| Author | Message | ||
     Bill Coburn (210.244.18.48) |
Of late there have been serious warnings about amateurs overhauling the GM Hydramatic gearbox. The advice moreover has been to take your car to your specialist for overhaul. This is wise for the complete novice and I think that most sensible owners would take heed, but there are many, especially owners of Shadows who either simply cannot access these facilities mainly through the tyranny of distance, or they cannot afford the labour costs, or the total cost of the overhaul far exceeds the realisable value of the car or worse they are forced to use a ‘general’ automotive repairman who moreoften is not interested or has to go on a journey of exploration to even understand the problem. What is the owner to do, scrap the vehicle or sell it to someone who will shove it in a corner to rot? Hong Kong is full of such Rolls-Royces by the way. If we are honestly trying to save these unique cars this is not the way to do it and I hope through this site at least we will offer every help to the genuine enthusiast to maintain AND repair his car. Gearboxes, especially automatic ones have always been a frightening prospect to overhaul; there are so many bits and quite often special tools seem to be needed. I have an old friend with an old S2 Bentley in my town. He and his wife love the vehicle and freely admit they run it largely on the goodwill of others. Many years ago he spent a small fortune with firstly a transmission specialist in town and then with another who specialised in the Hydramatic. For each overhaul the bill came to about a thousand dollars probably equivalent to five or six thousand today. On each occasion the transmission still did not perform even remotely satisfactorily. The thing would change but when moving from second to third it would hang on until the engine was roaring and change with a thump that threatened to rip the tailshaft out of the car. He asked me to have a go at the unit. I was keen to try as I saw it as a challenge and realised that funds were running out and the future of the car was in jeopardy. I had to consider how to get the unit out (they are very heavy), where to work on it, what technical instructions I had or needed, who could I call on if I was stuck, the cost and availability of spares and how I could overcome the problem of special tools. The answers to all these considerations are too detailed to go into here, but you will be relieved to know that the overhaul was entirely satisfactory. But of course I am an amateur so how come the specialist did not find the problem? I don’t know, but what I had that those people did not have was time to think and research and analyse the results. And I had the motivation to get it right. The message is that in buying a Rolls- Royce you should have some idea of what is needed to be done including maintenance and determine whether you can realistically tackle the task or afford to pay someone to do it. If the answer to both of these considerations is ‘NO’ don’t buy the car. | ||
| Richard Treacy (217.162.168.47) |
Hi Bill, I have just attended to two Silver Dawn Hydramatics and an S2. In every case they hung onto second gear and changed with an almighty Bang. Down changing while stopping was something else to experience, almost ripping the axles off. Simply by correcting the geometry of the throttle linkage to the transmission, they were all 95%. The last 5% came from simply setting the bands to spec. One gentleman, a musician from Geneva, almost fell out of his chair when he witnessed the enormous improvement. He had spent over A$12,000 having it overhauled by a so-called specialist in France. I suspect it was OK before the overhaul. While I was at it, I tightened up his steering box enough to eliminate free play at the steering wheel. Again, he was staggered at the result of this dead simple 15 minute adjustment. He drives the car daily now. I have met many, many owners who have suffered the thumps unnecessarily for years. I remember in 1983 or so when you and I both overhauled separate R-Type transmissions, including fitting new white metal bearings. The jobs were not too difficult but I do remember the pitfalls, especially the front pump bearing clearance which should be a little more than expected. Overhauls are not expensive DIY unless there is a major failure like a split rear drum. | ||
| David Gore (63.60.233.123) |
I plead guilty to being one of those who has actively discouraged owner intervention with Hydramatic transmissions given the difficulties associated with removal/replacement and band adjustment and the strong probability that inappropriate work could cause expensive component damage or embarassing "failure to proceeed". This caution is the result of my own success in destroying a Fordomatic 2 speed transmission in my early days of car ownership due to inappropriate band adjustment because I didn't have the right tools and used "guesswork" instead. Where we are in the situation of offering assistance to strangers where we are unable to personally assess their expertise and competence; we have a duty of care to err on the side of caution and not encourage these people to attempt work that is beyond their current abilities - after all it is our reputation and credibility that is involved. I would much rather be seen as being conservative/cautious in this situation until I can properly assess the level of competence of the enquirer. In the case of Bill and Richard, I would have no problem in encouraging them to undertake such work as their experience and abilities are known to me and their successful repairs have resulted from their expertise, however, a large percentage of those using the various Forums are nowhere near as competent and we have to be cognisant of the old adage "you have to crawl before you can walk before you can run" and not encourage people to get involved in work that is beyond their present capabilities. | ||
| Bill Coburn (203.51.35.157) |
