Timken Bearings Part Number for Triumph Spitfire Front Suspension

Replacing the front suspension bearings on your Triumph Spitfire is a straightforward job when you have the right parts. Timken bearings are a popular choice among enthusiasts for their durability and precise fit. This article provides the specific Timken part numbers for the front wheel bearings and other critical suspension bearings, along with practical guidance for ordering and installing them.

Understanding the Front Suspension Layout

The Triumph Spitfire uses a double-wishbone front suspension with a separate spring and damper. The wheel bearings are located in the front hub, which is a simple design using two tapered roller bearings per side. The inner bearing is larger than the outer, and both are standard Timken catalog items. There are no additional bearings in the upper control arm or steering knuckle; the pivots use bushings or ball joints. The only other front suspension bearing (aside from the wheel bearings) is the steering rack inner tie rod bearing, but that is not typically replaced during a front suspension overhaul. For a complete refresh, focus on the wheel bearings.

Wheel Bearing Part Numbers

Each front hub uses an inner bearing and an outer bearing. The correct Timken part numbers are based on the original factory specifications. Over the years, Triumph used different suppliers, but the Timken equivalents are consistent for most Spitfire models (Mk I through Mk IV, including 1500).

Inner Wheel Bearing

The inner bearing is the larger of the two. The Timken cone (inner race) part number is LM603049. The matching cup (outer race) is LM603010. This bearing set fits the inner position on both left and right front hubs. Always replace both the cone and cup as a matched set.

Outer Wheel Bearing

The outer bearing is smaller. The Timken cone part number is LM11949, and the cup is LM11910. This set goes on the outer side of the hub, behind the grease seal. When ordering, specify both the LM11949 cone and LM11910 cup.

Summary Table:

• Inner bearing: Cone LM603049, Cup LM603010
• Outer bearing: Cone LM11949, Cup LM11910

These part numbers are widely accepted for Triumph Spitfire front wheel bearings. If your Spitfire has been converted to later-model hubs or uses an aftermarket brake upgrade, verify the hub dimensions before ordering.

How to Identify the Correct Part Number

If you are unsure whether your Spitfire uses the standard bearing numbers, remove the hub and inspect the existing bearings. The part number is typically stamped on the cone (inner race) face or the cup outer diameter. Clean the bearing and look for a number like “LM603049” or “LM11949.” Cross-reference with the dimensions: inner bearing bore is 1.250 inches (31.75 mm) and outer diameter is 2.5625 inches (65.088 mm). The outer bearing bore is 0.750 inch (19.05 mm) and outer diameter is 1.875 inches (47.625 mm). If your measurements match, the Timken numbers above are correct.

Front Suspension Bearings Beyond Wheel Bearings

Beyond the wheel bearings, the front suspension has no other rolling element bearings that require regular replacement. The upper and lower ball joints are service items but use greased ball studs, not Timken bearings. The trunnion (lower pivot) uses a bushing, not a bearing. However, the steering rack may contain bearings: the inner tie rod end on a Spitfire is a ball joint, but the rack itself has a bearing on the pinion. If you are rebuilding the entire front end, consider replacing the steering rack bearings, but those are not typically Timken parts. Stick to the wheel bearings for this article.

Ordering Tips

When ordering Timken bearings for your Spitfire front suspension, keep these points in mind:

• Always buy the cone and cup as a set. Never mix old and new races.
• Purchase from a reputable bearing supplier or a classic car parts specialist. Avoid unknown brands that may have poor heat treatment.
• Also order new oil seals for the hub (Timken part numbers not applicable; use standard Spitfire seal part numbers). The inner seal fits behind the inner bearing, and the outer seal goes in the hub cap.
• If you are replacing bearings for the first time, buy two sets (one for each side). It is common to replace both sides at once.
• Timken bearings are made in the USA, but verify that the supplier is an authorized distributor to avoid counterfeit products.

Installation Recommendations

Installing Timken wheel bearings in the Spitfire hub is a job you can do with basic tools. Here are a few practical pointers:

1. Clean the hub thoroughly before installing cups. Use a driver that contacts the cup rim only.
2. Pack the cones with high-temperature wheel bearing grease. Do not use general-purpose grease.
3. Adjust the bearing preload according to the factory manual: tighten the nut to 100 ft-lb while rotating the hub, then back off and retorque to 12-17 ft-lb. This ensures proper end play.
4. Never reuse old grease seals. Install new ones after the bearings are in place.
5. After installation, check for smooth rotation and no excessive play.

Final Recommendation

For a Triumph Spitfire front suspension rebuild, use Timken bearing sets LM603049/LM603010 for the inner and LM11949/LM11910 for the outer. These are direct factory replacements that will provide many miles of reliable service. Pair them with quality seals and follow proper adjustment procedures. If your car has unusual modifications (e.g., aftermarket hubs), measure the existing bearings and confirm fitment. Staying with Timken ensures you get bearings made to the original equipment specifications, which is critical for safety and longevity.