Anyone here have a driving knee action front suspension GM ?

[arcticbuicks]

i was wondering how a GM around 1936 drives with the knee action suspension,dubonnet.

there must be an incredible amount of force on the kingpins ,and quick to wear ?

I wonder how they lasted ? I have several 36 chev parts cars with them.....and was looking them over with intrest.......one of the front axles mounted solid to frame has several cracks ......so there must have been a lot of twisting force on the axle also ?

Edited November 22, 2023 by arcticbuicks (see edit history)

[Bloo]

That "axle" thing is heavy and thick. I'm surprised it cracked. Kingpins wore out fast on every car of that age, so nothing special there. The main weakness of Dubonnet was the bushings or bearings and seals where the shafts entered the Dubonnet unit. When worn, they wouldn't hold oil, and when out of oil they just floated up and down in an extremely annoying manner, enough to make you seasick. They are famous for this problem, and it is probably what took most of them off of the road.  A family my parents knew well retired their 1935 Chevrolet because of this. A car equipped with a good working Dubonnet is going to drive much better than a car with a straight axle.

[arcticbuicks]

the axle is just stamped steel .......not cast .....fairly thin steel.....on these chevies anyways

[Fordy]

I had a 1950 L series Vauxhall touring car with the Dubonnet suspension. I never had to do much to it other than fluid checks and it was one of the smoothest riding cars I have ever owned. It is one I wish I still had!

Steve

[Rusty_OToole]

Rapid wear if not lubricated, and when worn became extremely knock kneed or, front wheels at cockeyed angles. This was their downfall. On the other hand, if rebuilt and working correctly they are said to be very good and once fixed, probably won't wear out given the limited use and good maintenance, that is, regular lubrication.

[arcticbuicks]

makes sense ......mine is loose and cracked axle.......in decades of car events and shows......i cant say i have ever seen any cars with the knee action being driven.

the steering would sure be precise in good shape ......as the outer  tie rods wouldnt move up and down ......and no drag link change of height movement.......the steering is level at all times

 

Edited November 22, 2023 by arcticbuicks (see edit history)

[Bloo]

The disadvantage there with Dubonnet, compared to a more conventional short-arm/long-arm suspension, is that there is no camber gain in compression, so less grip in corners.

 

A short-arm/long-arm independent suspension has the tie rods ends in very specific points in space to avoid bump steer. As the suspension moves up and down, the tie rod does not steer the spindle over most of the available suspension travel. Any deviation in tie rod length or location screws it all up, so yeah Dubonnet has an advantage there.

 

Dubonnet can have a little bump steer though. It still has that one rod going back from the spindle to the steering box that steers both wheels even though they are locked together. They kept that rod long and nearly level to minimize movement.

 

 

Edited November 22, 2023 by Bloo (see edit history)

[Rusty_OToole]

Here is GM's explanation of the new Knee Action system with illustrations of its advantages and how it works.

 

 

[Littlestown Mike]

3 hours ago, Rusty_OToole said:

Here is GM's explanation of the new Knee Action system with illustrations of its advantages and how it works.

 

 

OK, I am sold---what a great ad.

 

[arcticbuicks]

i want to put one of my suspension front units on a fenderless car like a speedster  or hot rod.........would be an attraction at a car show with the big bulky units in the front

[Rusty_OToole]

20 hours ago, arcticbuicks said:

i want to put one of my suspension front units on a fenderless car like a speedster  or hot rod.........would be an attraction at a car show with the big bulky units in the front

It certainly would be novel. Andre Dubonnet built several sports cars and racing cars  with skimpy fenders, don't know if any were fenderless.

[EmTee]

On 11/23/2023 at 8:30 AM, arcticbuicks said:

i want to put one of my suspension front units on a fenderless car like a speedster  or hot rod.........would be an attraction at a car show with the big bulky units in the front

I know someone locally who has a '37 Chevy with the knee-action front end.  I remember looking at the assembly and thinking it's a good thing it was hidden under the car. 

[arcticbuicks]

its so wild and strange looking ......so few on the road these days i imagine .......but would be fun and if they drive great [rebuilt]....bonus

[Rusty_OToole]

On 11/23/2023 at 8:30 AM, arcticbuicks said:

i want to put one of my suspension front units on a fenderless car like a speedster  or hot rod.........would be an attraction at a car show with the big bulky units in the front

Here is an Alfa Romeo race car with Dubonnet suspension. It does not look as unusual as I thought it would.

[arcticbuicks]

no,it dosnt......the chev have huge.......monster big units facing farward of axle.......and quite low........i have a 1928 chev roadster great body and several hundred open touring windshield frames of all unknown kinds.....wire wheels and some cool round NOS gas tanks from teens......a few bomber trainer aircraft seats........hmmmm.......what to use for an engine lol  ?

Edited November 24, 2023 by arcticbuicks (see edit history)

[Rusty_OToole]

3 minutes ago, arcticbuicks said:

no,it dosnt......the chev have huge.......monster big units facing farward of axle.......and quite low........i have a 1928 chev roadster great body and several hundred open touring windshield frames of all unknown kinds.....wire wheels......a few bomber trainer aircraft seats........hmmmm.......what to use for an engine lol  ?

For an engine... no doubt you want something slightly unusual.... a V12 Lincoln Zephyr, supercharged Graham flathead six, or a straight eight Buick? The smaller Buick Special engine so you don't overwhelm the suspension.

