How To Rebuild A Top Loader Four-Speed

Here, we have four gears.... 

   

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Here, we have four gears. On top is Second gear in 28-tooth (left) and 31-tooth (right), the latter being wide-ratio. On the bottom is a pair of Third gears, both 25-tooth, which applies to close- and wide-ratio.

Close vs. Wide Ratio
Which Top Loader transmission should you chose, close or wide ratio, and why? Close-ratio is centered mostly around quick acceleration, which is why you'll find them in the Boss 302, Shelbys, and other high-performance applications. Wide-ratio makes more sense for open-road driving.

Gear ratio boils down to how many revolutions the input shaft turns versus how many revolutions the output shaft turns in a specific gear. For example, if we have a First-gear ratio of 2.78:1 in a wide-ratio box, that means the input shaft turns 2.78 revolutions for every one revolution of the output shaft.

How do you identify close- or wide-ratio? Although we want to trust the identification tag, that's not always possible because many of these older transmissions have been rebuilt in the past. In some cases, close-ratio transmissions have been converted to wide-ratio and vice versa. In fact, we're taking a wide-ratio box and turning it into close-ratio for racing purposes. When you want to be certain, pop the top cover and count the gear teeth.

Assembly begins with shifter...        read full caption Assembly begins with shifter cams, which go in the case as shown. Each needs a lubricated rubber O-ring to keep the gear lube inside.	Observe cam positioning in...        read full caption Observe cam positioning in the case. Note proper location of shifter levers. This is something you don't want to get backward.	New needle bearings are loaded...        read full caption New needle bearings are loaded into the reverse idler, which is what goes in first. There are 22 needle bearings (Ford PN 7D271) in each end. Use transmission assembly lube and embed the bearings to create a perfect circle.
Here's the reverse idler and...        read full caption Here's the reverse idler and gear installed. Refer to the Ford shop manual for proper order of idler gear, retainer, and thrust washers.	The Reverse idler shifter...        read full caption The Reverse idler shifter fork and rail go in like this. Use plenty of assembly lube.	The cluster gear gets 21 needle...        read full caption The cluster gear gets 21 needle bearings in each end. Again, use assembly lube to retain the needles. Always use all-new needle bearings.
Cluster gear thrust washers...        read full caption Cluster gear thrust washers go in the case at each end like this.	This is what the cluster gear/countershaft...        read full caption This is what the cluster gear/countershaft and reverse idler should look like installed. We've gone to a close-ratio package with a 25/21/18/15-tooth package.	For smoother shifts, Anaheim...        read full caption For smoother shifts, Anaheim Gear massages the gear teeth. When you compare the Ford Top Loader to Borg-Warner's T-10, one of the major differences is smoother shifts from the T-10.
One of the first important...        read full caption One of the first important ingredients is the 31-spline output shaft for our close-ratio Top Loader. A 28-spline output shaft is fine for most street applications. But since we'll be running 600 hp through this box, we're using the 31-spline shaft.	Assembly is straightforward...        read full caption Assembly is straightforward by following this Ford shop manual illustration. The output shaft serves as a foundation for synchronizers, gears, and blocking rings. What you want is smooth operation with proper prep and close inspection before it all goes together.	Anaheim Gear dresses up all...        read full caption Anaheim Gear dresses up all the hard parts and their mating surfaces for smooth operation. The goal is to remove any irregularities and high spots. This also enhances lubrication control as well, keeping lube where it belongs between moving parts.