The Ongoing Cub Cadet Garden Tractor Restoration

The odyssey continues: Restoring an IH Cub Cadet garden tractor

Refurbished International Harvester Co. Cub Cadet Model 100 garden tractor.

Refurbished International Harvester Co. Cub Cadet Model 100 garden tractor.

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In the last episode, the Cub Cadet restoration odyssey was well underway, with the Cub Cadet garden tractor dismantled and parts meticulously cleaned and renewed.

That potentially overwhelming work offers nearly as much temptation to quit as Odysseus felt when he encountered the beguiling sorceress, Circe, on the island of Aeaea. Once begun, however, the assembly process will motivate you to continue the work, despite such temptations. When the Cub Cadet shines like new, the long journey will finally be worthwhile.

Turning the corner

The first real reassembly steps in an International Harvester Cub Cadet restoration project will convince folks that all the preceding work has been worthwhile. In fact, it's not unusual to begin some assembly as parts are cleaned and/or primed and painted. For example, after carefully thinking through the painting and assembly details, the frame (with pedals and other such hard-to-get-at parts installed), front axle and transaxle can be rejoined. Better yet, attach wheels to the assembly and the rolling chassis becomes a mobile foundation for later assembly steps. If the tractor is a hydro model, install a new oil filter before rejoining the transaxle and frame — filter access is much easier when the tractor is disassembled.

As the Cub Cadet comes together piece by piece, you'll have a tendency to rush because the finished product can be readily envisioned. Be patient. To avoid making hasty mistakes, be sure to regularly consult the manual. Be particularly certain that the levers and spacers on shafts are in order before buttoning them up so they don't have to be taken apart later.

To preserve the tractor's beautiful and hard-won finish, employ forethought during assembly to avoid dings. Nothing is more frustrating than taking a wrench and hammer to a beautifully painted assembly because a critical component was, left out or incorrectly installed.

As a rule, decal application is the last step of the restoration project, but the operator's pedestal decal on most Cub Cadet models must be applied before the steering column, choke cable, throttle, ammeter, cigarette lighter and steering wheel.

Engine considerations

Even if the engine runs well, it should be carefully cleaned and inspected. If it doesn't smoke or knock, then follow a few simple maintenance steps. Clean the cooling fins and remove the cylinder head(s). With the head removed, carefully scrape excess carbon from the top of the piston and around the valves. Inspect the cylinder wall for significant ridges and score marks. Using the manual as a guide, check that the head isn't warped, and re-install it with a new gasket. Be certain to tighten the head bolts to the proper torque in the sequence outlined in the manual. Then inspect and clean the entire breather assembly.

If the crankshaft seals are leaking, but the engine internals aren't worn enough to warrant a complete tear down, remove the PTO pulley and the flywheel from the crankshaft, pry out the old seals and install new ones (see details below).

With the pulley and flywheel back in place, paint the engine. The carburetor should be cleaned and the float adjusted before it's installed.

Unfortunately, if the engine knocks, lacks compression or smokes badly, it most likely must be disassembled. Following the manual carefully, take the engine apart, bagging and labeling components as you go. Keep track of which valve lifter, spring and retainer belongs with which valve.

The trickiest challenges might include removing the flywheel and the front PTO pulley from the crankshaft. Sometimes all you need is the right tool to make the work easier. A flywheel puller can be purchased or borrowed from a local auto parts establishment. This tool helps remove the flywheel and the bearing-retainer plate beneath it on Kohler single-cylinder engines. Two medium-sized pry bars will help you remove the PTO pulley - the Cub Cadet manual suggests two large screwdrivers. Carefully use the pry bars to put pressure on the pulley's hub and don't spare the penetrating fluid.

Once the engine is disassembled, use a micrometer to measure the cylinder bore, crankpin and piston, then compare those measurements against the specifications in the manual. Areas that are out of specification must be addressed. For example, if the crank pin diameter is worn beyond a specific point, or if it's no longer round, then it must be ground back to an undersized specification.

If the cylinder wall is tapered or the diameter is beyond a certain specification, then it must be rebored to a larger specification. These precise operations are best left to a trusted local machine shop, which can also do the measuring, if desired. Enthusiasts should save the fun of taking the engine apart and putting it back together for themselves.

