Copyright 2020 SMC-Auto
My gearbox rattles on idle, in neutral, with the clutch up
This is very common on Diesel engined vehicles. The clutch friction plate has a ring of springs, which are there to soften the knock of the diesel engine to stop it being transmitted to the driveline. Often especially with a new clutch these springs are quite tight and a lot of the engine knock goes through to the gearbox and makes the gears "chatter" together when the box is in neutral and the clutch up, it goes when the clutch is depressed. This can sound quite bad and does vary from car to car but is not detrimental to the life of the gearbox and we view it as an undesirable characteristic of the LT 77 and R 380 as opposed to a fault with either the gearbox or the clutch.
My TD5 gearbox rattles on idle in neutral with the clutch up
Usually on the TD5 this is due to a worn duel mass flywheel or if you have changed to a single mass flywheel type these can make the gearbox rattle very badly.
The R380 gearbox in my 300 tdi Defender / Discovery has recently started 'blocking' when I shift from 5th to 4th, to get 4th gear I have to nudge 3rd then it will drop into 4th no problem. Why?
A common fault on the early R380 gearboxes was the 4th gear baulk ring. The slot locating the synchro slipper wears and allows the baulk ring to rotate too far. This blocks the synchro assembly. It will be necessary to rebuild the gearbox, and replacing the baulk ring with a later type will eliminate this fault.
The R380 gearbox in my 300 tdi Defender / Discovery has recently started 'blocking' when I shift from 5th to 4th, to get 4th gear I have to move the stick to the left until it clicks then I can get 4th. Why?
There is an 'inhibit' latch in the shifter mechanism that stops you selecting reverse when you come out of 5th, this is the click. The latch should click and allow you to get 4th when you come over to the 3/4 gate but if its not clicking on its own you may have to adjust the 3/4 bias position slightly to the left until it does.
I have a Tdi 90 and it "clunks" when I take up drive. Why?
The most common cause is worn mainshaft spline but other things to check the A frame ball joint and the halfshaft drive flanges, especially if you have a 300 tdi Defender. To check mainshaft spline wear remove the PTO cover and with the main box in first gear rock the car backwards and forwards whilst looking into the end of the input gear. If the spline is worn you will see movement of the shaft in relation to the gear. Replace the gearbox and transfer box input gear (use a cross drilled gear to prevent recurrence of the problem).
I have a 300tdi/TD5 Disco /Defender with a 5 speed manual (R380) gearbox and have lost fifth and reverse gears. Why?
The layshaft extension has sheared off effectively disconnecting these two gears. You require a rebuilt or new gearbox.
I have a 300tdi/TD5 Disco /Defender with a 5 speed manual (R380) gearbox and have lost reverse gear. Why?
The reverse gear is made in 2 parts and laser welded together, the weld can fail which means you can select reverse but have no drive.
I have just fitted a R 380 and I can't get 2nd, 4th or Reverse. Why?
Some people put sealant on the front face of the gearbox before they fit the bellhousing, this sealant can cause a core plug on this front face to 'hydraulic' inwards which then stops the selector rail moving fully forward to select these gears. There is no need to put any sealant on this face.
After a long run in my Discovery, when the gearbox gets hot, the gear lever becomes stiff when moving from side to side. Why?
The nylon cage at the end of the selector rail can swell when hot, and cause friction. To rectify this, the parts needs replacing.
I have a short stick Disco R 380 which I would like to convert to a long stick to fit a Defender, how do I do this ?
There are 2 ways to do this:-
1) strip the gearbox and fit the Defender selector rail (FTC4588) and the Defender yolk (FTC5120) with grub screw FTC4536. Once these parts are fitted you can fit the R380 defender top housing and linkages or you can also fit the Defender LT77 top housing but you will have to remove the 'T' piece under the housing which is held in place with 2 M6 screws.
2) rather than strip the gearbox we make an adapter piece that you can fit to the end of the existing selector rail then fit the Defender yolk to this part then fit the Defender top housing.