Author |
Message |
Michael Moran
Experienced User Username: mjcmoran
Post Number: 29 Registered: 8-2005
| Posted on Wednesday, 27 August, 2014 - 22:35: | |
This may sound really simplistic but how do you know when the shock absorbers are no longer functioning on a Shadow I? If I push down or 'bounce' the front or rear end of mine (not easy) it recovers in one stroke. Is this alright? You cannot 'bounce' the car as freely as I used to do on less glamorous cars in the good old days. Should this 'test' be done with the engine running? Why I ask is that I have been told all mine need replacing even though they are not leaking. I am putting it on a shock absorber test pad tomorrow whatever that may be. The car has 'floated along' quite happily for years. No-one has ever mentioned this. Polish mechanics are simply not experienced in the matters of how a 'normal' RR Shadow might behave and I was wondering what the accepted test may be in case they are wrong. I have not noticed anything odd in the handling apart from the usual motorboat effect which does not bother me but they are probably the original shocks as I have had the car for 35 years now and never replaced them. Replacing all four is a significant expense. In the worse case scenario the Bilstein units are half the price of the Boge units and reports are that they are better. Is this true? Best Michael |
Brian Vogel
Grand Master Username: guyslp
Post Number: 1007 Registered: 6-2009
| Posted on Thursday, 28 August, 2014 - 00:39: | |
Michael, If the car is still wafting along, and based upon your description it certainly is, then it's not likely that you need to replace the shocks. One of the RROC-US modern car experts likes to say that a Shadow series car, when handling correctly, should be not unlike a currently-produced high-end SUV. They were and still should be boulevardiers and great highway cars, not sports cars. They are of the "rolling living room" era of luxury car. Good luck even finding the Boge shocks these days. The last person I know of who found them got them as NOS from Lebanon, of all places. The Bilsteins are the current Crewe-specified replacements and are made specifically for these cars. I have been told, though, that they definitely produce a firmer ride than the original Boge shocks, which wouldn't bother me one bit but seems to disturb others. Brian |
Michael Moran
Experienced User Username: mjcmoran
Post Number: 30 Registered: 8-2005
| Posted on Thursday, 28 August, 2014 - 00:55: | |
Thanks Brian Actually Flying Spares are advertising Boge shocks at 475 GBP incl. VAT. which is exactly twice the price of the Bilsteins. Personally I love wafting along (an absolutely unique feeling in a car unobtainable today) and will not easily be persuaded to adopt a stiffer ride. I think floating into an English Country House like say Waddesdon Manor or Blenheim Palace for a summer pic-nic is one of life's great motoring experiences. I have driven the older Bentley Brooklands and the 1996 Continental R and they are a different animal altogether. Clearly they handle far better and are a 'better' car but what a contrast! And the test for shocks? You do not mention this... Mike |
Brian Vogel
Grand Master Username: guyslp
Post Number: 1008 Registered: 6-2009
| Posted on Thursday, 28 August, 2014 - 01:07: | |
Michael, I will let others get into "the official test" since mine, for virtually any car, is the same as yours. If you cannot either get the car to "push down" with excessive ease nor to "bounce" multiple times upon coming back up then damping seems sufficient to me. I have a 1996 Buick Roadmaster Estate Wagon, and while it's not a Rolls-Royce it certainly has a ride not unlike one. When the shocks reached the end of their functional life in that car you knew it immediately. It went from floating along to bouncing like a ball at every railroad crossing or major bump/dip. Is your ride height OK in the back? These cars are well known for "saggy spring syndrome" where the springs compress a bit over the years and the rear end sits lower than it should and the height control ends up compensating if it gets low enough to need that consistently (which isn't good). I have Bilstein rear shocks that I have not yet installed. While the description I've gotten is that the ride is "firmer" I doubt that firmer in a Rolls-Royce Silver Shadow will every come close to the firmness of the ride in a Brooklands or Continental R. I hope someone who's gone that route and is driving on them will chime in with their impressions. Brian |
Michael Moran
Experienced User Username: mjcmoran
Post Number: 31 Registered: 8-2005
