VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1916-1922 - Model 490 Changing gears with cone clutch

Mark Gregush, with a 1924 Superior, encouraged me to make a post on my experiences of changing gears on my 1922 490. See his thread on the 1912-1928 forum.

All 490 models and the 1923-1924-Superior models have the same cone clutch, and practically the same transmission. On the 1912-1928 or 1916-1922 forums you can find a number of threads on the clutch and transmission. For instance, search for “cone clutch”. But I have not seen many posts on experiences of changing gears on these cars.

Therefore I decided to open a new thread, on both these forums, hoping that it will inspire others to make comments on their experiences. I am really interested, because I am not sure if I have got it all right.

I have owned my 490 ten years, during these years I have been driving 12 000 kilometers (7 600 miles).

If you don’t know the construction or function of the cone clutch and the transmission you can take a look in the “Instructions for the operation and care of Chevrolet Motor cars, Four Ninety and Superior Models”, Issued July 1 1923, which you can find here , pages 43-46. In the instructions for 1924 Superior, which you can find here , you can find them on pages 44-47.

I usually start on the first gear, and shift to second gear at a very low speed, one or two mph, and the motor still idling or with just a little revving. So usually I change after just a few meters or feet. I make the shift passing the neutral quite fast, or say resolute, after releasing the clutch. Why? Because as soon as the gear shifting lever reaches the neutral position, the main shaft going into the transmission (ingoing shaft), the counter shaft and the idler shaft retards and stops very quickly. Why? I think that the main reason is that the main shaft gear, the three gears on the counter shaft and the two gears on the idler shaft works in a very heavy oil, either you use the often recommended 600W Steam Cylinder Oil or the similar modern 250W straight transmission oil which I use. VERY heavy just as you have started the car, especially if it is a little chilly. Another reason is that as the clutch is released, the clutch yoke is pressed against of the rear part of the clutch hub. As the cone is not very heavy, the main, counter and idler shafts can retard and stop quite quickly. You can easily check how quick the cone and the ingoing shaft stops if you remove the floor, start the motor and press and let up the clutch pedal.

If the ingoing, counter and idler shafts has stopped and the car is still rolling slowly, I just let the clutch pedal up, immediately press it down and make a resolute shift from neutral to second gear. The idling motor mostly makes the ingoing and counter shafts revolve enough to make the “second speed counter shaft gear” match the speed on the “high and second speed sliding gear” on the main shaft going out from the transmission (outgoing shaft).

If the ingoing, counter and idler shafts has stopped and the car is rolling faster, it is necessary to rev up the motor before shifting from neutral to second gear. This situation happens to me every time I leave our house, because the drive is a quite steep slope. I drive down the slope on the first gear, letting the motor make the braking job. When I have left the slope the speed is maybe five mph or more. I release the clutch, shift from first gear to neutral, let up the clutch pedal, rev the motor quite a lot, immediately release the clutch and make a resolute shift from neutral to second gear.

I use to shift from second to third gear at 15-20 mph. After releasing the clutch, I move the lever from second to third position without a paus in the neutral position, or with just a very very short paus. Why such a hurry? Because if I make a longer paus, of the same length that I do on my 1931 Opel, my 1964 Volvo 121, and that I did on the 1925 Superior with the new flat clutch that I owned for two years, the ingoing, counter and idler shafts retards and stops, as described above. This happens to me now and then, and then I have to let the clutch pedal up, rev up the motor, immediately press the pedal down and make a resolute shift to the third gear.

So I do not quite agree with the advice in the “Instructions…” that I mentioned above. There you can read this: “Be deliberate: It is well to pause a moment or two after disengaging the gears before moving into the next speed. The fundamental requirements in every case are that the gears to be meshed shall be revolving at as nearly the same speed as possible (this is of course correct). By waiting a moment, time is given for this to take place.”

Can it be that the reason my experiences differ from the “Instructions…” is that the gears in my transmission are excessively worn? Or can there be other reasons?

Hello, Per-Ã…ke
Are you joining us in Lake Tahoe in short time?
I would say if you can get the gear shifts to work as you describe that is excellent. I also agree to avoid too high speed when changing to higher gear but you must give extra throttle when going down.

Upwards: I have learned to uncouple, and then let the engine slow down near to idle revolving before changing to a higher gear. I find that easier (not so noisy) than quick changes, which could break or wear out the teeths in the gear box much faster. This information was given to me by Mr. Getz, who passed away on 16th October last year. He restored/finished his 1920 490 in 1959 and had the far longest driven distance by a "Norwegian" Chevrolet that age.

So I would say I would go for the information in the instruction book even if you find it better to use another
gear shift technique.

Downwards: You have to give extra throttle after uncoupling to be able to syncronize the gears wheels and into lower gear. Some times when you need the engine to brake it is more convenient (and nice for the gear box) to stop and put the car in a lower gear before running again.

You should get a better complete gear box and change, Per -Ã…ke. You might find the "slow" way of shifting better in the long run.

I also made a mistake earlier as to the thickness of the ox leather on the cone. It is ment to be 5mm, to fit the system. But when you loosen the bolt/nut midways on the brake/clutch pedal (on my 1916), move the pedal forward or backwards to fit a right angle for shifting. Tighten the nut again and you will not have any problem later as to too thin or too thick leather on the cone. But use two dashes of the neat foot oil on the cone, 1 when season starts and 1 in July, Release the clutch fully before oiling to easen the job. After oiling start the engine, keep the clutch uncoupled for some very few minutes to spread the oil to the leather and test drive thereafter. The clutch is very smooth an well working when correctly adjusted and oiled. Have a nice run.

Hello Solan

I was also learned to let the engine slow down near to idle before changing to a higher gear. And of course I can change smoothly from second to third if the car is rolling at 3-5 mph ant the motor is idling. But at 10-15 mph it is impossible even to make the shift. As far as I can understand the reason is that the ingoing main shaft, revolving at the same speed as the idling motor, does not match the speed of the outgoing main shaft with its “High and second speed sliding gear”.

The gears in my transmission were quite worn when I bought the car ten years ago. See pictures, taken almost ten years ago.





At that time I had new, hardened washers and new bushings made for the main shaft as well as for the counter shaft, because the old ones were excessively worn.

Two years ago, when I had the transmission cover off, I inspected the gears and they didn’t seem notably more worn.

Still I think you can have a point that the information in the instruction book can work if the transmission is less worn. I would appreciate if someone can post a couple of pictures of transmission gears as they were when new, or at least less worn than mine.

About downshifting: The only problem I had in the beginning, shifting from third to second gear, was to find out that when the car was rolling at say 10-15 mph I had to rev the motor quite a lot before moving the shift lever from neutral to second gear.

I hope that you who are interested in this topic also reads the posts on the same topic on the 1912-1928 Forum

Solan, sorry to hear about Mr. Getz. The first time I met him was ten years ago, and he took me on a trip with his 490. I was extremely impressed of his way to handle the car, including the gear shifting. Once during this trip he shifted from second to first gear, quite smoothly though the car was rolling. But I didn’t notice exactly how he did the shifting, and I didn’t ask him.

I know from a couple of other posts/topics on this forum that you and I have different experiences on cone leather and using the neats-foot oil.

Solan, we are not joining Lake Tahoe. I am sure it would be really nice, but it is too far away and I don’t think I can manage to drive our 490 across the Atlantic Ocean.