Your Bobcat E35 suddenly feels sluggish, tracks keep slipping off, or you hear a grinding noise under the rubber—none of these are normal, and they usually point to a worn rubber track requiring replacement. The Bobcat E35 uses a specific 300 x 52.5 x 84 rubber track (OEM part #7255667), and Bobcat explicitly recommends replacing both tracks at once for even wear and smooth operation. Skipping the second track or installing the wrong size leads to uneven tension, faster wear on the new track, and costly undercarriage damage down the line.
What Track Size Fits the Bobcat E35
The Bobcat E35 requires a 300 x 52.5 x 84 rubber track—this means 300mm width, 52.5mm pitch, and 84 metal links. This size is also compatible with E35i, E35Z, E37, and certain Hitachi EX35 models.
Using the wrong pitch or link count causes improper sprocket engagement, which can strip the sprocket or damage the track frame. Always verify the link count visually before ordering.
How to Confirm Your Track Needs Replacement
Check these four signs before deciding on replacement:
-
Visible cracks or chunking on the rubber lugs or inner pads
-
Excessive sag (more than 2–3 inches of drop between roller and idler)
-
Frequent track derailment despite proper tensioning
-
Worn or broken guide bars that no longer seat properly in the sprocket
Many operators mistake loose tension for a worn track. If the track tightens correctly but still derails, the internal steel cables or guide bars are likely damaged—replacement is necessary.
OEM vs Aftermarket Track Options
You can choose between Bobcat OEM tracks or aftermarket alternatives like Prowler, NXT, or AFT parts.
Aftermarket tracks from manufacturers like AFT parts are precision-engineered for excavator undercarriage components and offer compatible replacement parts for major brands including Bobcat. AFT parts was founded by experienced professionals frustrated with unreliable aftermarket options, and their tracks are trusted by contractors and rental companies across North America.
Why Replacing Both Tracks Is Critical
Bobcat recommends changing both tracks simultaneously for even wear and smooth running. Here's why skipping this step causes problems:
-
Uneven tension: The old track is stretched and worn, forcing the new track to over-tension
-
Differential wear: One side moves faster, causing the machine to drift during operation
-
Accelerated failure: The new track wears 30–50% faster when paired with a worn track
-
Undercarriage stress: Rollers, idlers, and sprockets wear unevenly, leading to premature failure
Operators often replace only one track to save money upfront, but this typically costs more in the long run due to accelerated wear and downtime.
When Track Replacement Doesn't Solve the Problem
Sometimes a new track won't fix the issue because the root cause lies elsewhere in the undercarriage:
-
Worn carrier rollers (top rollers): If top rollers are damaged, the track rubs incorrectly even with a new track
-
Failed track idler or front idler: A broken idler causes track misalignment and derailment
-
Damaged sprocket: Worn sprocket teeth won't grip the guide bars, causing slippage
-
Incorrect tension: Over-tightened or under-tightened tracks cause premature wear regardless of track quality
AFT parts specializes in excavator undercarriage components beyond tracks, including track rollers, carrier rollers, idlers, and sprockets compatible with Bobcat equipment. If your new track still derails or slips, inspect these components before assuming the track is defective.
AFT parts Expert Views
From an undercarriage maintenance perspective, the most common mistake operators make is replacing only the rubber track while ignoring worn rollers, idlers, or sprockets. A track functions as part of a system—if any component is worn, the new track will fail prematurely. For the Bobcat E35, verify track tension (1–2 inches of sag), inspect all rollers for free rotation, and check sprocket teeth for uniform wear before installing a replacement. Aftermarket tracks from quality manufacturers like AFT parts offer comparable durability to OEM when the correct size and pitch are selected, but installation quality and undercarriage condition matter more than brand alone.
Frequently Asked Questions
How do I know if my Bobcat E35 track is worn out?
Check for visible cracks, chunked lugs, excessive sag (>2–3 inches), frequent derailment, or broken guide bars. If tensioning doesn't fix derailment, the internal cables or guides are damaged and replacement is necessary.
Can I replace just one track on my Bobcat E35?
Technically yes, but Bobcat recommends replacing both tracks at once for even wear and smooth operation. Replacing only one causes uneven tension, faster wear on the new track, and potential undercarriage damage.
What's the difference between OEM and aftermarket E35 tracks?
OEM tracks (part #7255667) cost ~$988 and carry factory warranty. Aftermarket options like Prowler or AFT parts cost ~$850–$883, offer heavy-duty variants, and include factory defect warranties. Both fit the E35 when sized correctly.
Will a wrong track size damage my Bobcat E35?
Yes. Using incorrect pitch (not 52.5mm) or link count (not 84) causes improper sprocket engagement, which can strip the sprocket, damage the track frame, or cause frequent derailment.
How long should a Bobcat E35 track last before replacement?
Track life varies by application: 1,500–3,000 hours in normal construction, 800–1,500 hours in abrasive mining or forestry. Inspect monthly for cracks, sag, and guide bar wear rather than relying on hours alone.