| Posted on Thursday, 28 August, 2014 - 02:10: | |
Hi Brian - a quick remark before my dinner! I was worried about the rear springs quite a while back and being in Poland where faulty items are still repaired rather than replaced I had them taken out, lengthened and properly re-tempered (as was done by mechanics years ago). Now the rear ride height is correct with a full tank of petrol, luggage or passengers. I went into that minor minefield of ride height and the height control valve settings in some detail. Interesting subject! I agree with you concerning the bounce test and as such will leave well alone I think. However despite this I will check it out. Some two tons of car would not react well to non-functioning shock absorbers and I think I would notice! Polish roads are hardly billiard tables and there is not a lot of shaking or bouncing going on... Of course everyone here is so used to Mercedes, BMW and Audi - the 'sportif' ride as opposed to the 'charming and civilized proceeding with no apparent motive force' of the RR. Mike |
Paul Yorke
Grand Master Username: paul_yorke
Post Number: 1248 Registered: 6-2006
| Posted on Thursday, 28 August, 2014 - 05:12: | |
Micheal, Definitely Bilsteins, no other way to go. Half the price , twice the quality. Put your knee on the bumper and try and bounce it up and down at the frequency it wants to bounce at. See how far you can get the car to move up and down. Does it bottom out either top or bottom? Will it not bounce at all? When you stop bouncing does it stop almost straight away? It's a tricky thing to describe, but if things have got too bad, you'll usually notice something like that. If you are going to go to the trouble of changing the dampers I would recommend fitting a Harvey Bailey handling kit. The Bilstien dampers were designed by them and only distributed by them initially. The kit hardly affects straight line suspension but completely transforms the cornering characteristics. I can often get them on special offer if you're interested. |
David Gore
Moderator Username: david_gore
Post Number: 1450 Registered: 4-2003
| Posted on Thursday, 28 August, 2014 - 07:50: | |
As detailed elsewhere on this forum, significant improvement in handling without compromising ride can be achieved by replacing the standard front anti-roll bar with one from a Turbo R. If my memory is correct, Richard Treacy posted this information. |
Michael Moran
Experienced User Username: mjcmoran
Post Number: 32 Registered: 8-2005
| Posted on Thursday, 28 August, 2014 - 08:28: | |
Thanks David and Paul. I will try this tomorrow Paul when I go to have the shocks electronically 'tested' whatever that may entail. And yes David, you are right, Richard T did mention this point along with many other brilliant things some of which I have carried out (strengthening the rear cross member, crack-testing the Pitman arm). Best Michael |
Geoff Wootton
Grand Master Username: dounraey
Post Number: 463 Registered: 5-2012
| Posted on Thursday, 28 August, 2014 - 11:46: | |
I was searching the net, out of interest, for the Harvey Bailey handling kit and came across an article by James May, the English television presenter. Here's his view "For years I also tooled around in an old 1980 Bentley saloon that had been fitted with something called the Harvey Bailey Handling Kit. This firmed it up and improved its composure etc etc. But I never really approved of it because it spoiled the ride, so I became the first man in history to book my car into a workshop with the complaint it handled too well." As with all these things, it is a matter of personal choice and preference. For myself, I prefer the "floating along" experience. Geoff |
Bob uk Unregistered guest Posted From: 94.197.122.91
| Posted on Thursday, 28 August, 2014 - 07:39: | |
Michael Moran, The engine doesn't need to be running because the car has conventional coil sprung suspension. The hydraulics simply push the rear spring top mountings down to level the car. To test Shock/dampers ( misnomer --shock absorber) they are timed usually over 100 seconds with a given weight over a given length. To do this means the dampers will have to be removed. It is a lot of Work for very little gain. Your dampers are fine. The original Shock/dampers are of high quality and most likely better quality than any replacements. So hang on to them. Shock absorbers are the tyres and rubber bushes and subframe mountings. And the rubber bushes on the dampers. And one auto engineer designer also included the coil springs. To which I conceded to by saying maybe. Note RR call them shock/dampers to save the arguments.
