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Post by johnwp5bcoupe on Jun 19, 2015 6:45:18 GMT
Will it be a P5B then ?- safety and mandatory current legislation mods are one thing but where does it stop this will turn the car into a replica or retro vehicle - almost like the BMW Mini If new parts or good secondhand ones for limited use classics are NLA then there is no choice - surely the somewhat slack road-holding which was good for the time and price is part of the attraction of classics of any make and as far as modern cars are concerned they can keep their so called improvements as far as I am concerned Much more on this topic I may moderate it to "Modified!  I find this topic irrelevant and I agree with Phil if the original mounts/parts are available just fit them!!!! the mount design is part of the original build/design of the car and IMHO perfectly adequate for what the car was designed for "IT IS A CLASSIC" not a modern look alike, if you uprate the performance yes you will have to probably "alter" components therefore it is modified! yes I fitted an OD to mine but it is purely for economy not handling and in no way alters the original look of the car. My car handles like it should as it is maintained as a Classic ie regular checks of "everything"! what worries me is the number of cars I see with shiny paintwork and you looks at the underside and is is another world of rust and crap! and they wonder why their car handles badly! My comments are in general and not directed to any one on this forum  |
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Post by Steve P5b on Jun 19, 2015 6:51:44 GMT
Steve that's the sort of thing I was intimating. It's great that the mounts are still so durable even when they apparently appear in poor shape but it's bad engineering practice to have the subframe impose any load on the steering coupling. These loads, up down and sideways are placed on a rigidly mounted steering box with only a rubber and fabric coupling to compensate for misalignment. Imagine the stresses imposed on the steering box (especially on rough roads.) If you disconnect the steering coupling then insert a spacer of the correct thickness between the body and the subframe until the shafts are directly aligned then there will be no initial loads imposed on the steering box. This is how it should have been initially setup. Having a good look at what goes on it would appear that vertical movement is possible, in my case 4mm.(assuming these subframe mountings are in good shape) and on rough or undulating roads this movement in a vertical plane will affect the steering coupling at the steer box to column joint( quite considerably) and of course the brake pipes! This is the effect of 25mm vertical movement between the subframe and body. Quite surprising!  This the effect of just 4mm vertical movement between the subframe and body, quite possible with normal driving. Attachment Deleted |
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Post by Steve P5b on Jun 19, 2015 7:08:53 GMT
So here is a picture of one of the rear mountings on my car, as you can see it looks in reasonable shape with no apparent movement that you wouldn't expect testing it with crowbars and the like in situe( all MOT'd and ready for the road).It's been said they don't suffer due to lack of oil etc like the fronts do.( and probably the case) However on removing this mount things weren't so good
Attachment Deleted
Attachment DeletedThis mounting fell apart and has been subjected to it's last high velocity trip across the workshop into the bin. So I conclude from this that even though they may look in good shape, they may not be. This one certainly wouldn't perform as originally intended and was effecting my car but showed no apparent defect fitted to the car. |
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Post by Deleted on Jun 19, 2015 7:59:16 GMT
So here is a picture of one of the rear mountings on my car, as you can see it looks in reasonable shape with no apparent movement that you wouldn't expect testing it with crowbars and the like in situe( all MOT'd and ready for the road).It's been said they don't suffer due to lack of oil etc like the fronts do.( and probably the case) However on removing this mount things weren't so good
This mounting fell apart and has been subjected to it's last high velocity trip across the workshop into the bin. So I conclude from this that even though they may look in good shape, they may not be. This one certainly wouldn't perform as originally intended and was effecting my car but showed no apparent defect fitted to the car. Visually, the mount was obviously shot, collapsed and in poor shape. I think anyone who had a mounting that looked like that would want to replace it asap! |
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Post by enigmas on Jun 19, 2015 8:53:05 GMT
That's interesting about the movement Steve! (No comment.) I'm glad you found it as it could have led to a dangerous situation given it's very corroded condition. Perhaps the severe corrosion is due to the 'salted' roads...I really don't know as the rear mounts on my car haven't suffered the same fate as yours in the climate down under. Whatever you do to remedy the situation I'm certain will be safe and an improvement. (PM sent).
