156 JTS front sway bar bushings and ball joints

[johnl]

So I now have all the parts required to do this job except for the exhaust gaskets. Will I need to replace them after having dropped the exhaust to do the sway bar bushes etc or do they usually survive this process? Our very good friends at Italian Automotive Spares don't carry them in stock.

If the exhaust flange gasket or the manifold gasket is still in reasonable condition (not falling apart, no bits missing), I've had success painting the old gasket with a thickish layer of 'silver frost' paint (an oil based paint containing particles of aluminium). Obtain a tin of this paint, open it, pour off as much off the clear liquid laying on top of the thick 'sediment' as you can, then mix in the remaining fluid into the sediment with a stick (whatever) to make a uniform paste. The 'paint' basically consists of aluminium particles held together with a binding medium (ie. the liquid component of the paint, whatever that actually is). Now clean the old gasket and surfaces of the components being 'gasketed' as well as you can.

Paint the gasket with a brush and allow to dry (which should take half an hour or so). Repeat. You want a thickish layer of the 'silver frost' paint, but it doesn't have to be a completely even layer (but as even as reasonably possible). The thickish dried paint layer won't be completely hard, but somewhat 'malleable'. When the gasket is squeezed by the clamping pressure (of the flange or manifold fasteners) the paint gets squashed 'flat', and the thickness evens out. The aluminium particles move and fill any voids in the gasket itself and / or in the metal sufaces (some of the 'paint' will be squeezed out at the edges of the gasket). The paint cures / hardens / sets with engine and manifold heat in use. I've used the paint successfully even if it has become a bit lumpy over time (since the last time I opened the tin). It has never failed to work for me, and I have even used it on head gaskets both new and re-used.

This method of sealing suspect gaskets was told to me many years ago, by an old bloke who made custom gaskets for a living (gaskets for anything from racing car engines, vintage cars, to massive ship diesels etc. etc.). His business ('Universal Gaskets' from memory, but I could easily have that wrong) was a charming ancient establishment located in Balmain or pehaps Rozelle, in a rust coloured tin shed, time having stripped it of any remnant galvanising. No longer there, a lost gem...

Regards,
John.

[Craig_m67]

I never replaced the exhaust gaskets on Sooty in well over 200Km of use (230K perhaps).  Pulled the exhaust off numerous times to change or check all manner of things; at least five I can think off the top of my head, including twice removing the turbo and manifold.

Never leaked
Wasn't an issue
Nothing to see here

Just bolt it up, if it leaks.. order new ones, it's not a big job to do later if an issue.
Just take care of the nuts and studs, try not to round anything off, replace with the correct bits if they're already ruined (you will thank yourself next time you need to remove it)

/C

[johnl]

One can be lucky, or perhaps unlucky. I have re-used manifold and flange gaskets that at least looked reasonably OK, but did leak when fitted 'dry'. This was when I had run out of the 'silver frost' paint, and was having trouble finding another tin (seems to be getting rarer). I've also successfully used 'high temperature' silicon gasket maker (sensor safe of course), which works OK to seal even very hot flanges.

Regards,
John.

[SeleMatt]

Thank you all for the replies. Just trying to find a day in a currently very busy schedule to get the job done. I'll try and take some pics throughout the process to hopefully assist others. At this stage, I'll take Craig's advice regarding the exhaust gaskets. Given it's the last thing to go back together, needing a gasket isn't going to hold any other part of the job up.

[johnl]

A lot may depend on the kind of gasket it is. If it's an all metal gasket with embossed ridges in the sheeting, and the ridges haven't been permanently crushed flat anywhere, then it will probably reseal OK when being re-used.

The ridges (as I understand it) flatten out when the fasteners are tightened, but exert a constant localised force acting against the component faces (flanges, manifold / head) because the steel sheet from which the gasket is made is 'springy', so the embossed ridges are in effect a kind of 'spring'. So, as long as the gasket hasn't lost its' 'temper' then the elastically flattened ridges exert a constant force against the component faces, and because the gasket ridges are elastic, they can compress more or less in different parts of the ridge as required to account for some degree of uneveness in the joint. The ridges should return to their uncompressed shape when the clamping force is removed, and then compress again when re-used, so, the number of times the gasket can be re-used should, in theory, be infinite. This helps to create a good dry seal, so long as all parts involved are clean and not excessively pitted, 'gouged' or warped.

