1966 A1

[kwb]

My 151A1 has about 300 miles on it now and can't be happier with the way it runs. I did buy a new nos diff and put it in the back because the original was ear pearsing loud. Who ever assembled the new one didn't pay attention to backlash. The dam thing had sixty thou. and sang like song bird. I set it to twenty and what a difference. Sure wish there was a way to move the pinion gear? Only other thing to do is, try to figure out why it's takes about 15 seconds or more to get it to start after it sits about 20 min when hot. It starts instantly when cold. It also starts instantly when hot as long as I don't let it sit to long. could it be the needle and seat leaking?

[rickf]

Did you run a pattern on the gears after resetting the backlash? That lash is a bit tight, spec is .022 -.035. Pinion depth is set with shims.They also tend to not set the pinion bearing preload tight enough from the factory on these.

[kwb]

This diff has a pinion preload of 11 lb-in. What problem would I have with only 11 lb-in. for the pinion? I did a pattern on the gears and according to the TM 9-2320-218-34-1 page 11-47 The pattern looks like the third down from the top. seems a little deep but it says acceptable. Are there any pinion shims available anywhere?

[rickf]

Pinion preload sounds good and I will take your word on the pattern, I was just wondering if you checked it for pinion depth. I have not been able to find different depth shims. I figured if I was ever able to find the double pinion race and bearing at a decent price I would then have guy from CMD laser cut me shims from different thicknesses of shim stock. But that one bearing is the elephant in the room. I have seen it from 25.00 to 250.00 and availability is very sparse. I have ten or more differentials that I can build but I am not even going to consider it unless I can find a consistent supply of affordable parts. One thing to consider is that these will be noisier than normal differentials mainly due to the fact that there is a lot less mass to them. Less there to absorb the sound in addition to being bolted solid to the metal body.

[kwb]

Hi rickf! You are correct about noise traveling through the vehicle because of the rigid mounting. This diff is now one of the quietest I have seen plus I went to our local farm store and got 3/8'' rubber matt and trimmed it to fit the entire rear floor. Big improvement. I have no planes to try the rubber isolator crap. Anyway, as my hearing goes away the quieter it gets.

[rickf]

The rubber isolator stuff was not a good idea since it allowed the bolts to move in the mounts. Plus the noise still traveled up the bolts from the differential where the steel diff mount contacted the steel bolt. Georg from Holland adapted some rear differential mounts from something that had independent rear suspension but they are separate isolators completely. Nice job but some serious fabrication. He also runs his mutt on Propane.

[kwb]

I'm not trying to make anything out of it that it isn't or modernize it in any way. the closer to original the better!

[kwb]

Hi rickf!
Check out my first post on this thread about my cold and hot starts! Sounds like a needle and seat problem but not sure?

[rickf]

Nature of the beast. These all start differently but what I would suggest is first try holding the gas pedal down just a bit on a hot restart since the carb does throw a show of gas into the intake tube at shut down. If that does not work try pulling the choke out for the first half a crank and push it in right away, do not wait for it to fire. And don't stop cranking. The carb feeds gas into the bowl from the top so the needle and seat would have nothing to do with starting. If you do not have an external leak then there is always enough gas in the bowl to start the vehicle. You just need to play around with it and find the combination that that vehicle likes for starting both cold and hot, once you find it it will remain the same.
Did you ever do a compression check on this engine? And did you ever set the valve clearances?

[kwb]

Hi rickf!
I need to remember the accelerator pump doesn't work until the engine turns over. I always hold the accelerator pedal down on a cold start and a little choke and starts instantly. I think my start when hot will need the accelerator down some also. The valves are set at .015 hot with engine running. compression is,118, 119,118,117. cold with throttle wide open. I think even though the engine is still warm but sits more than five min. some throttle will be needed to start.

[rickf]

You will have to remember this is not a modern computer controlled vehicle so some throttle work is always needed. Up, down or otherwise, nothing is automatically done for you on an old vehicle.

[kwb]

My 1924 model T is even more manual! A Model T guy could start or steal it in an instant, I haven't found anyone that could figure out what to do to get it started much less drive it. no one ever ask's me to drive it, but always like riding in it.

[rickf]

Is it close to the Model A procedure? I did a tune up on an A not all the long for someone in town. My neighbor suggested they bring it by and when it showed up in my driveway it was like OK? Gas on under the dash, mixture adjustment a little rich, pull mixture for choke, timing full retard, a couple clicks on the throttle lever and let her rip. Bring timing up, adjust mixture as needed. Am I close?

[Mark]

When starting it with hand crank, you have to do it a certain to avoid breaking your hand.If my dad was here he'd tell me all about it.

[kwb]

Your real close rickf. And Mark, it could and probably will kick back and break an arm or your wrist if the engine timing is not set to fire at 15 degrees past TDC with the spark rod in full retard when you crank it. And if you use the electric starter and don,t have that 15 degrease advance it could kick back and break the Bendix in the starter. these old fords aren't that bad, just got to make sure everything is set properly. My Model T and the 151 are equally fun vehicle's. Ken