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Post by Roy of the Rovers on Jun 19, 2015 9:12:33 GMT
Think of this as a pub where we can all get together and chinwag. The way the conversation has developed is exactly as it would do in the real world, with people with differing opinions, sat around the table with a pint in their hand. We do the same at the monthly pub meet, with tongue in cheek leg pulling between saloon and coupe owners, club members and non club members... and those that just deserve to have the **** ripped out of them  This post doesn't need any moderation, its a developing discussion. And those that don't wish to discuss subframe mounting replacement with NOS or newly engineered items don't have to take part! But lets not try and stop it, its interesting to see what people are thinking and how they overcome problems. By the way I don't need any new sub frame mounts, but I do like fixing problems.. I don't see a solidly mounted subframe as making the P5 the same as a BMW mini compared to a mini-mini! I find that a little extreme a comparison! Surely the Chrysler 300 is the new P5!  Adding an overdrive is far 'more' of a modification (eh John ) but as invisible as subframe mounts. (nudge nudge wink wink)   Back on topic - Interesting that the so called sound mount at the back was actually so rotten. I wonder how many others are like that too on cars that haven't had a thorough strip down in recent history?? Especially on cars used in the wet. |
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Post by Steve P5b on Jun 19, 2015 12:00:59 GMT
So here is a picture of one of the rear mountings on my car, as you can see it looks in reasonable shape with no apparent movement that you wouldn't expect testing it with crowbars and the like in situe( all MOT'd and ready for the road).It's been said they don't suffer due to lack of oil etc like the fronts do.( and probably the case) However on removing this mount things weren't so good
This mounting fell apart and has been subjected to it's last high velocity trip across the workshop into the bin. So I conclude from this that even though they may look in good shape, they may not be. This one certainly wouldn't perform as originally intended and was effecting my car but showed no apparent defect fitted to the car. Visually, the mount was obviously shot, collapsed and in poor shape. I think anyone who had a mounting that looked like that would want to replace it asap!Take another look at the picture with it fitted in the car, you would not see the corrosion, nor did the MOT inspector. Only on removal did the corrosion become apparent. Even if you as an individual think yours are fine , how do you know if you have not removed them and taken a good look. The initial question at the beginning of this thread was to ask for information for method of inspection and to ascertain any defects with these mountings so as others may benefit, as it turns out quite a bit has been discovered. |
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Post by Deleted on Jun 19, 2015 12:52:19 GMT
Visually, the mount was obviously shot, collapsed and in poor shape. I think anyone who had a mounting that looked like that would want to replace it asap!Take another look at the picture with it fitted in the car, you would not see the corrosion, nor did the MOT inspector. Only on removal did the corrosion become apparent. Even if you as an individual think yours are fine , how do you know if you have not removed them and taken a good look. The initial question at the beginning of this thread was to ask for information for method of inspection and to ascertain any defects with these mountings so as others may benefit, as it turns out quite a bit has been discovered. If you're referring to the rear mount and the one in the picture it looks out of line and has dropped so visually looks in poor condition and just looks worn.....................to my eyes  When I get my car back, I'm going to have a close look at the mounts. |
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Post by johnwp5bcoupe on Jun 19, 2015 18:22:53 GMT
Steve that's the sort of thing I was intimating. It's great that the mounts are still so durable even when they apparently appear in poor shape but it's bad engineering practice to have the subframe impose any load on the steering coupling. These loads, up down and sideways are placed on a rigidly mounted steering box with only a rubber and fabric coupling to compensate for misalignment. Imagine the stresses imposed on the steering box (especially on rough roads.) If you disconnect the steering coupling then insert a spacer of the correct thickness between the body and the subframe until the shafts are directly aligned then there will be no initial loads imposed on the steering box. This is how it should have been initially setup. Having a good look at what goes on it would appear that vertical movement is possible, in my case 4mm.(assuming these subframe mountings are in good shape) and on rough or undulating roads this movement in a vertical plane will affect the steering coupling at the steer box to column joint( quite considerably) and of course the brake pipes! This is the effect of 25mm vertical movement between the subframe and body. Quite surprising! View AttachmentThis the effect of just 4mm vertical movement between the subframe and body, quite possible with normal driving. View AttachmentIt may be the picture Steve but I can't see the locating plates on the flex coupling? |
