Well, you are right in what you are saying about the gauge of the
rubbers and I certainly agree that they were jacked up when they were
new, but I have to say that the crossbar in not a heavy gauge and the
cars have experienced some wear and use and, of course you can jack it
up where you want, but I for my part take the extra work and jack it up
on the stronger chassis rail. And I don't think this is misplaced at
> From: Justin Wagner[SMTP:firstname.lastname@example.org]
> Reply To: Justin Wagner
> Sent: Sunday, April 05, 1998 10:10 PM
> To: Steve Chandler
> Cc: email@example.com
> Subject: Re: New lister, query on TR6 jacking
> Have you ever held one of those bushings in your hand? Have you ever
> looked at a IRS frame, with the body off?
> How can you say they're "not designed to carry this sort of weight".
> Think about the sort of strains those bushings encounter when you
> down that gas pedal! And with your outer axles thumping up and down
> your drive down a rough road... No, it's not a live axle... but if
> differential weren't encountering strains... they would have mounted
> them in garden-hose washers....
> When you're jacking a car... it's a gentle slow process... Those
> bushings can handle it... the load is spread amongst 8 thick solid
> bushings!!!! the structure can handle it... it's the same piece of
> steel that handles your springs and suspension!!! And once the car is
> in the air, it's put on jack stands... so it's not even being kept on
> that weight for very long.
> Honestly, I would just let this ride... but when I think of some
> percentage of the newsgroup falling for some misplaced theory about
> dangers of jacking a car by the differential... I feel a need to say
> If you have two jacks... and no floor jack... by all means... jack up
> the outside rails... as you suggested... but if you have a floor
> (every shop should have one)... and you'd rather spend time working on
> your car, than jacking it... just jack the diff and lower the car down
> on a pair of jackstands... and be done with it.
> Steve Chandler wrote:
> > I have to disagree with your theory here. When you lift a TR6 on the
> > differential you are compressing the bushings which were not
> > 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
> > > > 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
> > > studs... you are jacking up the BUSHED differential... which
> spreads the
> > > weight across the structure very nicely... with little stress on
> > > studs themselves... In edition, there is not much SHEER strain on
> > > when lifting.
> > >
> > > The stresses encountered by the differential and it's mountings,
> > > jacking, are far less than anything they encounter on any given
> > > around town, with speed bumps and potholes... If jacking your car
> by the
> > > differential causes a mounting stud to "pop" through the
> > > would say, "BETTER TO FIND OUT NOW, THAN WHILE DRIVING AT SPEED,
> > > HITTING A BUMP"...
> > >
> > > Jacking "side to side"... takes time... and I would argue, the
> > > 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
> > > things up, by going up in higher intervals... leaving one side of
> > > car jacked up inches higher than the other...
> > > Which again... exposes you to yet even more danger... AND... for
> > > concerned with damaging there car... this does put a lot of strain
> > > 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
> > > IRS) about 8 years... nor do I have any problems with my solid
> > > 4A... (When IRS studs snap... it's because they're rusty and/or
> > > have a stress fracture, etc.) And my brother and I, the mechanics
> > > the family, have jacked up the family cars over the years...
> > > Jensen Heally, Jaguar XJ 6, Corvette Stingray, Mustang Mach I, 280
> > > Turbo, TR 7, Camaro, Ford LTD. Station WAgon with 429, and more...
> > > 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
> > >
> > > --Justin
> > --
> > Steve Chandler - Chandler-O'Bagy Associates firstname.lastname@example.org