Well Richard having been knighted by David I can say that the thumps in the car I mentioned were caused by excessive wear in the bronze bushes carrying the two clutch drums. You will be aware that in these quaint old transmissions the oil pressure supply for clutch application comes through the central mainshaft on which the drums rotate. What was happening was the pump(s) were working their little butts off to fill the drum clutches and clamp the drive plates but 70% of their output was squirting out through the drum bushes which are the only fittings there to keep the oil in. Eventually through the speed of the engine and hence increased pump output enough oil got into the clutch pistons and they slammed shut. Well there is a trade secret apparently unknown to anyone but me. Seriously I have often wondered about brewing up a test rig using oil rather than air to see all these little gim-gaws working on the bench - it would be very satisfactory but as I do one of the things about once every three years, I guess there is not a great need for it. And for David it was not your remarks I was referring to you as you will know. Few things discombobulate me more than attitudes of 'these are Rolls-Royces and should only be touched by sanctioned operatives'. As the production supervisor at the Factory once told me 'They are only cars you know'. It is this strange attitude that is the cause of so many of these great cars sitting unused in dusty garages and others wrecked (parted??) because no one is prepared to get in and have a go. Your experience with the Fordomatic (which is very different from the Hydramatic)is not unique. Some years back there was a certain Phantom VI that had better go unidentified, which professional mechanics decided to cushion the gearchange jerks by fiddling with the bands. The end result was reminiscent of the epic poem Horatio at the Gate, "Those behind cried forward and those in front cried back!" Such a conflict occurred in the grand old car's box until all the built-in spare strength was used up and the result was catastrophic. Apocrypha would have it that all was salvaged was the dip stick with the bill exceeding $18,000. By comparison a friend up here whose pristine Cloud tried to engage all gears at once, overcame the mystery of the boxes and bought a restored one in America had it airfreighted here and fitted it at considerably less cost than the fees charged by the so-called professionals we use. | ||
| Richard Treacy (217.162.168.47) |
Many thanks, David. Just to follow up on Bill's remark on the S2 transmission he overhauled (I know it and its owner from way back). There are indeed many reasons for rough or ill-timed shifts like on that S2, but it's always best to start with the linkages and bands to eliminate those possibilities first before starting an overhaul. At least then you know what to look for inside. I find rough shifts on a V8 intollerable; on a 6 cylinder they are more of a party trick, but better fixed in any case. Up to 1983, my R-Type auto transmission was performing well above average. At the time, Bill had just overhauled his first R-R auto transmission, the Hydramatic of a coachbuilt R-Type, and I had a drive. I was so absolutely impressed that I asked what the secret was, and Bill supposed it was mainly due to the new bronze bushes and white metal bearings. Jealous as hell at the perfect changes, I vowed to overhaul mine too, even though it didn't really need it. So, I sourced the white metal bearings from the same guy who sold a set to Bill. Unfortunately, all the other parts this guy sold me were rubbish, so the box was apart a few months later to fit genuine bucket seals and clutches as the guy had duped me into believing that the Cadillac plates (flat instead of wavy) and bucket seals (no expander) were a new updated line of genuine R-R parts. It changed OK, but a bit too quickly for my liking. That's another story, but with new bearings and correct clutch plates etc from Rolls-Royce (incidentally Bill ordered them for me) finally installed, the box has been superb and leak-free ever since. It was lucky that Bill lived nearby and I dropped in at the right time to see what was going on. | ||
| Bill Coburn (203.51.35.157) |
This is becomming incestuous. I have just returned from a very convivial evening and consumed a number of very fine single malts - the nectar of the aged, Richard being some 30 years younger than I you will appreciate. What comes to mind from his remarks harks back to your opening comments David. When I bought my first Silver Dawn, an almost basket case, I actually had to take an overdraft to keep feeding the family etc. The first job was to expand the Canberra Special garage as it was known from 20 ft X 10 ft to 30 ft X 15 ft! This was a labour in itself. When I returned from America I had procured every bit of published material on the Dawn that was available and by then I could almost recite it. That car was taken back to the rivets and re-built and I assure you it was a very carefully conducted enterprise given that I had three children to educate a wife to maintain and a job to fulfill. But we made it, not without trauma and cost and now the car sits with some owner in Queensland who is quite oblivious to its heritage and probably has no interest in knowing it. What I am proud of is that that car is still on the road a fact for which I am largely responsible. C'est la vie it is not important but many memories are wrapped up in that chassis. The attack on the 'Z' series Mulliner bodied 'R' type as Richard recounts was an indiscretion on my part when in a drunken moment I agreed to recover the car. Richard being a very young man has a far better memory that I! | ||
| Mark Tomlinson Unregistered guest Posted From: 211.28.232.59 |
As I have just purchased my first Rolls Royce (a 25 year dream come true), she is a 1966 srh2524 shadow and is going into a local mechanics here in western sydney who has experience with the old girls as he calls them to have the front end rebuilt and new rear disc rotors put in so it not only drives like a Rolls Royce, but stops like it should as well. I am not upset at all that this work needs doing, I am thrilled that I can bring her back to her best and be proud to have done it. | ||
| David Gore Moderator Username: david_gore Post Number: 68 Registered: 4-2003 |
Hi Mark, Congratulations on your acquisition and may you have may years of enjoyment from your car. To get the best from your car and to gain more knowledge about it, please join our Club and participate in our Self-Help Days where our members will help you with advice and assistance regarding your car. We have all been in the situation you are now in and are only too happy to share our experiences with you. If you need more information on membership, please contact me using the link provided in the UTILITIES/CONTACT section on the LHS of the page. | ||
| Bill Carnell Unregistered guest Posted From: 203.220.88.105 |
I am buying a 1984 Bently Mulsanne LWB Turbo for use in Townsville Nth.Qld. Could anyone advise me if their is anyone able to service these in Townsville? Also where do you source parts for these? I am not real good on email but my fax is 0747240888 | ||
| John Dare Unregistered guest Posted From: 144.138.194.193 |
Dear Bill, May I suggest that you contact Barry Sparkes who is a long experienced "R-R/Bentley" specialist in Brisbane. I feel that he may well be the best person to advise you in any worthwhile detail. His tel. no. is 07 3865 3062. Best Regards | ||
| Ian Anderson Unregistered guest Posted From: 203.164.58.81 |
I have learnt that a careful amatuer mechanic can do a better job then careless "professional" mechanic. It is also cheaper, more so if your talking about cars such as Rolls-Royce and Bentley. However, if in doubt, ask. And always read the manuals before you begin work, it saves time and heartache. |
