There is considerable confusion regarding the problems with 300 tdi timing belts. Martin Holder explains the situation.
Owners of Discovery, Defenders and Range Rovers are expressing great concern about the lack of Information from Land Rover regarding the premature wear of timing belts and consequent risk of failure. It is caused by misalignment of the belt and pulleys and affects a large numer of 300 tdi engines. Failure of the belt probably results in damage to the engine. Land Rover has identified the engines at risk, and it was believed that rectification they were being fitted as a matter of routine to affected engines during routine service visits to official dealers.
(This is absolutely WRONG. I found countless vehicles not retrofitted and even dealers who didn't know or care about the problem- the webmaster)
However, correspondence from LRO readers makes it obvious that this has not been happening universally, even with vehicles in warranty.
There have even been reports of unresolved disagreement concerning Land Rover liability where engines have been damaged following belt failure.
Yet as far back as March 25, 1998 Land Rover Issued Technical bulletin No 0008, headed: Timing belt failure - misalignment. This bulletin is supplementary to Service Action Bulletin A/D482 and should be used for first time failures which are outside the parameters of the Service Action. We don't have details of the Service Action Bulletin referred to, but it is believed this contained advice relating to the inspection and replacement of original timing belt parts to overcome the problem.
The Bulletin we have obtained provides infomation for workshops dealing with failed engines.
The Bulletin states clearly that normal warranty policy and producers apply, suggesting that if a vehicle with a failed engine is out of warranty conditions have not been met, the work cannot be carried out under warranty terms.
The technical bulletin contains useful information for anyone wishing to rectify engine damage themselves, perhaps where Land Rover has refused a warranty claim.
It states: Inspect fully for broken rocker arms and bent pushords. Should a rocker arm be broken the cylinder head must be removed and all valves inspected to ensure they are not damaged (tightness in a valve guide would signify a bent valve). If a cylinder head is removed, on completion of repair refer to Bulletin 10/2/94 for coolant refill procedure. (This implies special care is needing when refilling).
Before fitting the new idler pulley stud to either the new front cover, or the original cover where this retained, ensure that the stud hole is in the front cover has 2mm x 45 deg chamter. If no chamter is evident, produce it with a countersink tool.
When fitting the new idler pulley, do not refit the original spacer washer, it`s not required and must be discared.
When fitting the new tensioner, do not attempt to re-use the original slotted washer and flange bolt. These must be discarded as the slotted washer is incorporated into the hearing and the flange bolt is replaced by the new cap head bolt.
The new crankshaft gear has a flange added to each side. Before fitting, ensure they have not suffered handling damage.
The timing belt tension has changed from that published in the workshop Manual. The new Method is as follows (it is essential that the producer is adhared to precisily).
a) Ensure that the timing marks are aligned and appopriate timing pins are
used as described in the Workshop Manual.
b) Fit idler pulley and tensioner assembly and lighten the idler securing not to 45 Nm.
c) Loosen injection pump pulley fixings.
d) Locate timing belt onto pulleys.
e) Lightly tighten the tensioner locking screw then back off one full tum. Ensure tensioner is free to move.
f) Using a dial-type torque meter with a maximum length of 250 mm apply a torque of 11 Nm with the torque meter positioned vertically as shown. g)Tighten tensioner lock bolt to 45 Nm.
h) Tighten the injection pump pulley fixings to 25 Nm.
i) Remove timing pins. It is no longer a requirement to rotate the engine and repeat the tensioning procedure.
j) On later vehicles, fit a new crankshaft front seal to the front cover plate (see information regarding engine numbers) read cover plate and remaing covers and ancilaries as in the Workshop Manual.
There are two timing belt repare kits, Option 1 and Option 2 for engines produced
at different times. A crankshaft front seal is additionally required for some
eninges. Option kit 1, STG 4095K, contains front cover, timing belt, crankshaft
gear, tensioned idler, FIE pump bracket, side cover gaskets, dowles and fasteners.
Option kit 2 STC 4095 K, contains timing belt, crankshaft gear, tensioner, idler, gaskets and fasteners. The crankshaft front seal, ERR 7143 is needed in some cases with Option kit 2.
Option kit 1 is to be fittit to vehicles in the following VIN ranges:
Discover: Ma 081991 to TA 200000
MA 500000 to VA542370
TA 700000 to VAA 711273
Defender: MA 839976 to VA 101258
Range Rover: MA 647845 to Ma 664120
Option kit 2 is for the follow:
Discovery: VA 542371 to VA 558898
VA 711274 to 748935
Defender: VA 101257 to VA 129096
The crankshaft seal is for the following along with Option kit 2:
Discovery: VA 548520 to VA 558898
VA 716897 to WA 748935
Defender: VA 107351 to VA 129096.
Where the repair kits have been used workshops have been instructed by Land Rover for apply 22 cm square of yellow paint to the upper left side of the timing cover.