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Gear Ratios for:
All Land Rover manual gearboxes
Ashcroft high ratio transfer case
Every Land Rover nerd loves data. Especially if they are trying
to do something a little different with the drive train. I've
placed everything I could find about gearbox and Transfer case
gear ratios here in a hopefully readable way. If you are feeling
particularly nerdy you can also read my "history
of Rover gearboxes" web page.
Just for the fun of it I added the NP-435 close ratio gearbox and
Ashcroft high ratio transfer case that is in The Green Rover for
comparison. Then I got several requests to add other alternative gearboxes
available used in the North American market. Specs
for common alternative gearboxes have been placed on another
web page.
NOTE: Ratios are rounded off to the nearest hundredth.
Some ratios:
- Stock Series differential ratio - 4.7:1
- Stock coiler differential ratio - 3.54:1
- Common aftermarket differential ratios for the Rover differential
carrier - 4.1:1 and 4.75:1
- Standard Series transfer case high range ratio - 1.15:1 (making
it an under drive) . Low range varies
- Standard Coiler transfer case low range ratio - 3.32:1. The
high range varies with the engine used.
- Fairy/Superwinch overdrive ratio - 0.78:1
(which coupled with the 1.15:1 Xfer case under drive gives you
a 0.90:1 overall ratio through the xfer case)
- Roverdrive overdrive ratio - 0.8:1
(which coupled with the 1.15:1 Xfer case under drive gives you
a 0.92:1 overall ratio through the xfer case)
- Ashcroft high ratio kit high range ratio - 0.87:1
Some thoughts about low range first gear ratio:
I found the stock Series Land Rover low range first gear ratio
(40.7:1) to be too tall for most rock crawling and many climbing
situations.
Having 10 years experience with a 70:1 ratio I have found it
to be too low for anything but the most technical rock crawling
situations (with 33.3 inch dia tyre). At this time I'm leaning
towards somewhere around 55:1 as being the best overall low range
ratio for use in many different situations with 32 - 34 inch dia
tyres.
Figuring out a differential ratio: If you have an unknown differential sitting in front of you, you can calculate the ring and pinion gear ratio by counting the number of teeth on both the ring gear and the pinion gear. Divide the number of teeth on the ring gear by the number of teeth on the pinion gear and you get the differential ratio.
Page Contents:
Series Gearbox Ratios: (Does
not include 109 Stage I V8 which uses LT95)
| Main gearbox |
Suffix A & B
88 & 109 |
Suffix C on
88 & 109 |
Ser. III
88 and 109 |
Ser. IIA & III
109 1-Ton |
Top |
Direct |
Direct |
Direct |
Direct |
Third |
1.37:1 |
1.50:1 |
1.50:1 |
1.50:1 |
Second |
2.04:1 |
2.22:1 |
2.22:1 |
2.22:1 |
First |
3.00:1 |
3.60:1 |
3.68:1 |
3.60:1 |
Reverse |
2.54:1 |
3.02:1 |
4.02:1 |
3.02:1 |
Early Coiler, 101 Forward Control and 109 Stage 1 V8 Gearboxes
| Main gearbox |
LT95*
109 Stage 1, 101, Range Rover thru '83
V8 90/110 '83 & '84 |
LT85
All V8 90/110
'84-'91 |
LT77/LT77S
2.5L & 200 Tdi
'84 thru '93 |
LT77/LT77S
V8 Discovery thru '93
V8 90/110 '92 & '93 |
Fifth |
none |
0.80:1 |
0.83:1 |
0.77:1 |
Fourth |
Direct |
Direct |
Direct |
Direct |
Third |
1.51:1 |
1.436:1 |
1.507:1 |
1.40:1 |
Second |
2.45:1 |
2.18:1 |
2.30:1 |
2.13:1 |
First |
4.07:1 |
3.65 |
3.59:1 |
3.32:1 |
*Note: The LT 95 has an integral transfer case. A
number of transfer case gears were available.
