Spicer 5.29 ring and pinion set (37-7 teeth, 29-spline pinion, 10-bolt ring) for the Toyota 8 inch 4-cylinder axle, industry number T529.
A 4-cylinder Toyota pickup or 4Runner that went from stock tires to 31s, 33s or bigger usually ends up with the same complaint: it will not hold fifth on the highway, it labors on every hill, and first gear off road feels like second. The Spicer 2020891, sold under industry number T529, is a 5.29 ring and pinion set for the Toyota 8 inch axle in the 4-cylinder pattern, and 5.29 is the ratio most owners land on when the tires get big and the 22R or 22RE has to keep turning them.
The driveshaft turns the pinion, and the pinion turns the ring gear bolted to the differential carrier. On this set the ring has 37 teeth and the pinion has 7, so the driveshaft spins 5.29 times for every turn of the axle shafts. The ring gear mounts to the carrier with 10 bolts, the pinion shaft is 1.378 inches, and the pinion is listed with a 29-spline yoke end. Toyota built the 8 inch in more than one pattern: the naturally aspirated 4-cylinder trucks use one pinion and carrier layout, while the V6 and turbo 4-cylinder trucks use another, and the independent front axle on 1986-up 4WD trucks is a reverse-rotation design with its own gears. This set is the standard-rotation 4-cylinder pattern only.
Read the current ratio from the axle tag or count driveshaft turns against one tire turn, then confirm the axle is the 4-cylinder 8 inch and not a V6 or turbo housing. Count the splines on your pinion yoke before ordering: Toyota 8 inch pinions were made in both 27 and 29 spline, and if your truck has a 27-spline yoke you will need a 29-spline yoke or flange to run this pinion. Check whether your carrier accepts a 5.29 pinion. Toyota 4-cylinder carriers come in ratio ranges, and if the truck left the factory with a low numerical ratio, a carrier like the Yukon open carrier for the Toyota 8 inch 4-cylinder may be part of the job. Remember the front axle: a 4WD truck must have the same ratio at both ends or the transfer case will bind in four-wheel drive.
The listing covers the Toyota 8 inch axle in the 4-cylinder pattern with a 10-bolt ring gear and 29-spline pinion. In practice that means 4-cylinder Toyota pickups and 4Runners with the 8 inch rear, plus the 1979-1985 solid front axle, which uses a standard-rotation gear. It is not the gear for the 1986-up IFS front, V6 or turbo 4-cylinder axles, or the later Tacoma 8 inch. Because Toyota changed details over the years, match the old pinion spline, ring gear bolt count and carrier before you tear down, or send us the year and VIN and we will check it for you.
Pull the third member, mark the bearing caps and adjusters, and remove the old gears. Revolution Gear lists starting setup values for the Toyota 8 inch of 0.074 inch pinion depth, 12-15 in-lb pinion bearing preload, 0.006-0.010 inch backlash, and 70 ft-lb on both ring gear bolts and bearing caps. Start pinion depth with the original shim stack, set preload with a new crush sleeve, then set backlash with the side adjusters and read the pattern with marking compound on both drive and coast sides. This is the gear set only. Order it with the Toyota 8 inch master overhaul kit (Koyo carrier and pinion bearings, races, seal, shims and crush sleeve) or the Revolution 1979-1985 Toyota 8 inch master install kit. A bearing separator and puller set makes the carrier bearings far easier to pull. Fill with 75W-90 GL-5 gear oil, drive gently with no towing for the first few hundred miles, and change the oil after break-in.
| Part number | |
| Industry number | |
| Axle | |
| Ratio | |
| Pinion spline | |
| Ring gear bolts | |
| Ring gear diameter | |
| Pinion shaft | |
| Weight |
No. The V6 and turbo 4-cylinder trucks use a different 8 inch pinion and carrier pattern. This set is for the naturally aspirated 4-cylinder pattern 8 inch axle.
The set is listed with a 29-spline pinion, so a 27-spline yoke will not slide on. You will need a matching 29-spline yoke or flange. Count your yoke splines before you order.
Yes on any 4WD truck. Both axles must run the same ratio or the transfer case and driveline will bind in four-wheel drive. The 1986-up IFS front uses a reverse-rotation gear set, not this one.
On a 4-cylinder Toyota it is the common choice for roughly 33 inch tires and up, especially with a lot of trail use. Smaller tires usually suit a 4.88 better.
A master install kit with carrier and pinion bearings, races, seal, crush sleeve and shims, plus marking compound, an inch-pound torque wrench, a dial indicator and 75W-90 GL-5 gear oil.
Drive easy with no towing or hard launches for the first few hundred miles, let the axle cool if it gets hot, then change the gear oil to remove break-in wear metal.
