Post Number: 1198
|Posted on Wednesday, 28 March, 2007 - 07:22: |
For some time now, I have been puzzled about the front suspension rebound Stop of 1972 Silver Shadows from chassis 13485 onwards, extending also to all SZ cars. The early SY cars with compliant suspension were fitted with a rebound rubber stop, part UR16198. However, SZs do not show this part, and the parts catalogues quietly dropped it for SYs years ago. The spares outlets advise that this component should be deleted for all these cars. Furthermore, early SZ cars have the drilling and casting to suit the rebound rubber, but it was never fitted.
On Bentley cars from SZ chassis 12636 the drilling was deleted, and also on Rolls-Royce cars from chassis 23213, and apparently the rebound rubber was never fitted from 1979 onwards There is no provision for the stop on the later SZ cars whatsoever, although the rest is the same. Surprisingly, the SZ service manuals, as in our technical library, show the rebound rubber whilst the parts manuals do not, presumably an oversight by Crewe. Rebound is served by the front shock absorber instead. I double checked my Turbo R during some suspension work last week, and indeed it has the upper control arm with no provision for a rebound stop. Note that they didn't even bother to change the part number for the undrilled control arm.
Maybe some Silver Shadow owners could check to see whether theirs have been removed.
(Message edited by Richard Treacy on 28 March 2007)
Post Number: 1199
|Posted on Wednesday, 28 March, 2007 - 07:38: |
This is from the SZ workshop manual. Look for this rebound stop item 2: I don't believe that you will find it on an SZ, and maybe not on an SY either anymore.
Post Number: 24
|Posted on Wednesday, 28 March, 2007 - 08:20: |
Off the top of my head ( remember it's late here ) - I think the subframe and most front suspension parts carried forward from the Shadow to the Spirit.
There are often brake hose mounts which are artifacts from earlier cars. Often they added new/extra mounts etc to existing designs so the old fittings are there with the new ones.
Early dampers had much longer stems on them. Maybe that is the reason for the stops?
Strangely enough, there are also lots of empty mounting areas on early cars which are used on later cars - I always wonder if they were thinking 10 years ahead when I see them.
thinking aloud here : Front spring top plates never used to wear into ovals on Shadows and maybe early Spirits, but then started wearing badly. At the time, I kind of dismissed it as Turbo cars with wide wheels ( which seemed to be the worse ) but I wonder if it was the elimination of the bump stops? Hmmmmmmmm
Post Number: 878
|Posted on Wednesday, 28 March, 2007 - 08:28: |
Richard/ I first realised this on Bob McCulloch's old Shadow which desperately needed new front shocks. While they were off I noticed that item two above was pretty badly mangled and sought a replacement. The cost was enormous of course so with the aid of Mr Blackwoods I found a very usable alternative and a fraction of the cost. Having fitted it and then fitted the new shocks I was quite amazed that in full rebound the control arm would barely touch the rubber! The car was non compliant and the shockers were new 1980's stock! Enquiries were no help so I just accepted it. Seems a Hell of a strain to put on the mechanism but it works!
Posted From: brig-cache-4.server.ntli.net
|Posted on Friday, 30 March, 2007 - 23:34: |
I have in the past used wood such as pine in place of un-attainable proper ones.. Turn them on a lathe paint them black.
Recently my rear off side fell off. I drilled out the 5/16 UNF thread in the chassis and retapped welded a 5/16 bolt to the original whose rubber was in perfect condition.
I can see that at some stage the rubber has touched the bump stop on the arm. I guess when the car is loaded and moved before the engine has time to pump up the suspension. Which is how I probaly broke off the nearside rear ( the bolt was very rusted.)
But thats the rear. To get the front to bottom would take a lot.
(Message approved by david_gore)
Post Number: 1200
|Posted on Saturday, 31 March, 2007 - 18:10: |
Er, is this a Rolls-Royce or an Oxford-Cambridge bump race on the Thames ?
Post Number: 685
|Posted on Sunday, 01 April, 2007 - 18:04: |
Towing and a car fully loaded including LPG tank. is a doodle with the helper spring inserts that i fitted to the rear.
These can be fitted to the front to improve the ride.
Bump stops will then only be needed in the most extreme events on a compliant Shadow with the suspension in its standard form with helpers.
Not to be recomended on the old Turbo "r" for all its modern failings.
(Message edited by pat lockyer on 01 April 2007)
Post Number: 1203
|Posted on Sunday, 01 April, 2007 - 18:41: |
Curious. The subject is front rebound stops. Why has it attracted pine forests, bump stops and greasy gypsy wagons ?
Post Number: 686
|Posted on Sunday, 01 April, 2007 - 20:51: |
Ho hum,you can use the helper on the front and that will almost make the bump stop almost redundent on a shadow,not in the manual so i except that you may not know.
Cripes there are a great many true RR enthusiasts that love to tow caravans with their cars pre and post war.
We must not upset them as well with snooty remarks.