A Question About Jacking!

J

Jimbob-Squarepants

Member
Hi all, I wondered if you could tell me where the safest place is to jack up a P6 with a trolley jack? Unfortunatley my car didn't come with a jack and I don't want to be jacking up a 2 ton mansion in the wrong place lol.

BTW, it's the rear end I need to raise as one of my tyres has perished and wont pump up :(

Thanks in advance
Jim :D
 
In the centre of the rear panel is a block that sticks down about a couple of inches about 4" wide and 1" deep, that's the proper jacking point but you'll need a high lifting trolley jack and take care if it has a towbar bolted through it. If you jack up under the lower arms you won't get the tyre out from under the arch so probably best to go under the outer end of the diff pinion crossmember. It's a channel and you can make up some timber to just fit in there and jack up under that. You'll still need a good jack though because it lets the suspension hang down, which you need to get the wheel out from under the arch.
Forget about using the original jack in the jacking points.
 
I was going to start a similar thread to this one, as I've got some serious rear axle work to do. My workshop manual is suggesting I use 22mm steel bar in the rear jacking points, supported on axle stands. I have jacked the car up a bit using these points, but am under the impression there must be a better way. Where can I support the car to drop the entire rear suspension out. I need to remove mainly the diff and de-dion tube, but have decided to polybush everything, so the trailing arms have got to come out too. Where am I going to support the body for this...?
 
If you place wide pieces of board under the area of the jacking points,thereby spreading out the weight to be supported, you can safely support the vehicle without damaging the the base unit. I gave up on "jacking points" long ago.
I was able to remove all the rear components while supporting the car from those points.

Dick West
 
Hi All,

It's good to get back to the P6 Forum - had to work away from home for a few months, but now it's back to the P6!

I'm looking into a few winter jobs and came across this thread on jacking points which intrigued me. I've just gone out and bought a nice new trolley jack from Halfords - the 4x4 2.25 tonne variety that lifts really high - so that I could lift the car in the 'middle' somewhere and stick axle stands under each side at the same time. The front is easy with the front crossmember, but the back always puzzled me.

HarveyP6 - I've just taken this photo of my old girl's rear end (oh er!) is this the block that you meant for the rear jacking point? (shame about the quality of the pic, but its dark and hard to focus!) Do you know what it is connected to that will give this seemingly simple rectangle of metal the strength to lift the whole rear end of the car?

mini-RearJackingPoint.jpg


That's the first question, the second is - What do you guys put on your axle stands to spread the load. I intend to put the axle stands under the sills just under the normal jacking points - I know my old girl is really strong there, but I've got two sets of axle stands, one has a 'V' and the other a 'U' shaped top to them. Both obviously would prefer to have a cylindrical axle put in them rather than a bit of wood and plonked under the sill. I'd be interested in innovative solutions. Of course when you jack the car up, the car is at an angle and a bit of wood on top of the axel stand (as high as it will go) will put more pressure on one side than the other - because the car is not level. I'd like to be sure of my safety!

As always, I'd like your opinions.

Many thanks,
Brian.
 
When I stripped the suspension on my 3500'S' some years ago, I was fortunate enough to borrow a couple of lengths of old level crossing gate posts! They were about 10 - 12" square and were just the job. The only problem was when using them on the front of the car, the weight of the engine caused the car to pivot about the blocks of timber. This had the effect of lifting the rear of the car so that it ended up fairly level but with virtually all its weight on the 2 wooden blocks. Apart from being a bit unstable, I don't think it would have been too kind to the shape of the floor pressing! I counteracted the effect by placing 2 axle stands at the outer edges of the front crossmember so as to put the rear wheels back on the floor and regain stability. This left most of the front end weight on the blocks and the car didn't budge during all the heaving and grunting that gos with pulling the front suspension apart!
Roly.
 
Brian-Northampton said:
HarveyP6 - I've just taken this photo of my old girl's rear end (oh er!) is this the block that you meant for the rear jacking point? (shame about the quality of the pic, but its dark and hard to focus!) Do you know what it is connected to that will give this seemingly simple rectangle of metal the strength to lift the whole rear end of the car?

mini-Rear%20Jacking%20Point.jpg


Many thanks,
Brian.
Click to expand...

That is the proper jacking point, and providing the car isn't an absolute rotbox should have no problems taking the weight.

I have heard it said that they can fail but I've never come across one that has.
 
I use some old 6ft fence posts, cut to length (about the length of my fore arm), between my axle stands and the floor near the jacking points. Don't trust mine as I've A) not looked at them yet and B) Don't trust any repairs I've not done. Seems to work fine. I also jack up on the De Dion tube, works ok for me, then prop it up with the axel stands under the suspension near where the springs are
 
I also jack up on the De Dion tube, works ok for me, then prop it up with the axel stands under the suspension near where the springs are
Click to expand...

That sounds a little dangerous to me Richard - Do you mean that you jack up at the Dedion elbows, at the hub - rather than under the tube in the middle of the car!
 
