If your John Deere dozer pulls harder one direction than the other, won't hold a straight line, or has steering levers that feel different from each other, the steering clutches are telling you they're done. This is the most common internal failure on every JD crawler from the 350 series through the G-series machines — and it's also the part of the catalog where customers order wrong more often than anywhere else.

Two things make the steering clutch system confusing. First, it's a stack of parts — pressure plate, brake band, fiber discs, steel discs, release bearing — that all need to be replaced as a unit. Second, the kits are model-specific and serial-number-specific in ways that aren't obvious from the dozer's outside. A 450B is not a 450C. A 450E before serial 726647 takes a different kit than a 450E after serial 726647. Get one wrong and you've bought parts that won't fit.

Here's what you need to know.

How a JD steering clutch works (and how it fails)

Unlike modern hydrostatic dozers that steer with pumps and motors, the older JD crawlers (350 through G-series) use a mechanical steering clutch on each side. The transmission sends power to both final drives equally. To turn, you pull a steering lever, which disengages the clutch on one side — that track stops getting power and the dozer pivots toward it. Pull the lever further and the brake band on that side engages too, stopping the track entirely for a sharp turn.

The clutch itself is a stack of friction discs and steel discs, pressed together by a spring-loaded pressure plate. Years of engagement and disengagement under load wear the friction surfaces. When enough wear accumulates, the pressure plate can't generate enough clamping force to fully engage the clutch — even with the lever released. That side slips. The dozer doesn't pull straight.

Symptoms of a worn steering clutch

• Dozer pulls to one side with both levers released. The clutch on the side it's pulling away from is slipping.
• Sluggish acceleration under load. One or both clutches are slipping rather than fully engaging. You can hear the engine working but the tracks aren't keeping up.
• Track won't stop when you pull the lever all the way back. The brake band on that side is worn out, or the linkage has stretched past the point of adjustment.
• Different lever effort between left and right. One side's clutch and brake mechanism is significantly worn or out of adjustment.
• Burning smell from the engine compartment or final drive housing. A slipping clutch generates real heat. If you smell friction material, the discs are cooking themselves.
• Inability to counter-rotate. The dozer used to spin in its own length; now it requires multiple passes to turn around.

The two-kits-per-machine rule

Every JD steering clutch kit we sell is sold individually — but every JD dozer needs two kits, one for each side. This is the single most common ordering mistake on these parts.

You can't get away with rebuilding one side. The clutches need to wear evenly to track straight, and a rebuilt clutch on one side paired with a worn clutch on the other will pull as hard as a fully worn pair. Order both kits at the same time. Do both sides during the same teardown.

The kit decoder: which one fits your dozer

Each kit is built for a specific model range and contains everything you need for one side. Pressure plate, brake band, fiber or metallic friction discs, steel discs, release bearing. The exact contents vary by kit.

JD 350, 350B

Standard kit with fiber discs: JD-350-SK at $694. Includes pressure plate AT18886, brake band AT129805, eight T20790 fiber friction discs, seven T21315 steel discs, and AM3983T release bearing.

Updated kit with metallic discs: JD-350-SK-HD at $724. Same kit but with AT117553 metallic discs instead of fiber. Recommended for working machines.

JD 420, 430, 440, 40, MC (vintage crawlers)

JD-420-SK at $670. Vintage crawler kit with pressure plate AT16121, brake band AT10566, seven M3293T fiber discs, six M872T steel discs, and AM3983T release bearing.

JD 450B

Standard kit with fiber discs: JD-450B-SK at $955. Includes pressure plate AT18416, two-piece brake band set (AT129806 and AT129807), nine T20716 fiber discs, eight T31732 steel discs (0.097"–0.099" thick), and AT17464 release bearing.

Heavy duty kit with metallic discs: JD-450B-SK-HD at $1,030. Same kit but with T44129 bimetallic discs replacing the T20716 fibers. Strong recommendation for any 450B that does real work — the original fiber discs were the weak link in this generation.

JD 450C, 450D, 450E (before SN 726647), 455C, 455D, 455E (before SN 726647)

JD-450C-SK at $645. Already a metallic kit from the factory configuration — eight T44129 bimetallic discs, eight T31732 steel discs, brake band AT142175.

