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
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 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.
|