design - Land Rover section

 

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

 

 

 

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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