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Post by Phil Nottingham on Jun 19, 2015 19:00:10 GMT
I am not the only one on here that does it,  but I do like to provoke discussion and I give opinions as part of my day job regularly but it does not mean that I necessarily agree with them or that there are not other opinions As long as it does not get personal (or political ) I see no reason why I would moderate it - if everyone kept their opinions to themselves then this forum would not be much use to anyone. I liked the pub analogy and its a good idea especially if the ale is flowing but IMHO alcohol and cars do not go together in the driver or the petrol so this medium is the safer bet PS I think it is a bit much to expect OE parts to perform well for 50+ years - mine are not doing so personally or the cars even though our P5B is a mere 42 years old but the P5 is was 51 this month and none are original |
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Post by johnwp5bcoupe on Jun 19, 2015 19:13:38 GMT
Think of this as a pub where we can all get together and chinwag. The way the conversation has developed is exactly as it would do in the real world, with people with differing opinions, sat around the table with a pint in their hand. We do the same at the monthly pub meet, with tongue in cheek leg pulling between saloon and coupe owners, club members and non club members... and those that just deserve to have the **** ripped out of them This post doesn't need any moderation, its a developing discussion. And those that don't wish to discuss subframe mounting replacement with NOS or newly engineered items don't have to take part! But lets not try and stop it, its interesting to see what people are thinking and how they overcome problems. By the way I don't need any new sub frame mounts, but I do like fixing problems.. I don't see a solidly mounted subframe as making the P5 the same as a BMW mini compared to a mini-mini! I find that a little extreme a comparison! Surely the Chrysler 300 is the new P5! Adding an overdrive is far 'more' of a modification (eh John ) but as invisible as subframe mounts. (nudge nudge wink wink) Back on topic - Interesting that the so called sound mount at the back was actually so rotten. I wonder how many others are like that too on cars that haven't had a thorough strip down in recent history?? Especially on cars used in the wet. There will always be a division between owners in what is and what isn't a modification "for me" if it looks like the car that left the factory that's my aim at least my OD is purely bolt on and within an hour the car is back to Original! but I like the 1000 rpm drop and the economy and BTW the insurance company do not regard the OD as a mod as it in no way alters the handling and there are no modification to the structure of the car! I am still of the opinion if you can acquire the original parts "fit them" The P5/P5b handles well for a car of it's age IMHO |
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Post by Steve P5b on Jun 19, 2015 19:27:04 GMT
Having a good look at what goes on it would appear that vertical movement is possible, in my case 4mm.(assuming these subframe mountings are in good shape) and on rough or undulating roads this movement in a vertical plane will affect the steering coupling at the steer box to column joint( quite considerably) and of course the brake pipes! This is the effect of 25mm vertical movement between the subframe and body. Quite surprising! View AttachmentThis the effect of just 4mm vertical movement between the subframe and body, quite possible with normal driving. View AttachmentIt may be the picture Steve but I can't see the locating plates on the flex coupling? Please enlighten me " locating plates" are we talking lock tabs for the nuts on the flex coupling? |
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Post by johnwp5bcoupe on Jun 19, 2015 19:40:33 GMT
It may be the picture Steve but I can't see the locating plates on the flex coupling? Please enlighten me " locating plates" are we talking lock tabs for the nuts on the flex coupling? There is/should be a plate between the two bolts that are 90 degrees to the flanges about 3mm thick they fit in the two cut outs in the flanges, it may be the pics and I cant see them? |
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Post by enigmas on Jun 21, 2015 7:57:29 GMT
Have just recently returned from a weekend run (with a mixed marque CC) covering approx 600 plus kms into rural Victoria driving on various category A and B roads. Speeds were comfortable, ranging from 60 - 110 kph dependent obviously on road surface, condition and location. Since I've owned the car (24 years to date) I've always noticed movement in the steering wheel/column and shimmy from the front end (as felt through the driver's seat.) Interestingly, none of it I believe is attributable to the suspension geometry (e.g., bump steer or nil castor which effects high speed stability). Its always been noticable on B type roads with irregular surfaces (that comprise many rural roads in Victoria) and at legal, not excessive speeds. Obviously, billiard board smooth freeways have never been an issue, as this puts negligible stress on the suspension, chassis and subframe. Having rebuilt the standard front suspension several times during my ownership, my current focus will be to improve the quality of the 'original classic ride' by seeking simple, viable, alternate solutions to resolve this 'personal technical focus' using Steve's investigations/observations on sub frame mounts into consideration. I'd like to thank you Steve for your practical efforts in highlighting this matter. |
