PSA Autoboxes

DoubleChevron · Unread post by **DoubleChevron** » 20 Dec 2005, 00:53

Hi Anders

this one works exactly as designed... (you see there designed to be bloody annoying horrible things

).

seeya,
Shane L.

Unread post by **Peter.N.** » 20 Dec 2005, 10:04

My uncle had a Riley 'RME',I think, the one with the fabric roof, it had a 'Wilson' gearbox, it worked like an auto box but was in fact manual, all it did was to eliminate the clutch. It boasted a 'fluid flywheel' a sort of torque converter without the torque conversion. It had a 'preselect' lever on the steering column, not unlike the gearchange on some of my early cars. The 'modus operandi' was thus, you selected a gear and nothing happened, you then pressed a pedal where the clutch used to be and the gear would engage, you did this through all four gears and it worked very well as long as you didn't put it into reverse! Now that was an automatic I quite liked, but cant really see the point of it!

jeremy · Unread post by **jeremy** » 20 Dec 2005, 10:38

The point of the wilson gearbox was that it employed epicyclic gears (similar to those now used in some autos) and gear changing is done by applying a brake to the outer ring which causeds the thing to drive. These epicyclic gear systems can be stacked as in the wilson box to produce a number (in this case 4) speeds.

In fact - release the bands - no drive so the driver can use the change gear pedal as a conventional clutch and this was done for a number of racers.

cast your mind back to the 1920's - motoring was getting more popular and was appealing to a wider group - most of whom had little mechanical ability and even less training. No synchromesh was available and clutches varied in type and quality and all were without centre cusioning springs. Clutch control and gear changing were major problems - so daimler and others (Armstrong Siddley . . .) found the answer - no tricky clutch for moving off and no gears to crunch and no need for tricky hand/foot co-ordination - wonder of wonders - the fluid flywheel and Wilson pre-selector gearbox.

Syncromesh was introduced in the early to mid 30's and some worked quite well although without a baulk ring mechanism (a 50's invention) could easily be overridden.

The Wilson box had an additional advantage and that was it would change gear very quickly and therefore was desireable for high perfrmance cars. The fluid flywheel sapped power and certainly some Rileys (I remember helping a guy try and re-assemble a 15/6 Adelphi many years ago) used a centrifugal clutch more moving off and providing a solid drive and then the Wilson box provided rapid gear changes without the need for hand/foot co-ordination.

The things have a folk lore all of their own - for example if the thing isn't adjusted properly a 'false neutral' is obtainable and apparently the pedal shhots out of the floor and break the unfortunate driver's leg. Certainly when I drove a rather sick Daimler with it I didn't get on with it very well and couldn't get used to this pedal settleing to different heights all the time. I expect with more perseverance I would have mastered it.

The Wilson box was used on many busses and I recall in the 70's noticeing that the single decker I was traveling on had a minature gear lever on a heavy stalk behind the steering wheel and that the driver moved the lever some time before a gearchange happened.

Wasn't the Citroen 'C-matic' as used on the GS and CX a pre-selector on a normal syncromesh gearbox - using a torque converter?

jeremy

Unread post by **Peter.N.** » 20 Dec 2005, 11:41

Thanks for the enlightenment Jeremy.

He had this car back in the late '40s early '50s, when I wasn't really old enough to appreciate these things, although as you see, it stuck in my memory, but I can see the reasoning behind it now, thanks.

My first car was a '39 Prefect which had synchro on 3rd and top, so I probably thought they had allways been like that, although that gearbox was less relaible than the present auto's. I can remeber stripping it down, 3 times I think, to replace the thrust washer behind 2nd gear. When it broke the gear would slide off the shaft and jam it in reverse, you then had to lift the lid off as far as it would come and fiddle the gear back on the shaft with a couple of screwdrivers. They were the days!

My only excursion into epicyclic gears was with overdrives. I used to do diesel conversions with the Perkins 4/108 engine and used a Vauxhall overdrive box which I fitted with the commercial gears to get wide enough ratio's. But now we have some decent diesel cars I am redundant.

jeremy · Unread post by **jeremy** » 20 Dec 2005, 13:17

I have memories of the Ford 3 speed in a horrible 100E? Popular (Not the upright one!) that someone lent to me to do a short run. Thing died at traffic lights and in my panic to get the thing going - yes you've guessed - stuck the thing in reverse which was where first should be! Fortunately nothing was close behind and I didn't go far before I realised!

happy days!