(Message approved by david_gore) |
Mark Aldridge
Prolific User Username: mark_aldridge
Post Number: 147 Registered: 10-2008
| Posted on Thursday, 28 August, 2014 - 20:08: | |
Sorry Bob, but the best thing I did was to change the shocks to Bilstein allround and fit a Turbo R rollbar. The handling improvement is dramatic on twisty roads and the effect on ride negligible. I used my Shadow mainly for cross country business commuting and it became a lot less tiring to drive and easy to keep pace with the "normal traffic round bends.At the end of the day, it is personal preference and the intended use; I Guess a Shadow 1 would not be everyones choice for a cross country commuter, but I thoroughly enjoyed 10 years and 100k.Although now pensioned off and renovated, I still have this car and use it for pleasure. Mark |
Michael Moran
Experienced User Username: mjcmoran
Post Number: 33 Registered: 8-2005
| Posted on Thursday, 28 August, 2014 - 22:35: | |
Alright guys just to close this thread. The shocks were 'tested'electronically this morning and there is nothing wrong with them as I predicted. By the way Paul you may remember the lengthy discussion we had a while ago about a rear end vibration under load which disappears on lift off. I have not solved this problem although I carried out all your detailed advice except one thing. Next step is swapping over the Detroit joints (excuse if this is not actually the right way of expressing it but I know you know what I mean). The grooving and so on... I am not having this done in Poland however well meaning and clever the mechanics are(see above stuff). Either an RR service point in Berlin whom I know have had a lot of experience with Shadows or back to Blighty which is probably the best thing - but certainly not the cheapest. You see I had the car in London for 25 years properly looked after and know what it feels like when properly set up and running. It has been 'slipping' over the last 10 years and although running perfectly well it is at abut 80% of what I remember and want. Because of the fraught history of their country Poles cannot possibly have the accumulated experience required to solve knotty issues with RRs - it can be difficult even in the UK among specialists. They are brilliant mechanics but Shadows...a different kettle of vodka! Best Michael |
Bob uk Unregistered guest Posted From: 94.197.122.91
| Posted on Friday, 29 August, 2014 - 04:31: | |
I stand corrected on replacement dampers. Mine are 40 years old and work fine as far as I can tell. Shame they don't come apart for "adjustment" I shall write a piece about dampers and stick it in miscellaneous.
(Message approved by david_gore) |
Randy Roberson
Prolific User Username: wascator
Post Number: 290 Registered: 5-2009
| Posted on Sunday, 31 August, 2014 - 06:37: | |
As many outfits manufacture shock dampers in the US for modified 4 wheel drive vehicles among others, is it hard to believe that an appropriate damper cannot be made for less than $600 to $800each. I believe those on my Car are performing pretty well, remembering that the ride should be very similar to a 1960s-1970 Lincoln, not a sports car. |
Bob UK Unregistered guest Posted From: 94.197.122.81
| Posted on Sunday, 31 August, 2014 - 13:13: | |
Randy, Good point, a damper for a Shadow ain't exactly high tech and are run of the mill mono tube floating piston nitrogen gas dampers which although sounds hi- tech is what would fitted to a Nissan micra. Which cost about £15 each. The RR ones are bigger . They have the same number of bits. Only the mounts are different. The ones on my jeep are about the same size, and they cost about £30 each. They call them shockers because they're a shocking price.
(Message approved by david_gore) |
Brian Vogel
Grand Master Username: guyslp
Post Number: 1019 Registered: 6-2009
| Posted on Monday, 01 September, 2014 - 01:42: | |
Randy, When I bought the Bilstein B46-1430 rear shocks/dampers for SRH33576 in November 2007 they were $157 each. Today they're selling for lower prices, $122.30 and a bit higher, while the fronts are going for $185 USD. It also appears that Bilstein has done a renumbering in its own product lines and B46-1430 is now 24-014304 and B46-1429 is now 24-014298. If someone's charging $600 to $800 for a simple shock absorber, and they don't come any simpler than this as Bob UK noted, run, don't walk, away. Brian |
Randy Roberson
Prolific User Username: wascator
Post Number: 292 Registered: 5-2009
| Posted on Monday, 01 September, 2014 - 12:03: | |
Hi, Brian, where di you get the shocks? One vendor I use has them for a little over $300. I may convert my car to the short dampers in front when I do it. I havce my rear leveling valves back on. I think I will set them to the rear springs as they are now, to protect them until I can either shim the springs or replace them. |
Randy Roberson
Prolific User Username: wascator
Post Number: 294 Registered: 5-2009
| Posted on Monday, 01 September, 2014 - 12:21: | |
