Thread: high ratio transfer gears

Originally Posted by hillbilliywheelchair

their smaller than 7.50 16 you can fit 9.00 16 without lift

When did that happen?

IMHO You need a military chassis to use 9.00 16, or at least that is what Land Rover used.

I wouldn't like to be in a standard civvy suspension series LR with 9.00 16s - there would be that much grinding and rattling every time you changed lanes that I'd want to stop and find out what fell off.

Originally Posted by wozapinin

seriously considering putting high ratio gears in the 2a. She tends to get a bit warm in the summer months when highway cruising. She runs a xf 250 motor with c4 and has rangy diff centres but still revs too high, at 110kmh we're over 3000rpm....

Just out of interest, if as IsuzuRover suggests the ratios don't make sense, are we sure that the box is a standard series box and not the F/C 1Ton helical box?

Diana

cut the gards out extend the bump stops and they fit fine

Originally Posted by Lotz-A-Landies

are we sure that the box is a standard series box and not the F/C 1Ton helical box?

Diana

I''m pretty sure he said he is running a Ford C4 box

Originally Posted by series3

I''m pretty sure he said he is running a Ford C4 box

That's the gearbox, I'm enquiring about the transfer box the C4 is mated to!

Originally Posted by hillbilliywheelchair

cut the gards out extend the bump stops and they fit fine

With standard suspension on a standard chassis, what you'll end up with is significantly reduced suspension travel.

The 9.00 tyres will still hit the inside of the mudgards and particularly the springs, making you think you have had something fall off. I think you will also find that 9.00 16 tyres require minimum 6.5" rims and they will be hard to find, unless of course you acquire some Disco I rims or most Defender 130 rims which with their positive offset will make the steering and noise situation even worse.

Originally Posted by isuzurover

For that to be true you must be running 27.5" tyres.

I assume that you have:
1:1 top gear like all C4s
1.15:1 standard series t-case high range
3.54:1 rangie diffs

Which gives you a an overall drive ratio in top gear of 4.07:1

110 km/h = 1833.33 m/min

31" tyres have a circumference of 2.47 m

1833.33/2.47 gives you 741 rpm at the wheels.

741 x 4.07 = 3017 rpm at the engine.

So something doesn't add up. Either your tacho and or speedo are out, or your tyres are much smaller than it says on the sidewall.

I'll just stop my head from spinning with all those numbers
Have just recently changed the speedo for a rangy one and does seem to be understating compared to the original at same revs.

Originally Posted by hillbilliywheelchair

their smaller than 7.50 16 you can fit 9.00 16 without lift

Had a series 3 with 9.00 16's and they did rub on lock. Cut guards would fix but she's not ex-mil.

Originally Posted by Lotz-A-Landies

are we sure that the box is a standard series box and not the F/C 1Ton helical box?

Diana

Standard transfer box on back of c4

Originally Posted by wozapinin

Had a series 3 with 9.00 16's and they did rub on lock. Cut guards would fix but she's not ex-mil.

mine was on a 2a tray back and i just modded the steering bump stops
she made a briliant work rig up on the stations