Driving - Service and Maintenance Instructions
SCHULER PRESSES LIMITED February 1981
High Street Vehicle no: 10.0163
Your vehicle has been fitted with the universally acclaimed Schuler FF transmission.
The benefits you can now expect from having chosen the best in four wheel drive are listed below.
We would like to wish you many miles of enjoyable motoring and assure you of our best attention at all times.
YOUR SCHULER TRANSMISSION OFFERS THE FOLLOWING BENEFITS:
Higher Overall Gearing: - Less noise, less wear, less fuel wastage.
Economy: - 5% better with automatic. 15% better with manual, due to reduced power losses in
transfer box, advantageous overall gearing and reduced weight.
Handling: - 37% front / 63% rear torque bias from special centre differential improves both
response and stability to give an unrivalled level of safety and control.
Traction: - Automatic limited slip centre differential prevents wheelspin with viscous action to
cushion shock loads and protect driveline from damage.
Reduced Noise: - Silent transmission and reduced engine revs drastically reduce interior noise
Backlash: - Special Morse-Chain drive system is free from snatch due to tolerance build up.
Braking: - Viscous centre differential prevents instability due to uneven wheel lock up. Optional
Anti Skid system gives freedom from control loss due to locked wheels. Optimum deceleration
is available and the driver is free to steer the vehicle to safety.
Reliability: - From the outset, Schuler FF transmissions were stressed for engines of considerably
more than 3.5 litres. Generous margins of safety are allied to the reliability reaped from our 4 year
development programme to give a product that will many years of superior and uniquely enjoyable
A 12 month unlimited mileage warranty is provided on all conversions.
Rare Schuler-Voith FF - Service and Maintenance Instructions
A. GENERAL HANDLING
It should be emphasised that the ultimate limitation of car control is the grip between the tyres
and the road surface.
The Ferguson system of All-Wheel-Control helps the driver to use the full potential grip to the
best advantage in all conditions, but it cannot increase it; therefore, the car should always be
driven with due regard to the prevailing conditions.
An FF vehicle handles in the normal manner, but with a greatly increased margin of safety
when accelerating, braking, or cornering. The best characteristics of front and rear wheel drive
On vehicles fitted with anti-skid brakes the driver will feel a kick back through the brake pedal
when the anti-skid system comes into operation. This is normal and is a warning that you could
be driving too fast for the road surface conditions and your speed should be adjusted
It must be stressed that the ultimate limitation on braking is the grip between the tyres and the
road. Therefore great care should be taken on very slippery surfaces. The anti-skid system will
enable the available grip to be used fully. But it cannot be expected to compensate for errors
of judgement on the part of the driver.
Schuler FF advert - Automatic - Ferguson Formula - Anti-lock braking
SELECTOR OPERATIONS - 3 SPEED AUTOMATIC
NORMAL SPORTS (SPECIAL ORDER ONLY)
Fig 1 (See text) The famous Schuler converted 'Automatic FF' - badge on many RRCs
GEARCHANGE LAYOUT - 5 SPEED MANUAL
The more rare manual 5 speed JRT Schuler FF conversion
GENERAL - The automatic gearbox has been specially developed to give the best in smooth
and effortless driving.
Special attention to shift points gives an impressive blend of performance with economy.
fatigue due to stress is significantly reduced.
SELECTOR OPERATION - The centrally positioned selector lever allows free movement
through those positions marked on Fig. 1 with arrows. All other movements require the button
on the side of the T-bar selector to be depressed. Once the buttons is depressed, it is possible
to engage any gear. It should not be depressed when the lever is being pushed forward and
the car is in motion as this could involve the accidental selection of Reverse or Park.
P The engine will only start with the lever in P or N.
This is for reasons of safety. In the P position the gearbox output shaft is locked to provide
a back-up parking brake. It is not recommended that it be used for securing the vehicle on
slopes as it may prove difficult to disengage due to loadings on the locking mechanism.
On no account should P be selected with the vehicle in motion as transmission damage
will result. Converted Range Rover by Wood & Pickett with Schuler FF automatic
R Reverse. Never engage this position when the vehicle is moving forwards.
N Neutral. The engine may be started in this position.
D Drive. To be used for all normal driving conditions.