Nevermind: E-Shocks has them listed under the new number, for Rolls-Royces. A little over $500 for a set of four. Thhinking about it: I like my floaty ride. Amazing. Who'd a thunk it...? |
Brian Vogel
Grand Master Username: guyslp
Post Number: 1021 Registered: 6-2009
| Posted on Monday, 01 September, 2014 - 12:28: | |
Randy, I've sent you an e-mail. I've never heard of short versus long dampers at all. Brian |
Randy Roberson
Prolific User Username: wascator
Post Number: 295 Registered: 5-2009
| Posted on Monday, 01 September, 2014 - 12:34: | |
The earlier Shadows, because of the rig-up for front leveling, used one shock; short stroke I think. once this was deleted circa #11000, the other was used. Some get a later model front spring tower cap and convert to the (I think) later, long-stroke shock. |
Brian Vogel
Grand Master Username: guyslp
Post Number: 1022 Registered: 6-2009
| Posted on Monday, 01 September, 2014 - 12:38: | |
Randy, Interesting. I have no idea what the source would be for the shorts. All of the numbers I've ever had were for two of the same for front and rear, whether Boge or Bilstein. If the damping stats were known you could probably have custom ones made up based upon your earlier comment. Brian |
Randy Roberson
Prolific User Username: wascator
Post Number: 296 Registered: 5-2009
| Posted on Monday, 01 September, 2014 - 12:49: | |
A great explanation is on the Flying Spares web catalog for Shadows, then suspension, then front shocks. Although the front leveling was stopped early, the front cylinder was still in place when my car was built in 1970; these cars used the short-stroke damper. From approx. 11000 the front hydraulic cylinder was deleted, and the long stroke damper was fitted. Like your Cars. For the price you turned me on to, I would pay that and consider it reasonable. Thanks! |
Bob uk Unregistered guest Posted From: 94.197.122.91
| Posted on Tuesday, 02 September, 2014 - 05:38: | |
My car is SRH17668 1974. So has long dampers at the front. To get the readings one needs a new damper. Place in a rig and hang weights off it and time a given distance. The weight is unimportant to much and the damper will move to fast to time I usually pick a weight that lasts for 90 -100 seconds. However a damper maker would already have a good idea of the settings. However if the dampers are available at £75 each then that is not expensive. And a damper maker will want more for a special. I thought the dampers were £200 each.
(Message approved by david_gore) |
Jan Forrest
Grand Master Username: got_one
Post Number: 641 Registered: 1-2008
| Posted on Tuesday, 02 September, 2014 - 20:49: | |
This is where computerisation has hit us in the arse. You go into a parts supplier's shop and ask for a "left handed sprocket flange model number FUBAR1". The immediate response is "Reg number of the vehicle, please." which you then supply shortly followed by "That's a Rocking Horse Deluxe and the part you want is called Gold Plated Fertilizer ..." *teeth sucking noises* "Gonna cost ya!" Many years ago I had a Reliant Scimitar. Rear dampers were £20 each, while front dampers for the Robin or Regal were only £8. They're exactly the same dampers! The only way round it is to say that you're building a special/kit car and these are what the design calls for. As the vehicle isn't finished it can't have a reg number. |
Bob uk Unregistered guest Posted From: 94.197.122.79
| Posted on Wednesday, 03 September, 2014 - 04:50: | |
My reg no never shows up on the system. Brake hoses are not even listed yet are the same as Bedford CF van and FX4 taxi. I am sure that parts that are the same are given two part numbers. I had two steering shaft rubber disks that had the same moulding numbers one was Renault and the other a metro. The metro one was £5 and the Renault one £32. I found this out by accident when a Renault alpina needed a coupling and I thought it was similar to a metro ----.
(Message approved by david_gore) |
Randy Roberson
Prolific User Username: wascator
Post Number: 297 Registered: 5-2009
| Posted on Wednesday, 03 September, 2014 - 23:56: | |
Interesting that the Boge online catalog lists the Boge shocks front and rear for the Silver Shadow, 'from 09/70' as 46-050-1 front 46-051-0 rear. Looks like they are offering the later front shock after the front leveling cylinder was deleted and changed to the spring cap (the conversion). Also, it notes the rear shock is about to be (or has been?) discontinued. |
Randy Roberson
Prolific User Username: wascator
Post Number: 298 Registered: 5-2009
| Posted on Thursday, 04 September, 2014 - 00:01: | |
As for the original question (how to know when the shocks are not working and need to be replaced): Broken or leaking oil (obviously) the wheel shakes wildly when encountering significant bumps the car sways wildly or is unusually difficult to control. Remember these are built for comfort, not for speed and the suspension is much softer than modern cars. Resistance at a particular corner of the car when bounced by repeatedly pressing down on the bumper or fender, is noticably absent or is different from the other corners of the Car. |