Floppy driver's seat

[fortnum1977]

Hello,

I drive a 1972 P5B Coupe and the driver's seat has collapsed. The adjuster handle to the left has completely freed up and is loose... the chair just falls back horizontally now. I have wedged a bucket behind me to keep it upright... that's what I call a bucket seat.

Are there any experts here who know what may be wrong with it... do I need to buy parts?? can I repair it??? etc...

Many thanks,

Chris

[johnwp5bcoupe]

Chris remove the ss trim both side and see if the adjustable locking screws are in place first and the long locking rod is screwed into the large adjustable hexagonal locking pads

[Phil Nottingham]

Parts should not be necessary - there is something on the Forum about the correct adjusting sequence

[johnwp5bcoupe]

He has to check that the locking screws are there Phil before thinking of any adjustments often the screws fall out due to the threads stripping or just fall out

[Phil Nottingham]

I was not disputing your comment merely adding to it

[johnwp5bcoupe]

Me Toooooo Phil just trying to point him in the right direction

[fortnum1977]

cheers... yes there seems to be some loose screws inside those plates on either side... but I'm a bit worried 'cos I think the chair has been bodged up at some point. A screw fell out of it a while ago which was a self tapper... clearly not original.

The locking screws are in place though, I've had those plates off to take a look. Not sure about the 'long locking rod'... will inspect that soon.

[johnwp5bcoupe]

Is there any torsion on the torsion bar?? this is probably where the self tappers came from if the seat back falls under it's own weight there is no torsion applied best to sort this problem first

[fortnum1977]

that's right, no torsion at all and the seat just falls back.

What do you reckon?

[johnwp5bcoupe]

First check the threads in the seat frame make sure you can get 2 good screws in if the UNF threads have gone you may have to retap with metric you then have to put a spanner on the end of the torsion bar where the screws are and wind up the torsion bar maybe half a turn in the correct direction while holding the spanner you then under tension try and fit the 2 screws in the nearest hole if you have done it correct the seat should fly back to the upright position

[fortnum1977]

ok I think i understand but what are the UNF threads?

[Phil Nottingham]

The last Imperial standard threads based on INCHES. The thread diameter is say 1/4" and UNF means Unified National Fine as opposed to UNC which has a course thread ie bigger pitch which is less threads per inch. The course threads are used in Allo etc

Metric/UNF nuts/bolts are not interchangeable although some AF spanner sizes are virtually equivalent

Without looking I think they may be 1/4 UNF (or 3/16th) on the seat which is very common and there are many on the P5 - a metric version nearest is 6mm which is actually smaller so the next size up will 8mm or 3/8ths

[miguel]

Hi,
This issue is important for me because in Portugal we use the metric system. When recently working in the Riley, I encounter problems with the spanner sizes. Although many are equal there are some sizes that dont fit exactly and that damages the bolts/nuts. I decided to buy a "English" (inches??) set. What size range should I look for?
What´s UNC and what´s the difference to UNF?
Thanks,
Miguel

[johnwp5bcoupe]

If you get a set of imperial spanners to cover these sizes you should be Ok 1/8, 3/16, 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16 and 3/4 there are a few more odd sizes but several metrics will fit have a look here www.vars.freewire.co.uk/tech/charts/spanners.htm
As Phil said UNF is Unified National Fine and UNC is Unified National Course there were so many standards used in England I can understand your confusion

[Phil Nottingham]

Fortunately its not a P4 they had BSF/BSW on the chassis with a 55 deg fine and coarse thread respectivly - AKA Whitworth. The seats may have them of course. Electrics will have the small BA (British Association) threads and some pipe fittings use BSP British Standard Pipe!

Metrinch spanners/sockets fit both AF Metric/Imperial & Whitworth

[fortnum1977]

Correction - my seat sits upright but is completely floppy and won't take any weight. It doesn't, as I said earlier, fall down horizontal.

[johnwp5bcoupe]

philnottingham said:

Parts should not be necessary - there is something on the Forum about the correct adjusting sequence

That's a different problem as Phil quoted there is a correct sequence probably best read in a manual or from the forum there are several things to check compression tube dimension, adjusting the pad and locking rod etc etc

Still check the screws in the squab mechanism

[fortnum1977]

compression?? tube dimension??? is this a chair we're talking about???

