Chain tensioner

[stonedrive]

Hi everyone, in the middle of taking cylinder heads off, started with drivers side lined all the markers up, took one bolt out of timing chain/camshaft put locking nut on and tightened then took other bolt out everything fine. Passenger side not so good ended up taking both bolts out without locking it off, chain has now lost its tension. So I was wondering is there a way I can retention it to make it right again, before I carry on. Many thanks Steve.

[NeilR]

Timing cover off to sort that out, but as your removing heads anyway that's not an issue.

[flying farmer]

Since you have now got to go as far as removing the timing cover, I would replace the chains and crank sprockets as a minimum unless they have done a very low mileage.

Neil

[stonedrive]

Hi Neil, many thanks for that, what is the procedure for retentioning, once I have the timing cover off. Cheers Steve

[flying farmer]

The shaft of the tensioner has a spring loaded ratchet assembly.
Remove the centre of the tensioner and twist and compress the outer part of the tensioner so the little lug on the centre pin returns to the top hole. It should lodge there while you carefully replace it in the outer section.
Pressing the end of the rubber will immediately release the ratchet assembly again.

New tensioners come with a plastic horseshoe that clips on the shaft under the tensioner head to prevent the ratchet being set off unintentionally while the chain guides are adjusted

[stonedrive]

Many thanks for that flying farmer, I shall give that ago tomorrow. Cheers Steve

[jbuckl]

The shaft of the tensioner has a spring loaded ratchet assembly.
Remove the centre of the tensioner and twist and compress the outer part of the tensioner so the little lug on the centre pin returns to the top hole. It should lodge there while you carefully replace it in the outer section.
Pressing the end of the rubber will immediately release the ratchet assembly again.

New tensioners come with a plastic horseshoe that clips on the shaft under the tensioner head to prevent the ratchet being set off unintentionally while the chain guides are adjusted

That plastic spacer or a home made cardboard version is essential imho.

seen so many over tensioned rebuilds it’s untrue…. Most complain about early life wear of guides and sprockets.

reality is mostly poor re-assembly.

[Chris01573]

Surely if you have only removed the sprockets the tension would not be affected when the sprockets are bolted back on to the cams again. ?

[MikeParker]

Surely if you have only removed the sprockets the tension would not be affected when the sprockets are bolted back on to the cams again. ?

In practice it is difficult to remove the sprocket from the cam and bolt it onto the bracket without a slight relaxation of tension in the chain. The ratchet can then click out to its next stop. You may of course be lucky if the ratchet is just past the last stop, but sods law normally says otherwise! I have got round this issue by making a hook out of thick wire and pre-tensioning the chain as it comes up through the head on the section of chain from the crank socket that has the tensioner acting on it. That is, I think from memory, the lower chain run on the RH bank and the upper chain run on the left had bank. The wire needs to be good and tight, so I use a tourniquet on a looped section of the wire to torque it up.

[stonedrive]

Many thanks for the info much appreciated.Steve

[stonedrive]

Hi quick update on progress. Driver side bolts and studs came out quite easily from cylinder head using stud removing tool, on to passenger side managed to remove one more stud with removing tool then it didn’t seem to do it’s job after that. Onto US PRO stud extractor managed to get three out and the only one left is the one nearest the front of the car, the us pro is to wide to go onto stud straight it ends up going at an angle. So the last one I’m going to weld a nut on. I don’t know if this helped but what I did was cut up small pieces of plastic plumbers tubing and mastic it over the stud and then filled the tube with diesel and let it find its way down the stud. I mean I have read all the horror stories about removing studs. Unless I was just lucky with mine although when removing them the shafts were oily wet. Photos attached could someone tell me what my next step should be and what you make of the photos. Cheers Steve. I’m going IMG_0329.jpg to worry about timing chains after I’ve done head and inlet manifold gaskets. IMG_0325.jpg IMG_0327.jpg IMG_0325.jpg

[jbuckl]

… my take is if the studs are very stuck, no amount of release agent will help much.

only helps on slightly stuck.

maybe if they are left soaking for weeks with a big pool? Engine out and on its side?

I once had luck that way with an engine that had hardly ever run since it was rebuilt….. but had been left for nearly 2 decades. Still pretty stuck even though it hadn’t been used!

vibration does, force does, but release agent can’t get past the corrosion to help from what I’ve seen.

good wishes.

[sujitroy]

Take the cam off. so the valves will clear the pistons while u work on the other head just in case u have to rotate the crank.

[stonedrive]

Hi Sujitroy, good advice many thanks. This is my first attempt with working on an engine. Doing lots of research and watching videos,taking notes and photos, I’m just hoping I haven’t got in over my head. I’ve just completed suspension refurbishment and fitted poly bushes which was very satisfying, but engines are in another league. Many thanks Steve.

[MikeParker]

If you have one head off and only one stud left in the other, you are in a good position! It could certainly be a lot worse. If you can't free the stud, you have to cut it off between the head and block after lifting the head say 10mm. As it is the end stud you may be able to start the process by lifting the other end of the head. That is what I was able to do the first time I removed a head. You must avoid the temptation to use a hard chisel between head and block. That will damage the head if not the block as well. Once lifted a mm or two, put a hardwood spacer at the stud end between block and head over the entire width and then lift the other end some more. Add more spacers and repeat.

When cutting with a hack saw blade obviously be very careful not to touch the head or block surface with the saw blade.

If the head won't budge when lifting the other end of the head, then I would use the angle iron method. So bolt the removed head back on put the other studs back in the stuck head and fit the two angle irons and jack at the stuck- stud end. That is the belt and braces method. I have used that method on my two later head removals where multiple studs were stuck.

Once you have the heads off, you don't need to worry about timing chains. You remove the timing chain cover and replace (and reset) the tensioners and retime the cams and jackshaft when you re-assemble.