M54 engine and gearbox preventative maintenance before refitting

[mrscalex]

With the engine and gearbox out I'm wondering what preventative maintenance it would be sensible to carry out.

I shall definitely change the gearbox oil.

I was going to change the CCV system but I don't want to introduce too many variables into why the engine may not fire up after it goes back in... but I plan to do it once it's in (more difficult I know).

Anything else on the engine?

With the gearbox is there anything sensible to change? Is there a seal at the back that should be done? Anything inside the box that's quick and easy? Linkage bushes?

Thanks.

 

[the Nefyn cat]

Depending on the age of the donor it might be worth checking the clutch, I know they seem to last forever these days but while it's out and easy? Mine's done nearly 130000 and no sign of anything going wrong, but it ain't going to last infinitely.

 

[colb]

Agree about the clutch whilst its all out of the car, might as well put a new plate in and a thrust bearing especially if your going to keep it for a long time. Putting new in will bring peace of mind.

 

[5harp3y]

Rear seal if the gearbox is out

 

[NZ00Z3]

I'ld add the following:

- Gear box gear selector rod seal. You can tap the first (old one) in and fit a new one on top of it. Saves fiddling around with removing the old one.

- The two hard plastic cooling system pipes that come out under the inlet manifold and behind oil filter housing. These have two (2) O rings on them. Check that they both come out when you remove the old pipe. Many only have one (1) on them with the other still in the block. Clean out the holes with a bit of wire wool. Insert the new pipes with a bit of high temp silicon.

- The crank sensor and knock sensors with OM replacements. Only if you intend to keep the car a long time. They are in a really hard place to to get to with the engine installed.

 

[mrscalex]

Thanks for all suggestions.

I'm a bit loathe to have the gearbox off to even check the clutch, let alone replace it. I keep thinking about not getting a new clutch or even the gearbox back right and having to have it all back out.

I'm still not even clear how you fit a self adjusting clutch. If it doesn't come pre-tensioned does it need tensioning in some other way? Or does it self adjust on pumping the pedal?

Is there an indicator on the clutch mechanism as to how worn it is without taking the clutch off?

Strange isn't it. Don't mind doing an engine swap but clutches freak me out!

 

[Jimmy Weston]

I'd replace the clutch slave cylinder and hose whilst the gearbox is out, as it's a bug**r to get at when the gearbox is back in.

 

[NZ00Z3]

New Self adjusting clutch comes with a spider on the clutch fingers to lock the pressure on the self adjusting mechanism. Once the clutch is all bolted up, you remove the spider.

With the box removed, you can see the self adjusting mechanism springs. The below photo is one that has used up all of its self adjustment. When new, that little spring is all compressed. There are two markers on the spring finger. The left one is "as new" and is just visible under the spring.

 

[mrscalex]

New Self adjusting clutch comes with a spider on the clutch fingers to lock the pressure on the self adjusting mechanism. Once the clutch is all bolted up, you remove the spider.

With the box removed, you can see the self adjusting mechanism springs. The below photo is one that has used up all of its self adjustment. When new, that little spring is all compressed. There are two markers on the spring finger. The left one is "as new" and is just visible under the spring.

But supposing it doesn't come with a spider? They don't all have this. And I have a perfectly good used one with lots of meat left?

 

[the Nefyn cat]

What the hell was wrong with the old style perfectly normal clutch? Another case of "improving" things that worked just fine already?