R380 Gearbox
| Main gearbox |
R380
All 300 Tdi Discovery & Defender
'94 to present |
R380
All V8 Discovery & Defender
'94 to present |
ZFHP22
Range Rover Classic
'92 - '03 Discovery, Defender V8
|
Fifth |
0.77:1 |
0.73:1 |
N/A |
Fourth |
Direct |
Direct |
0.728:1 |
Third |
1.30:1 |
1.39:1 |
Direct |
Second |
2.13:1 |
2.13:1 |
1.480:1 |
First |
3.39:1 |
3.32:1 |
2.480:1 |
GFT MT-82 Gearbox
| Main
gearbox |
GFT
MT-82
'07 Defender |
Transfer
case |
Sixth |
0.742:1 |
Hi range: 1.211:1 |
Fifth |
Direct |
Lo range: 3.269:1 |
Fourth |
1.223:1 |
|
Third |
1.721:1 |
|
Second |
2.839:1 |
|
First |
5.443:1 |
|
Note: Overall low range first gear is 57.1:1 and overall high
range sixth gear is 3.18:1
Series Transfer case Ratios:
| Transfer
case |
II, Suffix A &
B
88 and 109 |
IIA
suffix C on & III
88 and 109 |
109
1-Ton
IIA & III |
Ashcroft high ratio |
High transfer |
1.15:1 |
1.15:1 |
1.53:1 |
0.87:1 |
High transfer with 4.7 R&P |
5.4:1 ( 3686 RPM @ 65mph*) |
<- Same |
7.19:1 ( 4900 RPM @ 65mph*) |
4.01:1 ( 2737 RPM @ 65mph*) |
High transfer with 4.1 R&P |
4.7:1 ( 3208 RPM @ 65mph*) |
|
6.27:1 ( 4279 RPM @ 65mph*) |
3.57:1 ( 2437 RPM @ 65mph*) |
High transfer with 3.54 R&P |
4.07:1 ( 2788 RPM @ 65mph*) |
|
5.42:1 ( 3699 RPM @ 65mph*) |
3.08:1 ( 2102 RPM @ 65mph*) |
Low Transfer |
2.89:1 |
2.35:1 |
3.27:1 |
2.35:1 |
Low transfer with 4.7 R&P |
13.58:1 |
11.05:1 |
15.37:1 |
11.05:1 |
Low transfer with 4.1 R&P |
11.85:1 |
9.64:1 |
13.41:1 |
9.64:1 |
Low transfer with 3.54 R&P |
10.23:1 |
8.32:1 |
11.58:1 |
8.32:1 |
* Engine
RPM calculated with 4th gear (1:1) and 32 inch diameter tyres (stock
109 size) Calculator at csgnetwork
LT230 Transfer case Ratios
Transfer
case
LT230 |
Early Range Rover |
V8 D 110
300 Tdi |
V8 D90
Discovery |
2.5L Ninety, One Ten |
High transfer |
1.00:1 |
1.41:1 |
1.22:1 |
1.67:1 |
high transfer with
3.54 R&P |
3.54:1 ( 2416
RPM @ 65mph*) |
4.99:1 ( 3406
RPM @ 65mph*) |
4.32:1 ( 2948
RPM @ 65mph*) |
5.84:1 ( 3986
RPM @ 65mph*) |
high transfer with
4.1 R&P |
4.1:1 ( 2798 RPM
@ 65mph*) |
5.78:1 ( 3945
RPM @ 65mph*) |
5.00:1 ( 3414
RPM @ 65mph*) |
6.85:1 ( 4675
RPM @ 65mph*) |
high transfer with
4.7 R&P |
4.7:1 ( 3208 RPM
@ 65mph*) |
6.63:1 ( 4525
RPM @ 65mph*) |
5.73:1 ( 3911
RPM @ 65mph*) |
7.85:1 ( 5358
RPM @ 65mph*) |
Low Transfer |
3.32:1 |
3.32:1 |
3.32:1 |
3.32:1 |
low transfer with
3.54 R&P |
11.75 |
|
|
|
low transfer with
4.1 R&P |
13.62 |
|
|
|
low transfer with
4.7 R&P |
15.60:1 |
|
|
|
* Engine RPM calculated
with 4th gear (1:1) and 32 inch diameter tyres (stock 109 size)
LT95 Transfer ratio ( Integral part of LT95 gearbox)
LT95 gearbox
transfer part |
101 Forward Control |
110 |
90, Range Rover |
High transfer |
1.17:1 |
1.34:1 |
1.11:1 |
Low Transfer |
3.22:1 |
3.22:1 |
3.22:1 |
Overall gear ratio (final drive)
| gearbox position |
Series Suffix C &
newer |
109 1-Ton |
The Green Rover
(NP-435 close ratio) |
|
High transfer |
Low Transfer |
High Transfer |
Low Transfer |
High Transfer |
Low Transfer |
Top |
5.4:1 |
11.10:1 |
7.19:1 |
15.40:1 |
4.09:1 |
11.10:1 |
Third |
8.05:1 |
16.50:1 |
10.80:1 |
23.10:1 |
6.91:1 |
14.47:1 |
Second |
12.00:1 |
24.60:1 |
15.96:1 |
34.1:1 |
9.32:1 |
25.18:1 |
First |
19.88:1 |
40.70:1 |
26.46:1 |
56.56:1 |
18.65:1 |
50.37 |
Reverse |
21.66:1 |
44.30:1 |
28.91:1 |
61.78:1 |
|
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Engine RPM comparisons for Series gearbox with Roverdrive or
high ratio kit and for LT77S (same bellhousing bolt pattern)
Here is a comparison chart showing the differences for high range
fourth gear (1:1 ratio) RPMs at 65 MPH with 32 inch diameter
tyres mounted. Arranged in decending 4th gear RPM order.
vehicle & gearing |
Fourth gear RPM (32" tyres) |
Fifth gear or Roverdrive |
2.5L Ninety and One Ten |
3986 RPM @ 65 MPH |
3349 RPM @ 65 MPH |
Stock Series Land Rover |
3686 |
2951 |
V8 Defender with 4.1 ring and pinion |
3414 |
2628 |
tdi Ninety and One Ten |
3406 |
2827 |
Series Land Rover with 4.1:1 ring and pinion |
3208 |
2554 |
V8 Defender |
2948 |
2270 |
Series Land Rover with 3.54 ring and pinion |
2788 |
2223 |
Series Land Rover with Ashcroft high ratio kit |
2737 |
No fifth gear or overdrive |
ACKNOWLEDGMENTS:
This data came from several sources. It started with a 1971 Land
Rover technical document and mid eighties Rover Ninety and One
Ten dealer hand out brochure and grew through the help of many
people who volunteered additional data through e-mail. Particular
thanks to John Barge for his help in sorting out the coiler gear
ratios.
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