Daniel5691

1981 928S Euro 5 speed

So I am the proud owner of a set of brand-new LiftBars!

At some point, my 928 will be up on these LiftBars and the transmission will be removed for a trip to Greg Brown.

Probably before that, however, my engine will be coming out to repair a cam tower oil leak.

I will more than likely only be jacking up the front of the 928 for the motor pull,
and therefore not use my LiftBars,
it did make me wonder about any changes to the center of gravity for the LiftBars when bigger chunks of the 928 are removed.

Do you have to change the central "jack point" either fore or aft when these larger parts are removed? For example, would my 928 "tip" nose-downward toward the engine
after the transmission is removed
and the LiftBar is back and balanced only
by the centrally-placed jack (and not 2 jack stands)
in the process of returning the 928 to the ground ?

Just wondering. I welcome your comments, laughs, and mild insults. LOL.

Wisconsin Joe

I wouldn't worry about it.

Since you are only lifting one side at a time, the other side is either on the tires (down) or on the jackstands (up).

That will keep it stable.

And while the engine and tranny are definitely not light, they aren't that big of a percentage of the weight of the car.

One more time, not an unreasonable question. Lifting a 3000+ plus pound car off the ground isn't a task to be taken...

Lightly

Ducman82

i did all of that. had ZERO issues with balance.

bogdann

Why wouldn't you use the liftbars when taking out the engine? I would have thought it would be more stable than jackstands at the front and better access than ramps. Just curious

Ducman82

i used them while taking mine out, keep the car level, makes life easier while moving that engine around

Dave928S

+1 Keeping the car level makes it easier to get the motor out.

medipedicman

I used my lift bars for a transmission swap. It helped out big time. I always use two jack stands per side, under the bar, near the factory jack points. It is as stable as you could ever need. I was in and out of the car and up and down from underneath. Doors open, doors closed, trans in, trans out.......

It never budged.

bureau13

I'm guessing having the car sitting on a level surface is key with these? I have been doing most of my work in the driveway, which is not level, or I'd have purchased a set already (I don't put both front and back up on stands on my driveway, either...one or the other).

depami

FredR

For those interested in statics instability would be created if the overturning moment at the front and rear support points were reduced to either zero [tip point] or created a positive overturning moment in the overhang.

A quick calc based on the following assumptions:
1. Weight on each axle is 800kgs
2. Distance from front support to front wheel is 50cm
3. Distance from rear support to rear wheel is 65cm
4. Distance between supports 1.45m.
5. Engine straddles the front wheel centreline
6. Transaxle straddles the rear wheel [in practice it is slightly more forward].

In stock condition there is a safe overturning moment of 1200 kgM on the front support point and about the rear support point there is a safe moment of 1000kgM. If the engine is removed the rear support number drops to about 525kgM - still plenty of safety. if the transaxle is removed the safe overturning moment at the front support point drops a little.

In simple terms with the engine out and the car on liftbars to create instability you would need to have about half a tonne of concrete or 5 big chaps in the rear hatch area.

Rgds

Fred

bureau13

Ha ha my driveway is not quite that bad!

Daniel5691

Guys,
Thanks for all the input.
I am confident in the sturdiness of the LiftBars. They are built like tanks!
And Fred, thanks for the math and comparison.
Also, I do appreciate the observation that a car level and up on LiftBars actually assists in the removal of the engine.
You guys are the best,
PS that photo is hilarious. In a way I hope it's a real photo and not photoshopped LOL ! ! ! ! !
Dan

Wisconsin Joe

Apparently real, although the angle of the shot makes it look worse than it is.

http://www.contractortalk.com/f11/steep-driveway-36589/

bogdann

I have a house across the road with a similar but not so steep drive and anything but an SUV scraps going up or down the drive so they park on the street. Funny watching new tenants move in and they realize they can't use the garage.

mickster

Good to know re: liftbars, jacks and jackstands.

When we were house shopping in 2013, any house we pulled up to that had a steep driveway was out. We saw some great ones and they were steep, but with a good approach angle; however, we also knew one of us would slide down in ice or snow...and our friends parked their Tahoe on their steep driveway...left it in drive-nearly went down a steep hill into moderate traffic.