All three gears are used in sequence and the best gear for prevailing conditions is
automatically selected. At town speeds a part throttle downshift operates under load
to prevent the engine labouring in a high gear. Beyond the normal full throttle position,
heavier pressure activates the kickdown facility causing the transmission to downshift
into the most suitable gear for maximum performance when overtaking. In this position the
engines full rev range will be used.
At town speeds, full throttle will engage 2nd gear for brisk acceleration while kickdown
pressure will engage 1st for really rapid overtaking. Those used to other less responsive
transmissions may be surprised by this eagerness of response and learn to adjust their
throttle usage accordingly.
2 Manual Second. In this position the normal upward shift into 3rd does not occur. It can be
used for extra engine braking (taking care not to overspeed the engine) or to prevent
overfrequent automatic shifting where the driver is transferring repeatedly from power to
No performance improvement is gained by delaying the 2-3 upshift manually. In this position
1st gear is used as normal where appropriate.
1 Manual First. Engages 1st gear to provide increased power at low speeds and extra engine One of the 25 Schuler converted 'Super Ranger' approved by LR
braking. An inhibitor prevents engagement until road speed is reduced to safe levels but
the speed inhibitor can be overridden to engage 1st at speed by briefly pushing the
accelerator pedal to its kickdown position then releasing.
It should be stressed that this must only be used in a dire emergency (total brake failure at
below 50 m.p.h. for example) as it will cause severe stress and possible damage to the
gearbox and driveline.
NOTE The above general comments also apply in low range although speeds in the gears are
severely limited and shifts will be firmer. Delicate use of the accelerator is recommended.
Manual selection for engine braking off road should be made well in advance of requirements.
For low range instructions see below.
DRIVING THE 5-SPEED FF RANGE ROVER
GENERAL - The five speed Range Rover offers all the advantages of vehicle control of the Typical Range Rover from Wood & Pickett with Schuler FF transmission.
normal manual control with the addition of a slick, sporting gearchange and a high fifth gear for Most probably between 1-2000 Schuler transmisions were installed in RR
cruising. It should be noted that new maximum speeds in the intermediate gears apply, these
1st 31 m.p.h.
2nd 50 m.p.h.
3rd 75 m.p.h.
4th 104 m.p.h.
GEARCHANGE LAYOUT - See Fig. 2
To assist gear-changing there is a spring bias into the 3rd/4th plane. To engage reverse slap
lever sharply across to the left and then forwards.
HIGH-LOW RANGE SELECTION - IMPORTANT
To change from high to low, or low to high:
1 Stop vehicle.
2 Apply handbrake.
3 a) Automatic - select P on auto selector.
b) Manual - select neutral on main gearlever.
Jensen FF and other carmakers used a similiar, but slightly different
4 Move transfer gear lever smartly and firmly to desired range. If a delay is made in neutral Ferguson Formula system produced of GKN - in Range Rover the
the shift may not be accomplished. In this case the engine must be switched off before Schuler Presses Ferguson Formula transmission was produced of
attempting to complete the shift. Schuler-Voith.
Low range would normally only be required in severe 'off-road' conditions, i.e. deep mud
or sand or very steep hills. Low/low should always be used when descending off-road
steep hills. When in doubt use low range off-road.
A - Automatic
B - 5-Speed JRT Manual (Jaguar Rover Triumph)
1 A WEEKLY
Check automatic transmission fluid level. The dipstick/filler tube is located at the rear
of the engine compartment close to the bulkhead on the vehicles right hand side. The
oil level should be up to the high mark on the dipstick with the engine idling and the
gear selector in neutral.
Topping-up requires Mopar, Dexron, Dexron II or equivalent.
Any persistent loss of fluid must be investigated.
2 A/B AFTER FIRST 500 MILES
Check transfer gearbox oil level. The combined filler/ level plug and also the drain plug
are situated in the rear-facing wall of the main casing and both should be carefully
cleaned before refitting.
Filling must be carried out slowly to achieve the correct level. Automatic transmission
fluid must be used. (If ATF is not available, any S.A.E. 10 engine oil may be used in an
emergency, but the unit should be drained and refilled with the correct oil at the earliest
3. EVERY 6,000 MILES
a) A Check automatic gearbox fluid level as in point 1 above.
b) B Check 5-speed gearbox fluid level. The oil level should be up to the bottom of the filler
Topping up fluid should be as per Jaguar/Rover/Triumph recommendations for this unit.
c) A/B Check transfer gearbox fluid level as in paragraph 2 above.