FrenchLeave · Unread post by **FrenchLeave** » 20 Dec 2005, 15:02

Hi all,

Rossnunn, Sibsey, about 5 miles north of Boston. The A16 through Stickney and on up to the Wolds is quite entertaining.

Peter, no, I wasn't getting at you (how could I ever get at another XM owner?). Yes, I'm a little older than you. My first car was an M type MG fitted with a J type 4-speed box. 20bhp on a good day and a chassis that flexed so much that if you stopped on a hump you couldn't open the door. OHC driven through bevel gears via a vertical dynamo that regularly filled up with oil - those were the days.

Whilst we're all reminiscing, I once had a Talbot 105 sports saloon, the George Roesche designed car, that had a Wilson self-selecting preselector gearbox driven by a centrifugal clutch. As you released the gear change pedal the selector lever moved to the next higher gear, so once 1st was selected, you just kept pressing the pedal to change all the way up the box. If you needed to change down you had to remember to move the lever (under the steering column) down two notches. I've never heard of any other mention of this arrangement and wonder if it was unique to this car. The car itself was almost Citroenesque in its design (that's my excuse for writing about it here). Aluminium four door body, the engine had a T-handled pump fitted on the side, half a dozen pumps on that sent engine oil to all the chassis lub points. Engine, gearbox, torque tube rear drive shaft and rear axle (quarter eliptic springs) were all lubricated by engine oil direct from the engine sump, an external pipe took the oil to the gearbox which then ran down the inside of the torque tube to the rear axle. There was a rivetted chassis cross member between the engine and the centrifugal clutch. As I found out, to take the engine out you had to take the rear axle off and work your way forward - like I said, very Citroenesque!

With reference to old fogeys selecting the wrong gear on automatics with disastrous results, I have to admit to having been guilty of that (without the disastrous results) a few months ago. I have a thing about not sitting in traffic with the car in gear, so if it looks like being a long wait I select neutral, it's then a simple one click back to put it into drive. On this occasion for some reason I can't explain I stuck it in "Park" rather than neutral. One click back from "Park" is "reverse". On starting off I was pleased to find that my reflexes are still pretty sharp, although the look of shock on the face of the driver behind remains etched on my memory.

Finally, isn't the auto box in Citroens made by ZF?

bxbodger · Unread post by **bxbodger** » 20 Dec 2005, 15:21

I have no axe to grind either way- I just always seem to end up with manuals, but I do like a drive in an auto when I get the chance!!!

But, can any of the slushbox haters tell me when the last time an F1 or WRC race was won by a car with a clutch pedal and gearstick.......

stuck the thing in reverse which was where first should be!

Unlike my old Marina which used to do the opposite!!!!!

fastandfurryous · Unread post by **fastandfurryous** » 20 Dec 2005, 17:49

bxbodger wrote: can any of the slushbox haters tell me when the last time an F1 or WRC race was won by a car with a clutch pedal and gearstick.......

F1 cars do have a clutch, it's just that it's only needed for pulling away. As far as I'm aware, most competition gearboxes are Manual-esque in their design, just with a rather large amount of electronic control. Still controlled by the driver though, by flappy-paddles.

You won't find a F1 or WRC car with a Torque converter though.... and this is the reason I don't like Autos... The torque converter. Makes driving horrible.

mbunting · Unread post by **mbunting** » 20 Dec 2005, 21:32

Well, how about this for my biggest mistake yet:

I travel about 40 miles each day on the M1, and one day it ground to a halt very quickly from 70-0mph.

It caught the van in front by surprise, caught me by surprise, and caught the C5 behind me by surprise - he was the lucky one with ABS !

So, since then, I've always made a concious effort to throw the selector into 3 for a bit of engine braking, then press the button and move to 2, then 1 as appropriate.

So, recently, this happened again - not so serious this time, but I tried the technique ( tibshelf hill for those interested ), and I got all the way to 2.

The traffic started moving again. Now, to get 'upwards' from D to N, you have to press the button.

