Timing Gears

[Richie]

Along with a general service - oil n filters and greasing etc, assuming that my 120,000 mile 383 still has the fibre timing gears in place, I plan on replacing them with metal ones. I'll be doing the job with my retired mechanic future father in law but before getting stuck in, What's involved? Any pitfalls to be aware of? Any top tips would be appreciated.

[taximan]

Front 2 bolts of oil pan hold bottom of timing case, so have an oil pan gasket handy as it may get damaged, and be careful not to cross thread the same bolts putting them back in as access is poor.
Shaun.

[AH1951]

See http://jensenmondayclub.co.uk/" onclick="window.open(this.href);return false;
Tech menus/Technical archive/Plastic cam gears
For further info.

[Richie]

Thanks both - so, oil sump has to come off? The link to the Monday Club is useful but, whilst it clearly states that if you have nylon teeth, change em - but doesn't actually give advice as to how to do the job...but I'm guessing (hoping!) that its relatively straight forward??

[cannonball]

Thanks both - so, oil sump has to come off? The link to the Monday Club is useful but, whilst it clearly states that if you have nylon teeth, change em - but doesn't actually give advice as to how to do the job...but I'm guessing (hoping!) that its relatively straight forward??

No
you dont take the sump off but there are 2 bolts go through the sump up in to the timing cover so when its removed you can se the front 1" of sump so be carfeull you dont tear the sump gasket as you remove timing cover it is avail as a short front edge gasket,

[taximan]

Sump doesn't have to come off, but may be sensible option as the possible oil leaks are numerous, also if it's not been off before you may have lots of bits to clean out of the pickup strainer and the pan can never be too clean. (I had 40 plus grit like pieces I removed from mine, but only one visible broken tooth)
Shaun.

[Christian]

That is what you'll find:

P1090024.JPG (91.16 KiB) Viewed 5640 times

I agree with Shaun that there will be lots of debris in the sump and the pickup. The sump-sealing will be hard to save after 40 years. And even if you manage to save it, it will be still more difficult to get that old stuff sealed properly again. So I would give the advice to pull the sump, clean sump and pickup, and then replace all the sealings (sump, shaft seal ring and timing cover seal). If you want to reuse the harmonic balancer, get the correct puller. Never pull on the outer circumference.

[Richie]

Cheers gents. Much appreciated.

[thomaslk]

... pulling the oil pan with engine in situ is not a big issue. If i remember right, the hardest part was to get the pan off the gasket/block after all screws were out already
have fun
Thomas

[Dino Fritz]

Most have said it already, it's going to be a bit of a difficult job due to engine bay access.

My brother (who was former mechanic) would always say to me "make yourself comfortable when doing a moderate to large job in an engine bay", and in 30 minutes would proceed to remove so many ancillaries that it frightened me in thinking how long it would take to get back together.

With this in mind, may I suggest that along with removing the radiator fans, that you may want to consider removing the radiator itself (you'll be draining the coolant to remove the water pump housing to gain access to the timing chain), and maybe the bonnet too.

If you're happy to go the extra mile, then I agree with dropping the sump too, as you'll find where all the plastic gears disappears to, and it may help resolve any oil pressure issues.

My other suggestions:
- get a quality, double row timing chain set. When I replaced mine during the engine rebuild, I purchased a reputable Australian manufactured brand, but still found that the timing markers (dots) didn't line up. 6 hours later with a cam wheel and dial indicator and much trial and error, I got it right (but it didn't need to be that way).
- if you've gone this far with the timing chain (and removal of the sump), then another thing to consider is if you should inspect the valve train (simply remove the rocker covers and look at the 16 hydraulic lifters, 16 rocker arms, 16 pushrods, etc.). There's a lot to go wrong here, and you may be surprised at what you find, which may also point to a camshaft problem. Now, if you've gone so far as to replace the timing gears and need to repair valve train problems, then a little more work at this point would see you replace the camshaft and timing gears at the same time.

Just some food for thought, and to see how far you want to take the task.

Cheers, Dino

[taximan]

A compression test will tell you if there is anything else worth investigating along the way, timing gears and chain will give you peace of mind, but a top end rebuild is a thousand pounds and only necessary if you have very poor compression, before you know it you are buying piston rings and other items you never planned on, the costs spiral upwards and eventually you wish you had never started tinkering. When the time comes to rebuild the engine buy all you need first, otherwise you lose use of the car for too long.
Shaun.

[Richie]

Cheers all - my first move will be to remove the dizzy and have a look at what's there...I wont hold my breath but you never know, i might be pleasantly surprised...
I assume that it's easy enough to see with the dizzy out?

[Dino Fritz]

I had to go back and look at my bare block photos to answer this one!

The good news is that, yes, with the dizzy out, there is an opening which will enable you to see the larger timing gear, but I think you'll be really struggling to see the condition of the teeth for two reasons:
- its up near the top of the opening/hole when you remove the dizzy (you'll get a great view of the middle of the gear, but you'll be struggling to see the teeth)
- the chain is still fitted to the gear.

However, if you can identify whether the gear has been replaced at some point and does not have plastic teeth, that may be a start.

Good luck, Dino

[Barrie]

Of course you need to remember to put the gear cover plate on the right way round otherwise this will happen......

image.jpg (81.6 KiB) Viewed 5538 times

As it was the car ran perfectly well without additional noise and the oil filter appently picked up the dross before it did any damage.
It's still not a good idea though.

[taximan]

Isn't that the oil slinger Barrie? goes on crankshaft over the small sprocket.
Shaun.