Front spring change

Hello BB,

I use retainers similar to the ones used in the artice, except that they are very much longer. This way, once the spring is removed, I can undo each retainer alternating between the two until the spring has reached its static length. Works a treat... :D

Ron.
 
You need to be very careful with home made spring compressors . I once saw something a garage had made to compress the rear springs on a RR Silver Shadow and it had come close to breaking under load
 
Hi Ron,

Thanks for the reply I take it you aren't the Ron mentioned in the article then!

Anyway should have checked the link before posting it it was actually this article I meant to link too
http://www.p6roc.co.uk/download.asp?fil ... +27-29.pdf

It's a novel idea whereby large diameter threaded bar is drilled and tapped and then screwed onto the existing 5/16 UNF studs and then used to release the tension in the spring. May use the method you have described to refit though as at least it will make removal and refitting easier for the future especially if some shimming is required to adjust the ride height.

I'm keen to try and remove the springs intact rather than flame cutting so I can confirm at least that they are the reason for the lopsided suspension. One thing i'm not to clear about though is once the shock absorber is removed what will the top suspension rocker arm do? I plan to let it down gently on the jack but how far will it move once released?

JP Restorations have told me they (used) to remove the springs by just undoing the four rocker arm retaining nuts and letting nature take it's course but not sure I fancy that one!
 
Hello BB,

Yes indeed, the Ron in the article is a different fellow altogether.

With the front of the car raised and resting on stands, the guard removed and a jack supporting the swivel pillar, shock absorber off, anti roll bar removed, and the flexible brake hose released so as to allow sufficient movement of the pillar, the spring retainers can be positioned. Try to arrange them so that they are roughly opposite each other. Tighten each in turn until the spring is fairly well compressed. You might find it easier also to remove the top ball joint from the top link. Lower the jack supporting the swivel pillar and allow the top ball joint taper to come away from the top link.

Remove all 4 nyloc nuts from the top link securing rods, accessing the inner two after having removed the glove box. With the spring captured by the retainers, the top link can now be withdrawn. You will find it easier if you can secure an assistant to hold the spring up as you pull the top link free, else the spring and retainers may well come crashing down once the top link is free.

If you leave the top ball joint within the top link, you will need to release the lower link and stabiliser from their base unit fixings in order to allow sufficient movement of the swivel pillar and top link to remove the spring.

Once released from the retainers, the spring is approx 17" in length, far longer than when in position, so the retainers need to be long enough to cope.

I assume you will also be fitting all new suspension bushes into the top link along with new rubber ball ends that fit into the top link pressing against the spring cup? If so, are you going for rubber of poly bushes?

Ron.
 
Cheers for the info Ron. Are the retainers you refer too a pair of standard spring compressors?

What did you think of the method outlined in the second article I posted a link too?

Yes indeed I am planning to replace the bushes. I've ordered a set of rubber bushes from JRW which are apparently made to the original pattern. I have been told that the poly bushes can cause problems if used here.

I say this with some trepidation and hope that you are not about to tell me I should have ordered poly ones!!
 
Hello BB,

Yes the method outlined in the second article would appear to be quite effective. As was mentioned, if it were me, I would still like a friendly helper present, especially when it comes to refitting.

I have never used poly bushes, prefering either the oiginal Metastik bushes or quality remanufactured items such as those available from JRW. If at some point I do fit poly bushes, then the top link is one place that would remain off limits.

When it comes to fitting the the bushes into the top link, the outer pair of cone bushes are quite straight forward, but the inner bush is a different matter entirely. The bush must first be pressed onto the top link, and then the bracket with its two long threaded rods must then be pressed over the bush, ensuring that the angle made by the face of the bracket with the anti roll bar mounting face is 90 degrees.
This pre requiste when using either original metalastik bushes or remanufactured items to the original specification makes for refitting the top link shall we say rather more than difficult. The inner bush squirms during normal suspension movement, so you have to pull down on the top link while simultaneously keeping the spring up and located correctly. I think it remains physically the hardest thing I have ever done on a P6. Some bushes that were available years ago were far too soft, so fitting the top link in this case was no where near as difficult, but the sub standard quality of the bushes meant that they would wear out very quickly.

