Marlon

Hey - wonder if the glass popping issue is exacerbated by the DIY jacking procedure??? Realize that all 911's come up on both ends when starting in the back. But maybe the 993 chassis rigidity or lack of it in certain areas is contributing to the popping glass during the DIY jacking??? I'd like to figure out a way to jack the rear and 'help' the front at the same time so as to reduce chassis strain. I was thinking that if you had a couple floor jacks you could keep the body flatter while going up, but you need to be able to place the jack stands when the desired height is reached. Maybe ths is they way everybody does it and I've just missed a critical element of the procedure. Anybody thought about this???

Novice

I am looking at this new "Lift N Secure" design from Sears
I think this will work by jacking a little at a time at each corner.


http://www.sears.com/sr/javasr/produ...id=00950187000

Terry Adams

I feel a similar chassis strain going in and out of my inclined driveway at an angle. No glass popping, though.

AOW162435

Marlon,
Here is my fail-safe method. It does not introduce twisting motions to the jacking procedure:

I have had the car on 4 stands an inordinate amount of times since buying it in '05. This takes me less than 10 minutes and results in a very stable setup.

Since my 993 is slightly lowered, I first drive the front wheels on to a set of short 2x6" boards. Then using a normal Craftsman aluminum floor jack, I lift the rear by the engine case (hockey puck under the case) high enough to get one set of flat-top AC stands under the rear lift points. I let the car rest on the rear stands and then place a 2' length of 2x6" on the jack cradle. I fold a towel a few times to cover the board and then lift the entire front very easily by placing the board directly behind where the front bumper plastic ends (same place that a FPB would go). Since the weight of the engine and tranny are behind the rear stands, the car will pivot nicely as the front is raised. I then place the stands under the front lift points and get to work. Depending on what I'm doing under the car, I may then raise the rear a bit more, but you get the point. I've never had an issue with this method and feel very safe under the car using the AC stands.

Andreas

Mark in Baltimore

Marlon,

A cage is always the best way to reduce chassis flex, but I will say that I have never noticed much torsion with my car, even before the full cage.

jaholmes

It just happened to me. Looks like I have original glass and after jacking my car from the rear to get the front wheel up the bond holding the glass broke a the bottom at the wiper location.

The new sears jack looks interesting. I just wonder how many jacks you get and how low they are.

https://rennlist.com/forums/993-forum/365205-help-windshield-about-to-pop-out.html

Novice

I just got back from the sears store.
It comes with 2 "jacks" and lift to 17 inch. There is one left at the store, but sold out online. I still think it will work perfectly, but want to wait for others to chime in.

RallyJon

Great idea--the 993 NEEDS a front center jack point. But, is it really strong enough? It's supporting about 12-1300lbs.

Marlon

Concur with the center jack point idea - I was thinking about how to do that too. I seem to recall that the earlier 911's had a protective 'box' that bolted up around the steering rack (maybe I'm remembering something else). My guess is that AOW might be on to something, but I'd want to take a good look at the car while it's up in the air to assess it further.

One thing to consider if yyou are jacking the entire rear from under the engine as the first step, is that you must chock the front end first so as to not move fwd unexpectedly:^)

AOW162435

Jon,
The trick here is that a majority of the car's weight is now pivoting behind the rear stands. I lift the front from as far forward as possible - not directly under the spare tire well (which could easily deform). I've used this method for nearly two years and find it to be fast and worry free. It's amazing just how easy the front is to lift with this method. It borders on featherlight. Using this method, the car is lifted without any twisting actions.

I'll stick with what works for me

Andreas

RallyJon

My old 911 had no reinforced jackpoints at all, and jacking it up was always a precarious combination of rubber and wood to pad and distribute the load near pinch welds so as not to dent the floor. That's why I've always been skeptical that there is no place under a 993 other than the engine case and four welded pads that can support any load. Looks like there are a few spots that could, as long as you avoid the removable plastic covers.

stubenhocker

Andreas, that's a great idea!
I too feel very secure using my 'flat top" AC stands, I will try using your method!

Amfab

I think that any twisting that occurs with Cabs and Targas while being jacked is probably absorbed by the relative looseness of the structure holding the glass to the chassis. I'm sure the body actually flexes more in the Cabs and Targas, but I would think, especially with the Targa, which has a fixed glass rear window, there isn't the glass breaking issue because the relatively flexible body-top joint absorbs some of the deflection putting less stress on the glass. MikeJ can probably chime in on this. I would assume he squirted a ton of the insane "instant rubber" adhesive between the body and top of his Targa.