JD 450E (after SN 726647), 455E (after SN 726647)

JD-450E-SK at $625. The serial break matters — Deere changed the disc design and stack count at SN 726647. Kit includes brake band AT142175, six T82355 metallic discs, six T82356 steel discs.

JD 450G, 550G, 650G, 455G, 555G

JD-450G-SK at $650. The G-series shares the same kit across multiple frame sizes. Includes brake band AT142175, six T82355 metallic friction discs, seven T82356 steel discs.

JD 1010 Crawler

JD-1010-SK at $695. Vintage crawler kit: pressure plate AT16121, brake band AT129805, eight M3293T fiber discs, eight M872T steel discs, AM3983T release bearing.

JD 2010 Crawler

Two different kits depending on serial number:

• Before serial 42000: JD-2010-SK-E at $1,010.
• After serial 42000: JD-2010-SK at $995.

Fiber vs. metallic discs: which should you choose?

For models where both options exist (350/350B and 450B), you have a real decision to make. The original-equipment fiber discs were designed for moderate-duty work and they work fine if that's what you do. The metallic upgrade buys you heat resistance and longer life — but at higher cost.

If you bought a JD dozer to do actual work, get the metallic kit. The price difference disappears the second time you don't have to tear down the final drives to swap discs. If the dozer is a backup machine or sees light use on a small property, the fiber kit will serve you fine.

The brake band detail nobody mentions

Brake bands are the part that stops the track when you pull the lever all the way back. They're included in every steering clutch kit, but they don't all look the same.

The 450B uses a two-piece brake band set (AT129806 and AT129807). The 350/350B uses a one-piece band (AT129805). The 350C/350D/400G uses yet another one-piece band (AT142174). The brake bands have bonded friction lining, and the lining wears just like the disc friction material does.

Buying just discs without replacing the brake band is a common shortcut. Don't take it. If the discs are worn enough to need replacement, the brake band lining is worn too. The complete kits include the band for a reason.

What else to inspect during the teardown

The steering clutch lives behind the final drive housing. Pulling it apart is a significant job — a half-day to a full day per side depending on the dozer. While you're in there, inspect:

• The steering clutch shaft. If it's worn, scored, or the splines are damaged, replace it now. The T125579 shaft for G-series at $173 is far cheaper to install during a clutch rebuild than to revisit later.
• The pressure plate. Included in the standard kits, but if the plate is heat-discolored, warped, or has hot spots, the included replacement is doing real work.
• The brake drum. The drum is the part the brake band squeezes against. Drums wear too. The T20713 brake drum for the 450 and T154186 drum for G-series after SN 770808 are common replace-while-you're-there parts.
• The pilot bearing. Small, cheap, easy to replace during teardown, expensive to revisit. The JD8567 pilot bearing for 350/350B and 836203 for 400G–455 dozers are inexpensive and easy to install while everything is apart.
• Seals on the final drive housing. If you're pulling the cover, replace the gasket and any seals exposed during teardown. A leaking final drive seal can dump oil into the clutch pack and contaminate fresh friction material.

Common ordering mistakes

• Ordering one kit instead of two. Always order both sides at the same time.
• Confusing the model letter. 450B, 450C, 450D, 450E, 450G — they are all different machines internally. Check the serial number plate, not the badge.
• Ignoring the serial number break on the 450E and 455E. Before SN 726647 and after SN 726647 take different kits. The dozer's outside is identical.
• Trying to buy a clutch kit for a J or K series dozer. These are hydrostatic. They don't have steering clutches.
• Reusing brake bands. Replace them with the kit. They wear at the same rate as the discs.
• Reusing the release bearing. Included in most kits for a reason. A worn release bearing makes a new clutch pack feel like an old one.

The bottom line

JD dozer steering clutch failure is one of the most predictable wear patterns on these machines. Diagnose carefully (adjustment first, parts second), order both kits at the same time, and inspect the supporting parts — shaft, drum, pilot bearing, pressure plate — while everything is apart. Choose metallic discs over fiber if the dozer does real work. Skip the J and K series; they don't have this system.

Done right, a rebuilt steering clutch pack adds thousands of hours to the dozer's working life. Done wrong — wrong kit, one side only, reused brake bands — and you'll be back in there next season.