These are the procedures you'll perform most often. Each one is structured around a single failure mode, calls out the parts you'll need before you start, and includes the verification step Sumner specifies before returning the lift to service.
Any visible damage to the cable — fraying, kinking, broken strands, or burn marks from arc strike — requires immediate replacement. Never field-splice a lift cable.
Crank the carriage all the way down to the base. Remove all material from the forks. Tag the lift out of service.
Continue cranking down past the carriage's resting point until the cable goes slack. Do not back-drive the winch — let the brake hold while you work the slack out by hand.
Remove the cable anchor clip from the carriage attachment point. Withdraw the thimble and free end.
Crank the handle in the direction that pays cable off the drum until the cable terminus on the drum is exposed. Sumner specifies a minimum number of cable wraps that must remain on the drum at full carriage extension — 4 wraps for the Series 2100; 3 wraps for the Series 2400. Note your starting point and confirm against your operator's manual.
With the cable removed, this is the moment to spin the upper sheave by hand. Replace it now if it's grooved, sharp, or rough — installing a new cable on a worn sheave will destroy the cable in days.
Feed the new cable up through the internal mast routing (or external guides on older 2000-series lifts), over the sheave, and down to the carriage. Keep tension on the cable while routing — a single twist becomes a permanent kink under load.
Pass the cable through the thimble, double back, and install the anchor clip with the saddle on the live side ("never saddle a dead horse"). Torque to spec.
Crank up while guiding the cable so the wraps lay tightly side by side. Verify the minimum drum wraps remain at full extension (4 for Series 2100; 3 for Series 2400; verify your model's operator's manual).
Cycle the carriage full up and full down with no load. Then test at 10% of rated capacity, then 50%, then 100%. Re-torque the anchor clip after the first 100% cycle — cables seat into clips under load.
Log the cable replacement, date, and your initials on the lift's maintenance record decal.
If the winch slips when the operator stops cranking, or the brake doesn't fully hold rated load, the ratchet pawl, brake disc, or both need attention. This is the single most common winch issue Sumner techs see.
Follow Procedure 01 steps 1–4 to free the cable. Don't fully remove it; just unspool enough to access the drum and reel.
Pop off the retaining ring on the drive shaft, slide the drive shaft out the side, and lift the reel free.
Remove the brake pad. Light wear with shiny spots ("glazing") can be restored by lightly sanding both faces with fine paper. Heavy scoring, cracking, or oil contamination = replace.
Look for chipped or rounded ratchet teeth, and a pawl with a worn engagement tip or weak spring. If teeth are chipped, replace the entire pawl assembly — sharp pawl on rounded teeth will wear through quickly.
Critical: the ratchet wheel is directional. Confirm the engagement faces of the teeth point in the direction shown in the operator's manual diagram. Reversed = winch will free-spool under load.
Press the pawl down out of the way with your finger and slide the drive shaft back into the bushing. Release the pawl — it should snap into the ratchet teeth. You should hear a sharp click on every tooth as you turn the drive shaft by hand.
Light machine oil on the pawl pivot and brake-ratchet contact. Avoid getting oil on the brake disc face.
Wind cable back onto the drum. Test at 10%, 50%, 100% of rated capacity. Stop cranking at each level and verify the brake holds without drift for at least 60 seconds.
A grooved or seized sheave will fray a brand-new cable in days. If you find one during a cable change, swap it before installing the new cable.
Follow the cable-removal portion of Procedure 01.
On Series 2100/2400 with internal cable routing, the sheave bracket is integrated into the mast head. Remove the pulley guard (one or two screws on most models).
Some lifts use a clevis pin and cotter; others a shoulder bolt with locknut. Note the order of any spacers or washers as you remove them.
Look at the bracket bore. If it's worn oval (cable side-loaded the sheave), the bracket itself needs replacement, not just the sheave.
Spin the new sheave by hand before installing — verify smooth rotation and no measurable play. Reassemble in reverse order, including any spacers.
Confirm the guard fully captures the cable in the sheave groove — a cable that jumps the sheave under load can sever instantly.
Symptom: the inner mast wobbles side to side at full extension, or the carriage chatters as you crank up. Both point at worn nylon slide pads between the mast sections.
Crank the carriage all the way down. Remove the cable per Procedure 01 steps 1–4 to take tension off the inner mast.
Disconnect the cable terminal at the carriage. Lift the carriage off the inner mast.
Pull the inner mast straight up out of the outer mast. Be ready for the inner mast's weight — get a second tech for the longer-mast lifts.
Pads are typically held by Phillips screws or pop in/out of slots. Remove old pads, clean the seat, and press new pads in. Verify thickness matches your model — the pads are not interchangeable between series.
Slide the inner mast back into the outer mast. Reinstall carriage, route cable, terminate, and test as in Procedure 01.
