Change timing chain - what is needed to do?

[Tailhappy]

Well my 105 Lux is going well, but after 40k the chain is getting a bit noisy. I'd like to replace it - or get my garage to if its too hard to do.

 

I understand the procedure but a few questions.

 

Do you need to remove the back panel?

Is putting the car in gear and handbrake on enough to stop the cogs turning? 

Are there any special tools needed?

What is a good quality replacement chain - I read about some wearing out prematurely. 

 

Thanks in advance for any help - want to decide whether to take this job on myself. 

[petergarforth]

You need to take the rear engine cover off but you can do it with the back panel of the car on - no special tools needed and you follow the marks on the chain and the 12 cogs between rule that is in the Haynes manual......the instructions are usually also in most chain kits. Buy your chain kit from Skopart.de and you will be fine. It is laborious but no special skills needed. The screwdriver head bolts that hold the cam chain cover on can be very difficult to get undone...don't worry about the engine moving whilst you're doing it.....the cogs and their setup govern where everything goes so a bit of movement is easily cured when you align the cogs/chain

Edited 7 December, 2017 by petergarforth

[Tailhappy]

Thank you kindly Peter - I actually have the Skopart.de chain and oil and everything - and am hoping that I am able to do it myself. I have a garage so if I need to leave it in bits overnight if it takes a long time no problem.

[petergarforth]

Do you have the Haynes manual? It is not always perfect but for this job it is ideal.......everything is described and correct. 

Those screwdriver headed bolts can be a real problem though....I've snapped a few in my time.....terrible design

[Tailhappy]

Yes, have the Haynes - and read it a few times. If a bolt does snap is it a problem (needs to be drilled and tapped) or can one get away with leaving it out?

[petergarforth]

There are a few of them so you should be able to get away with one missing. When they have snapped for me they snap leaving a fair amount sticking out which I've then been able to extract once I have the cover off. 

[Tailhappy]

Understood. I have just picked up a can of penetrating spray so I'll give all of them a squirt every now and then to see if I can give myself the best chance of them undoing. 

[petergarforth]

Its the age old problem of steel bolts going in to alloy.....

[Tailhappy]

Well good news - just tried them and they are all easy to turn so thats one positive!

[Tailhappy]

Well I had today off work so have the sump dropped, pulley off and just the oil pump remains, however do I need to remove all five bolts fixing it on or can I get away with just removing the bolt holding the pipe to the crank?

Edited 22 December, 2017 by Tailhappy

[petergarforth]

The pump is driven by the camshaft which it intertwines with - I've never tried to remove the pump still attached to the cover so it may be possible but I doubt it.....and for the sake of 4 bolts and 1 minutes work it is best to take it to bits. If you had a whole day off work you should have been able to complete the job at least twice! 

[Tailhappy]

Thank you. Well I did take the pump off earlier today and have now fitted the new chain but need a few more hours work as daylight is limited and I am also cleaning up all the parts etc. I have set aside two more days as I really want to get it running before the New Year. l'll report back hopefully with positive news.

[petergarforth]

If you follow the 12 links rule you cant fail.....it is worth comparing the old and new cogs to check the marks are in the same place on both sets because I've had them where new ones have had the mark a tooth out which f*!ks up everything

[Tailhappy]

Cheers Peter - and hope your Christmas is going well.

 

Well I am done, just cleaning up everything, scraping off old gasket, cleaning all bolts etc. I have the new chain on fine, however I noted something that I have not seen mentioned. I stopped the engine at TDC cylinder one, distributor pointing at No.1 Cylinder (about 2 O'clock looking from behind), however doing this means that the chain is 29 pins between marks (confirmed by checking the old chain prior to removal) and the 12 pins only applies when the distributor points to No.4  cylinder. This had me confused so I just turned the crankshaft one rotation (half camshaft) and voila - 12 pins. Apart from that its just cleaning everything that is laborious - but will be done tomorrow.

 

Take a look at the photo - taken with distributor aiming at No.1 cylinder TDC. 29 Pins!

[Tailhappy]

Well all done and the car runs lovely - all smooth and revvy! I will add some points that I found along the way:

 

The oil pump is above the oil level meaning the engine runs dry when fired up after the job. To save this, drive the oil pump through the distributor hole clockwise with a drill and suitable blade until the pump primes. Mine took a good few seconds and I'm glad I used the drill. Would have been about 10 seconds of 2000 RPM dry engine.

The oil pump gasket was not easily available so I cut one from quality paper - worked fine.

When fitting the chain cogs, push the large one home over the elliptical key, removing the woodruff key from the crankshaft - then you can see how much to twist the crank or cam to align the key...and press home.

Make sure you get a new timing chest gasket - mine came off in bits.

 

[petergarforth]

11 hours ago, Mr105LUX said:

Well all done and the car runs lovely - all smooth and revvy! I will add some points that I found along the way:

 

The oil pump is above the oil level meaning the engine runs dry when fired up after the job. To save this, drive the oil pump through the distributor hole clockwise with a drill and suitable blade until the pump primes. Mine took a good few seconds and I'm glad I used the drill. Would have been about 10 seconds of 2000 RPM dry engine.

The oil pump gasket was not easily available so I cut one from quality paper - worked fine.

When fitting the chain cogs, push the large one home over the elliptical key, removing the woodruff key from the crankshaft - then you can see how much to twist the crank or cam to align the key...and press home.

Make sure you get a new timing chest gasket - mine came off in bits.

 

 

The sieve under the pump is where the oil is pulled from and if that's not sitting in oil then you have something wrong? It will only take  a second or 2  to draw from the sump (your drill wont be turning at anything like the speed of the engine when it fires) . You will still have oil sat in places like the crank bearings, cam galleries and in the head......apart from which you fill the engine via the top cover so you treat the whole engine to an oil shower. I've never done anything beyond turning the engine to start.....and that's on my 7500rpm race engine. 

You can do away with the oil pump gasket.....in fact its almost recommended because you get a better fit with the pump and less chance of pressure leaks. I don't bother with cam timing gaskets......I tend to use sealant instead.....but if you bought a cam chain kit did you not get a gasket with it? I always do from Skopart.de?

Edited 31 December, 2017 by petergarforth

[Tailhappy]

Hi Peter. Thank you - and yes, I'm sure you are right and that starting the engine would have been fine, but I was worried about scoring the bearings as it was so cold and the oil was quite thick even though it was the correct grade. yes, the strainer was under the oil - just not the pump gears.

 

Well all is all running fine and I just tweaked the C/O and idle (1.2% and 815 RPM warmed up). New chain made such a difference with how the car drove - now pulls up hill much better, probably because the timing is better regulated. Also it is quieter and passengers enjoy the ride more.

 

I have spent the last week on other tasks, stripping and rebuilding the distributor, servicing the alternator, cleaning up all electrical contacts in the engine bay, new thermoswitch and thermostat and finally took apart all the dials to clean out the haze that was inside (had to make a special tool to remove the bezels without damage) and upgraded the plastic MERA Lumel rev counter to an all metal PAL one with better insides (just had to swap the anti-reflective glass). I was never very happy with the MERA one, as it unde-read here and there so the needle went up in jumps as the engine was revved. Oh, and it got new antifreeze as well as new mudflaps - and a coat of Gold Class wax as a treat.