5 speed to six speed swap

[mark89]

can i replace the 5 speed gearbox on a transit t350 crewcab whith six speed box on a 137 ?

[MrMPuk]

Why would you want to?

[ake]

Waste of time unless you change the diff to match

[214si]

Why that?? i thought the sixth gear was just a 'cruising' gear, reducing the engine revs as my 350 crew cab seems like its ragging its nuts off at 65

[barabas]

Why that?? i thought the sixth gear was just a 'cruising' gear, reducing the engine revs as my 350 crew cab seems like its ragging its nuts off at 65

That sounds like the 5.88 diff, you'd be better off swapping diffs....

[angeleye]

Why that?? i thought the sixth gear was just a 'cruising' gear, reducing the engine revs as my 350 crew cab seems like its ragging its nuts off at 65

you will have 5.13 diff look out for a 4.63.as mentioned the difference between a 6sp /and 5sp top gear ratio is minimal would of thought different fitting as well.
iirc think gearbox ratios are
5spd 4th....1.00
5th....0.76


6sp 5th....1.00
6th....0.79

[ake]

Why that?? i thought the sixth gear was just a 'cruising' gear, reducing the engine revs as my 350 crew cab seems like its ragging its nuts off at 65

Because the 6 speed box is designed to work with a lower diff ratio than a 5 speed