A flat-spotted or seized carriage roller chatters as the carriage moves and accelerates cable wear at the carriage attachment. Always replace as a set of four.
Per Procedure 04 steps 1–3.
Each roller is held by a shoulder bolt + locknut, or a clevis pin + cotter, depending on production year. Note the order of any thrust washers.
While the rollers are off, inspect the roller seats. Egged or peened seats indicate a previous roller failure under load — replace the carriage if the seat is no longer round.
Spin each new roller by hand before installing. Torque mounting hardware to spec.
Slide the carriage onto the inner mast. Verify smooth travel by hand, with no rocking. Reattach cable and test.
When Procedure 02 has not restored brake or pawl function — or the worm gear inside the winch is damaged — Sumner's sealed current-production MX winch is intended to be replaced as a complete assembly rather than rebuilt. This procedure swaps the winch as a unit. Older GH-5T winches may be field-rebuildable using the OEM rebuild kit.
Follow Procedure 01 steps 1–4 to disconnect the cable from both ends. Coil and label as “reuse” or “scrap.”
Pull the spring pin and slide the handle off the input shaft. Stow it; you'll re-fit it on the new winch.
Snap a photo of the winch's orientation before you remove anything. The MX has four mounting bolts (1/4-20 typical). Loosen all four before fully removing any one.
Support the winch with one hand as the last bolt comes free — it weighs ~6 lb. Set aside.
Check the bracket bore for elongated holes (sign of a previous overload event). Clean any corrosion off the mating surface. The new winch must seat flat or it will load the mounting bolts in shear.
Hand-thread all four bolts before tightening any. Cross-pattern torque to spec (8 ft-lb dry for 1/4-20 Grade 5).
Re-install the handle and verify smooth rotation through the full range with no load. Then route a new cable per Procedure 01 from step 5 onward.
10% → 50% → 100% of rated capacity, with a 60-second hold at each step to verify no brake drift. Re-torque the cable anchor clip after the 100% cycle.
A loose or non-engaging outrigger latch is one of the highest-risk failures on the lift — the leg can swing free under load and the lift becomes top-heavy. The latch and spring kit is inexpensive; replace at any sign of weakness.
Fold the outrigger leg out to its locked position. Place a wood block under the leg so it can't swing as you remove the latch hardware.
Compress the spring with your thumb (gloved) and slide the latch cam out of engagement. Catch the spring — it likes to launch.
Use snap-ring pliers to remove the e-clip or c-clip securing the latch pin. Slide the pin out, capturing any thrust washers.
Look at the cam-engagement pocket on the leg itself. Egged or peened pockets indicate the leg has been operated with a worn latch — a fresh latch in a worn pocket won't hold for long.
Reverse the disassembly. Lubricate the pin and cam contact face with white lithium grease before assembly. Capture the spring under the cam before installing the retaining clip.
Stow and re-deploy the leg ten times. Each cycle should produce an audible snap as the latch cams home, and the leg should require deliberate force on the release lever to disengage.
A worn pivot pin lets the fork shift under load, increasing tipping moment and accelerating wear at the carriage. The pin is among the cheapest parts on the lift and also among the most overlooked.
Forks empty, carriage all the way down.
Pull the R-clip from the end of the pin. Capture in a magnetic tray — these get lost on jobsites.
Using a brass drift to protect the pin, tap the pin out from the side opposite the R-clip. Note the order of any thrust washers as you pull the fork off.
The bore in the carriage that the pin rides in is what wears second — if it's egged, you need a carriage, not just a pin.
Slide the new pivot pin through the carriage and fork. Reinstall any thrust washers in the same order. Install a new R-clip; do not reuse the old one.
Reverse the fork through its full travel. The motion should be tight without binding. A fork that swings under its own weight has an undersized pin or overworn carriage bore.
| # | Procedure | Symptom | Time | Skill | Safety-Critical? |
|---|---|---|---|---|---|
| 01 | Replace lift cable | Frayed / kinked / broken-strand cable | 45 min | Intermediate | Yes |
| 02 | Winch ratchet & brake service | Slips under load / drifts when released | 30 min | Intermediate | Yes |
| 03 | Replace cable sheave | Grooved sheave / cable wear at top | 20 min | Basic | Yes |
| 04 | Replace mast slide pads | Mast wobbles at full extension | 40 min | Intermediate | No |
| 05 | Replace carriage rollers | Carriage chatters during raise/lower | 25 min | Basic | No |
| 06 | Replace winch assembly | Brake won't hold after pawl service | 35 min | Intermediate | Yes |
| 07 | Service outrigger latch | Outrigger leg loose or won't latch | 20 min | Basic | Yes |
| 08 | Replace fork pivot pin | Fork shifts under load | 15 min | Basic | No |