Overhaul kit ~$200-400. Most DIYers send the OD section out and do the main case at home. Watch for solenoid and 3-4 clutch wear.
The AW4 rebuild is doable in a home shop but not trivial. The standard advice: pay a trans shop to do the overdrive section (requires specialty spring compressor) and do the main case yourself.
Rebuild kit contents (e.g., ExtremeTerrain 53007998KT, Transtec):
What usually needs replacing at high mileage:
Tooling: standard mechanics hand tools, a snap-ring tool set, a press for the OD section (or send it out), a flat clean workbench. The shop manual or the Toyota A340 manual (they're 95% the same internals) is mandatory.
Timeline: a competent DIYer takes a long weekend. A pro shop turns the job in 2-3 days for $1500-2500 all in.
Cost reference:
| Part | Vendor | Est. price |
|---|---|---|
| AW4 rebuild kit | Transtec/ExtremeTerrain | ~$380 |
| AW4 torque converter (reman) | Sonnax/Punch | ~$180 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.
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