Gaskets that are made from an 'organic' material, or that are an organic / metal sandwich, become permanently crushed to a specific shape when they are first compressed by the fasteners (i.e. the compressed thickness may significantly vary in different parts of the gasket), and may not reseal as perfectly if re-used. Such gaskets might fail to seal when re-fitted dry (or may be OK), but be more likely to seal when using some sort of added sealant. This is also only my understanding (correct or not).

I've used some kind of sealant on many different kinds of gaskets, and never had one fail to seal. I have also not used a sealant, and had failures to seal. I have used the 'silver paint' sealant where the sufaces to be sealed were significantly rough, and it still worked.

Regards,
John.

More or less related (or not really); it's my understanding that Ettore Bugatti considered the use of gaskets (or sealant) as indicative of a deplorable inabilty to machine perfectly flat and leak free mating surfaces, and insisted on dry gasketless joints at his factory (and no head gaskets since Bugatti engines had the block and head cast as one unit). This may have been a perfectionists' pursuit of the ideal, the problem being that in the real world Bugattis leaked oil copiously. Modern day Bugattistas generally do use gaskets and sealant. I once worked for a Bugatti purist who didn't use gaskets and sealant when he first had his Type 35B engine rebuilt, and he regretted it later (leaked Castrol R makes a nasty mess that is almost impossible to remove, took me forever even with the engine fully disassembled...).

[SeleMatt]

Thanks again to JohnL for the comprehensive gasket summary.

I'm ready to lower the sub-frame although I can't get to it until Sunday as I'm working tomorrow. Would somebody be kind enough to tell me what size/length bolts I need to buy to put the ARB brackets back together, following drilling out the rivets? I have a window of opportunity to buy them in the morning, leaving me Sunday to get it all back together again...all going well.

I reckon they must have run competitions at the factory to see who could do up the steering rack bolts the tightest...

[SeleMatt]

So anyway, having finished the job, I can advise the following.

Follow the Alfa Workshop UK guidelines for the lower control arm removal, but add REMOVE THE SHOCK FORK following removal of the fulcrum shaft from the lower control arm/shock fork. Why it's not listed as a step is completely beyond me. The fork is fixed to the shock shaft by one bolt and its removal makes everything SO MUCH EASIER it's not funny.
If you're doing the upper control arms it's the same deal. Follow the Alfa workshop guidelines but remove the shock fork after taking out the fulcrum shaft. The shock will then drop out easily enabling an equally easy removal of the upper control arm cast mount from the shock turret.

It's also important to remember to load up the the suspension before torquing up the fulcrum shaft bolts/nuts so as not to ruin your new lower control arm bushes.

This video link below is helpful but ignore the removal of the hub-nut to slide the hub unit outboard. Totally unnecessary if you've removed the shock fork.

https://www.youtube.com/watch?v=UpnP9e23PyQ

Peace.












 

[bazzbazz]

Ahhh, Just checking, while you were replacing the lower arms and had them off, did you take this moment to lower the Subframe and replace the roll bar bushes?

[SeleMatt]

I was wondering if anyone was going to ask Bazz. I did remove the bar but the bushes and bar were fine. When I shone the torch on them before dropping the sub-frame I could see the bush A-frame and sintered collars on the arb; they looked almost new. So when I pulled it out, I wasn't surprised to find them good; despite having a new set of Superpro bushes on hand, I couldn't bring myself to destroy a perfectly good set, so I just put it all back together. The car only has 88,000 on the clock which is not many k's.  As you know, it has a replacement engine; perhaps they put a new factory bar in when the motor was out...
Either the lower ball joints (rooted) or one torn large lower control arm bush was the knock culprit.

Next is working out what the knock is in the rear. 

PS Just before starting this job, I had the engine light again. Post cat sensors this time...so that's all four now.   

[bazzbazz]

Before going and replacing all 4 O2 sensors you may want to remove the upper 2 sensors and see what condition the actual Catalytic Converter Blocks are in, and to see if they haven't started to disintegrate.

[SeleMatt]

Been there and done that Bazz. Cats are perfect. Repeat error codes on pre cat sensors and so replaced those about 2 months ago. Then I had oxygen sensor 2 code (being the post cat sensor) about six weeks later. So now they're all done. For what it's worth, I found all the exhaust ports dry and equal colour having just had the headers off which is encouraging regarding the ring wear.

[bazzbazz]

So, you've replaced all the O2 sensors or you mean now all four have thrown codes?

[SeleMatt]

They're all now new Bazz.