I have to disagree with your theory here. When you lift a TR6 on the
differential you are compressing the bushings which were not designed
to carry this sort of weight. I dont know if the mounting are strong
enough or not, but the bushings will certainly be abused by this.
Also I do not know how you can say this is less stress than driving
the car. This is not a live axle, there is very little stress on the
diff itself when driving.
I would still recommend jacking up on the chassis rails with a piece
of wood between the jack and the frame, and if you have 2 jacks do
both sides at the same time, to minimize frame twisting.
Not a flame, just my $0.02.
cheers
steve
Justin Wagner wrote:
>
> 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
--
Steve Chandler - Chandler-O'Bagy Associates stevec@rtd.com
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