USA Standard Axle For Mustang. T-Bird & Cougar / 8.8in / 31 Spline / 5 Lug / 29 1/4in Long
A Mustang that suddenly will not move with the engine running, a rear wheel that rumbles louder every month, or a 31-spline posi swap that needs shafts to match all send Fox and early SN95 owners shopping for 8.8 axles. The USA Standard ZA F750011 is a replacement rear axle for the Ford 8.8 inch rear: 31 splines, a 5-lug flange and 29-1/4 inches long.
The Mustang 8.8 is a C-clip axle. The inner end of each shaft slides into a side gear in the carrier, and a C-shaped clip in a groove on the shaft end keeps it from walking out. The outer wheel bearing rides directly on the shaft, so the shaft surface is the bearing's inner race. That is why a bearing that runs dry or fails often ruins the axle too: the rollers wear a groove in the shaft, and a new bearing on a grooved shaft fails again quickly. Ford built the 8.8 with 28-spline (1.29 inch) and 31-spline (1.32 inch) shafts. This one is 31 spline, so it has to match 31-spline side gears.
Our Ford 8.8 rear axle problems guide covers the other common failures, and the axle bearing noise guide explains how to separate bearing noise from gear whine.
Pull the shaft and look at the bearing journal near the outer end. A visible groove or pitting there means replace the shaft along with the bearing. Then check the three numbers that matter: count the splines (31), measure from the wheel mounting face to the spline end (29-1/4 inches), and count the wheel studs (5). If you are switching from 28 to 31 spline, the side gears or limited slip must change too; our 28 vs 31 spline guide walks through it.
USA Standard titles this axle for Mustang, Thunderbird and Cougar 8.8 rears. Its fitment table lists 1993-1994 RWD Mustang, while the 1541H twin of this shaft from Yukon is described as fitting 1979-1993 Mustang. Ford put the 8.8 under V8 Mustangs from 1986, and the 1989-1997 Thunderbird and Cougar used an independent 8.8 with half shafts, so this solid-axle shaft does not fit those cars. Because many Fox-body rears have been swapped or converted, measure and count before ordering, or send us the year and axle tag code. If you want a stronger version, the Yukon 1541H alloy twin has the same dimensions. Sold as one shaft.
| Brand | Yukon Gear & Axle |
| Part number | ZA F750011 |
| Fits | USA Standard Axle For Mustang. T-Bird & Cougar / 8.8in / 31 Spline / 5 Lug / 29 1/4in Long |
| Type | Axles |
| 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.
Only if you change the side gears or limited slip to 31 spline. The shaft splines must match the carrier.
This shaft has a 5-lug flange, so it only makes sense on a car with 5-lug brakes and wheels or as part of a 5-lug conversion.
No. Those cars used an independent 8.8 rear with half shafts. This is a solid-axle C-clip shaft.
Yes. The bearing rides directly on the shaft, so a new shaft deserves a new bearing and seal.
75W-140 or 75W-85 gear oil, plus friction modifier if the rear has a Traction-Lok or other clutch-type limited slip.
No, it is one axle shaft. Order two for both sides.
