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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.  It you have some more or better info., please let me know and I'll update the list.  Send any comments to my e-mail address: red90 ampersand red90.ca  “Spam blocking, replace ampersand with @ and no spaces”
 

Manual Gearboxes

Automatic Gearboxes

Transfer Cases

MT82

ZF4HP22

LT230

LT77/LT77S

 

LT95 (Transfer Case Section)

R380

 

 

LT85

 

 

LT95

 

 

Series Gearboxes

 

 



Manual Gearboxes

MT82 Manual Gearbox  (Getrag Ford transmissions)

Model

1st

2nd

3rd

4th

5th

6th

Reverse

2007+ Defenders

5.443

2.832

1.721

1.223

1.000

0.742

4.935

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.

Strength and suffix information courtesy of  Ashcroft Transmissions:  The LT 77 was introduced to the Landrover range in approx 1983 with the suffix D box and was developed over the years to the suffix H which was last used in 1994.  The D and E are very similar the only difference being the reverse gear was a little fatter in the E. When they went from E to F larger layshaft bearings were used.  The G was further improved by all the gear teeth including the pinion getting approx 20% thicker. Also a much wider pump was used to increase the lubrication and cope with the fact that some of the LT 77"s were now being supplied oil cooled, ie V8 NAS 90, 3.9 RR Classic and the 3.5 EFI Discos.  The H (termed the LT 77S) was the same as the G in terms of strength but used a different syncro set up called the "Double Syncro", In reality it didn’t work much better.

R380 Manual Gearbox

Updated information on 2005/01/22 from Ashcroft Transmissions

Model

Box Prefix/Suffix

1st

  2nd

3rd

4th

5th

Reverse

Defender 2.5NA (short bellhousing)

50A (TRC103150)

3.700

2.300

1.507

1.00

0.831

3.701

Defender 2.5NA (military, short bellhousing)

51A

3.985

2.519

1.5074

1.00

0.8314

3.701

Defender 200TDI (short bellhousing)

Disco/RR 300TDI
Disco TD5
Defender 300TDI
Defender TD5

44A (TRC103140)

55A
???
56A
68A

3.692

2.132

1.397

1.00

0.770

3.429

Disco/RR V8i

53A

3.321

2.132

1.397

1.00

0.732

3.429

The R380 gearbox was used from 1994 to 2006 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.

Strength and suffix information courtesy of  Ashcroft Transmissions:  The R 380 was introduced in 1994 with the suffix J which was a significant improvement on the LT 77 it supercedes, differences included a steel oil pump (as opposed to the LT 77 fibre one), an additional 2 support bearings were used on the layshaft and the mainshaft, wider gears, bigger diameter syncro rings, syncromesh on reverse and a longer mainshaft spline.  This suffix J did unfortunately have a couple of design flaws which gave the R 380 some bad press, they were prone to the mainshaft shearing across the oil feed holes, the layshaft also sheared at a stress concentration behind the sandwich plate causing loss of 5th and reverse also early ones still suffered from mainshaft wear until the cross drilled transfer case gears became fitted as standard on the suffix G transfer cases.  In 1999 the suffix K was used very briefly for a few months then came the suffix L that is used currently. The J and L are very different, 2 of the bearings were substantially uprated and pinion and layshaft teeth were widened again, this results in a much stronger unit.

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

 

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

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.