The spring retainers that I use comprise lengths of threaded rod, easily 24 or 25" with hooks sliding over the rods and nuts at either end, one end being fixed with double nuts, the other is free to move.
As the available space is rather limited, compressing the spring in situ will take a while, as all too often when the spanner is on the nut, there will be no where for it to swing, especially with the inner retainer closest to the base unit.. :evil:

Ron.
 
Well as they say fortune favours the prepared man so thanks for all the hints tips. I have to say I'm not at all looking forward to doing the job but it has to be done at some point so I may as well get on with it!

The suspension on this car has always been less than satisfactory. The front springs have sagged and the rear springs are far to heavy. The ride height at the rear of the car is 3 inches higher than it should be according to the manual and consequently the rear shock top out with bang on rebound. I've got new springs coming for the front and a set of good second hand saloon ones for the rear.

I've got the GAZ adjustable shocks from Classeparts fitted now which have improved things considerably but I know the ride can be better...

Will report back once the job has done with photos of job and any minor injuries sustained!
 
Bushes for the top link are indeed a tricky issue! When doing the Thai car I specified Polybush bushes without really thinking about it. When fitted they "locked" onto the pivot arm with the result that the front suspension would stick in whatever position it had been assembled in, even with the engine in. Now that I have driven Lucky a bit I am also extremely nervous about doing anything to increase noise transmission into the bulkhead from this source.

The JRW bushes, if rubber, may still be missing the bonded in steel bush down the centre of the bush. If so, do they also "lock" onto the pivot arm?

My first preference would be for Rover o.e. bushes wih the metallastic insert. Second preference would be for the Polyurethane bushes with boded in steel bush that Alan at Classeparts sells. Third preference for rubber repro bushes without the steel bush and only finally for get out of jail Polybush bushes.

These bushes are surprisingly important to P6 front suspension. The clue for worn bushes is incorrect or unequal camber on the front wheels.

Chris
 
The bushes from JRW are bonded with a steel insert in the middle so as per OE?



I'd much rather be giving my money to Alan at Classeparts who was an absolute gent when I bought the Gaz shocks from him, unfortunately my preference was for rubber bushes and he only does poly.

Anyone got any comment on the free length of 15.5" on the supplied front spring. Considering the hassle of changing them i'd rather not put them in until sure they are correct.

Got a set of SH standard springs to fit to the rear as the ones fitted at the moment are far to stiff. The suspension sits a full 3" higher than spec and is topping out the shock absorbers. This is making the rear of the car very noisy as it will knock on rebound. Also it means that the drive shafts are at a more acute angle than they should be and the De-Dion tube creaks as the track tries to change when you push on the rear with the car stationary.
 
Hello BB,

The replacement springs that I fitted that were manufactured in Australia by spring specialist K-MAC were also shorter than the originals. The reason being that they were stiffer, so the length is reduced to compensate.

The original springs had specifications for the 1974 model as : front 170lbs/" 17.000" long (The factory workshop manuals list the length as 16.281")
rear 260lbs/" 13.038" long

The replacements were................................................front 220lbs/" 15.250" long
rear 340lbs/" 13.000" long

In the case of mine, the car sat a tad higher all round, but that may have been down the the originals starting to sag. In any case the ride improvement was sensational and the overall appearance looked excellent!

Ron.
 
Cheers Ron. Interesting that the Rover manual disagrees with the Haynes one

I'm sure the JRW springs will be shorter for the same reason i.e. slightly stiffer. As I'm sure you agree it's just nice to know the details!

When you say a tad higher did you check against the ride height specified in the manual or was it just a general observation.

With the experience i've had with the rear shocks topping out I do wonder when i see how high the rear of some P6s sit whether it is a common problem. The travel on the rear suspension isn't anywhere near as long as the front suspension (presumably the design of the rear suspension prohibits excessive travel) and therefore the correct height setting is reasonably critical to ensure the shock absorbers sit roughly in the middle of their throw.
 
Hello BB,

I must admit that I have never checked the ride height. Certainly I have never experienced any problems with the rear topping out, or any issues either with the front for that matter. If you have a look at my introduction in the new members section, you will see some photos of my Rover for comparison.

