Land Rover Gear Box Info

Reprinted with permission from: Land Rover Gear Box FAQ - Thanks John!

This page has been set up as a reference source for gear sets that have been used in Land Rover gearboxes.  Data has come from a variety of sources.  It has not necessarily been cross checked and verified, so use the information with the appropriate amount of discretion. 

In other words don't blame me if the gears you get don't fit.  It you have some more or better info., please let us know and we'll pass it along to the author.

Manual Gearboxes

Automatic Gearboxes

Transfer Cases

LT77/LT77S

ZF4HP22

LT230

R380

 

LT95 (Transfer Case Section)

LT85

   

LT95

   

Series Gearboxes

   


Manual Gearboxes

LT77/LT77S Manual Gearbox
Model
Box S/N

1st

2nd

3rd

4th
5th
Reverse

90/110 British Military

51A
3.985

2.519

1.5074
1.00
0.8314
3.701

90/110 pre' 200TDI

50A

3.585

2.3008

1.5074

1.00
0.8314 3.701

Disco 200TDI
90/110 200TDI

55A
56A

3.692

2.132

1.397
1.00
0.77
3.429
90/100 V8
Disco V8
60A, 61A
53A, 57A
3.321
2.132
1.397
1.00
0.77
3.429

The LT77 gearbox was used from 1983 to 1989 on 90/110s with 4 cylinder engines and 1990/91 on all 90/110s.  LT77S were used all all Discoverys to 1993 and 90/110s during 1992/93.  All of these boxes use a separate transfer case called the LT230 which is mounted directly onto the output flange of the gearbox.  The "77" refers to the centerline spacing in mm between the mainshaft and the layshaft.  Reverse is to the left and up.

R380 Manual Gearbox
Updated information on 01/22/2005 from Ashcroft Transmissions
Model
Box Prefix/Suffix
1st
  2nd 3rd
4th
5th
Reverse
Defender 2.5NA (short bellhousing)
50J
3.700
2.300
1.507
1.00
0.831
3.701??
Disco/RR 300TDI
Disco TD5
Defender 200TDI
Defender 300TDI
Defender TD5
55J
???
55H
56J
68L
3.692 2.132
1.397
1.00
0.770
3.429
Disco/RR V8i 53J
3.321 2.132
1.397
1.00
0.732
3.429

The R380 gearbox was used from 1994 to present on Defenders and Discoverys.  All of these boxes use a separate transfer case called the LT230 which is mounted directly onto the output flange of the gearbox.  Reverse is to the right and down.  This box was brought in as a replacement for the LT77S.  It is noted to be smoother shifting than its predecessor.

LT85 Manual Gearbox

Gear

Ratio

Models Used

1st

3.6497

90/110

2nd

2.1804

90/110

3rd

1.4362

90/110

4th

1.00

All

5th

0.7951

90/110

Reverse

3.8242

90/110

The LT85 gearbox was used from 1984 to 1991 on 90/110s with V8s and 1986 on for Isuzu diesels.  All of these boxes use a separate transfer case called the LT230 which is mounted directly onto the output flange of the gearbox.  This is normally referred to as the "Santana" gearbox as it was used on Santana Land Rovers.

LT95 Manual Gearbox

Gear

Ratio

Models Used

1st

4.0691

All

2nd

2.4480

All

3rd

1.5049

All

4th

1.00

All

Reverse

3.6643

All

The LT95 gearbox was used from 1969 to 1983 on Range Rovers, all 101s, Stage Is and 90/110s with V8s in 1983/84 and 1985 with Isuzu diesels.  All of these boxes use an integral transfer case.  The transfer case is a "full time" units with a lockable, mechanical differential.  The differential is locked via a vacuum actuator.  Overdrives are available that mount off of the PTO flange and replace the transfer case input gear.  Note that the gearbox and transfer case use separate sumps.  See the transfer case section for information on transfer case ratios.