Engine assembly is best done in a clean, careful and methodical manner. The precise relationship of engine parts with one another is critical to long service life for your Cub Cadet. The crankshaft and the camshaft must be aligned perfectly or the valves may collide with the piston, resulting in a complete loss. Luckily, marks on the crankshaft and cam gears are there to help obtain the proper alignment.

The piston rod cap bolts must be tightened to a specific torque. Use the engine manual religiously at this point, and understand how to accomplish each step before you start turning wrenches. The engine assembly requires a minimum of three specialized tools - a torque wrench, a piston ring compressor and a valve spring compressor. A torque wrench, in fact, should be in everyone's toolbox. The other two tools are inexpensive, but may also be borrowed from a parts store or a fellow restoration buff.

Specialized tools aren't necessary for driving main bearings and seals. The key to driving large ball-type main bearings into a bore is to apply even pressure to the outer race of the bearing. Use a large socket or drift made of hard plastic, soft metal or wood, and a hammer to tap the bearing into the bore until it lands against the shoulder. If you are installing the bearing directly onto a shaft, then apply pressure on the inner race.

Crankshaft seals can often be replaced before the shaft is installed. Carefully start the seal, making sure that it is perpendicular to the bore. Gently and slowly drive the seal to the proper depth using a socket or drift that is as close to the outside diameter of the seal housing as possible. If the seal must be installed after the crankshaft, the driving tool must be hollow and tall enough to engage the seal edges while avoiding interference from the shaft. A piece of schedule 40 PVC pipe of the appropriate diameter may be used as an effective hollow seal driver.

Install the completed engine in the tractor before installing the grille casting. The process involves delicately placing it between the frame rails and careful alignment with the driveshaft. A hoist will facilitate both proper placement and minimal damage to finishes. Once the engine is mounted, you’re one step closer to the successful end of your restoration journey.

Finishing touches

With the engine in the tractor, set the carburetor to the initial adjustment outlined in the manual. Next, carefully follow the manual and attach the governor linkage and make that preliminary adjustment — this is critical because the governor keeps the engine from over reving, which can lead to spectacular and costly catastrophic failure. Attach the throttle and choke cables, install the starter/generator and connect the wires.

Install the gas tank next, and connect the plumbing to the carburetor. Install the grille casting and mount the voltage regulator if it's not already in place. Add fluids to the engine and transaxle. Install the battery. Now you can start the engine, adjust and tune it to perfection. Check and adjust the steering, clutch or hydro, as well as the brake linkages, and you're ready for a test drive. When the Cub Cadet's performance is satisfactory, install the grille and hood.

The final step in the process is to apply any remaining decals. At the factory, decals were applied by hand, so be aware there was variation in how the decals were placed and where some of them were located as they came from the factory.

Using pictures as a guide, locate the proper place for each decal on the tractor and apply them carefully. Several methods exist for placing sticker-type decals into position. For example, hold a decal in place with small pieces of easy-remove masking tape along the top edge. Before removing the paper backing on the decal, flip it up using the masking tape as a hinge, and wet the metal with soapy water or Windex. Peel the paper off the back of the decal and flip it onto the wetted surface.

Quickly adjust the position of the decal by sliding it and use a credit card to squeegee the moisture from beneath it. This method may seem counter intuitive, but it's proven to work.

The end or the beginning?

When the Cub Cadet restoration is complete, stand back, take a good long look at it and smile. Call friends, snap pictures and take the Cub Cadet for a well-deserved ride. Be happy that the tractor was restored to something of value and beauty. Yet, be warned: That feeling of pride will be accompanied by a pang of regret. With the long-anticipated goal achieved, you’ll no longer have an engaging project waiting in the garage. To cheer yourself, mow the lawn, plow some snow or till the garden with your like-new Cub Cadet — and ponder what will inevitably be your next Cub Cadet project as you ride the shiny tractor.

Whether the Cub Cadet renovation takes one week or a year, the restoration experience and the end result are entirely rewarding. A refurbished Cub Cadet should serve another 40 or more years with dependability and style — and will certainly attract many Cub Cadet companions to the average enthusiast's garage. With so many tractors needing restoration, the exciting odyssey need never end. FC 

Crazy about garden tractors? Check out Oscar H. Will III's book Garden Tractors: Deere, Cub Cadet, and All the Rest and Kenneth Updike's Original Farmall Cub and Cub Cadet in the Farm Collector bookstore!