[arcticbuicks]

i do have 30-50s buick 8's....hudson 8's 1928-30......a huge 20s Rolls engine possibly aircraft....but would be crazy costly to rebuid for a speedster........but i am liking the idea.....i have a young machinist friend who is crazy talented and made a new crankshaft for a 1912 White 7 pass. here...............ugh....i get going on a crazy project idea ....and ends up costing $60k..........sounds fun though

Edited November 24, 2023 by arcticbuicks (see edit history)

[Rusty_OToole]

Or you could keep it all Chevrolet with a Chevy six. The last best old style stovebolt  was the 1954 - 1962 261 used in Chev trucks and Canadian Pontiacs. They can produce decent HP with a few simple hop up tricks. 135HP stock, nearly 200HP with a little this and that.

[Rusty_OToole]

Keep in mind the capacity of the chassis, steering and suspension when it comes to weight and performance. You could have a very sweet running light weight fun car with a small engine or an unwieldy monster with a big one.  I would go with the smaller engine, even a 4 cylinder if you have a good one.

[arcticbuicks]

yes true ......my 28 chev frame is huge and strong .......the 36 stovebolt 6 is pretty hefty ......but not like a buick 8

[arcticbuicks]

i have to think of a strange interesting big 6.......essex were fast running engines.......i like nash twin ign. and they have good mains.... or i have a couple 30s packard engines

Edited November 24, 2023 by arcticbuicks (see edit history)

[EmTee]

Maybe an OHC Pontiac?

 

[arcticbuicks]

is that a 1968.......never thought of that....very cool !...im trying to maybe use a engine i have in the closer 1930s

[Rusty_OToole]

Hudson straight eight was very small and light, no bigger than a lot of six cylinders. They gave a hot performance in the Terraplane and the English Railton. In 1935 Railton made 2 special light weight models with a claimed 0 - 60 time of 8.8 seconds which was dynamite for the time. A Hudson engine might be just the ticket especially if you could jazz it up with twin carburetors and exhaust header.

Only thing wrong with the Hudson is the splash lubrication which does not lead to long life for the bearings at high speeds. But I doubt you would be driving for long periods above 60 MPH anyway.

[Rusty_OToole]

Found an article on hopping up the Hudson straight eight from 1950 Hot Rod magazine. Apparently most standard hop up tricks will not work, you can't bore the engine much because of the siamesed cylinders. Stroke is already 1 1/2 times the bore. No room for larger valves, multi carb manifolds and headers not available. Flywheel/clutch assembly is Hudson's own oil bath unit and can't be lightened.

About the only thing you can do is mill the head for more compression, even that is limited because it is a flathead.

 

The last ones did come with two barrel carburetor so that is something, and they were  quite powerful for their size at 128HP.

[arcticbuicks]

awww......and the oil bath clutch is not good.......pontiac ! ......were full oil pressure earlier than chev and flathead.......

[Rusty_OToole]

The oil bath clutch worked great and had no problem even with the powerful Twin H Power 170HP engine. They contain no asbestos and can be relined with bottle corks which gives you an excuse to buy wine by the case. Hudson did a lot of things that make you go "What??" but they worked.

[arcticbuicks]

i had a friend .....[ passed on now ]....that i got a huge pile of interesting race/or speedster items and cars  a few years ago after his passing......Dr. Frank Gunston,a interesting gruff britt...he invented the artificial knee joint {i think he received something like a Nobel piece prize for his work }....with the help of another car guy......they hammed out the prototypes etc at night with a few drinks and big fat cigars  combined with working on old vintage model T and A's....and some whippet ......the medical system said no way your going to experiment on people with mechanical parts .......and i think he had to leave canada to install some of his prototypes in living humans......kind of hot rodding humans lol.......what he had  were race cars and parts nothing too exotic .one with the Frontinac [spelling ?] head ,inline hose water pump running off belt simply by twisting water pump in hose to apply pressure of little wheel on belt,buffalo style wheels....oval brass windshields etc....he also had a model T you could order without body but had fenders and dash etc......it was near new with temporary wood seat box/gas tank from factory never having been used after it was bought......in his later years the big shop [a RCAF army barrack he had moved to his country estate from nearby WWii Bomber training base] was collapsing from a bad roof and snow load damage........his wife said can you help me do something with everything.......she said i want $5000.......and trust you to go through the place.....at the time i was busy with a museum build....but took  my big skid steer over and semi trailer and other trailers.......scrambled to dig through old shop .....its tough when everything is left and some apart to sort......the one overhead valve  T race car had engine apart and i never did find pushrods......it also has a aluminum transmission with no mags i couldnt identify....but that was lucky with only missing pushrods in the end.....i then thought maybe i should donate everything in his name as he invented the artificial joint out of his car hobby........and i said to his wife $5000 is too cheap but i will give you the money but donate most of it....... and i have enough also....basically i kept was a rare single cylinder free air polaris race snowmobile from the 60s...a few speedster gas tanks and bomber style buckets etc that didnt match the cars he had...it took days to remove everything and pack and load,i got big plastic 4 ft meat totes and we loaded even what we couldnt identify as once its gone-its gone ......it all went to the right guys to get prepped for a museum......i keep in contact with his wife and this reminds me i have to go back  ......there are few other small items i want to save yet............i often thought it would be a lot of fun to have a speedster of the era

Edited November 26, 2023 by arcticbuicks (see edit history)

[arcticbuicks]

Hudson yes.... a twin h........i really dont see a lot of hudson in this area past early 1930s....and few 40s and early 50s like commadore..... but there is still so much on Canadian prairies around yet......i was never a fan of the cork clutch but maybe ok ........i do know of a Viking with V8......car is rough....interesting engine and intake ....they just couldnt get away from the updraft carb yet lol