Series Gearboxes

Gear

Ratio

Models Used

1st

3.00

Series I, II, IIA

 

3.60

IIA 109, 6 cylinder and '1 ton'

 

3.68

III

2nd

2.043

Series I, II

 

2.22

IIA 109, 6 cylinder and '1 ton', III

3rd

1.50

Series I, IIA 109, 6cyl, 1 ton, III

 

1.38

Series II

4th

1.00

All

Reverse

2.547

Series I

 

3.02

IIA 109, 6 cylinder and '1 ton'

 

4.01

III

High Range

1.148

I, II, IIA, III

 

1.53

IIA 109, 6 cylinder, 109FC and 1 ton

Low Range

2.89

I, II, IIA

 

2.35

IIA 109 6 cylinder, III

 

3.27

1 ton

 

2.92

109FC

Overdrive

?????

Rocky Mountain “SX” Overdrive


Automatic Gearboxes

ZF4HP22 Automatic Gearbox

Gear

Ratio

Models Used

1st

2.48

All

2nd

1.48

All

3rd

1.00

All

4th

0.728

All

Reverse

2.086

All


Transfer Cases

LT230 Transfer Case

 Gear

Ratio

Tooth Count
in/int/int/out

Models Used and Comments

Box S/N

Low Range

3.320

26/41/19/40

LT77, LT77S, LT85

13D, 22D, 28D

 

4.340

26/41/20/55

Maxi-Drive Engineering Low range gear set.  Exact ratio depends on input and intermediate gears that are used which vary slightly by model.

 

High Range

1.003

 

RR 3 speed auto (TF727)

 
 

1.222

26/41/40/31

LT77/LT77S

28D

 

1.1923

 

90 V8s with LT85 gearboxes 

29D

 

1.211

     
 

1.206

     
 

1.410

 26/41/?/?

All 90s except V8 
All 110s except 2.5/2.25l petrol and N/A diesel

13D, 22D

 

1.667

 26/41/35/37

110s with 2.5/2.25l petrol and N/A diesel

 

OverDrive

 ??

 

Rocky Mountain “DX” Overdrive

 
 

0.74?

 

Tim Payne Overdrive Designs Ltd Total t. case ratio is multiplied times the existing transfer case ratio.  i.e. 0.9028 = 0.74 * 1.22 high/high

 

Underdrive

2.690

 

Ashcroft Transmissions Ltd, Total t. case ratio is multiplied times the existing transfer case ratio.  i.e. 8.933 = 2.69 * 3.321 low/low
Unfortunately no longer in production

 

The LT230 is an all gear transfer case.  It has been used on all Defenders, Discoverys, pre' 1989 Range Rovers and 90/110s with LT77/LT77S/LT85/R380/ZF4HP22 gearboxes. The transfer case is a "full time" unit with a lockable, mechanical differential.  The differential is locked via a mechanical linkage through a spring inside the box.  Overdrives and underdrives are available that mount off of the PTO flange and replace the transfer case input gear.  The gear set is comprised of 4 pieces:
 

LT230 Gear Set
LT230 Gears

LT230 Gear Part Numbers

Box S/N

Input P/N,teeth

Intermediate,
low/drive/high

Low

High

13D

FRC5428,26

FRC5424,19/41/?

FRC5435,40

FRC5425,?

22D_suffix_B

FRC5428,26

FRC7884,19/41/?

FRC7434,40

FRC7885,?

29D suffix B

FRC5428,26

FRC7428,19/41/?

FRC7434,40

FTC7429,?

22D_suffix_C

FRC8917,26

FRC9460,19/41/? 

FRC7434,40

FRC7885,?

29D suffix C

FRC8917,26

FRC9552,?/?/?

FRC7434,40

FRC9551,?

22D suffix E on

?

?

FTC1741,40

?

32D_to_LA939975

?

FRC9552,?/?/?

FTC1084,?

FTC1085,?

32D_from_MA939976

FTC4188,?

FRC4190,?/?/?

FTC1084,?

FTC4189,?


LT95 (Transfer Case section)

Gear

Ratio

Tooth Count

Models Used

Low Range

3.3206

 

All

High Range

0.996

 

Australian Spec 110 with 4BD1 Isuzu Diesel

 

1.113

   
 

1.174

 

101FC

 

1.3362

 

110

Overdrive

     

All LT95 transfer gears are interchangeable.  They can be changed with the gearbox on the vehicle.