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Land Rover Gear Box FAQ

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.
 
Manual Gearboxes Automatic Gearboxes Transfer Gearbox
LT77/LT77S ZF4HP22 LT230
R380 LT95 (Transfer Case Section)
LT85
LT95
Series Gearboxes


Manual Gearboxes


LT77/LT77S Manual Gearbox

Gear Ratio Models Used Box S/N
1st 3.321 Disco V8  
  3.585 90/110 50A, 56A, 60A, 61A
  3.692 Disco 200 TDI  
2nd 2.132 Disco  
  2.3008 90/110 50A, 56A, 60A, 61A
3rd 1.397 Disco  
  1.5074 90/110 50A, 56A, 60A, 61A
4th 1.00 All All
5th 0.77 Disco  
  0.8314 90/110 50A, 56A, 60A, 61A
Reverse 3.429 Disco  
  3.7007 90/110 50A, 56A, 60A, 61A

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

Gear Ratio Models Used Box S/N
1st 3.32 Disco V8i  
  3.39 Disco 300TDI  
2nd 2.13 Disco  
3rd 1.39 Disco V8i  
  1.30 Disco 300TDI  
4th 1.00 All  
5th 0.73 Disco V8i  
  0.77 Disco 300TDI  
Reverse 3.43 Disco  

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

 

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

 Gearbox S.No. Ratio Tooth Count
in/int/int/out		 Models Used and Comments
20D 1.667 2.5 NAS 110
22D 1.410 ALL  90/110 4cyl
25D 1.410 V8 110 LT85
26D 1.003 RR CLASSIC 3speed auto (TF727)
27D 1.192 early RR Classic
28D  1.222 26/41/19/40 RR, Disco I, LT77, LT77S, LT85, R380   (Discovery 200tdi) Low Range 3.321
29D 1.192 90 V8s with LT85 gearboxes 
32D, 34D 1.222 2.0 Disco I
36D, 38D, 40D,  1.211 NAS 90 & Disco
41D 42D 1.211 Disco II diff lock stud
43D 57D 1.410 90/110 td5
61D, 62D, 68D, 69D, 70D  1.410   Disco II - NO diff lock 
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
http://www.autoconv.com/crawler.htm		  

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 GearsLT230 Gear Set
LT230 Gear Part Numbers

Input gear bearings FRC 5564      
Box S/N Input gear Part No. /teeth Intermediate,
low/drive/high		 Low High
GENERAL Suffix A or B use a FRC5428 Up to 461123E use a FTC5089 From 461124F to 551442F use a FTC5087 From 551443G use IEH500010

200 Tdi Disco & Defender & 300 Tdi defender USE FTC5089, the 300 Tdi Discos have a FTC5087.		      
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 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.

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