Rover's Vikingship Overhaul of the Rover SD1
GM 180 Automatic
part two
Rover's Vikingship


This part of site is an attempt to organize and add to the web resources for the Rover SD1 to form a cohesive and easily usable guide for those of us without easy access to expert repair and/or advice. It is not offered in any way as a definitive source and we take no responsibility for any errors that may exist.

Gear Train Dismantling

In this part we will dismantle the gear train and examine the power flow through it. First remove the torque converter housing and the fluid pump as an assembly. Do this by unscrewing the outer ring of bolts.
Then remove the pump from the housing by unscrewing the inner ring of bolts.
At the front of the gear train you will notice a special thrust washer. It controls the gear train endfloat which is adjusted during the rebuild.
You can now remove the 2nd and 3rd gear clutches as an assembly. The clutch plates you see arrowed are the reverse clutch; they are splined cm to the 2nd gear clutch hub and the steel discs into the transmission casing.
Then take out the reverse clutch pressure plate.

You will need special tool No. 18G 1417 to remove the one-way clutch from the third gear clutch. The one-way clutch is held in by an internal circlip which has to be compressed using these six spring clips. With the clips correctly located, an outward pull on the sun gear will move the circlip clear of its groove.
Then remove the clips to allow the one-way clutch assembly to be pulled clear of the housing.
To dismantle the clutch piston use special tool No. 18G 1415 to compress the release spring. With the springs compressed you can remove the circlip and dismantle the assembly.
This special tool No. 18G 1016 with adaptor 18G 1016-2 is used in a similar way to compress the reverse and second clutch springs.

Turning to the rear of the box, remove the rear extension housing and the speedometer drive gear.
Then remove this circlip which will allow you to slide off the governor hub.
Now pull the planet carrier and output shaft clear and remove the brake band and rear sun gear. That completes the dismantling of the gear train components.


Rebuilding is reasonably straightforward but there are some important points to note. First make sure that all the components are clean, then examine them for signs of scoring or wear. This includes seals, thrust washers, thrust bearings, clutch plates etc.
Lubricate all the gears and clutch plates with Dextron fluid before installation, and you may find it useful to locate thrust washers and bearings in position with petroleum jelly.
To rebuild second and third clutch assemblies you will need the same special tools that were used for dismantling. Use them to compress the clutch springs so that you can fit the retaining circlip.
To fit the clutch discs, start with the cushion ring, then fit a plain steel disc followed by a clutch lining disc. Continue fitting alternate discs, the last to be fitted is a plain steel disc.
Before fitting the one-way clutch into the third gear clutch, check its operation like this. Hold the assembly and check that the sun gear will turn freely in an anticlockwise direction. As soon as you try to turn it clockwise it should lock.
Continue rebuilding the gear train in the reverse sequence to dismantling.

After fitting the second and third gear clutch assembly and the reverse clutch discs, you must now check the gear train end-float. It is adjusted by this selective thrust washer we mentioned earlier.
First support the gearbox case in a vertical position, allowing the gear train to drop. Then locate this special tool 18G 1419 across the front flange. Select a washer to fill the gap between the tool and the second clutch thrust face.
Next assemble the oil pump to the converter housing, leaving the bolts slack.
Use a pair of dummy studs to align the gasket, and then refit the housing to the gearbox. Before you finally tighten all the bolts, use this special tool 18G 1420 to position the pump gears.

GM 180 Automatic part one
GM 180 Automatic part three