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

Driving the car

We will start by looking at gear selection and driving techniques. There are six selector positions as on the Borg Warner transmission: Park, Reverse, Neutral, Drive, Second and First. Incidentally in Park a mechanical parking pawl is engaged so it must only be used when the car is stationary.
Drive is used for normal driving, giving automatic upshifts and downshifts. A kickdown facility is provided for additional acceleration.
With the selector in '2', gearchanging is restricted to first and second gears only. It will change up and down normally between '1' and '2' but will not go into top.
Whenever '2' is selected from 'D' the transmission will change down immediately. So this must not be done at high road speeds or the engine will overrev.
In '1', the transmission will remain in first gear and provide engine braking. But like '2' it will engage at any road speed.

Selector Rod

Now let us see how the selector is adjusted. First position the gear lever in 'N'.
Then disconnect the selector rod at the transmission. The selector lever must now be placed in the 'N' position. Do this by turning the lever fully anti-clockwise, then turn it clockwise by two detents.
Next adjust the length of the selector rod until it aligns with the hole in the selector lever. Then reconnect the rod and tighten the adjuster lock nuts. The adjustment is now complete.

Inhibitor Switch/Reverse Light Switch

Next the combined inhibitor switch and reverse light switch adjustment, this can be done while the selector rod is still disconnected. Start by loosening the selector lever securing nut and the adjuster plate nut (arrowed).
Now position the selector lever in 'N' as you did before. Mark the lever to identify its position and remove it.
Next turn the switch until you hear a click, the marks on the switch body and hub should now line up.
Before you replace the selector lever and tighten up, check that the engine will only start in 'N' and 'P', and that the reverse lights work in 'R' only. If the engine will not start in Park, turn the switch clockwise by 1.5mm (0.060 in.) and recheck.

Fluid Level Check

Next the fluid level check. It must be at normal operating temperature, which is reached after 10- 13 miles driving (15-20 km).
Park the car on level ground and apply the handbrake and foot brake. With the engine idling, move the selector lever through the complete range of quadrant positions three times, leaving it in Park.
With the engine still idling, remove the dipstick. Make sure you use a lint free cloth to wipe it before replacing.
The fluid level must be between the minimum and maximum marks on the dipstick. If it is low, top up with Dextron 2D specification fluid.
Fluid changes must be made every 2 years or 24,000 miles (40,000 km) which ever comes first. There is no drain plug so you have to take off the sump. With the sump off, you can change the pick-up filter, which must be done at the same time as the fluid change.

Brake Band Adjustment

You also have access to the brake band adjustment, which is checked at the same service interval. Do it like this. First take off the brake band servo cover.
Next slacken the adjusting bolt locknut, and tighten the bolt to a torque of 4.5 Nm. (40 lbf. ins.)
Then undo the bolt five complete turns and hold the piston sleeve to tighten the lock nut. Renew the gasket and replace the cover.

Stall Test

Next the torque converter and stall testing.
The torque converter is of conventional design, and is made up of three components; an impeller (on the left) bolted to the crankshaft, a turbine (on the right) driving the transmission, and a stator (in the centre) to give torque multiplication. It is a sealed unit which cannot be dismantled.
Now the stall test: first make sure the fluid is at normal operating temperature and at the correct level. Then connect the tachometer function of 18G 677ZC to the coil negative terminal and earth. Chock the road wheels and apply the hand and foot brakes.
With the engine idling, select 'D' and depress the accelerator fully to the kickdown position for not more than 10 seconds.
Make a note of the highest engine speed obtained; on this Rover 2600 it should be 2300 rpm 100. The figure is different for other models. Repeat the test in '1' and in 'R'.
A very low stall test reading would confirm a road test finding of poor pulling power and indicate a slipping stator. But be careful in your diagnosis, a smaller drop off in power is likely to be as a result of poor engine tune. A high stall test figure would indicate gearbox slip.
A seized stator would show up on road test with overheating and poor top speed.

GM 180 Automatic part two
GM 180 Automatic part three



© rwp june 2003