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Post by Steve P5b on Jun 21, 2015 16:10:24 GMT
Please enlighten me " locating plates" are we talking lock tabs for the nuts on the flex coupling? There is/should be a plate between the two bolts that are 90 degrees to the flanges about 3mm thick they fit in the two cut outs in the flanges, it may be the pics and I cant see them? Could you please supply a picture of these as fitted to your car for a comparison? |
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Post by Steve P5b on Jun 21, 2015 17:40:17 GMT
Have just recently returned from a weekend run (with a mixed marque CC) covering approx 600 plus kms into rural Victoria driving on various category A and B roads. Speeds were comfortable, ranging from 60 - 110 kph dependent obviously on road surface, condition and location. Since I've owned the car (24 years to date) I've always noticed movement in the steering wheel/column and shimmy from the front end (as felt through the driver's seat.) Interestingly, none of it I believe is attributable to the suspension geometry (e.g., bump steer or nil castor which effects high speed stability). Its always been noticable on B type roads with irregular surfaces (that comprise many rural roads in Victoria) and at legal, not excessive speeds. Obviously, billiard board smooth freeways have never been an issue, as this puts negligible stress on the suspension, chassis and subframe. Having rebuilt the standard front suspension several times during my ownership, my current focus will be to improve the quality of the 'original classic ride' by seeking simple, viable, alternate solutions to resolve this 'personal technical focus' using Steve's investigations/observations on sub frame mounts into consideration. I'd like to thank you Steve for your practical efforts in highlighting this matter. Thank you very much for your kind thoughts Vince, very much appreciated and thank you for your input. As yet I haven't reached a conclusion regarding these mounts, but I am giving it much thought. If any one else has any progressive thoughts, then lets hear them. |
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Post by Deleted on Jun 21, 2015 19:52:30 GMT
As with all things on this forum, I will be following developments with interest but I did have a quick look at the old Pathe films showing the development and construction of the 3 Litre with all the care and pride Rover put into this very important car. It was particularly interesting to view the suspension tests in which they were trying to break something and it certainly throws the badly designed "contrasonic" suspension bush theory out of the window It seems to me that no Rover left the factory with shimmy, steering wheel shake, sub frame movements (thus endangering the brakes and straining the steering box) or any other malady affecting the ride so any problems must be down to wear, tear and unsuitable component replacement. Isn't the solution to unsatisfactory riding qualities, simply to methodically replace those worn components with as close to the original as possible including the sub frame mounts until the suspension is as it should be (for the period) By that I mean the correct components and not PU bushes, incorrect shockers, lorry springs, wrong tyres et al. All IMO and no disrespect to the guys who want to try something else. |
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Post by bissmire on Jun 21, 2015 19:59:05 GMT
Have just recently returned from a weekend run (with a mixed marque CC) covering approx 600 plus kms into rural Victoria driving on various category A and B roads. Speeds were comfortable, ranging from 60 - 110 kph dependent obviously on road surface, condition and location. Since I've owned the car (24 years to date) I've always noticed movement in the steering wheel/column and shimmy from the front end (as felt through the driver's seat.) Interestingly, none of it I believe is attributable to the suspension geometry (e.g., bump steer or nil castor which effects high speed stability). Its always been noticable on B type roads with irregular surfaces (that comprise many rural roads in Victoria) and at legal, not excessive speeds. Obviously, billiard board smooth freeways have never been an issue, as this puts negligible stress on the suspension, chassis and subframe. Having rebuilt the standard front suspension several times during my ownership, my current focus will be to improve the quality of the 'original classic ride' by seeking simple, viable, alternate solutions to resolve this 'personal technical focus' using Steve's investigations/observations on sub frame mounts into consideration. I'd like to thank you Steve for your practical efforts in highlighting this matter. Just a thought Enigmas.   |
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Post by Steve P5b on Jun 21, 2015 20:29:33 GMT
