First timers introduction!!!!
First timers introduction!!!!
Hello to everyone. After almost three months of reading, I thought it was time to introduce myself. My name is Rick, I have bought the model AA truck I rode away on 20 years ago when I got married. We left the wedding on the back of the truck and rode out to the cornfield to finish planting corn. The truck is pretty much complete and is titled as a 1931. It has a old wooden flat bed. the truck has sat in a enclosed workshop,with the oil pan off. the building had no heat,but has a concrete floor. The oil pan has mice/rats nest in it. The engine has what looks like pillow stuffing up around the front crank . My guess the work of more mice/rats. The truck ran five years ago. It was not driveable.I have a lot of questions, i just dont know where to start.I have worked on old tractors from the 20s thru the the 60s.My first question is,How do i clean out the tar like goo in the trans? It looks like tar. where is the best place to get parts? what should i do to get the mice offerings out of the engine? I would like to fix the truck just to drive in parades, and for fun. I will end by saying, I understand more about how the truck works then i know about computers. My kids/grandkids said i needed a computer so here i'am. Thank you in advanced for any help. I look forward to learning a lot, Rick
1931 AA
Rick, The tar like goo in the transmission is the old dark colored 600W gear oil. If there is no water or dirt that has gotten into the transmission, I'd leave it. Modern hypoid gear oil, such as 85/140 is too thin and causes the gears to grind during shifting. THe modern equivalent of the old 600W is SAE 250. Some people use MOBIL 600W used for steam cylinder lubrication.
If the mice nest is up inside the crankcase, pull as much of it out as possible and use an air tank and blow the rest out with an air hose. You might have to refill the air tank several times.
If the oil pan was removed, it was most likely that the engine was knocking. I would carefully inspect the crankshaft and connecting rods for fit. When the main bearing caps are removed, one at a time, inspect the condition of the crankshaft. With mice living in the engine, it is possible that mouse urine has run down between the rod and main caps and caused the crankshaft to rust. If the crank is not rusty, look at the condition of the babbitt to make sure there are no cracks and to make sure the babbitt is not worn to the metal cap. The mice may have gotten up into the valve chamber. Remove the valve cover and inspect that area.
If the crank is rusty, you might have to remove the engine and have the crank cleaned up or machined. If the crank is not rusty, squirt oil into the main bearing passages in the valve chamber, and if the engine will turn over with the hand crank, check if there are any shims in the mains and rods one at a time, try removing one lamination from one side and reinstall the cap. This trial and error go-no-go method was most often used. You could also get the job done quicker using plastigauge found at NAPA.
The center main and the rear main bearings are most often the culprits causing an engine knock. If the flywheel housing is cracked and if the two .010 shims are missing from the two top flywheel housing to block bolts, most likely, the flywheel housing is not square to the block. When the flywheel housing is out of square to the block, the transmission input shaft causes a wobble in the flywheel pilot bearing, This additional tension in the pilot bearing will cause the crankshaft to wobble in the rear main bearing, causing excess vibration. THe original gasket between the engine and the flywheel housing was .010 thick. The brass shims at the top flywheel housing bolts are .010. Currently, there is no one supplying the correct thickness gasket. One has to make the gasket from .010 thick gasket paper. The .010 shims are available at any Model A parts supplier. Unfortunately, the only way to check the flywheel housing to block runout is to have the engine out of the vehicle
When the crank is out of tolerance, the rear main will wear excessively and the oil drain tube will not be able to handle the excess oil from the extra crank to bearing clearance, resulting in a large puddle of oil under the flywheel housing when the engine is turned off. The early production engines had a 5/16 oil tube. The later engines have a 3/8 oil drain tube. If your engine is the same one that came in the truck, it most likely has the 3/8 drain tube, but check it. Someone in years past may have changed the rear main with an earlier one that had more babbitt in it, in order to get by without having to have the block repoured and align bored.
In addition to the rear main wobble, the crankshaft will also flex at the center main, banging the center main bearing . The center main bearing is often the knock heard when the engine is running. If the babbitt is found to be squeezed out from the sides of the cap, the crankshaft is definitely flexing and the flywheel housing is most likely out of square.
