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Ford Bronco Parts - Classic Vintage Early Bronco Parts

Toploader 4 speed manual – Transmission Guide

Tech article by admin and filed under - Manual, Transmission

Tech article by Jon Hanna (Admin)

Manual Trans Intro
Gear Ratio Chart
NP435
T18
Toploader
ZF
NV4500

See also: Automatics

Transmission:
Toploader (also called “T&C” or “10 bolt top cover”) 4 speed manual
Sources:
1967-1982 Ford cars and some trucks. Since it was used for so many years there are several different versions of this transmission. Tail shaft lengths will vary, but you won’t need the tail shaft anyway, just the case.
Identification:
As the name implies, this transmission has a 10 bolt top cover to the case, rather than the more usual side cover plate. The case itself is 10.25″ with a side mounted, external style shifter. These came in both “close ratio” and the more common (and more desirable for Broncos) “wide ratio” versions. Look at the tooth count on second gear. A “close ratio” will have 28 teeth and a “wide ratio” will have 31 teeth.
Adapter required?
The “adapter” needed in this case is an aftermarket output shaft, along with a shifter bracket and rod kit. The Toploader case takes the place of the stock Bronco transmission, so no adapters are needed to correct the bolt pattern. The stock Bronco 8 cylinder intermediate housing is retained, although modified (see below)
Pros:
The Toploader is a fully synchronized, quick shifting and strong transmission. Because they came in so many vehicles they should be easy to find. However, they’re also a popular choice for several swaps including the Mustang and Jeep crowd, so demand may inflate pricing for both parts and transmissions.
Cons:
Gearing is even higher than a stock 3 speed, which can be a pro or con, depending on how you drive. The high 1st gear is not typically ideal for the trail, especially rock crawling. However, if you spend most of your time on the highway the gearing may be exactly what you want. The closer shift points are also an improvement over the stock 3 speed. Since the shifter rods are on the side they can be vulnerable to getting jammed with mud and snow. An alternate top shifter came on some truck transmissions and replaces the top cover with one that has the shift forks built in.
Cost: (Approximate)
Transmission: $400 used and $750-1000 rebuilt
Adapter (output shaft): $250-350
Shifter $250
Bell housing:
Standard Ford. The Toploader will bolt up to your existing bell housing on small block (289-302-351) engines. The existing Bronco clutch is also used.
Modifications needed:
The entire assembly is 1″ longer than a stock 8 cyl Bronco transmission, so drive shaft modifications may be necessary depending on the amount of suspension lift you have. The stock Bronco 8 cylinder intermediate housing needs to be machined for the larger Toploader bearing and drilled to accept the shift rail. You’ll also need to cut a hole in the floor for the side shifter. A four speed floor shifter needs to be installed, requiring some floor board cutting.

Manual Transmissions 1st 2nd 3rd 4th 5th
Bronco 3 spd (6 cyl) 3.41 1.86 1.00
Bronco 3 spd (8 cyl) 2.99 1.75 1.00
NP 435 6.69 3.34 80>1.79 1.00
T-18 6.32 3.09 1.69 1.00
Toploader (Close ratio) 2.32 1.69 1.29 1.00
Toploader (Wide ratio) 2.78 1.93 1.35 1.00
Toploader (Overdrive) 3.29 1.84 1.00 0.81
ZF 5.72 2.94 1.61 1.00 0.76
NV4500 (Dodge) 5.61 3.04 1.67 1.00 0.73

One Response to “Toploader 4 speed manual – Transmission Guide”

  1. agent orange Says:

    Hello I was curious if anyone has had any experience with the toploader with the overdrive? It looks like a good situation with the low gear lower than the normal top-loader and the high gear woud be good for the highway? If anyone has any info or ideas, please let me know. I currently have a complete set-up to change to a np435! I’m just a little concerned about how they shift and the size and weight. Also the low gear which I probably won’t have much use for.
    Thanks, Bryan

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