Yukon Gear Spider Gear Kit 3 Pinion - 03-14 Ford E-250 10.5in w/ 35 Splines

A work van that clunks every time you pull out of a driveway, or ratchets in a tight turn at a job site, often has spider gears on the way out. YPKF10.5-S-35 is Yukon's replacement spider gear kit for the open (non limited slip) Ford Sterling 10.5 inch rear with 35-spline axle shafts, and this listing is fitted to 2003-2014 Ford E-250 vans. It uses the three-pinion layout that the 10.5 carrier introduced.

What the spider gears do in a Ford Sterling 10.5

When Ford enlarged the Sterling from 10.25 to 10.5 inches for the 1999 model year trucks, it also changed the open carrier. The 10.25 used a one-piece case with two pinion gears; the 10.5 got a carrier with three pinion (spider) gears on a cross shaft arrangement, sharing the load from two 35-spline side gears. Driving straight, the pack turns as one unit. In a turn the pinions spin between the side gears so the outside wheel can run faster. Three pinions spread torque over more teeth than two, but a loaded van or a hard one-wheel-spin hookup can still chip teeth and wear thrust washers. This kit is a matched gear set made from higher grade material than the factory gears, so the side gears and pinions are replaced together.

Symptoms of worn Sterling 10.5 spider gears

• A clunk taking up slack when you accelerate in a turn
• Clicking at low speed in tight turns, once every wheel revolution or two
• Noise that only shows up turning, not straight ahead
• Steel flakes or a chunk of tooth on the cover magnet at a fluid change
• One-wheel peel followed by a bang when the spinning tire grabs, which is what usually breaks them

How to confirm before buying

Pull the 12-bolt cover, drain the oil and look at the magnet. With one wheel held, rock the other back and forth: lash you can feel inside the carrier, beyond normal ring and pinion backlash, points to worn thrust washers and gears. Look through the carrier windows for chipped or pitted spider teeth. Sterling howl that rises with throttle is usually the pinion bearing, not the spiders, so read our Sterling 10.5 problems and rebuild guide and the spider gear failure guide before tearing in.

Fitment

This kit is for the Ford 10.5 inch rear with an open three-pinion carrier and 35-spline shafts, and the listing is fitted to the 2003-2014 E-250. E-series vans were built with more than one rear axle over these years, so confirm your van has the Sterling 10.5: it has a 12-bolt cover, full-floating shafts with bolted flanges at the hub, and an axle tag you can match. It does not fit a Trac-Lok limited slip carrier; for that, use the Tracloc clutch set for the 3-pinion 10.5. If in doubt, send us your year and VIN. More Sterling parts are in rebuild kits.

Install notes

• Pull both axle shafts at the hubs first so the side gears are free, then remove the carrier. Mark the bearing caps and note the threaded adjuster positions so backlash and preload go back where they were.
• Replace every gear and thrust washer in the kit as a set; mixing old and new teeth shortens the life of both.
• Oil all parts on assembly and lock the cross shaft retainer properly.
• While the carrier is out, check carrier bearings and the pinion bearing. The Yukon 10.25/10.5 carrier installation kit has the carrier side parts.
• Refill with 75W-90 or 75W-140 gear oil. An open carrier does not need friction modifier.
• If spiders keep breaking, a Dura Grip for the Ford 10.5 ends the one-wheel-spin shock loads.

Does this fit a Ford 10.25 rear?

No. The 10.25 uses a two-pinion one-piece case. This kit is the three-pinion design for the Ford 10.5 with 35-spline shafts.

Will it work in my Trac-Lok limited slip?

No. Yukon lists this kit for the open differential only. A 10.5 Trac-Lok needs the Tracloc positraction clutch set for the three-pinion design.

How do I know my E-250 has the Sterling 10.5?

Look for a 12-bolt rear cover and bolted axle flanges at the hubs, then read the axle tag. E-series vans used more than one rear axle, so send us your VIN if the tag is missing.

Do I have to reset backlash after changing spider gears?

If you keep the same ring and pinion and carrier bearings, mark the threaded adjusters before removal and return them to the same positions, then check backlash. New carrier bearings mean a full preload and backlash setup.

What fluid goes in an open Sterling 10.5?

75W-90 or 75W-140 gear oil. Friction modifier is only needed in a limited slip carrier.