Bushing and suspension tautness

[colnerov]

Hi Chris, Do you think your car is a one off error or have you come across others that are that far out?
I know you are telling other people to check this but any feedback about more?

[chrisyork]

I'm sure from what I've heard from people trying to fit wider tyres, and the other two P6's I've tried that on myself, that the variation in mudguard / D post dimension is common. But in a way I can accept that, because with 185 tyres it wasn't a critical dimension for Rover. Mind you, it must have caused fun and games on Denovo cars which were 205 section.

I've never heard of the problem with spring platform location in specific terms before. But then I very much doubt whether anyone has thought to measure it or had the technical knowledge to devise a technique before. I have heard of cars with springs of unequal lengths before, and to my mind that is a prime pointer to this problem. I'm also a bit suspicious of Rover having provided a procedure and the facility to pack springs with spacers. I've never heard of that on any other car before.

I've only actually driven four P6's sufficiently to form an opinion of their road behaviour. these were a '65 SC, '72 TC and '73 V8S, all when new, and Lucky of late. Of these Lucky steers and corners by far better than the first three, and of them the '65 was much better than either the TC or especially the V8S. All had manual steering. The V8S was like steering a ship! Besides steering quality the underlying stability of the car - its propensity to need steering correction - detiorated very markedly with the two newer cars.

Another factor that makes me suspicious was that Rover were not in control of base unit production. This was done at a separate facility by Pressed Steel Fisher. Such an arrangement is prone to problems in quality control.....

At the outset, Rover's vision was that the cars would not require "fitting" of the body panels - they'd just bolt straight on! We know today that this is a huge distance from the facts! I think it's telling that Rover had a specific gang on the line to sort the panel fitting out. That would have got up my nose if I'd been production director, so you can bet that Rover tried pretty hard to dispense with it.

So the answer to your question is that I don't have any specific evidence as to how common the spring platform problem is. But there are lots of pointers which suggest to me it could be very common. Basic engineering experience of what happens in real production situations tells me that, at the very least, there will be a batch of cars around my chassis no getting progressively worse until the problem was identified and corrected. My experience of the times, my knowledge of what was happening with Rover's financial situaution and the management upheaval inevitable with two take-overs in quick succession suggest that the identify and correct bit are unlikely to have happened. Again, Rover's intention was to have had P10 into production to replace P6 around '74. Inevitably that would lead to a lack of interest in what was happening on the P6 line. Especially with the demotivation resulting from a cancellation and start again instruction from on high.

So yes I do think this problem is very common.

Chris

[Tor]

Thanks Chris for your description, I buy your take on events completely (whilst hoping my car isn't one of the bad ones obviously ). Considering what you say about bulkhead and leading edge of sills as the alignment basis for the body shell, it makes sense in my non-engineer head to set the car up level at the forward end of the sills and supporting the rear at a given middle point akin in function to the front crossmember (the tow bar strengthener if you have one) - somehow the opposite of what you did with Lucky - and then gauging the spring platform at the rear, as it sounds like the rear half of the car could be progressively getting out of line as you go?

[chrisyork]

Well for all the small amount of extra time and trouble why not satisfy yourself that the sills are square to the bulkhead by doing a four point check of the four sill ends first? This isn't quite as easy because you need to remember the possibility of the shell twisting so as to sit on your four points.

So; support level under the front of the sills, then support at a single point at the back and measure whether level under the rear of the sills. Then reverse process by supporting at the rear and checking the front. At that stage you then can proceed to the spring seat checking. I would do this from the rear sill supports as they are much closer to where you are measuring.

Chris

[Tor]

Had a quick inspection of offending-side top link today, and the bushes seem intact but very soft. The LHS diff bracket mounting bolt spacers were found rattling and we found the bolt needed a few turns and tightened that up... Hmm. I've been finding various bolts and nuts not torqued up since I got the car... But anyway, I think I'll order four trailing arm bushes and top link ones, as I have a feeling it'll help. My local helper remarked that the LHS rear trailing arm bush was crumbling badly, as I've mentioned before.

Thanks again Chris for your helpful description. I'm asking around and it's very hard to get help with checking the base unit by the hour in these parts. There's a youth motoring centre left to contact so fingers crossed.

[BBLongman]

I have a similar problem on my car. I have read through all the posts but could have missed something so apologies if I am repeating advice already given.

A method I used to give a quick check of the front and rear springs independantly was to jack the each of the car using a piece short piece of tube as fulcrum. Under the jacking pad at the rear and under the cross member at the front. (I used a piece of stout timber at the front since the cross member is curved) Through this I was able to determine that the car sagged on the right solely because the front drivers spring had sagged. The rears were fine as the car sat level when jacked at the front.

I've bought the new front springs.... still haven't fitted them yet!