Frequently Asked Questions

What type of hydraulic oil do I use in my ZT mower?

Lastec hydraulic fluid is equivalent to Special Mobil 20W50 and Mobil One Synthetic 20W50.
Units with one hydro filter: Lastec Item # 028490 (2.5 gal. Oil, 1- filter) or # 028536 (5 gal. Oil, 2 filters)
Units with two hydro filters: Lastec Item # 049929 (2.5 gal. Oil, 2- filters) or # 049928 (5 gal. Oil, 4 filters)

What type of engine oil do I use in my unit?

Diesel Engines- API Service Class CJ-4, SAE 10W-30
Gas Engines- API Service Class SJ or Higher, SAE 10W-30

What different blade types are available for my mower?

Ultra-Low Blade (Lastec Item # 063265 for 21” Blade and # 063266 for 25” Blade) Use Ultra Low Lift Blade when the conditions are dry and in sandy soil areas. When conditions like this are evident, lift created by the cutter blades can be reduced, decreasing the abrasion wear to the cutter blades and deck caused by sand. The Low Lift Blade will also help reduce cutter deck blowout during the conditions stated above. 

Low-Lift Blade (Lastec Item # P246 for 21” Blade and # P849 for 25” Blade) Low-Lift Blade is recommended for 1”-2” cutting height. Use a Low Lift Blade when the conditions are dry, the region is experiencing a drought, in sandy soil areas or when performing seasonal scalping. When conditions like this are evident, lift created by the cutter blades can be reduced, decreasing the abrasion wear to the cutter blades and deck caused by sand. The Low Lift Blade will also help reduce cutter deck blowout during the conditions stated above. 

High-Lift Blade (Lastec Item # P128 for 21” Blade and # P701 for 25” Blade) High-Lift Blade is recommended for cool season grasses and cut heights of 2” and above, unless in sandy conditions. These blades are shipped standard on all mowers. Use a High Lift Blade when the conditions are extremely wet or heavy. The High Lift Blades will create greater lift that may be needed in difficult cutting conditions. Additional deck cleaning may be required when using High Lift Blades. 


Gator Mulching Blade (Lastec Item # P322 for 21” Blade and # P848 for 25” Blade) Mulching blades are designed for use with a mulching (discharge block-off) plate or with a complete mulching system. These blades feature a high lift, “double-cut” edge for quick, thorough shredding of grass clippings, leaves and debris.

What type of grease does Lastec utilize in the assembly process on their mowers?

We use Lucas Oil Extra Heavy Duty Grease on our mowers; download the technical data sheet for specific information.

Is there touch up paint available for my unit?

Yes, paint is available in 12 oz. aerosol cans.

Lastec- Red Item # P229
Lastec- Black Item # L07467

What type of diesel fuel should I use?

Diesel Fuel No.2-D (ASTM D975) Please refer to your owners/parts manual for specific model information.

Can I register my unit’s warranty registration online?

Yes, you can go to our Warranty Registration page and fill out the necessary information and click, submit.

How do you recommend cleaning my equipment?

When cleaning your mower, do not use any type of pressurized water spray, such as a garden hose with a nozzle or pressurized washer. If you need to wash the unit, first wait for the unit to cool completely, blow dust and debris off of the unit using air, rinse using a low pressure hose, blow off any excess water.

How much grass can I cut off at once?

The amount of grass you cut off depends on several factors, how wet the grass is, your travel speed, and what type of blade you are using. We like to use the 1/3 rule it states: you shouldn’t remove more than 1/3 of the total length of the blade of grass.

Example: If your grass is 4 ½” tall, your cut height should be set at 3”, thus removing about one third of the total blade length.

Can I buy parts directly through Lastec?

If you have a dealer in your area you must go through them to purchase Lastec parts. If you are not sure who your dealer is you can visit Dealer Locator at the top of the page, input your location and your dealer information will be displayed. If there is not a servicing dealer listed in your area, contact Lastec at (800) 515.6798

How can I adjust the forward ground speed of my unit?

You can adjust the ground speed of your unit by adjusting the stop bolts on the control arm pivot weldments.Be sure to adjust both the left and right side bolts to insure your unit tracks straight.

I found loose hardware on my mower, what should I do?

Before each use of the equipment, the operator should inspect it thoroughly for any loose hardware and tighten them accordingly. Missing hardware should be replaced with the proper original equipment parts. It is the operators responsibility to make sure that the unit is in safe working condition before operating the product. Inspecting for loose or missing hardware is part of this process and is outlined in the owners/parts manual.

Are there mulching kits available for my unit?

Yes, various types are available for your mower. Please refer to your owners/parts manual for specific model information.

Where can I find the maintenance schedule for my mower?

The maintenance schedule can be found in the owners manual of your unit, section 5.

If I need to tow my ZT unit can I?

Yes, when towing the Lastec Mower, it is necessary to make minor adjustments to both of the hydrostatic pumps. This will allow the hydraulic fluid to bypass the hydrostatic pump. Please follow the instructions below for the proper procedure: 1. Locate the bypass valve. This will be located on the side of each pump. NOTE: The bypass valve is zinc plated with the hole drilled through the sides. 2. Use a 5/8” wrench to turn the valves no more than (2) two turns in a counterclockwise motion. The drive tires should rotate freely. 3. Tow the unit to the desired destination at a slow speed. 4. When towing is completed, return the valves to their original position by turning them in a clockwise motion until they are tight (84-120 in-lbs).

