Secondary timing chain set for water pump/balancer shaft,
with sprocket and gasket, Made in Germany, aftermarket & GM parts
If a slapping rubbing noise can be heard in the front engine area when the engine is cold, it is highly likely that the slide rail of the secondary timing chain drive for the balancer shaft / water pump is broken. This damage affects around 1/4 of all GTs with a mileage of 75,000 km or more. In principle, only the secondary timing chain needs to be replaced in the event of this damage.
Visual inspection of a broken tensioning rail for the water pump drive is possible via an inspection opening for the water pump.
Secondary timing chain set with sprockets, aftermarket / GM
We offer a very high-quality complete set from the aftermarket sector, as the original GM spare parts are very difficult or even impossible to get and do not have the best reputation (see broken slide rails). There are many secondary sets on the aftermarket, some of which are much cheaper, mostly from Eastern Europe or China and often of dubious quality. In addition, the crankshaft gear* in these sets CANNOT be used! Our replacement comes from Schaeffler and contains only quality parts from INA/SKF as well as the original GM crankshaft gear with shock absorber and German seals.
To be on the safe side, you should also replace all sprockets if the secondary timing chain is elongated or damaged by a broken slide rail and its tensioner. Most of these are no longer available from Opel in Europe, but the crankshaft sprocket* must be fitted to the Opel GT by GM, it is NOT available on the aftermarket!
Scope of delivery secondary timing chain set without sprockets:
Balancer shaft chain (like GM 12645237)
Balancer shaft chain tensioner (like GM 90537300)
Chain tensioner rail (like GM 90537299)
Slide rail (like GM 90537336)
Slide rail (like GM 90537369)
Crankshaft sprocket with shock absorber (original GM 55557168 / 12642713, Made in Germany)
Balance shaft gear 1 (like GM Original GM 90537295 improved design)
Balance shaft gear 2 (like GM GM 90537435 improved design)
Gaskets (Made in Germany)
* The water pump and the two balancer shafts are driven by gears. There is a special crankshaft sprocket with a shock absorber that is NOT included in any aftermarket timing chain kit. The crankshaft sprocket in cheap aftermarket timong chain kits CANNOT be used in the GT engine. The water pump sprocket is not included in this kit as it is often supplied with a new water pump.
