gearbox info.

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ormus

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found this on tinternet.
may be useful to newbies. useful t oldies too i suppose.
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Land Rover Gearboxes Land Rover gearboxes.

In the beginning when Rover needed a stronger gearbox for the new Range Rover and the 101 V8s they developed the LT95. During this time Rover was part of British Leyland so the LT stands for Leyland Transmission. "95" stands for the distance between the main and lay shafts in mm.

The LT 95 was a robust four speed gearbox with the transfer case built into the same enclosure (but they have different fluid reservoirs). One of the nice things about the LT95 was that there were a number of transfer case ratios available and you did not need to pull the box to change them. The bad thing is that it is a four speed gearbox and Rover decided that they needed a fifth gear for highway driving. The gearbox was used on Range Rover through 1983, all 109 Stage 1 V8, all 101 and on 1983 and 1984 V8 Nineties and One Tens.



1984.
Models Rover abandoned the LT95 four speed gearbox and went to five speed gearboxes, the LT77 and the LT85. The LT77 is the lighter duty of the pair. The LT85 was used on the V8 versions of the Ninety and One Ten. Since the LT77 is a 2WD passenger car gearbox, Rover added the LT230 transfer case for full time 4WD. (LT230? Yes, 230 mm parallel spacing between input and output shafts!)



1984 through 1990.
When Rover (still part of British Leyland) decided to go to a five speed gearbox they picked the existing LT77 for use in certain vehicles. The LT77 is an updated version of an old Jaguar gearbox that found its way into current model British cars manufactured by British Leyland. Yes the distance between the main and lay shafts is 77 mm. There were two version of this gearbox. The earlier version is known as the short stick version. The later version, introduced around 1988 is known as the long stick version.

The Range Rover received the LT77 in 1984 because it was less expensive than the new LT85 and considered strong enough for the 3.5L V8 to use as a street cruising gearbox. The four cylinder Ninety and One Ten also received the LT77.


When the Discovery was introduced it got the LT77 as well.



1984 through 1991: The LT85 (85 mm shaft spacing) was used in all V8 110 and 90 Land Rovers. The LT85 was originally designed under contract by Land Rover for Santana in Spain and was considered to be a strong working gearbox. Rover purchased LT85 gearboxes directly from Santana. It is also known as the Spanish Box. This gearbox was used as originally designed until 1988. A cost reduced, lighter weight, divided case version of the LT85 was introduced in 1988 and used through 1991. The main short coming of the divided case version was its main and lay shaft bearings. The loading on the bearings in 5th gear caused frequent gearbox failure when cruising for long periods of time under high throttle. There was also a bearing quality problem at one stage of manufacture and the gearbox was sensitive to the type of oil used.

1991.
The relationship between Rover and Santana ended and the LT85 was no longer available to Rover. They needed to find a quick short term solution while they developed a new stronger gearbox.



1991 through 1993.
The LT77S was introduced to the Defender V8 line and all models using the Tdi engine as an interim replacement for the no longer available LT85. The LT77S was a strengthened version of the LT77. The 'S' on the LT77S stands for 'Synchromesh'...it was modified for a 'smoother gear change'. The bell housings and input shafts of the LT77S differ between the V8 and Tdi due to Tdi's more aft location.

1994 and newer.
The R380 box was introduced as brand new LR gearbox across the entire Land Rover and Range Rover product lines. The R380 is a radically reworked LT77 (The 1940's Jag gearbox remember) with improved main shaft bearing arrangements that provided an overall strengthening of the box. The R380 name stands for "Rated to 380 Nm input". But the R380 still has the LT77's 77 mm shaft spacing. Since Rover was no longer part of British Leyland the LT prefix was abandoned.

The V8 and Tdi R380 gearboxes have different bell housings and primary input shafts. They will interchange by swapping these parts.

The R380 quickly got a bad name from gear problems and accelerated main shaft spline wear where it mates with the LT230 transfer case.

The LT230 accelerated main shaft spline wear problem had been present on all previous LT230 equipped Land-Rovers, irrespective of the gearbox it was mated to. This design problem was kept low key until a lot of customers complained about R380 problems.

A number of different fixes, such as flingers and special transfer case input shafts have been added to try solve the LT230 problem.
 
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