Ron.
 
Mmm. The workshop manual gives the actual manufacturing specs for the various rear springs - I've been trying to get some made to factory heavy duty spec! My experience (via Ian Wilson) was that the wire diameter used wasn't readily available - I'd have had to buy a full roll in order to precisely replicate the factory spec. So it looks like I shall finish up with a compromise with more coils to achieve the same rate.

The circuit racing fraternity go to a great deal of trouble to precisely balance the wheel loading on each axle by putting weight transducers under each wheel and then adjusting the spring packing as per the Rover workshop manual. This eliminates both any fractional variation between each spring and also any dimensional "tolerence" or distortion in the bodyshell. Rover never quite got that far - they satisfied themselves by getting the ride heights equal side to side which addresses spring variations but not bodyshell errors.

To get the ride height substantially wrong - eg 3" too high - the springs can't have been wound correctly. Either too many coils or too large a wire diameter or both. It would be pretty difficult to pack the ride height up by more than about 1/2" using the factory packing rings.

Much more common is low ride height due to the springs sagging over the years. You might like the appearance but you've thrown away potential suspension travel, so you'll hit the bump stops in normal driving much earlier than you ought to. As an aside the P6 is designed with unusually large bump stop rubbers and I believe these are intended to start to come into play in normal use to act as a sort of variable rate element to the springing.

Chris
 
i have been looking on here for some advice as i will be changing the front spring on my series 1 v8 but i have been told that i got to be careful with the shims they must go back on the right way wot is the worst thing if i did not put them on the right way wots happenes if i left them off
 
The shims are there to get the ride height correct both sides. That implies a huge performance taking springs on and off and trying various combinations of shims until you either get tired, break the spring compressors, wake up in hospital or are satisfied with the result!

I suggest in the real world there are a few short cuts. First assume the car is built symmetrically and therefore given equal length springs the car will sit level. (this is actually a significant assumption with BL / PSF buil tolerences!) Place your new front springs next to each other on the ground. Do both springs have the same free length? If not add a shim to the short one to bring it to the same length as the long one. Fit to car. Only go back and repeat if there is something visually and obviously awry!

For the more picky of us the true objective is to get the load of the car spread equaly side to side at both front and rear. To achieve this you will need a set of four weight transducers. First step is to verify the bodyshell. With suspension removed land the rear of the car on struts locating in the spring seats on the base units and resting on the two rear weight transducers. At the front there is a problem with the P6 because of the round the corner suspension design so I would arbitrarily choose a point on the front chassis rail (one of the bottom link pick ups?) and support similarely. Is the weight evenly distributed? Alocate packing shims at the rear until it is. Fit suspension and support the hubs on the weight transducers. Measure the ride height at each corner. Insert shims until the ride height is correct and the weight is evenly distributed side to side (there will be some degree of compromise there). Dismantle suspension,insert shims and reassemble. Now the suspension preload at rest is as the design intended which will make a measurable difference to handling and reaction to bumps at least in circuit racing mode! Needless to say this is substantially beyond what Rover and BL attempted with production cars.

Chris
 
so if the springs are the same hight is it worth putting the sims on as i said b4 i think my car was to high then the standard setting so i am thinking is it worth me leaving them off
 
Hello Gareth,

By how much is the front of your car outside the ride height specification? Taking shims out will influence ride height by more than the thickness of the shims removed.

Ron.
 
Hi Ron if i recall i think it was about 1 inch or 2 but i dont know if the springs have been replace is the past so i dont know if its got the power steering 1's on there or not. What i would like it to sit a bit lower then standard but not loads if you know what i mean so i got new spring to go on there so i thought if the both new spring as the same hight could i leave the shims off and if its to low i could just put 1 on so i got the hight were i would like it 2 be as i said i dont want it to be to low just a bit lower then standard i did put new spring on the rear couple of years ago and i dont recall it having any shim in the back as mine does sit a bit 2 low so i will have to look into the back
Gareth
 
Hello Gareth,

That sounds like a plan.. 8) Fit the new springs and see how she sits and then add any shims if you need too. Excellent!!

Ron.
 
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