Also, don't forget the connecting rods. The rod dippers create as much as 80 psi when the engine is running and when a dipper becomes clogged from sludge, that rod will knock.
When engines are rebuilt, most current day crankshaft grinders don't know how to mount the Model A crankshaft in the crank grinder. Modern crank grinders put too much pressure on the live end, causing the crank to flex and bow at the center main. The crank is machined to the undersize that cleans it up and when it is removed, the crank relaxes and when inspected with a dial indicator on a crankshaft fixture, as much as .025 out of round can be measured. There should be no more than .001 out of round on any of the main bearing journals. .000" is desired.
When a crank is found to be badly ground, the rod journals are also found to be out of round. this will cause the piston skirt to contact the cylinder wall, as the piston and rod are going up out and down in the cylinder in a wobbling fashion, and is some cases, when the engine is run hard under load, the engine will lock up due to the excess drag of piston to cylinder wall. When the engine cools down, the engine will start up again.
There are a lot of small things to examine in the model A engine during an inspection and if the rear main bearing is not cracked, and the flywheel housing is square to the block, and you still have shims, and the crankshaft is not warped, you should be able to adjust the bearings and get it running.
There may be a valve or several that are stuck or burned. It may be a good idea to remove the head and visually inspect the valves and seats. This would also be a good time to see how much cylinder wear there is in the top of the cylinders. Also inspect the condition of the lobes on the camshaft and replace the timing gear.
Be sure to rebuild the oil pump and squirt oil from an oil gun into the main bearing passage holes in the valve galley before turing the engine over. When the main bearings are adjusted to within .0015", the main bearing oil galley holes will stay filled with oil for 15 to 20 minutes.
Brattons, Smith & Jones, Gaslight, Snyders, all carry a wide selection of Model A parts. You should be able to find their phone numbers doing a search using GOOGLE.
If the mice nest is up inside the crankcase, pull as much of it out as possible and use an air tank and blow the rest out with an air hose. You might have to refill the air tank several times.
If the oil pan was removed, it was most likely that the engine was knocking. I would carefully inspect the crankshaft and connecting rods for fit. When the main bearing caps are removed, one at a time, inspect the condition of the crankshaft. With mice living in the engine, it is possible that mouse urine has run down between the rod and main caps and caused the crankshaft to rust. If the crank is not rusty, look at the condition of the babbitt to make sure there are no cracks and to make sure the babbitt is not worn to the metal cap. The mice may have gotten up into the valve chamber. Remove the valve cover and inspect that area.
If the crank is rusty, you might have to remove the engine and have the crank cleaned up or machined. If the crank is not rusty, squirt oil into the main bearing passages in the valve chamber, and if the engine will turn over with the hand crank, check if there are any shims in the mains and rods one at a time, try removing one lamination from one side and reinstall the cap. This trial and error go-no-go method was most often used. You could also get the job done quicker using plastigauge found at NAPA.
The center main and the rear main bearings are most often the culprits causing an engine knock. If the flywheel housing is cracked and if the two .010 shims are missing from the two top flywheel housing to block bolts, most likely, the flywheel housing is not square to the block. When the flywheel housing is out of square to the block, the transmission input shaft causes a wobble in the flywheel pilot bearing, This additional tension in the pilot bearing will cause the crankshaft to wobble in the rear main bearing, causing excess vibration. THe original gasket between the engine and the flywheel housing was .010 thick. The brass shims at the top flywheel housing bolts are .010. Currently, there is no one supplying the correct thickness gasket. One has to make the gasket from .010 thick gasket paper. The .010 shims are available at any Model A parts supplier. Unfortunately, the only way to check the flywheel housing to block runout is to have the engine out of the vehicle
When the crank is out of tolerance, the rear main will wear excessively and the oil drain tube will not be able to handle the excess oil from the extra crank to bearing clearance, resulting in a large puddle of oil under the flywheel housing when the engine is turned off. The early production engines had a 5/16 oil tube. The later engines have a 3/8 oil drain tube. If your engine is the same one that came in the truck, it most likely has the 3/8 drain tube, but check it. Someone in years past may have changed the rear main with an earlier one that had more babbitt in it, in order to get by without having to have the block repoured and align bored.
