MGB Engine Removal

Procedure

By Joseph Legan

Beginning Notes:

All work must be done by a minimum of 2 people for safety reasons.

There is one metric tool needed for one the following procedures.

There are no power tools needed for any of the following procedures.

Read ALL directions before any work is begun.

Adhere to all lab rules at all times.

Step 0 Questions and Torque Values

When in doubt, ask. There are no wrong questions so ask away. When working on the MGB or

any other vehicle use the assigned torque values. The torque values for this car can be found in

the resource area of the class website and in the various service manuals in the lab.

If there is no torques value listed then use the appropriate torque for the fastener size. A chart

of torque by fastener size can be found in the resources area of the class website.

Step 1 Disconnect battery

Battery is located under parcel tray cover immediately behind drivers seat on the passenger side. Battery terminals require a 10mm metric wrench to remove.

Step 2 Elevate Car on jack stands

Elevate as high as possible. The rear jack stand are to be placed on the rear axle itself as wide as possible without crushing and brake line. The front jack stands are to be placed on the unibody frame 6 to 8 inches in front of the cross member. Once the weight of the car is on the jack stands test the rigidity of the stand placement by shaking the car moderately. Adjust the position of the stands if any there is any doubt to the safety a worker underneath the car.

Step 3 Drain fluids

Drain engine oil, coolant, transmission lube and remove the oil filter. Drain coolant through petcock on radiator. Remove oil filter after the engine oil has been drained. Place all drained fluids into the correct waste fluid barrels in the lab and clean any funnels, catch pans and tools used before putting them away.

Step 4 Remove radiator and hoses

Pay attention to the orientation of the lower hose assembly, label wiring connections for the fan and the temp sensor on the radiator.

Picture of radiator, upper

radiator hose and

temperature switch for

cooling fan.

Picture shows the lower radiator hose assembly, the cooling fan and

the cooling fan wiring. The wiring needs to be disconnected prior to

radiator removal.

Step 5 Disconnect fuel lines

Disconnect from carbs and tuck away in the drivers side firewall area.

Picture shows the dual fuel

lines coming from the fuel

pressure regulator and the

crankcase ventilation line as

well.

Step 6 Remove carbs and intake manifold

Includes phenolic spacers, metal heat shield, linkages with springs, throttle cable and rubber fuel overflow drain hoses.

Picture shows the

dual 1.5” SU

carburetors, the

throttle cable

(blue cable

housing) and the

linkages.

Picture shows

the intake

manifold, metal

heat shield, and

the phenolic

spacers.

Step 7 Remove Alternator

Includes removing the alternator, the belt and belt tensioner bracket.

Picture shows the alternator, the belt, the cylinder head temp sensor, and

the main ground for the engine.

Picture shows the

wiring on the back

side of the alternator.

Be sure to take note

of the configurations

as the vehicle will not

operate correctly if

not wired in the

manner shown.

Picture shows the

alternator, belt and

the belt tensioning

bracket. The bracket

is the only fastener

that holds the belt

tension.

Step 8 Remove rear half of the exhaust system

The rear section of the exhaust consists of a bolt together flange in the front, a hanger before the axle and another hanger on the trailing edge of the muffler itself.

Front bolt together

flange. Use red high

temp RTV silicone

to form a gasket.

Middle hanger in

front of the axle.

Rear hanger on the muffler.

Step 9 Remove exhaust header

Remove the O2 sensors by unplugging them and twisting the wire as the sensor is rotated. Failure to do this will damage the wires rendering the sensors inoperative. Pull header up and out, NOT down through. Requires a rotation of the header to complete this.

Sensor 1

mounted in the

primary runner

for cylinder 1.

Sensor 2 mounted

in the primary

runner for

cylinder 4. The

center primary is

not used as it is

shared by

cylinders 2 and 3.

Step 10 Remove driveshaft

Pay attention to the hardware and the orientation of the hardware that is used as it HAS to be kept that way in order for the u-joints to have the full range of motion. Both ends of the driveshaft have bolt together flanges making installation and removal easy. Take note of the location of the grease fittings during removal. The u-joints should be greased upon driveshaft installation.

Step 11 Remove clutch slave cylinder

Unbolt slave cylinder from the transmission housing WITHOUT disconnecting the fluid line and tie it up out of the way.

Step 12 Disconnect wiring

Label each with respect. Cylinder head temperature is on the passenger side towards the front. Oil temperature in on the oil pan, best reached from the underside of the car. The distributor has two wires. Follow the black insulation coming from the backside of the distributor to locate the connectors. There is one main ground that is on an alternator mounting point. The starter has two wires connected to it. One is a larger battery power cable and the other is the signal wire coming from the starter switch.

Step 13 Disconnect oil lines and crankcase vent line

Pay special attention to the routing of the oil lines and the in-line filter. Includes oil pressure sensor line, and all oil cooler lines and the oil filter adaptor and also the crankcase vent line.

Picture shows the oil line system and the flow diagram.

The picture also shows the oil line that leads to the oil

pressure sensor.

Picture shows in detail the oil flow through the oil filter adaptor. The

line coming from the oil cooler feeds the oil filter and the Accusump

simultaneously.

Picture shows the oil path through the oil cooler lines.

Step 14 Remove shifter and surround

Careful with the small hardware, it’s easy to lose or drop them into the transmission.

Step 15 Connect engine hoist with leveler

Must install the legs into the hoist first. Must use the load leveler as it is needed to control the angle during engine removal. Bolt on using "L" brackets at the locations pictured. Load leveler requires 1-1/8" socket to adjust.

Engine hoist will require 2

people minimum to assemble.

Retaining bolts on the legs

require a ¾” wrench or socket.

Load leveler used to control the

angle of the engine transmission

assembly during installation and

removal.

The front passenger

side pickup point for

the engine hoist.

Once the alternator is

removed the

indicated through

hole on the water

pump serves as a

pickup point. Removal

of the cylinder head

temperature probe

may be necessary.

The drivers side rear

most exhaust header

bolt works as the

second pickup point

for the engine hoist.

Step 16 Take up chain slack with engine hoist.

Just take the load off the motor and transmission mounts.

Step 17 Remove transmission mount from cross

member

See picture. Remove the hardware from the transmission mount that goes into the transmission housing then remove the cross member from the car. Cross member hardware used goes through the floorboard and into the passenger cabin. Takes two people to remove correctly.

The fasteners indicated attach the

transmission mount to the transmission

housing and must be removed first.

Picture shows the cross member and the long

hardware that goes up into the passenger cabin. This

hardware is why the cross member requires 2 people

to remove properly.

Step 18 Remove the front engine mounts, both sides.

See picture. The hoist may have to be raised or lowered to decrease the resistive force upon the indicated hardware. Do NOT try to separate the motor mount rubber pad from the engine until after the engine is out of the car.

The drivers side motor

mount is pictured here.

Only remove the

indicated hardware from

both of the motor

mounts. Do NOT try to

separate the rubber pad

from the engine until the

engine is out of the car.

The passenger side motor mount is

pictured here. Only remove the

indicated hardware from both of

the motor mounts. Do NOT try to

separate the rubber pad from the

engine until the engine is out of the

car.

Step 19 Remove engine and transmission as a single

unit

Slowly raise the unit and tilt with leveler as needed along with pulling forward to safely remove the unit from the car. The best technique found is a set of alternating steps repeated until the engine and transmission is removed.

Raise the unit as high as possible without the unit contacting the car

Pull the unit as far forward as possible without the unit contacting the car

Change the angle to allow another raise or forward pull to be possible

Repeat these steps until the unit is removed from the car