Not only should a lack of fluid be investigated but also an excess of fluid which may
indicate an internal fluid migration which requires rectification.
d) A/B Check centre diff operation. Apply handbrake and leave gear lever in neutral. Chock
the wheel diagonally opposite to that being jacked up. Jack one front wheel clear of Schuler-Voith Ferguson Fomula transfer case - clearly seen badge
the ground. If this wheel is stiff to turn the viscous coupling unit is functioning correctly.
If the wheel will not rotate either the front axle or the 4 wheel drive unit is at fault. If
the wheel rotates freely the viscous coupling unit is at fault.
If the wheel turns freely, and the front drive-line is all intact, it means that the V.C.
unit is not functioning correctly, in this case contact Schuler Presses Limited.
e) A Check automatic gearbox shift performance. Test shift speeds against those shown
The transfer box sprocket ratio is shown next to the serial number on the rearward
face of the transfer gearbox.
If the gearbox shift points are not as shown below follow the rectification
Cable adjustment can be carried out (after removing the engine air filter) using
the threaded portion of the outer cable. To raise line pressures and shift speeds,
tighten cable. A slack cable will cause clutch and band slip giving premature failure
of the unit.
If the kickdown cable fails the vehicle must not be driven.
f) A/B The whole transmission should be visually examined for oil leaks. Advice for
rectification can be obtained from Schuler Presses Limited.
No attempt to carry out warranty work should be made without prior authorisation
from Schuler Presses Limited.
Larger picture of the number #488 Schuler FF transmission
PARAMETERS FOR ADJUSTMENT OF THROTTLE VALVE CABLE ON A727 / RANGE ROVER
1. With the accelerator in the kickdown position and the transmission selector lever in 'D',
full throttle downshifts should be available up to speeds shown below.
Change of gear Sprocket ratio
1.16:1 1.08:1 1:1
3 - 2 56-66 mph 60-71 mph 65-77 mph
(90-106 kmh) (96-114 kmh) (104-123 kmh)
2 - 1 24-29 mph 26-32 mph 28-34 mph
(38-46 kmh) (42-51 kmh) (45-54 kmh)
Adjust throttle valve cable to minimum tension at which these downshifts are obtained
and then tighten 1 turn.
2. Allow car to gather speed downhill with throttle closed and transmission selector lever
in 'D'. Upshifts should occur at speeds shown below.
Change of gear . Sprocket ratio
1.16:1 1.08:1 1:1
1 - 2 8-13 mph 9-14 mph 10-15 mph
(13-21 kmh) (14-22 kmh) (16-24 kmh)
2 - 3 12-17 mph 13-18 mph 14-20 mph
(19-27 kmh) (21-29 kmh) (22-32 kmh)
Part throttle shifts should be comparable in terms of smoothness with conventional
If the vehicle does not pass the above test, check:
a) That basic engine tune is satisfactory. Inside view of the transfer case - visible with the morse-chain drive
b) Carburettor butterflies are fully open at kickdown position.
d) Throttle valve return spring is fitted and functioning correctly.
e) Transmission oil level is correct.
On completion of road test the adjustment of the gear selector must be rechecked. If
it does not correspond in every position exactly with the detents on the automatic box
early transmission failure will result.
1. Engine Failure
In an emergency a car equipped with automatic transmission may be towed safely
with the high/low selector lever in neutral and the automatic selector in 'P' without the
need to disconnect the front or rear propshaft.
Similarly manual gearbox cars may be towed with the high/low selector lever in
neutral and the main manual gearbox in 4th gear.
2. Front Axle Failure
Tow with rear propeller shaft removed and front end pick-up.
The viscous lamels shown in this demonstration cut-out 37/63-ratio
3. Rear Axle Failure
Tow with front propeller shaft removed and rear end pick-up.
4. Failure of Transmission or 4-W-D Unit, or doors locked and transmission in gear
Tow with either:-
a) Rear propeller shaft removed and front end pick-up
b) Front propeller shaft removed and rear end pick-up,
c) Both propeller shafts removed with/without pick-up.
5. Roller Rig Operation
Due to the integral limited-slip centre differential a special purpose 4 wheel drive
roller rig must be used.
TNS/LAW The Schuler-Voith FF seen from the upper side with hand-brake drum