| 4.2 Supercharged Timing Chain Tensioning | |
I spent the afternoon replacing the timing chains on my 4.2 SC prior to finishing reassembly.
I started with everything laid out on the toolbox so I could identify things as the tensioners for the secondary chains are sided.
After that I pulled up the manual and set about following the process for setting up the timing to a tee.
Following the manual made it very straight forward!
You put the secondary chains on the sprockets then put the sprockets on the cams and put the new bolts into the cams whilst leaving them loose so the sprockets can turn. Once you’ve done this you pull the pin out of the secondary tensioners.
You then build up the LH and RH primary chains by installing the guides, then installing the chains, then you add the guide for the tensioners and then you fit both tensioners. Once this is done you pull the pins on these too.
Once you’ve done this lot you use the special tool from the timing kit to hold the exhaust sprocket stationary whilst you tighten the inlet sprocket bolt to 20nm, then a further 90 degrees. Once the inlet sprocket is tight you do the same for the exhaust sprocket, and then repeat for the other cylinder head.
It was very simple and went without a hitch. I then removed the timing tools that lock the cams, lifted the car up and then pulled the pin out of the flywheel.
I then spun the engine over by hand. 1 x 360 degree rotation of the crank is only a 180 degree rotation of the cams so I spun the crank round 8 times which is 4 complete rotations. Everything moved very freely and felt lovely when turning it by hand.
However, and unfortunately with this car there’s always a “However” 😩… the cams and crank were slightly out of line when I went to repin them.
So, everything was removed and the process was started again following the workshop manual, again, to the letter. The results were the same 
These tools should sit flush with the heads. One side was nipped so it was flush, the other side wouldn’t sit flush.
LH:
RH:
Flywheel:
 | | Click image to enlarge |
Has anybody done this before? Is this normal? I was expecting the cam locking bars to fit straight on and be flush with the heads and for the crank to pin straight away.
I’ve only ever worked with belts before, never chains and every time I’ve spun them after setting the tension the pins have always slid in perfectly. I just don’t know if I’m expecting something that won’t happen with this car.
Any help will be appreciated!
Thanks,
David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior
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1st Aug 2022 6:14pm
