The HydraMatic Transmission - Rolls-Royce and Bentley Motor Cars

OK, lets talk about our old friend/mortal enemy, the HydraMatic. First off a bit of history on this complex lump of iron. Introduced after very exhaustive testing by GM in 1941 it saw service in everything from Cadillacs to Sherman tanks (same thing!) and in its day was regarded as being pretty well bullet proof. After WWII Rolls Royce knew that the future was in America and that they had to offer a GOOD automatic transmission to compete for sales. GM had spent HUGE money developing the HydraMatic and was using it with great success in the Cadillac, Oldsmobile and Pontiac ranges of cars. R/R had a great rapport with GM but nowhere near the kind of budget to develop anything that was even close to the HydraMatic and so made a deal to use it under license from GM. The added bonus was that mechanics across America were familiar with the thing, all except that big whirly gig brake booster thingey hanging off the side! Rolls performed a lot of modifications to make it work with the six cylinder engine and then later the V8, and NO they will not interchange completely no matter what anyone tells you.

We have seen some terrible things done to the much maligned HydraMatic, including one that a young Miss Schworer from Cincinnati brought to us that had previously been taken apart by Attila the Hun using a variety of sledge hammers when he was good and drunk!!! When customers tell us (once a month on average) that they have had the HydraMatic worked on but its either not right or actually worse we ask one simple question,  "How old was the guy working on it? "  Not the shop owner but the guy WORKING on it. Transmission shops will promise you the sun, moon, and stars but if the guy working on it is less than 50 years old - I seriously doubt if it will be right when he is done for three reasons: One. The HydraMatic was replaced in the early 60's and you need someone who has a LOT of experience with them, the kind of experience you get working on them every week like when LOTS of cars that are driven every day are still using them. Two. In the early 60's the whole of the American auto industry switched to vacuum governed shifting. The HydraMatic is a mechanical shift transmission, that means it shifts dependant upon throttle position and load. If you are a mechanic, sorry, technician, brought up on a diet of vacuum and now electric and electronic shift transmissions you will have a hard time even understanding the basic PRINCIPALS that make the HydraMatic work. Like an earth surgeon working on an alien from the X-Files and saying "well he sure did look pretty familiar, two arms, two legs, a head, etc. but when I opened him up it was all very different in there! Still I've done the best I can and closed him up and we will just have to hope he's OK". Three. Special Tools. Ah!!! The Special Tools! These tools have not been readily available for over thirty years. That's right, thirty years! If you don't have them, well.. Enough said.

Hyperion Parts does offer transmission restoration services. We will rebuild your R Type, Silver Cloud, Phantom V or early RHD Silver Shadow HydraMatic using all new drive clutches, seals, bearings gaskets etc. in ten to fourteen days. If it needs any HARD parts such as the front pump, cone clutch housing, clutch drum etc. we will quote you upon inspection, in writing. Once a HydraMatic is rebuilt and set up correctly you should get 100,000 miles out of it with nothing more than routine service. Here's a few tips to make your HydraMatic last and give good service. Do not let it sit for months without being used, drive it or at least run the car so the fluid is being  pumped around and the seals are being lubricated. THE most common problem with HydraMatics is seal failure because they have dried out. When you park the car pull the handbrake on, put your foot on the brake pedal, put it in reverse and then shut the motor off. Change your  transmission fluid once a year, drop the oil pan and clean the mesh filter. Its cheap insurance. Don't forget that R/R were thoughtful enough to put a drain plug in the torus also. Bring the 7/16 brass drain plug around to the six o`clock position and place at least a ten quart drain pan under it and let it drain. DO NOT over tighten the drain plug when you put it back in, brass strips easily. If a band adjustment is deemed necessary  drop the pan, measure the distance to the band stop FIRST and then make the adjustment. NEVER do it by eye and NEVER over adjust, it will self destruct if you do! Road test for at least 50 miles and re-adjust if necessary which will mean draining the fluid and dropping the pan again. As with most things Rolls Royce it's the two P's. Painful but Precise. THE golden rule is the simplest one. If the unit starts to act up in any way shape or form attend to it right away. IT WILL ONLY GET WORSE!!!

As for the Turbo Hydramatic that came with all the LHD Shadow series cars, Spirits, Spurs etc. there is not a whole lot to say. They are pretty well nuclear bomb proof. That's right, the Feds actually exploded a nuclear device IN a Turbo HydraMatic, then bolted it into a Cadillac and drove it around the US five times with only three quarts of fluid in it! Point is that they are so good, so dependable that you kind of forget they are there. If yours goes bad we will rebuild it and we usually have some on the shelf ready to go.

We will rebuild your Mk VI, Wraith etc. four speed manual transmission for. Well to be honest it really depends on what's wrong with it. Most often the ailment is the first motion shaft, or should I say the gears that are machined onto it. Most drivers under 40 years old do not know how to "double de-clutch" when going down through the gears. You have to depress the clutch pedal and slip into neutral, rev the engine a little to match engine and transmission speed and then gently slide into the lower gear. Lots of folks just "dog" it into the lower gear and wonder why it makes this terrible graunching noise. The noise is all the gear teeth trying to destroy each other because they are not aligned and the idiot at the helm is trying like mad to "force" them into alignment by pushing like Samson on the gear lever and whistling a merry tune while trying not to make eye contact with other motorists and pedestrians. Other problems are selector fork wear, ovalation of the bearing housings in the aluminum case, cracks in the case, bearing failure etc.. Doesn't sound to pretty does it? Well it can all be fixed and we will be happy to quote you upon inspection. In writing. We also have excellent access to pre-war manual transmissions and parts by the way. Happy motoring.