John Deere — Checking Belt Tensioner Spring Tension and Belt Wear (Automatic Tensioner)
Maintenance · Automatic belt tensioner
From a John Deere owner's manual covering: 4045TF120, 6068HF158, 6068TF120, 6068TF250. Check it applies to your exact model before use.
Applies to: John Deere 4045TF120, John Deere 6068TF120, John Deere 6068TF250
Before you start
- Threads on belt tensioner roller cap screw are LEFT-HAND threads.
Procedure
- Release tension on belt using a breaker bar and socket on tension arm. Remove belt from pulleys.
- Release tension on tension arm and remove breaker bar.
- Put a mark on swing arm of tensioner.
- Measure 21 mm (0.83 in.) from the mark and put a mark on tensioner mounting base.
- Install torque wrench so that it is aligned with center of pulley and tensioner.
- Rotate the swing arm with the torque wrench until marks are aligned.
- Record torque wrench measurement and compare with specification. Replace tensioner assembly as required.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Spring Tension—Torque 18-22 Amazon eBay FridayParts $45.30 N·m (13-16 Amazon eBay FridayParts $22.99 lb-ft)
Full service-parts list: John Deere 6068TF250 →
Source: John Deere owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.