Maintenance and Repairs

12-Volt Conversion

How do I convert my 8N to a 12 volt system?

4-speed Transmission Locked

One of the complaints we hear about now and then is a 4 speed transmission that “locked up” when it was shifted from one gear to another.

Brake Spring Removal

These brake springs are hefty and are under a lot of tension. Don’t fight it.

Engine Oil

“Do I have to use non-detergent engine oil in my 8N?” No. Todays motor oils are far superior to what the manufacturers suggested 50 years ago.

Engine Stalling

Why does my 8N run for a few minutes and then die?

Fluid in Tires

Why is water leaking out of my rear tires?

Front Distributor Timing

The front mount distributor engine has no external timing marks. Instead, the timing is set mechanically with the distributor out on the bench.

Front Kingpin

How do I remove the front axle kingpin?

Gear Oil

Originally, the 8N used 90w (GL-1) gear oil for the transmission, rear gears and hydraulics common sump. Capacity is 5 gallons. Many people today recommend using Ford 134 oil.

Hydraulic Problems

The 8N hydraulic system is simple yet elegant and works great when properly adjusted and maintained.

Lead Additives

Do I need to add a lead substitute to my gas?

Low Oil Pressure

The relief valve spring is designed to hold the poppet on the seat until oil pressure is 35-45 psi (Yes, the poppet IS supposed to have that flat spot on it). The relief valve only sets the maximum pressure attainable and has no effect on raising a lower pressure unless the spring is weak or broken.

Pistons & Sleeves

There are numerous methods for removing and replacing the sleeves. Obviously, the easiest and safest way is to use a commercial sleeve puller set.

Rear Axle Seals

Rear axle seals leaking gear lube onto the rear brake shoes and onto the wheel rim is very common on 8Ns, especially the early models before the added inner seal.

Rebuilding a Combination Transmission

Due to their usefulness by adding several more gear selections, the popularity and demand for Sherman combination transmissions remain high among Ford “N” tractor owners.

Rebuilding a Step-Up Transmission

Due to their usefulness by adding several more gear selections, the popularity and demand for Sherman transmissions remain high among Ford “N” tractor owners.

Repairing a Select-O-Speed Input Shaft

One of the most common failures with the Select-O-Speed transmission is the splines on the input shaft and drive clutch disk.

Rocker Pin Removal

People seem to have a terrible time getting the rocker pins or sleeves out, but I’ve never found it to be that difficult. The right tools make all the difference.

Select-o-Speed Trans Problems

Sometimes there are issues with Ford Select-O-Speed transmission, here are some troubleshooting methods.

Sherman installation instructions

Split the tractor between the engine and transmission. Once separated, remove the left brake pedal and the brake cross shaft. Use the diagram below to locate the spot to drill the shifter hole. The measurements should get the hole location within 1/8″ or closer of where it should be. You may want to use a…

Steering Box Info

Can I upgrade my ’48 to use the newer style 8N steering box?

Steering Box Lube

The early (’47-’48) 8N steering box had a 1/4″ pipe plug on the upper right side of the box. It could also be filled by removing the nut that holds the steering wheel on and pouring the oil down the hollow steering shaft where it flowed out a cross drilled hole and over the upper bearing (very slow process).

Tie-Rod Removal

The tie rod or “draglink” ends on the N tractors have a tapered stud that goes in to the steering arm and hold them tightly in place even after the nut is removed. It takes some mechanical force to pop the stud loose from the taper.

Wiring Diagram

Where can I get a 8N Wiring Diagram?

12-Volt Conversion

How do I convert my 8N to a 12 volt system?

4-speed Transmission Locked

One of the complaints we hear about now and then is a 4 speed transmission that “locked up” when it was shifted from one gear to another.

Brake Spring Removal

These brake springs are hefty and are under a lot of tension. Don’t fight it.

Engine Oil

“Do I have to use non-detergent engine oil in my 8N?” No. Todays motor oils are far superior to what the manufacturers suggested 50 years ago.

Engine Stalling

Why does my 8N run for a few minutes and then die?

Fluid in Tires

Why is water leaking out of my rear tires?

Front Distributor Timing

The front mount distributor engine has no external timing marks. Instead, the timing is set mechanically with the distributor out on the bench.

Front Kingpin

How do I remove the front axle kingpin?

Gear Oil

Originally, the 8N used 90w (GL-1) gear oil for the transmission, rear gears and hydraulics common sump. Capacity is 5 gallons. Many people today recommend using Ford 134 oil.

Hydraulic Problems

The 8N hydraulic system is simple yet elegant and works great when properly adjusted and maintained.

Lead Additives

Do I need to add a lead substitute to my gas?

Low Oil Pressure

The relief valve spring is designed to hold the poppet on the seat until oil pressure is 35-45 psi (Yes, the poppet IS supposed to have that flat spot on it). The relief valve only sets the maximum pressure attainable and has no effect on raising a lower pressure unless the spring is weak or broken.

Pistons & Sleeves

There are numerous methods for removing and replacing the sleeves. Obviously, the easiest and safest way is to use a commercial sleeve puller set.

Rear Axle Seals

Rear axle seals leaking gear lube onto the rear brake shoes and onto the wheel rim is very common on 8Ns, especially the early models before the added inner seal.

Rebuilding a Combination Transmission

Due to their usefulness by adding several more gear selections, the popularity and demand for Sherman combination transmissions remain high among Ford “N” tractor owners.

Rebuilding a Step-Up Transmission

Due to their usefulness by adding several more gear selections, the popularity and demand for Sherman transmissions remain high among Ford “N” tractor owners.

Repairing a Select-O-Speed Input Shaft

One of the most common failures with the Select-O-Speed transmission is the splines on the input shaft and drive clutch disk.

Rocker Pin Removal

People seem to have a terrible time getting the rocker pins or sleeves out, but I’ve never found it to be that difficult. The right tools make all the difference.

Select-o-Speed Trans Problems

Sometimes there are issues with Ford Select-O-Speed transmission, here are some troubleshooting methods.

Sherman Drawing & Installation

Split the tractor. Remove the clutch fork and shaft. Remove the brake shaft. Remove the transmission input shaft and tube. If you’ve had a Sherman Step-Up installed before, you will have a shifter hole already drilled in the transmission case. If not, locate and drill a 1 1/4″ hole. Without a template to mark the…

Sherman installation instructions

Split the tractor between the engine and transmission. Once separated, remove the left brake pedal and the brake cross shaft. Use the diagram below to locate the spot to drill the shifter hole. The measurements should get the hole location within 1/8″ or closer of where it should be. You may want to use a…

Steering Box Info

Can I upgrade my ’48 to use the newer style 8N steering box?

Steering Box Lube

The early (’47-’48) 8N steering box had a 1/4″ pipe plug on the upper right side of the box. It could also be filled by removing the nut that holds the steering wheel on and pouring the oil down the hollow steering shaft where it flowed out a cross drilled hole and over the upper bearing (very slow process).

Tie-Rod Removal

The tie rod or “draglink” ends on the N tractors have a tapered stud that goes in to the steering arm and hold them tightly in place even after the nut is removed. It takes some mechanical force to pop the stud loose from the taper.

Wiring Diagram

Where can I get a 8N Wiring Diagram?

Thanks to John Smith of Old Ford Tractor for allowing us to use this information.