Parts for your 1990 Suzuki Jimny-Wheel hubs

1990 Suzuki Jimny wheel hubs: what they do and how to look after them

Wheel hubs absolutely are relevant and used on the 1990 Suzuki Jimny (often sold locally as the Suzuki Sierra). Period factory literature and technical references – including the Suzuki SJ410/SJ413 Factory Service Manual, the Suzuki parts catalogue of the era, and Aisin free‑wheeling hub service instructions – show the model shipped with front locking hubs. Most Australian and New Zealand vehicles of this vintage came with manual Aisin free‑wheeling hubs, while some trims and markets also saw auto hubs or fixed drive flanges.

On a part‑time 4WD Jimny, the wheel hubs sit at the centre of each front wheel and handle the job of connecting or disconnecting the wheel from the front axle shafts. Unlocked in 2H, they let the wheels free‑wheel, cutting driveline drag and wear. Locked for 4H or 4L, they positively couple the wheel to the axle so engine torque gets to the ground. Simple, tough, and perfect for a light, live‑axle Suzuki.

For servicing, a little attention goes a long way. If the Jimny sees beach work, mud or regular water crossings, plan on inspecting and cleaning the hubs more often. Otherwise, a check every 20,000 km or yearly is sensible. Look for:

• Stiff, gritty or jammed dials, cracked or perished O‑rings and gaskets
• Grease diluted with water or sand, rust staining on springs and pawls
• Clicking under load, intermittent front drive in 4WD, or obvious play at the wheel

When replacing or overhauling, support the vehicle safely, leave the transfer in 2H and the hubs unlocked. Remove the hub cap screws and cone washers, ease off the hub body, and keep track of thrust washers and circlips on the outer CV stub. Clean everything with solvent, blow dry gently, then apply a light coat of quality NLGI #2 wheel‑bearing or marine‑grade grease to moving parts and splines. Don’t overpack the hub, too much grease can make the dial sluggish, especially in cold weather.

Fit new O‑rings and paper gaskets as a matter of course, reassemble, and tighten fasteners to the factory torque specs from the Suzuki service manual. If you’re also servicing wheel bearings, set preload per the manual before the hub goes back on. After reassembly, lock the hubs and engage 4H for a short, low‑speed dirt test to confirm drive and disengagement.

Some owners swap worn auto hubs to manual Aisin units for reliability, or to fixed flanges for hardcore tracks. Fixed flanges add a tiny bit of drag but remove a failure point. Whichever way, a tidy, sealed hub means fewer surprises on the track.

How can they tell if the hubs are locked or unlocked?

Most factory Jimny/Sierra hubs have a dial marked FREE/LOCK. Turn to LOCK before shifting into 4H or 4L. If unsure, jack the front (safely), turn a wheel and watch the front prop shaft, if it turns with the hub locked, the coupling’s doing its job.

How often should a 1990 Jimny’s hubs be serviced?

For mixed road use, inspect yearly or every 20,000 km. After beach runs, mud, or deep crossings, clean and re‑grease as soon as practical to prevent salt and grit chewing out springs, pawls and splines. Replace O‑rings and gaskets whenever the hub’s opened.

Can auto hubs be replaced with manual hubs on this model?

Yes. Manual Aisin‑type hubs are a common retrofit on 1990 Jimnys/Sierra for durability and positive engagement. It’s typically a bolt‑on job using the correct spline count, with new gaskets/O‑rings and adherence to factory torque settings from the Suzuki service manual.