1937 special cant go over 35 mph

With the help of some of you fine gentleman , I was able to put my 37 special / 40 back on road after garaged for 8 some years. It was a great experience to see my 10 y old girl looking at the car she dreams of driving when she turns 18 , and hopefully until shes 68 or so. The oil [pressure seems fine , also temp , but once got on the parkway , I notice that I couldn't go over 35 mph . it just feels like the gears are too short or something. also can you guys recommend a gear and diff oil ? it shoul be 80 90 rite ? but I got the GL5 by mistake . Where can I get the correct one ? tx

Is the clutch slipping maybe?

Cheers, Dave

There are so MANY things it could be. Check the clutch by sifting into high gear at around 10mph and accelerating hard; if the engine revs but the car doesn't move faster clutch is probably OK. I'm suspicious of the exhaust of a car this happens to, everything from rats nest to pipe collapse. Take the exhaust pipe bolts loose at the manifold and try it out; ignore the noise. Check to see if the advance is working on the distributor. Try without air cleaner on. My 37 Special had 4.44 gears in it and would still run 65 easily (8.25/15 tires).

35 mph will sound like the comfort zone on any '37 Special due to the gearing, but they can safely go faster. My '38 (same gearing) would sound stressed at 50, then smooth out at 60. If you put the pedal to the floor and 35 mph is all you get, then you've got problems.

There is a good chance your carb jets are varnished too. I suggest that you replace the fuel filter, remove the carb. and use a carb cleaner to remove any fuel varnish.

There is a good chance your carb jets are varnished too. I suggest that you replace the fuel filter, remove the carb. and use a carb cleaner to remove any fuel varnish.

THANKS , im gonna start with the carb first . WELL , first the clutch then carb . The muffler sounds good and got some pressure . What about the gear oil ? Any sugestions on a non detergent , not GL5 ? tx

Updraft carburetors are MUCH more reliable than downdraft carburetors :confused: The reason being that most updraft carburetors are so difficult to get to that the real problem is fixed before the carburetor is touched!

Seriously, while the carb might be an issue; lots of other items to check first:

(1) Have a helper push the footfeed to the floor while you observe to see if the carb goes to wide open throttle

(2) If the vehicle has been sitting a long time, a new fuel filter (even if you just changed it)

(3) The whole ignition system

(4) Will the engine rev to higher RPM's in the lower gears? If so, NOT the carburetor.

(5) Fuel tank vent clogged.

(6) Auto choke not opening.

You will find it.

EDIT: It's early in the morning. The fact that it is a 1937 just sunk in. In 1937 Buick used Strombergs and the marvelous Marvel carburetors. If yours is a Marvel, it just might be the problem.

Jon

Marvel carburetors ...

I had a '34 Plymouth with this problem it would run great to 30MPH but nothing over that. Turned out the old coil would short out when I reached the 30MPH mark. As soon as I backed off the engine ran fine. Just something else to check out. Good Luck

I had a similar problem with my 29 Buick and found it was a weak spring in the points.

Bill McLaughlin

1929 McLaughlin Buick Roadster

Supporter of "All Together Parking by Era"

OK , as soon as warms up a bit , and after the spring snow stops falling , I will check it out . And by the way what I got is a CARTER WDO, and it seems to be the original on some specials according to Bobs and dave tacheny . Does everybody agrees on that ? And also any clues on the trans and differential oil ? The only one that I can get is the GL5 but I know is not recommended . tx

Buick did NOT use the Carter as original equipment in 1937!

Buick finally ended their relationship with Marvel in 1939, and added Carter as their second carburetor vendor. As even the Stromberg carb used in 1937-1938 was not the best (because of Buick's insistance on the use of the captive Delco choke); both Stromberg and Carter were asked by Buick to offer "service replacement" carburetors (with hot air choke) for the 1937 and 1938 Buicks.

Your Carter WD-0 (it is a zero, not an ooh) may be one of these.

Jon.

Hi,

Another possibility if you can stand it:

Cracked distributor cap, or a carbon track on the inside or outside of the cap. I have experienced both.

--Tom

EDIT: Two other thoughts:

1) Pull off the ignition wire side cover and fire this thing up at night--ie, in the dark--and see if you're getting a light show of misdirected ignition sparks. It could be that your wires are shot and either grounding or talking to each other.

2) Have you installed new "old NOS" spark plugs, maybe from an EBay vendor? I did once, and found that all the porcelains were cracked.

--Tom

--Tom

With the help of some of you fine gentleman , I was able to put my 37 special / 40 back on road after garaged for 8 some years. It was a great experience to see my 10 y old girl looking at the car she dreams of driving when she turns 18 , and hopefully until shes 68 or so. The oil [pressure seems fine , also temp , but once got on the parkway , I notice that I couldn't go over 35 mph . it just feels like the gears are too short or something. also can you guys recommend a gear and diff oil ? it shoul be 80 90 rite ? but I got the GL5 by mistake . Where can I get the correct one ? tx

Hi, I'm new to the forum, new to '37 Buicks, but an old hand with cars.

Does the engine feel like it's misfiring at 35 mph, or does it just not want to go any further? BTW I would doubt that the oil in your gearbox or diff is causing this problem.

Does it keep going at 35 mph or does it start to slow down? As suggested previously - does it feel like it goes OK in the lower gears but once in top gear it "runs out of puff"?

If it feels like a misfire but keeps going at 35, then I would be looking at closely at the ignition - leads, cap, rotor, points, and coil.

If it just won't go any further but doesn't feel like it's misfiring, then I would look at the exhaust.

If it starts to die at 35 at then gets worse as you keep going, I would look at fuel - pump and carb.

If it stops going any faster (particularly on hills) but the engine sounds louder (revs harder)- then look at the clutch.

Hope this helps.

Rob

IT DRIVES PERFECTLY , BUT DOESNT GO OVER 35 MPH BUT JUST FEELS LIKE THE ENGINE IS STRUGLING OR THE GEARS ARE TOO SHORT ! AND OF COURSE IM IN THE 3RD GEAR ! AND ALSO CAN ANYONE RECOMEND A 80 90 GEAR OIL NOT GL5 ? IM HAVING A HARD TIME TO FIND IT TX

I drive in my Gearbox a SAE 140 Oil and in rear axle a 80w90 hypoid (gl 5) oil.

And with the speed: your Oilbath oilcleaner are free ? Try another one, hope your chokeflapper dont sucks tight while accelerating ?

The Coil, Consenser, points and spark cables (still under the "secrets"- cover ?) are inside ?