For jacking the rear I use the suspension / diff front crossmember. I then put the axle stands at the outer ends of the crossmember. It sits in the 'U' shaped bit of the stands a treat.
 
Brian-Northampton said:
I also jack up on the De Dion tube, works ok for me, then prop it up with the axel stands under the suspension near where the springs are
Click to expand...

That sounds a little dangerous to me Richard - Do you mean that you jack up at the Dedion elbows, at the hub - rather than under the tube in the middle of the car!
Click to expand...

Under the middle, works well, always have. Seems very strong, any reason why not? (waiting to be corrected ;))
 
richarduk said:
Under the middle, works well, always have. Seems very strong, any reason why not? (waiting to be corrected ;))
Click to expand...

Says the man who's just had to overhaul his DeDion tube..................... :wink:

TBH although it's better to use the jacking point, I've never had a problem after jacking under the tube, not that I did it a lot but sometimes you have to.
 
Under the middle, works well, always have. Seems very strong, any reason why not? (waiting to be corrected )
Click to expand...

No (experienced) reason to doubt - I just believed that the middle part (tube) isn't built to take the strain of the car and would put undue pressure on the tube/elbow joints that would take the strain.

Part of my querying (and grateful for the responses) is that I want to raise the car and suspension together at the moment, trolley jack doesn't quite fit under the trailing arm at the shock absorber fastening.....

Still - the voice of experience (HarveyP6) has spoken and that's good enough for me. :)

Cheers,
Brian.
 
The only thing I would say is use a jack with a big saddle so it spreads the load a bit, not those tiny things that are normally found on the budget jacks.
 
I bow to HarveyP6 knowledge but it was a definate "NO-NO" jacking under the deDion tube when I worked on P6`s in the 70`s, if for some reason the rear jacking post was not available to use (by way of accident damage etc) rear was jacked up using a cut length of wood planking as a load spreader, under the diff nose cross-member which is attached to a very strong part of the base unit.

I have known a de-Dion tube indented by ham-fisted jacking (courtesy of an AA man on punture repair call out IIRC) I remember this well because I did the repair and it was not cheap. Customer and AA were in correspondence for some time afterwards ! ( think they did admit some liability ) Anybody who has had a de-Dion assembly apart will know the inner and outer tubes are made of quite thin metal, I rest my case......

I`ve said my piece, will now shut up
 
I have always understood that jacking under the DeDion tube was a no-no as it put undue pressure on the seals, and could also slightly bend the tube making it judder when moving in and out. Could upset the handling a bit when cornering.

Never thought to question this.

I don't think I will jack my car in this way.
 
harveyp6 said:
richarduk said:
Under the middle, works well, always have. Seems very strong, any reason why not? (waiting to be corrected ;))
Click to expand...

Says the man who's just had to overhaul his DeDion tube..................... :wink:
Click to expand...

LoL, I expected that, but that was just down to old age, not mine but the rubber boot. :)
 
That center jacking point behind the boot is incredibly strong....holds well even on my 2000 which has 1/2 of the boot floor rusted away. I wouldn't take a chance on deforming the DeDion tube and causing sticking or friction within the tubes, Good sized pieces of wood to distribute the weight are always a good idea, placed beneath the side jacking points.

The rover jacking points are nowhere near as amusing as those in my XK120. those require the removal of a plate, and dropping the jack down within the car. Don't ask me if I ever used them !!

Dick West
 
Having just replaced all the bushes/uj's/shocks on the rear suspension on my 1964 car (and you were worried about metal fatigue in yours?) may I offer the following. I do not use or indeed trust axle stands as they always seem inherently unstable to me, nor, for obvious reasons would I trust the jacking points. I obtained some 250mm x 250mm x 300/400mm long Oak timbers on which i would happily put a Routemaster bus. Where possible support directly under the rear shocks which transfers weight directly onto the top spring/shock support which is designed to take it. In this position you can remove/work on the de-dion tube, watts linkages, rear driveshafts and diff. In the event you need to work on the springs/shocks/trailing arms then I used the cross member that runs transversly and supports the diff mount bracket. True it means removing the diff but it is very strong and hence safe and the height and clearance that can be gained is a joy to work under.
Re jacking under the de-dion i would strongly advise against it, the tube is only designed to cope with lateral forces contracting and expanding it, critically so are it's supports. Remember it's fore and aft location is only by two flanges welded to the top/bottom of the driveshaft flange. By jacking under the de-dion you are in effect levering against the watts linkage which could very easily cause it to to pull out of the boot floor side or pull out of the de-dion top flange. Many a 3500 S has had these ripped out by over enthusiastic wheel spinners, arguably the larger lower link bush/flange is better equipped to cope but why risk it? The force on these when you take into account the weight and leverage by jacking so far back must be immense. Sometimes you have to take a chance and bend the rules in a 'get you home' situation but I wouldn't recommend using this method as a 'norm'.
 
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