I've got the manual so will consult that... but as I remember, when I was trying to bleed my PAS box, that book was about as helpful as a kick in the b*lls...

[Phil Nottingham]

Its quite a complicated set-up and gives stepless adjustment of the back by the twisting of a hollow tube that runs across the back. They are generally quite reliable but can sieze through lack of use/damp. They can also fall apart. They were used only on P6 Rover and Rover P5 Mk3's onwards so parts can be obtained if needed.

The seat back is locked by pressing hard down on the big grey lever at the side of the cushion - you have tried this? Lifting up releases it. Adjust it so that it quickly returns upright without any help from fully reclining when lever is lifted up.

The workshop manuals were not designed for novice owners but for trained mechanics and so assumes sometimes quite advanced knowlege.

This said one is essential whether you DIY or give it to a modern mechanic who is used to throw way and fit new rather than repair a component

[Warwick (Ozcoupe)]

The main thing to remember Miguel, is that UNF, UNC and Metric spanners are described in "AF" sizes. AF simply means "Across the Flats". If you measure the size of the bolt-head from one flat side of the hexagon across to the opposite flat side (across the flats), whether in inches or in mm, that's the size spanner you need.

Therefore you can usually make do with a 13mm spanner on a 1/2" bolt-head for example.
If you have a bolt-head that measures 5/8" across, you need a 5/8" spanner.

Whitworth, being the grandfather of standardized bolt and screw sizes, is the odd one out. The size written on the spanner represents the size of the bolt shank, not the head.

A 1" AF spanner measures 1" across its jaws and fits a bolt that is actually nominally smaller since the bolt size is determined by its shank diameter.

A 1" Whitworth spanner however fits a 1" bolt. That is, the shank of the bolt is 1" in diameter. The head of such a bolt is very much bigger and so a 1" Whitworth spanner is huge since the jaws are much more than 1" across.

I hope that makes sense.

Warwick.

[fortnum1977]

Ok Phil, thanks for this advice. As i said, the back sits upright but can take no weight and the grey handle is completely free/loose/does nothing.

So, what do you think I should try doing?

thanks

philnottingham said:

Its quite a complicated set-up and gives stepless adjustment of the back by the twisting of a hollow tube that runs across the back. They are generally quite reliable but can sieze through lack of use/damp. They can also fall apart. They were used only on P6 Rover and Rover P5 Mk3's onwards so parts can be obtained if needed.

The seat back is locked by pressing hard down on the big grey lever at the side of the cushion - you have tried this? Lifting up releases it. Adjust it so that it quickly returns upright without any help from fully reclining when lever is lifted up.

The workshop manuals were not designed for novice owners but for trained mechanics and so assumes sometimes quite advanced knowlege.

This said one is essential whether you DIY or give it to a modern mechanic who is used to throw way and fit new rather than repair a component

[johnwp5bcoupe]

The first thing to check is that when you operate the lever the hexagonal pads try to pinch the squab frame either side of the long slot? if it is trying? it could be that the adjust pad (the large nut on the tube) needs adjusting the start point is 18 11/16" (474.662 mm) if nothing is happening it could be the rod is rusted up! something may be missing (screws?) or broken? the principle is when you push the lever down the pads pinch the frame by pulling on the rod this can be adjusted on the pads either side but the tube must be the correct length first and the rod must run freely! put white grease on the threads and rod to save further problems

[fortnum1977]

Well, instead I picked up a set of all four seats from Enfield on Saturday for £180... and they are in great original condition.. the stitching is still fresh... look like they havn't been sat on... just a little dull after a long period of storage but can be brought up no problem.

The front seats are, however, thinner than my old ones.. the back of them I mean.

I know that the seats were redesigned at some point but thought it was the base.

Anyone know the deal here?

cheers

Chris

[Phil Nottingham]

The thick back seats were for MK3 3 Litres and very early P5B's up to about Mid 69. They were changed to thin ones to give more legroom in the back especially with Coupes

[dorsetflyer]

Phil, have you got your wires crossed on this one.
I thought the thicker back seats were changed in 1969 to the thinner version to give more legroom in the Coupes and this standard of seat remained to the end of production in 1973