2000 F350 SD 5SPD Transmission / Swap a 6spd

[cmb1998]

I have a 2000 F350 with a v10 and the 5spd manual, the gear code shows it has 4.30's with a LSD.

Truck only has 89K on it and I like everything about it except that I am pulling 2600RPM's at 65MPH. Is it possibile to swap out for the 6spd manual with OD.

Does anyone know if the 5 spd manual trans has an OD? I can't find the gear ratio for 5th gear anywhere. Looks like the 6spd is 0.82 so that would by nice!

Thanks,

Chris

[YT90SC]

6 speed would be worse. Here are the ratios:

S5-47 :
First 5.72:1
Second 2.94:1
Third 1.61:1
Fourth 1.00:1
Fifth 0.76:1
Reverse 5.24:1

6 speed would just speed it up in OD.

[fireguywtc]

Yup, swaping transmissions never helps with your overdrive, just gives you another gear to have closer ratios while shifting.

If you want to lower your RPM's while cruising, you will have to change your axel gear ratio to a lower one.

[95YJman]

2600 at 65 mph seems a little high even for a 4.30 ratio. If you don't tow a lot of weight, often, then a 3.73 would do you right. Would put you at about 2K at 70 mph.

[SmokeyWren]

Originally Posted by cmb1998

Is it possibile to swap out for the 6spd manual with OD.

Anything is possible with deep enough pockets.

But I know that the 4R100 automagic tranny for a diesel cannot be installed in a gasser - different bolt pattern. So I suspect the same answer for the ZF manual tranny of the same year.

However, Ford began putting the ZF 6-speed in the gassers in 2002. So I suspect if you can find a 2002-up 5.4L or V-10 with a stick shift it will probably bolt up without major problems.

But you'll just be spinning your wheels. Granny low and the top two gears are almost the same. The difference is you have an extra gear in the middle - between granny low and direct drive.

Gear   5-speed 6-speed
---     --------- ---------
granny    5.72   5.79
next              3.31
next       2.94   2.10
next       1.61   1.31
direct     1.00   1.00
O/D        0.76   0.72

Does anyone know if the 5 spd manual trans has an OD?

Yes.

[95YJman]

There must be different bellhousing patterns for the 4R100, cuz I have one in my 4x4 Expedition with the 5.4, and the 5.4 and 6.8 have the same pattern IIRC. They also put the ZF in SD trucks with gassers, so they have 2 different trannys for the man. and auto?

[manioso]

Smokey's ratios for 5sp and 6sp are correct. Not sure about bell housing pattern. Suggestion about later (2002 or 2003) gas 6sp might be best idea.

That said, going from 5sp to 6sp (.76OD to .72OD) will result in RPMs dropping from 2600 to 2460. <2600/.76>x.72=2463

If you keep 5sp but change axle from 4.30 to 4.10 RPMs drop to 2480 <2600/4.30>x4.10=2479

and from 4.30 to 3.73 RPMs drop further to 2250.

I have 6sp and 3.73 in my PSD with stock 235/85-16 tires and i do just under 2100rpm at 65mph. When you do the with your numbers, I calculate 2140rpm. Your tires might be slightly smaller.

Conclusion: 6sp (.72 OD) and existing 4.30 axle will give you taller gearing than your 5sp (.76OD) and changing to 4.10 axle. However, if you really want to slow things down you need to look at 3.73 rear.

[cmb1998]

Originally Posted by manioso

Smokey's ratios for 5sp and 6sp are correct. Not sure about bell housing pattern. Suggestion about later (2002 or 2003) gas 6sp might be best idea.

That said, going from 5sp to 6sp (.76OD to .72OD) will result in RPMs dropping from 2600 to 2460. <2600/.76>x.72=2463

If you keep 5sp but change axle from 4.30 to 4.10 RPMs drop to 2480 <2600/4.30>x4.10=2479

and from 4.30 to 3.73 RPMs drop further to 2250.

I have 6sp and 3.73 in my PSD with stock 235/85-16 tires and i do just under 2100rpm at 65mph. When you do the with your numbers, I calculate 2140rpm. Your tires might be slightly smaller.

Conclusion: 6sp (.72 OD) and existing 4.30 axle will give you taller gearing than your 5sp (.76OD) and changing to 4.10 axle. However, if you really want to slow things down you need to look at 3.73 rear.

Thanks for all the help. Looks like swapping the trans out is not the way to go. I am about 5000 miles away from needing new tires so I may just go up a size and see how that works. Next step will be swapping out the gears...

Thanks!

Chris