DIY timing belt replacement
Land Rover 200TDi (11L)
These are few photos that I've made during the replacement of timing belt on my 1992 D90. The vehicle has 240000 km on the clock, was recently purchased for €4800 and I've decided to change the belt as a precaution since no records of previous maintenance exists. The whole job was done on parking lot in front of apartment block where I live and took two weekends (with some additional tasks like painting of some chasis parts, radiator and intercooler cleaning, steering box inspection...)
decided to remove the radiator. All hoses have to be removed anyway and
radiator and intercooler needed cleaning. So for the sake of some extra
working space and front access I have removed the radiator. Oil inlet
and outlet unions proved difficult to remove so I left the oil hoses
attached to radiator and unscrewed the unions on oil filter adapter on
engine block. I don't have the special bent spanner needed to remove the
fan from water pump so I had to remove radiator before removing the fan
cowl (shroud). This can be done if fan belt if removed to push cowl as
far back as possible and then remove radiator. This will take extra pair
of hands and some fiddling and "manouvering" to get it out
pass that large fan cowl. This will result in some coolant and oil
leaking out. Once the radiator is out, it can be easily disassembled
and cleaned. Watch for corrosion of bottom framing member.
Later, it proved that is much easier to refit radiator in parts, first the frame without top framing member, than radiator, then intercooler, then top framing member. It may have been easier to remove radiator that way in the first place.
Before commencing any works on the vehicle remove the cables from battery terminals. This is a safety must. Also bear in mind that if engine is being cranked with electrical starter with timing belt removed, the pistons may hit the valves and cause $eriou$ damage.
radiator and cowl out of the way, there's a lot of space to access the
timing belt casing cover and water pump.
used clean rags to cover all air ducts left open by removal of hoses and
air filter. Original hose clips can be used to hold the rags. This was
done since it was clear from the start that this repair may drag on for
days. And it did.
It was not necessary to remove thermostat top housing but I did this to test it. I've placed thermostat in saucepan, filled it with water, heated on the stove while holding the thermometer. It opened at 85°C and closed shortly after I turned off the gas. I guess it works fine.
the water pump can be removed. Some bolts can be akward to access.
The large stud bolt unscrewed from the engine block together with it's
nut. Later, this stud bolt was screwed back to engine block before pump
refitting. This was necessary to ensure that it's short thread is fully
engaged in thread in engine block. There is some strange corrosion on
the rotor pointing to long period of storage while pump was partially
filled with coolant. The corrosion was porous and easy to remove.
Water pump and timing belt cover are fitted with lots of bolts of same diameter but in variety of lengths. Note the position of each and every bolt and save yourself from jigsaw puzzle during refitting or even thread damage if a slightly shorter bolt is used. Also do not mix up those bolts with similar ones from crankshaft pulley.
|Before that large tubular hex key (held by my dad) came to use, the pulley had to be removed from harmonic balancer. 10 mm tubular hex key had to be used since the four bolts holding it are deep and close to inner side of pulley ring. The pulley came off easily without the need for puller, but this may not always be the case.|
the stone age engineering and practical recycling came into act. Lacking
the proper special tools we jammed the round pipe under chasis so it
held the 30 mm tubular hex key. The crankshaft was turned clockwise
(normal right hand thread but the crankshaft was being turned while bolt
stood still) by means of 1.5 meter long tube to break the thread locking
compound and huge tightening torque specified for that bolt (330 Nm!).
With the bolt removed, the harmonic balancer can be easily removed. Now
all the bolts holding the front plate can be unscrewed and the plate
removed. The gasket will probably be ruined as it will stick to both
. . . .
Later, the same "equipment", positioned in opposite way, was used to refit the bolt. Several drops of Loctite 243 were placed cca 1.5 cm before the thread inner end in the threaded hole in crankshaft and then the bolt was retighten by applying "guessed" 35 kg of force on 1 m of leverage. A 330+ Nm torque wrench was out of the budget.
sprocket is camshaft sprocket, the left sprocket is on fuel pump shaft,
bottom right is crankshaft and bottom middle is tensioner pulley.