What type of gasoline should I be using?

Fuel must meet these requirements:
Octane rating of 87 (R+M)/2 or higher.
Research Octane Number (RON) 90 octane minimum.
Gasoline up to 10% ethyl alcohol, 90% unleaded are acceptable.
Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blend (max 15% MTBE by volume) are approved.

 NOTE: E15, E20 and E85 are NOT approved and should NOT be used.

What direction does my blade bolt turn for loosening?

The blade bolt is a standard bolt and can be loosened by turning it counterclockwise. Please refer to your owners/ parts manual for specific torque specifications when tightening.

How can I contact Lastec?

Lastec LLC.
7865 North CR 100E
Lizton, IN 46149.
Phone: (800) 515.6798
Fax: (317) 892.4188

Can I order foam filled tires without the rims?

No, foam filled tires are not available for order without the rim.

What type & size of belts should I use?

Lastec belts are engineered with specific lengths and materials therefore when replacing belts you should use Lastec OEM belts. This will ensure you are getting the best performance out of your unit. Refer to your owners/ parts manual for the correct belt number.

Can I get replacement keys for my mower?

Yes, replacement keys are available.

Units with diesel engines- Lastec Item # 028507
Units with gas engines- Lastec Item # 045693

Are there different tire options available for my ZT unit?

Yes, you have the option of a Softrtrac II tire that has a less aggressive profile than the standard tires.

Lastec Item # 064649

Can I buy a complete replacement deck assembly for my unit?

Yes, replacement decks are available through your servicing dealer. If you do not have a servicing dealer please contact Lastec.

421D/3682 Lastec Item # 055903
425HD/3696H Lastec Item # 057202
425MD/3696M Lastec Item # 057201

How often should I sharpen my blades?

You should sharpen your blades when they become dull. Many factors can cause a blade to become dull therefore you should inspect them on a daily basis and sharpen if necessary.

My 721XR doesn’t want to tow straight, it’s swaying left & right.

If your unit is swaying left and right, check the pull arms, be sure the connection between the tractor and the pull arm lift pins are tight, be sure to adjust the tractor pull arms to take out any side to side play. Check the pull arm pivot bushings and insure they are not excessively worn. Check the gearbox pivot nut located on the top of the deck cross-tube weldment. If the nut is loose tighten until you cannot pivot the pull bar assembly by hand when grasping the ends of the pull arms. It may be necessary to tighten the nut in 1/6th increments to ensure alignment with nut retainer.

Where can I get replacement parts for my hydro pumps?

Although Lastec does not stock all of the parts included in the various hydro pumps we can order them through our supplier. Contact an authorized Lastec service dealer or Lastec at (800) 515.6798 for more specific information.

What oil should I use in my gearbox?

Superior 100 series gearboxes, used on ZT & EF series mowers use: Mobilube- SHC 75W-90 (or equivalent) 6oz.

Superior 500 series gearboxes, used on R, X, XR, ER and some 621EF series use: Mobilube- HD 80W-90 (or equivalent) 28oz.

Please refer to your owners/parts manual for specific model information.

What engine RPM should my mower be set at?

Engines are set at various RPM’s, refer to the engine information in the maintenance section of your owners manual. Contact an authorized Lastec service dealer or Lastec at (800) 515.6798 for more specific information.

When and how should I clean my radiator?

Prior to operating your machine, remove radiator cleanout screen and clean of debris. Clean radiator and oil cooler fins of dust and debris using compressed air, taking care not to distort the fins. During operation Lastec units draw air across the radiator fins from the side opposite of the cooling fan, therefore when cleaning you should blow the air through the radiator from the fan side out. A coolant over-temp condition on the 3380, 3300 and 4520 models will trigger an alarm and water temp light. A coolant over-temp condition on 3682/96 models will result in PTO clutch shutdown and trigger the water temp light.

How often should I grease my spindles?

One of the most common misconceptions that causes a high number of bearing failures is that a bearing needs to be completely packed full. Many people have been taught; the more grease, the better. We have even heard of cases where people do not feel bearing manufacturers use enough grease in sealed and shielded ball bearings, so they remove one seal or shield and pack the bearing with more grease. These misconceptions are completely false. Over lubricating the bearings forces the motor to work harder.

Nachi standard grease fill for sealed and shielded ball bearings is 20% to 30% full. Too much grease can cause excess friction, thereby overheating the bearing and causing premature failure. Only a small of grease is required to lubricate a bearing in motion. When a bearing is in motion, most of the grease is pushed to the side (channeling) leaving a thin film of oil between the raceways and rolling elements. One shot of grease every 40 to 60 hours of operation will keep moisture out of the spindle housing.

What are my responsibilities as a Lastec Owner?

The owner is responsible for required maintenance and adjustments as stated in the Lastec Owner's Manual for your specific product.

Contact Us

Not seeing an answer to your question? Send us a quick message.