Yukon Gear Steel Spool For Dana 80 w/ 35 Spline Axles / 4.10+
Sled-pull trucks, drag-race Cummins Rams and dedicated off-road one-tons break factory Trac-Lok carriers and spider gears in the Dana 80, and once a carrier is broken some builders stop replacing it with another differential at all. The Yukon Gear & Axle YP FSD80-4-35 is a full steel spool for the Dana 80 rear axle with 35-spline shafts and ring and pinion ratios of 4.10 and numerically higher. It replaces the carrier assembly and locks both rear axle shafts together all the time. It is a competition and off-road part, and Yukon says plainly that it is not recommended for street-driven vehicles.
A differential lets the left and right wheels turn at different speeds so the truck can corner. A spool removes that: there are no spider gears, side gears or clutches, just one piece that the ring gear bolts to and both axle shafts slide into. Both tires get 100 percent of the available traction at all times, and there are no internal parts left to shatter under a hard launch or a heavy pull. Yukon machines it from 8620 steel and heat treats it for strength. The trade-off is that in every turn one tire has to scrub or chirp, the truck pushes wide on wet or icy pavement, and tire wear goes up. On a dual rear wheel truck that scrub is spread across four tires on a full-floating axle, which is why many pulling trucks accept it.
Confirm the axle is a Dana 80: a rear-only full-floating axle with an 11.25 in. ring gear, with 80 cast into the housing. Read the ratio from the ring gear tooth count or tag. Dana 80 carriers are split at 3.73 and 4.10, and this spool is the 4.10-and-up series only. Count the shaft splines; this part needs 35-spline axle shafts, and some Dana 80s were built with 37-spline shafts. Our Dana 80 rear axle problems and rebuild cost guide covers the bearing and Trac-Lok failures that usually start this decision, and the open vs limited slip vs locker guide lays out what you give up with full lockup. If the truck still tows on the street, the Dura Grip 4.10-up positraction is the better fit.
Yukon's chart lists 35-spline Dana 80 rears in 1994-2002 Dodge Ram 2500 and 3500, 1995-1998 B3500 and 1999-2003 Ram 2500 vans, 1988-1997 Ford F-350, 1999-2015 F-350 Super Duty, 1999-2005 F-450 Super Duty, E-350 and E-450 vans, GM C3500 and K3500 trucks of the 1990s, the 1991-2002 C3500HD, 1996-2005 Express 3500, G30 and P30 chassis. Some of those trucks were also built with 37-spline shafts, which this spool does not accept, and Dana 80s can be swapped between trucks, so check the shafts and gear ratio, or send us your year and VIN and we will confirm. Read about how full-floating axles carry the load in our full-floating vs semi-floating guide.
| Brand | Yukon Gear & Axle |
| Part number | YP FSD80-4-35 |
| Fits | Yukon Gear Steel Spool For Dana 80 w/ 35 Spline Axles / 4.10+ |
| Type | Differentials |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yukon does not recommend a spool for street-driven vehicles. Both tires are locked together, so the truck scrubs tires in turns and can push wide on wet or icy roads. It is meant for pulling, drag racing and dedicated off-road trucks.
No. This is the 4.10-and-up carrier series. A 3.54 or 3.73 axle needs a 3.73-and-down part, or new gears of 4.10 or deeper installed at the same time.
No. It is machined for 35-spline shafts only. Count the splines on your shafts before ordering, because some Ford and GM Dana 80s used 37-spline shafts.
No. A spool has no clutches, so standard GL-5 gear oil in 75W-90 or 75W-140 is all it needs.
Yukon makes its full spools from 8620 steel and heat treats them for added strength.
Plan on new carrier bearings and correct shims. If you are changing the ring and pinion at the same time, use a full Dana 80 master overhaul kit sized for your pinion race.
