Thread: 30 or 49% lower low range ?

Originally Posted by MLD

Based on Ashcroft ratio calculator a 30% reduction for a TDI is about 62:1 for first low. A standard Puma is about 64:1 in first low. Can you borrow a puma for a comparison?

Granted the ratio step up from first to second in the puma is wider than the R380. But you fit reduction gears for the benefit of first low primarily.

MLD

I dont know what numbers you are using, but the MD 30% low range, in a 300
Tdi defender result in approx 56-1, the 49% low range result in appox 65-1

2nd low 30% = 32.574-1
2nd low 49% = 37.335-1

3rd low 30% = 21.341-1
3rd low 49% = 24.464-1

4th low 30% = 15.279-1
4th low 49% = 17.512-1

5th low 30% = 11.765-1
5th low 49% = 13.485-1

1st high = 18.441-1
2nd high = 10.649-1
3rd high = 6.978-1

Tony, current low range just doesn't cut it, particularly descending.

Far too many times I've been riding brakes hard trying to prevent the old girl running away and modulating the pedal to prevent lockup when I'd rather be inching my way downhill utilising engine braking.

I know, I know, a 4BD1T fixes that, but it's not going to happen anytime soon.

I just had a gut feeling that the 49% lower gearing was going to be a tad too low for what I do, I'm just interested to see if anyone has actually experienced this in use.

Originally Posted by rick130

Tony, current low range just doesn't cut it, particularly descending.

Far too many times I've been riding brakes hard trying to prevent the old girl running away and modulating the pedal to prevent lockup when I'd rather be inching my way downhill utilising engine braking.

I know, I know, a 4BD1T fixes that, but it's not going to happen anytime soon.

I just had a gut feeling that the 49% lower gearing was going to be a tad too low for what I do, I'm just interested to see if anyone has actually experienced this in use.

Rick,save yourself all the heartache and just buy an Underdrive
You get the best of both worlds,you retain all your original ratios,and gain a lot of lower ratios,for those times that you need them

Originally Posted by LowRanger

Rick,save yourself all the heartache and just buy an Underdrive
You get the best of both worlds,you retain all your original ratios,and gain a lot of lower ratios,for those times that you need them

In an ideal world Wayne......

But it's not a rockhopper, it's my work truck and weekend/holiday escape vehicle so is a little hard to justify the expense of the UD.

And the t/case is about to get a rebuild which is the reason for the Q.
While it's apart....

Originally Posted by rick130

Tony, current low range just doesn't cut it, particularly descending.

Far too many times I've been riding brakes hard trying to prevent the old girl running away and modulating the pedal to prevent lockup when I'd rather be inching my way downhill utilising engine braking.

I know, I know, a 4BD1T fixes that, but it's not going to happen anytime soon.

I just had a gut feeling that the 49% lower gearing was going to be a tad too low for what I do, I'm just interested to see if anyone has actually experienced this in use.

if only you were closer i could show you how good they are on the steep stuff

probably to low for other uses - but you change your driving habit and that becomes safer for the vehicle

Originally Posted by uninformed

I dont know what numbers you are using, but the MD 30% low range, in a 300
Tdi defender result in approx 56-1, the 49% low range result in appox 65-1

R380 first 3.692
LT230 stock 3.321
LT230 30% reduction (3.321 divided by 0.70) = 4.744
Diff 3.54

3.692 x 4.744 x 3.54 = 62.006

To net up you divide by 0.70 not multiply by 1.3.

MLD

Originally Posted by MLD

R380 first 3.692
LT230 stock 3.321
LT230 30% reduction (3.321 divided by 0.70) = 4.744
Diff 3.54

3.692 x 4.744 x 3.54 = 62.006

To net up you divide by 0.70 not multiply by 1.3.

MLD

Not according to Mal Story.

Original low gear ratio 19/40 = 2.105 - 1
30% low gear ratio 20/55 = 2.75 - 1
49% low gear ratio 23/72 = 3.130 - 1

Def t/case 26t x 41t = 1.577 primary reduction

Total t/case low range reduction:

Original = 3.319585 (say 3.32)
30% = 4.337
49% = 4.936

Uniformed you may be quoting the correct ratios produced by Mal but your mathematics to call it a 30% reduction as a mathematical equation is incorrect. 4.744 x .70 = 3.32. If your ratio is correct then it's not a 30% reduction.

MLD