Rear end questions?

L

lotsagas4u

Well-known member
Hello, was messing with 31 pickup this morning, have rear end on jack stands. Was checking adjustments on brakes, trans in neutral, while turning the right wheel, I noticed the left wheel was not turning. I went to left side and turned it, the right wheel was moving. Brakes are fully backed off on each side. It has a 3:78 gear set in it, it will only run about 40, and that's pushing it. Does this sound correct? Engine is timed proper, and was rebuilt last year. When trans in gear, both wheels turn, opposite each other. Thanks
 
Sounds normal. if left wheel not turning, trans in neutral while you turn right wheel, simply means that the driveshaft is turning.
Does it only run about 40 because it runs out of power, or does it just sound like it doesn't want to go faster? Sound can be deceiving if you are used to new cars. Is it a stock fan, or a four blade which could be noisier.
 
Model A speedometers are notoriously inaccurate above 40-45mph. You may actually be going faster than what your speedometer shows by several extra miles an hour. Can you use a GPS device that shows actual speed to check your Model A speedometer? Or have some in a modern car follow you and signal or communicate by phone what his/her modern car speedometer reads compared to yours at that moment. At least that will show if you have a majorly inaccurate speedometer.
A Model A with a healthy engine and timed properly should easily do 50mph with stock gears, if not 55mph. It should also reach - but perhaps not maintain - 60mph on a level road. If your car truly only goes 40 mph, something is wrong somewhere. Run a compression check to get an idea of the engine's internal health and go from there. The best ignition timing and carburetor cannot overcome a tired engine with low compression caused by worn rings/pistons and/or valves.
Marshall
 
Along with what Marshall said , check to see if your carburetor is opening all the way, many A throttle linkages are bent from R&R engines.
 
Big Hammer is right. When owners switch carburetors, it is imperative that the travel of the linkage be checked to ensure it pegs at full throttle on the carb. Very often - especially when going from a Zenith to a Tillotson/Marvel carb and visa-versa - the long arm on the accelerator linkage must be bent in order to provide full throttle. I have surprised dozens of disappointed Model A owners over the years by restoring full power to their engines simply by bending that linkage arm to achieve full throttle. "What a difference!", is the usual comment by the owners. I would bet many Model A's are running around out there with only 3/4 throttle. THAT is really going to limit top speed. Follow the Hammer's advice and check for full throttle. Your problem could be as simple as correcting that.
Marshall
 
Like everybody said, make sure the carb is opening all the way under full throttle before you try anything else.

My dad restored a '29 woody, except that he lightened the flywheel a little and put 3.54 gears in it so he wouldn't get run over on the freeway. I only drove it once before he sold it. It zipped along just fine on the street, but I never had a chance to drive it on the freeway.
 
Even with the brakes backed off there can be a little drag from the service brake shoes or the parking brake shoes. There is a little drag on the left brake.

The little drag can be caused by the cam not sliding freely inside the bushing. Take the left hub off and check to see that the cam can slide back and forth. It should have a tiny bit of grease on it.
 
REAR END QUESTION :

Women most often ask this question.

"Is my *** fat ? "

- ( For the purpose of self-protection, I will not identify myself in the post. )
 
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