3J Driveline - Performance Gear kits and Gearboxes 

Ford Rocket Four-Speed 

The Ford 'Rocket' Four-Speed gearbox is still a very popular choice on road and on track.  
3J Driveline's Rocket straight-cut close-ratio gear kits are manufactured in the UK, using UK sourced materials, designed with competition in mind.  
The mainshaft gears are designed with unique oil pockets on the face, the bore contains a scroll to increase oil flow, and a performance coating that aids oil absorption.  
 
 
 
 
"The unique 3J 'Milled Oil Pocket' design of the gear faces and oil scrolls running throughout the bore increases oil flow and aids the lubrication of gears, producing the most reliable Rocket gear-kits and gearboxes available today" 

3J Driveline Straight Cut Gear Ratios 

1st 
2nd 
3rd 
4th 
2.48 
1.69 
1.28 
1.0 
2.38 
1.69 
1.28 
1.0 
2.29 
1.62 
1.22 
1.0 
3.03 
2.07 
1.98 
1.0 
2.92 
2.07 
1.98 
1.0 
2.48 
1.69 
1.61 
1.0 

3J Driveline Rocket Dog-Engagement Gearbox 

Our 'RACE' specification, complete alloy casting gearbox. As run in the SHP Pickup truck championship. This unit showcases all of our experience in this classic replacement 'dog box' transmission.  
Built in house by our experienced transmission technicians, all gearboxes are thoroughly tested on our in-house test rig prior to dispatch.  
The design of this unit features a new, heavy duty, mainshaft and layshaft spindle and reverse gear system. This helps rank our gearbox above any of its rivals in the market place.  
Features include: 
Each mainshaft gear has a 6-dog design with tapered teeth for unrivalled quick shift 
Heavy duty mainshaft layshaft spindle and reverse gear system 
All mainshaft gears run on caged needle roller bearings 
Our unique 3J alloy main casing makes this the strongest casing and box available 
Steel selector forks 
Unique spool system for even slicker shift 
Quick-shift gear lever 

3J Driveline Rocket Dog Gear Ratios 

1st 
2nd 
3rd 
4th 
2.04 
1.53 
1.21 
1.0 
1.83 
1.38 
1.14 
1.0 
 
 
 
 
"Our Alloy Rocket Gearbox option gives a weight saving of 5KG" 
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