Description

Bolens 5117H, 5118HS, 5120H, 5118H 1992 Service Manual

Every season I see tractors come into the shop with stripped threads, burned wiring, or a hydro whining because someone used a generic torque chart or skipped the factory sequence. If you’re working on a Bolens 5117H, 5118HS, 5120H, 5118H 1992 Service Manual is the only source I trust to get it back together right. Aftermarket copies swap numbers, leave out sections, and waste your Saturday. This is the original 104-page OEM print from 1992, Form 1760169 (3/92). You get the exact specs Bolens engineers laid down when the DuraTrac 5100 series rolled off the line.

Electrical System: Wire Color Codes and Wiring Diagrams

Section II of this manual starts with a troubleshooting guide (page 2-1) that actually lists symptoms in the order I see them most – no start, dead battery, lights flickering. Then the wire color code chart on page 2-3. If you’ve ever fought a tractor that had a melted harness because somebody crossed a green-with-tracer with a solid black, you know why that page is worth the price alone. The wiring diagrams from page 2-4 cover the full system: starting circuit, charging, safety interlocks, PTO clutch. Testing procedures on page 2-16 walk you through voltage drop checks and resistance tests with the OEM meter settings – not the generic “check battery” advice you get in a parts-store reprint.

Torque Specs for Hex Screws and Lubrication Schedules

GENERAL section, page 1-6. Torque values for hex screws – the factory values in foot-pounds for every common bolt on the tractor. I have seen a front axle fall off because somebody used dry torque values on a lubricated bolt. This chart gives you the correct rating for each thread size and grade. Same section has the lubrication charts starting page 1-7 (5117H) and page 1-8 (5118H, 5118HS, 5120H). Grease points, oil types, intervals – all there. Do not guess which lube goes into the hydrostatic sump. The chart says.

Does This Manual Cover Both Gas and Diesel Engines?

Yes, and it separates them cleanly. Section IV (Fuel System) starts with a gas troubleshooting guide (4-1), then carburetor adjustments (4-3), then a separate diesel troubleshooting guide (4-4) and fuel tank/valve removal for the diesel models. Section VII (Engine) gives removal and installation procedures for both gas and diesel – torque specs for the head bolts, valve clearances, starter R&R. The 5117H is diesel (DGT 1800), the 5118H and 5118HS are gas (GT 1800), the 5120H is gas (GT 2000). You get exact procedures for each, not a one-size-fits-many paragraph.

Drive Train: Hydrostatic Repair and Transaxle Reassembly

Section III is where this manual earns its keep. Hydrostatic repair starts page 3-2, breakdown page 3-3. Then transaxle removal page 3-6, disassembly page 3-10, differential disassembly page 3-12, reassembly page 3-13. Planetary repair (page 3-14) includes the shim selection procedure that every aftermarket source I have seen omits. If you are rebuilding a hydrostat without the factory clearance specs, you are gambling on a $1,200 part. This manual gives those numbers. Also note the interlock switch testing in section V (page 5-9) – those switches cause more no-start complaints than any bad starter.

Hydraulic System: Test Procedures and Valve Repair

Section VI walks you through principle of operation (6-1), then a troubleshooting guide that actually works (6-4). Hydraulic test procedures on page 6-5 – pressure and flow readings, where to tap in, what the gauge should read. Single-spool and two-spool valve repair (pages 6-10 and 6-11) with exploded diagrams. Systems schematics on page 6-12. If you have a three-point hitch that drifts down overnight, the troubleshooting tree in this section will find the leak without pulling random hoses.

I have been doing this 28 years. I still reach for the OEM manual on every job because it saves me from re-doing work. The section on PTO clutch removal and belt replacement (page 7-14) includes the belt routing and tension spec – not a diagram from a different model. Tractor attachments (section VIII) covers mowers, tiller, and snowthrowers with mounting instructions and part references. You also get the serial number location and model identification pages (1-1) so you can confirm which variation you have before ordering parts. For related documentation, check the Bolens 5117H (1700) Tractor Parts List”>parts list for the 5117H and the Bolens Duratrac Tractor 5118HS 5120H 520H Parts”>parts breakdown for the Duratrac series. If you need the larger HCD-80B service manual, see the FMC Bolens HCD-80B Service Manual – 254-Page OEM Shop Manual”>254-page OEM shop manual for that model. For background on how a hydrostatic transmission works inside, read the Manual Transmission”>Manual Transmission article and the Manual Transmission”>operation theory on Wikipedia – but get your specs from this factory manual.

Does the manual include the wiring diagram for the 5120H?

Yes. The wiring diagrams on pages 2-4 through 2-15 cover all four models – 5117H, 5118H, 5118HS, and 5120H – with separate schematics for gas and diesel. Each diagram is labeled with the model prefix.

What torque spec does it give for the head bolts on the gas engine?

The torque chart in Section I, page 1-6 lists the values. You need to look up the specific bolt grade and thread size – it does not give a single number because head bolt torque depends on whether the threads are lubricated or dry. Use the chart, not a guess.

This is the same manual Bolens sent to dealerships in 1992 – no rewrites, no “simplified” versions that leave out the critical numbers. 104 pages of factory procedure. Access the Factory Manual and put it on your bench next to your torque wrench. Then when the job is done, you know it’s right.