The belt was found to be in fair condition but who's to tell how much it's going to last. Besides the belt I've also had a new tensioner pulley so I have decided to change it as well. Before removing the belt, set the engine in 1st cylinder top dead center (TDC) with injection pump and camshaft sprocket in timing position. When woodruff key on crankshaft is on top (aligned with the arrow on casing), and the dot on camshaft sprocket is aligned with it's arrow, you will be able to block the fuel pump shaft by inserting the smooth end of 9.5 mm drill bit into the U notch on fuel pump sprocket retaining plate. On this picture the crankshaft is in TDC (woodruff key on top, facing arrow) but engine needs exactly one full turn so the timing marks on both large sprockets face their arrows, because they make one full turn for each two crankshaft revolutions.
the three bolts holding the fuel pump sprocket can be loosened to allow for independent timing of
engine and pump. I removed the sprocket for easier cleaning. The drill
bit remained holding the pump shaft blocked.
Black stuff on belt casing interior was mostly dry rubber deposits, there were no evident oil leaks so oil seals are still in good condition.
4 mm allen key proved to be a handy tool for cleaning rubber deposits on sprockets. Wrapped in piece of cloth it fitted perfectly between teeth.
|When engine is in TDC, a timing notch on engine flywheel is visible through the hole at the bottom of clutch housing (bell). There is a special tool available (LRT-12-045) to lock engine in TDC, but I used an improvised tool made of wading plug (ERC7295) and M6 bolt. Wading plug was precisely drilled through center and tapped M6 by a machine shop. Instead of chamfering the top like I did, you can do a better job if you reduce the bolt diameter to 5 mm on it's top to fit into the notch.|
|First the wading plug is fitted and then the bolt is screwed in into the flywheel notch.|
fuel pump blocked with 9.5 mm drill bit, engine blocked in TDC and dot
on camshaft sprocket facing arrow, a new belt and tensioner pulley were
fitted. The important thing is to leave 3 bolts on fuel pump sprocket
plate loose until the belt is tensioned. The pump sprocket must adjust
itself to the belt. Make sure that those bolts have enough freeplay in
their slots, in both ways.
There is a square hole on tensioner pulley support plate for 1/2" square drive torque wrench. Haynes manual states that new belt must be tightened to 19 Nm and LR manual says 21.7 Nm. So let's make it 20 Nm. Since that torque must be continuously applied, a break type torque wrench can not be used.
|So how do you get continuous 20 Nm of torque? How about suspending 5.1 kg of various metal artifacts on a rope, giving you 5.1 x 9.81 = 50 N of force, feed that rope via low rolling resistance pulley (a.k.a old tensioner pulley) 90° to a 0.4 meter long lever giving you 50 x 0.4 = 20 Nm of torque. The torque wrench used here is used merely as a lever and was set to a larger value. After the tensioner bolt was tightened, the 3 bolts on fuel pump sprockets can be tightened, and the drill bit and flywheel locking bolt can be removed. Now it is necessary to manually crank the engine for at least two complete revolutions. I've used a harmonic balancer loosely placed on crankshaft and previously described lever to do that. The engine was turned back to TDC timing position, tensioner bolt was loosened and belt was tightened again to 20 Nm. After that cranked the engine for another turn and checked the fuel pump timing by inserting the drill bit through sprocket and checking if the engine is in TDC. It was off a bit. So I have loosend those 3 bolts on pump sprocket, set the engine precisely in TDC (flywheel notch centered with clutch housing hole) and retightened the bolts.|
|Now, it was all about refitting all the
parts back. I've took the opportunity of radiator being removed to paint
some rusty spots on chasis, also under the steering box that is one of
the places that never get to be properly cleaned of mud. The steering
box can be easily unbolted from chasis (and suspension parts below) and
simply moved aside without removing steering rod and steering column.
Before refitting, radiator and intercooler were cleaned, both inside and
outside and proved to be far more dirty than they appeared. Yuk.
After refitting everything (don't forget the battery terminals) and filling the cooling system with fresh antifreeze, it was time to start the engine. Being extra cautious, I've removed the + wire from fuel pump and just cranked the engine just to be sure that everything was right. After that, wire was refitted and I started the engine. It worked fine.