it? is that what otto was asking about?

Eplebnista

What I had in mind was compressing the suspension with the car on the ground, not with the car on the lift. Drooman's description of driving over a steel plate or bar and using that as an anchor is perfectly apt. I guess I really like drilling holes in concrete, since that did not occur to me.

To the extent that it matters, I wasn't thinking about this as preparatory to or part of doing an alignment and more in terms of dialing in ride height, adjustable sway bar links and stuff.

The WSM excerpt is particularly helpful. Thanks

hacker-pschorr

I do this all the time on my 4-post lift. Steel bar & a ratchet strap, piece of cake.

GregBBRD

We do this all the time, on cars that have been on a lift.
Just don't go crazy and pull it down so hard that the front control arm bushings tear.

FredR

Mr Bulvot's photo shows how it is done. If you can do that with the car on the deck all power to you but I rather suspect it would be nigh on impossible.

Maybe build some kind of ramp to drive up on to and get some ground clearance one could work with, that and a couple of redhead bolts to form an anchor?

Eplebnista

Yes, clearances and space would make doing this completely on the ground a pain in the rear. One approach would be to set anchors in the floor under the attachment points to the car, grab some seat belt anchorages from the local u-pull-it, bolt the seat belt anchors to the floor and then thread the straps through the anchors. With extra strapping you could position the ratchet mechanism so it would be between the two anchors and aligned parallel the floor. If you are attached to the car at two points operating the ratchet would suck the car down but the ratchet mechanism would still be accessible.

Its a concept in progress. I still love my two post lift.

hacker-pschorr

I've been pondering some kind of rig to pull down the suspension while up on Rhino ramps or something similar. Maybe a steel 2x4 with eye loops welded (or screwed) on that is held down by the ramps.

Bulvot

If you're doing it on the ground, ramps would make it much easier.

If you're willing to put holes in your concrete floor (I prefer internally threaded drop in anchors so the bolt can be removed and not be an obstruction on the floor), then you could run the straps down to hooks in the anchors and then forward to a point in front of the car so that you can work the ratchet from in front of the car. This still runs into the issue of precise positioning of the car.

However, you could use some home made wood ramps like this:






Then attach a long piece of flat bar to the bottom of the ramps, then attached a square tube to that flat far, making sure it just barely fits between the ramps. That should give you enough clearance to work the ratchet mechanism under the car.

However, keep in mind that the pull down point on the car is behind the center point of the tires. Ideally, you want to pull it straight down. Pulling it toward a point that is forward of the anti-sway bar attachment points isn't pulling it in the right direction. It may work, but not as well or as easily.

Which leads to the second point...it takes a significant amount of force to pull the car down the correct amount. Even that thick round steel structural tube that I have in my photo above bends a bit. You absolutely don't want to use just a flat steel bar or a 2x4 laid flat. Maybe a 2x4 on edge would work, but I wouldn't want to attempt it with less than a 4x4. And if you put the bar to the rear of the front tires, the correct position, under the ramps on the ground, it will probably tend to pull the ramps up off of the ground. So, maybe have the bottom board be long enough to remain under the rear tires so that they will hold it down flat.

One very important point...you must have the front wheels on slip plates. Either homemade or regular alignment slip plates. As the car pulls down, the wheels will want to move laterally. If you don't let them slip, you'll lose a lot of the effect of pulling it down. Homemade works fine, but regular alignment slip plates are fairly cheap these days. Just search for aluminum wheel alignment turn plates.

Alan

My Porsche dealer had inserts in the concrete floor for this exact purpose.

Alan