jonmac wrote:
>
> John
> Many people use the diff for lifting as it is central. That does not mean
> it is a wise thing to do. There's a risk you might pop the diff mounting
> bolts through the top of the chassis....(snip)...
I would differ with you on this...
When you jack up the differential... you are NOT jacking up the mounting
studs... you are jacking up the BUSHED differential... which spreads the
weight across the structure very nicely... with little stress on the
studs themselves... In edition, there is not much SHEER strain on them
when lifting.
The stresses encountered by the differential and it's mountings, while
jacking, are far less than anything they encounter on any given drive
around town, with speed bumps and potholes... If jacking your car by the
differential causes a mounting stud to "pop" through the chassis...I
would say, "BETTER TO FIND OUT NOW, THAN WHILE DRIVING AT SPEED, ANd
HITTING A BUMP"...
Jacking "side to side"... takes time... and I would argue, the more
messing around one does while jacking a car exposes you to more
danger... and it is human nature that people will tend to try to speed
things up, by going up in higher intervals... leaving one side of the
car jacked up inches higher than the other...
Which again... exposes you to yet even more danger... AND... for those
concerned with damaging there car... this does put a lot of strain on
the car when flexed like that.
I've jacked up TR 4A's, in the rear, with floor jacks under the
differential since 1977. I never experienced a broken stud... (on my
IRS) about 8 years... nor do I have any problems with my solid axle
4A... (When IRS studs snap... it's because they're rusty and/or already
have a stress fracture, etc.) And my brother and I, the mechanics in
the family, have jacked up the family cars over the years... 280zx,
Jensen Heally, Jaguar XJ 6, Corvette Stingray, Mustang Mach I, 280 zx
Turbo, TR 7, Camaro, Ford LTD. Station WAgon with 429, and more... all
by the rear differential.
Jacking by the differential is safe. Safe for the car, safe for the guy
under the car. My humble opinion... others are welcome to comment.
--Justin
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