In addition to the rear main wobble, the crankshaft will also flex at the center main, banging the center main bearing . The center main bearing is often the knock heard when the engine is running. If the babbitt is found to be squeezed out from the sides of the cap, the crankshaft is definitely flexing and the flywheel housing is most likely out of square.
Also, don't forget the connecting rods. The rod dippers create as much as 80 psi when the engine is running and when a dipper becomes clogged from sludge, that rod will knock.
When engines are rebuilt, most current day crankshaft grinders don't know how to mount the Model A crankshaft in the crank grinder. Modern crank grinders put too much pressure on the live end, causing the crank to flex and bow at the center main. The crank is machined to the undersize that cleans it up and when it is removed, the crank relaxes and when inspected with a dial indicator on a crankshaft fixture, as much as .025 out of round can be measured. There should be no more than .001 out of round on any of the main bearing journals. .000" is desired.
When a crank is found to be badly ground, the rod journals are also found to be out of round. this will cause the piston skirt to contact the cylinder wall, as the piston and rod are going up out and down in the cylinder in a wobbling fashion, and is some cases, when the engine is run hard under load, the engine will lock up due to the excess drag of piston to cylinder wall. When the engine cools down, the engine will start up again.
There are a lot of small things to examine in the model A engine during an inspection and if the rear main bearing is not cracked, and the flywheel housing is square to the block, and you still have shims, and the crankshaft is not warped, you should be able to adjust the bearings and get it running.
There may be a valve or several that are stuck or burned. It may be a good idea to remove the head and visually inspect the valves and seats. This would also be a good time to see how much cylinder wear there is in the top of the cylinders. Also inspect the condition of the lobes on the camshaft and replace the timing gear.
Be sure to rebuild the oil pump and squirt oil from an oil gun into the main bearing passage holes in the valve galley before turing the engine over. When the main bearings are adjusted to within .0015", the main bearing oil galley holes will stay filled with oil for 15 to 20 minutes.
Brattons, Smith & Jones, Gaslight, Snyders, all carry a wide selection of Model A parts. You should be able to find their phone numbers doing a search using GOOGLE.
Thanks!!!! more questions
Thank you very much for all the information. I start on two weeks vacation and will work on the truck. I will let you know what we find. What kind of rearend ratio did the 1931 truck have? I have read posts refering to different types. How can I tell, with ease, what type i have? What parts,besides the engine are the same as on the car? I need to find out the type of carb i have also. How do you tell the difference between the carb types? The man took the carb apart as well.One last question, do the parts venders use the old ford co numbers in there catalogs? After compareing the part numbers from different venders, they seem to be the same. Thanks Rick
1931 AA
The posts for the rear end gears shold be printed. You should become a member of the AA truckm club. Email Neil Wilson. He has back issues of the news letters which contain very valuable information on the AA's. Ford recently demanded that parts vendors discontinue using the old Ford part numbers, so all of the parts vendors new catalogs should have new part numbers for the parts. You should also obtain a copy of a reprint or original parts book for 1931. The car & truck parts can be identified easily. Zenith 1,2,3 carbs were used. Zenith 1 were made by Zenith, Zenith 2 were identical but were made by Holley and Zenith 3 were made by Ford. The late 31 used a top section that was different from prior years.
Tillotson was an aftermarket carb that many people still like and use. Tillotson had sevaral variations and are found to be made from aluminum. There were other carburetor suppliers, but the ones that came on the truck were from Ford. I like the Zenith.
Tillotson was an aftermarket carb that many people still like and use. Tillotson had sevaral variations and are found to be made from aluminum. There were other carburetor suppliers, but the ones that came on the truck were from Ford. I like the Zenith.
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mikeg
- Site Admin
- Posts: 179
- Joined: January 15th, 2003, 4:08 pm
- Body Type: 150B
- Model Year: 1930
- Location: San Juan Islands, Washington
- Contact:
Hello Rick,
FMAATC (Ford Model AA Truck Club) contact info can be found here:
http://www.fmaatc.org/
There is a downloadable form to join, Neil's contact info is there too.
FMAATC (Ford Model AA Truck Club) contact info can be found here:
http://www.fmaatc.org/
There is a downloadable form to join, Neil's contact info is there too.