As with all things on this forum, I will be following developments with interest but I did have a quick look at the old Pathe films showing the development and construction of the 3 Litre with all the care and pride Rover put into this very important car. It was particularly interesting to view the suspension tests in which they were trying to break something and it certainly throws the badly designed "contrasonic" suspension bush theory out of the window It seems to me that no Rover left the factory with shimmy, steering wheel shake, sub frame movements (thus endangering the brakes and straining the steering box) or any other malady affecting the ride so any problems must be down to wear, tear and unsuitable component replacement. Isn't the solution to unsatisfactory riding qualities, simply to methodically replace those worn components with as close to the original as possible including the sub frame mounts until the suspension is as it should be (for the period) By that I mean the correct components and not PU bushes, incorrect shockers, lorry springs, wrong tyres et al. All IMO and no disrespect to the guys who want to try something else. Thanks for that |
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Post by johnwp5bcoupe on Jun 21, 2015 20:30:22 GMT
There is/should be a plate between the two bolts that are 90 degrees to the flanges about 3mm thick they fit in the two cut outs in the flanges, it may be the pics and I cant see them? Could you please supply a picture of these as fitted to your car for a comparison? Here you go Steve item 12 it just may be your picture? for sure the flex coupling will feel strange without them!  |
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Post by petervdvelde on Jun 21, 2015 20:43:15 GMT
Also followed this thread with interest and here's my view for what its worth. I have a hydraulic press with a scale in my workshop and put one of my spare old mounts under the press and put some pressure on it. With a load of approx 300kg on the flat surface the mount is suppressed by approx 3mm. After increasing the load the suppression soon reaches its "bump stop" at approx 6 mm. So the theory could be that if the car is on its wheels the rubber mounts will be roughly suppressed half way and then the steering box and brake lines should be fitted free of stress. Then when the car is driven, the mounts, due to uneven roads and acceleration and braking, will be moving between +3mm and - 3mm before reaching the upper and lower "bump stop" positions. As Steve's test showed that the steering coupling can deal with 4 mm frame movement, my believe is that the brake lines can also coop with this movement, also because of the circled routing of the brake line to the rear wheels has near the rear of the sub frame. Although there is room for improvement, i don't feel frightened by the movement of the mounts.
Also had a look a the contrasonic specs Kev posted and looking at the specs of the modern mounting rubbers, there is looking at the specified load, in theory no way that these modern rubbers will last.
Peter
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Post by Deleted on Jun 22, 2015 8:37:41 GMT
Just for information. From delving in some dusty old workshop manuals I've found the contrasonic bush was not (as I thought) confined to the rover. Leaving aside similar rubber bushes on subframes used by all sorts of makers in the past ,the contrasonic rubber bush was used on some very heavy commercial vehicles in the late 40s early 50s. The term contrasonic apparently is meant to refer to the distortion of the rubber opposing the movement caused by the leaf spring flexing.
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Post by Steve P5b on Jun 22, 2015 9:04:30 GMT
Thank you for your observations Peter, it is interesting how you have been able to test your mountings. I am assuming yours were new items recently bought?. I notice that your mounting had a deflection( squashed)of 3mm , however where it is mounted on the car to a raised platform it allows movement in excess of 10mm. However let us assume deflection of 3mm is a maximum. The force applied to compress four ( and I know there are six) mountings is in the region of 1200 Kg.( 4x300Kg) The rover p5 has a kerb weight of 1500Kg and making a rough assumption that half the weight is on the front then the mounting would be loaded to half of the assumed maximum deflection of 1.5mm.
As the steer coupling is assembled with the mountings compressed at 50% of the assumed 3mm full deflection , things would be unstressed at the coupling and all is "rosie"
Now my next assumption is the part that needs further investigation:- As the vehicle is driven on undulating roads and heavy braking the further maximum of load applied to the mountings has only to be 600Kg before they have reached maximum deflection ie. 3mm
It is my assumption that more than maximum deflection is easily reached with normal driving by the dynamic energy of the vehicle, even with new mountings.
Do you have any thought on this principle?
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Post by Deleted on Jun 22, 2015 10:04:54 GMT
You would need to compare a compression test between a genuine NOS mount and the current replacement to arrive at any worthwhile data.
You can bet any money on the fact that the new mount will have a different rubber composition than the original one which, I'm sure would have been designed to allow the correct amount of movement.
It's a bit unfair on the original designers to compare handling etc with far inferior products, now available and fitted, to the ones they were able to use.
Door seals, bushes and boots remade today for our cars are rubbish IMHO.
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Post by Steve P5b on Jun 22, 2015 10:56:22 GMT
Thanks for that
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Adding an overdrive is far 'more' of a modification (eh John 
but I do like to provoke discussion and I give opinions as part of my day job regularly but it does not mean that I necessarily agree with them or that there are not other opinions 