I grabbed the selector, and threw it all the way to the top ( at about 10mph ) - thinking that it would go into D, and i'd be off again.

It didn't, it went through D, into N, into R, and the P ( and yes, P does stop you when moving ).

I'm sure the bloke behind wasn't amused ( neither was the box ! )

rossnunn · Unread post by **rossnunn** » 21 Dec 2005, 00:37

FrenchLeave wrote:Rossnunn, Sibsey, about 5 miles north of Boston. The A16 through Stickney and on up to the Wolds is quite entertaining.

Blimey small world! I live 10 miles out of boston on the new leake / old leake border! lol

Village · Unread post by **Village** » 21 Dec 2005, 13:30

I understand that the C-matic gearbox was similar to a pre-select gearbox in that it had a torque converter/fluid flywheel in place of a clutch, but the gears shift was the same as a manual gearbox. ie move the stick and the gear changes.

I also understand that, in the GS inparticular, the performance was, well, slow. You could also start it in any gear, with acceleration in first being slow and third being glacial!!

Unread post by **Peter.N.** » 21 Dec 2005, 13:44

Hillman, did a system on the Minx, I think it was called 'easy drive' which used an ordinary manual box and a centrifugal clutch, gearchanging was facilitated by a switch on the gear lever which automaticaly declutched when you grasped the lever. I think it was pnumatically operated.

fastandfurryous · Unread post by **fastandfurryous** » 21 Dec 2005, 23:51

mbunting wrote:So, since then, I've always made a concious effort to throw the selector into 3 for a bit of engine braking, then press the button and move to 2, then 1 as appropriate.

This shouldn't be necessary. if your brakes work properly, then you should have enough power in them to be able to lock the front wheels, even on a good day with dry roads and decent tyres. If this is possible, then what help is any engine braking?

If you can't lock the wheels with your brakes, then there's something wrong with them.

Plus... according to correct and advanced driving techniques, when braking you should have both hands on the wheel for maximum control. You shouldn't be changing gear under braking (despite many people habitually doing so)

I'd suggest the best thing you can do is find a deserted car park, or very quiet bit of road and practice heavy braking from high speed. You'll be amazed just how hard you can press the brake pedal, and how fast the car will stop. I had to do similarly when I got my 405, as the brake feel isn't great, and I too was finding I wasn't stopping well.

Unread post by **alan s** » 22 Dec 2005, 00:23

My last CX that I sold only about 2 years ago was a C-matic; best CX I ever drove.
Worked on an electrovalve operating a piston within a valve block that released/shut off ATF to the torque converter.
Brilliant performance once you got the car rolling, but unless you really knew some tricks, very slow off the mark for the average driver, acceleration from around 110 kph was like a sports car with unbelieveable torque for overtaking and fuel consumption was good for a big heavy vehicle (I got as good as 8.6L/100 klms (33 MPG) on a couple of runs)

It worked on the principle of having the top 3 gears of a 4 speed CX box attached to the torque converter so all (including reverse) were synchromesh and a control box with a few sets of terminals in controlled the electrovalve to facilitate gear changes.
Smoothest driving CX ever due to no clutch heaviness or backlash.
A young guy over here bought one and was somewhat disappointed with the performance in some respects, but called up here to visit me whereupon I took him for a short drive in his car. I didn't realise until later when he posted on another forum that I scared the $#!+ out of him as he described the drive as "I didn't know a C-matic could go like that. Alan was chucking mine around like it was a BX" so don't be fooled into thinking they're slow and sluggish; it's a bit of an art form, but in the right hands they go like the clappers and I would own another C-matic in a heartbeat should the opportunity arise.

Alan S

bxbodger · Unread post by **bxbodger** » 22 Dec 2005, 09:03

Hillman, did a system on the Minx, I think it was called 'easy drive' which used an ordinary manual box and a centrifugal clutch, gearchanging was facilitated by a switch on the gear lever which automaticaly declutched when you grasped the lever. I think it was pnumatically operated.

Proving that there's nothing new under the sun, Rootes easidrive was an electric system, which did away with the torque converter and replaced it with a magnetic clutch which was developed by Smiths.

It made small engine auto's possible in an age when conventional torque converter autos were much more innefficient than thet are now.

It goes to show that Citroen weren't the only people dabbling in the avante-garde!!