Exhaust manifolds - Center lower bolts removal

[Jabba]

Hi,

I after some advice, I'm in the process of removing the heads. I am trying to remove the exhaust manifolds as I've got a head pulling tool that bolts to the heads at the exhaust and the lower cam bearing housing. I've managed to remove/loosen all the bolts on the RH side all bar the middle lower (rear) bolt, cylinder 5, I just can get a purchase on it to undo. I have removed the steering shaft already. Also the LH middle lower two bolts, cylinders 4 & 6, do I need to remove the starter to get better access. I'm trying to use a cranked spanner on these bolts but if anyone has any better ideas please let me know.

Many thanks

Craig

[marshman]

remove the heads with exhaust manifolds still attached. much easier. thats how i did mine


EDIT: Whoops didn't read the OP properly. Sorry can't help as never taken manifolds off with heads in place.

[Lingen]

I don't think that is the answer Craig was looking for! He needs to remove the exhaust manifolds in order to attach his head removing tool as, not surprisingly, he can't get them off.
As for removing the bolts Craig, it is so long since I have had to do it that I can't remember how I did it. I do know that it was a bas..rd of a job. Perhaps you could heat the shaft of an old ring spanner and bend it into a helpful shape.
Or perhaps someone else will read this and come up with a better suggestion.
Mike.

[marshman]

Craig,

Does this mean that some of the head studs are seized into the heads?? or are you removing the manifolds ready to use a head puller just in case? To my mind a head puller/pusher should be a last resort after all else has failed.

Lots of things to try up to the point where one or more studs actually shear off.

Roger

[Jabba]

Hi guy's many thanks for your replies, much appreciated.

Hi Roger, to be honest I'm preparing for the worst but hoping it won't get that far. I've successfully removed all the bolts from both heads and the nuts from the studs. Whilst removing one nut, the stud unwound with it. Looking at the bolts and the single stud, there doesn't seem to be much, if any, corrosion on the them, so I'm hoping that next weekend I might be able to use the two nut method as I've been soaking the studs in diesel this weekend. I thought I might as well try and remove the exhaust manifolds in case I need to use a puller, I've disconnected the downpipes already. A friend of mine has made one for me using the drawings found on here by drew.

Craig

[marshman]

Hi guy's many thanks for your replies, much appreciated.

Hi Roger, to be honest I'm preparing for the worst but hoping it won't get that far. I've successfully removed all the bolts from both heads and the nuts from the studs. Whilst removing one nut, the stud unwound with it. Looking at the bolts and the single stud, there doesn't seem to be much, if any, corrosion on the them, so I'm hoping that next weekend I might be able to use the two nut method as I've been soaking the studs in diesel this weekend. I thought I might as well try and remove the exhaust manifolds in case I need to use a puller, I've disconnected the downpipes already. A friend of mine has made one for me using the drawings found on here by drew.

Craig

In that case I would see if the studs come out before struggling further to get the manifolds off. When you refit the heads put the exhaust manifolds back on before refitting them.

Roger

[SHL565S]

i took my manifolds off the other day to get to the engine mountings, i found with a bit of fiddling and time i was able to get them off with a wobble socket and universal angle extension adaptor, it wasnt easy but it worked

[Jabba]

Yes, I will try the studs next weekend and see how I get on.

Its a shame regarding the manifold bolts as I've only got one on the RH and two on the LH to remove. I think the RH one is slightly rounded off as if someone has tried before, I just couldn't get the spanner to grip at all. There doesn't seem enough room between the head of the bolt and the manifold to get a socket in there.

Craig

[Jabba]

Sorry, I'm thinking ahead here, if I am unable to remove the studs with the extractor, I've read that using an air chisel on each stud can loosen them within the head and this can aid with removal. Unfortunately I don't have a compressor, would any other tool be able to do the same job, i.e. an SDS drill on chisel mode ?

Craig

[marshman]

In theory yes. I have both and the "vibration" rate is similar. I have read reports/accounts about using an air chisel but I would be worried about "squashing" or deforming the stud so that it ends up too fat to go through the hole, not sure they are the correct terms but you get the idea. You would need to come up with an adaptor between the SDS drill and the stud that prevents this. My preference if things get a bit sticky would be to weld a nut onto the stud and use an impact wrench to try to undo the stud. If you turn the torque down on the wrench you can get to a stage where there is a lot of "vibration" and only a moderate torque so you don't shear the stud off but effectively try to shake it loose. The problem as I see it with the air chisel or SDS drill it is only really of use if you have a head puller and are applying an upward force to the head. Just banging on the stud in my view will do very little.

Having said all that from what you have described I don't think you will have a problem getting the studs out and I think you ought to try removing first before exploring/preparing for other eventualities.

Roger

[Jabba]

Thanks Roger, yes I did wonder if the air chisel/SDS would be too much for the studs. Unfortunately my mains Clarke impact wrench is either on or off, forward or reverse with 450nm of torque, which is great for when I'm working on my Land Rover. I must admit I could do with buying a battery one, they're a lot smaller than my mains one and more controlable. So, I'll see how I get on at the weekend with the extractor. Thanks for your advice, always appreciate it.

Craig

[DJT]

When I had to remove the heads on my Stag 5 years ago I had several studs shear off using the double nut and/or extractor method. Julian helped me using his electric chisel. We cut off one of his chisel bits, then ground the flat end concave so that it would stay on the end of the stud. This worked for one stud, but that was all.

Using the pusher tool that you have made is ok if the studs are intact and you use a collar to keep the pusher bolts aligned with the studs. If they have sheared off, there is too much distance between the underside of the plate and the studs and the pusher bolts won't stay aligned with the studs. In that case, you will probably have to resort to pushing one head against the other with hydraulic jacks or screw bolts like I did.

IMG_0613.jpg

[Jabba]

Thanks for the 'heads' up Dave, sorry for the pun, but thank you for the information, much appreciated

Craig

[jbuckl]

When I had to remove manifolds years ago it was possible with cheap tools eg open end spanners & 3/8 drive sockets...these days I use high quality 1/4 drive sockets & it seems comparatively easy.

[Jabba]

When I had to remove manifolds years ago it was possible with cheap tools eg open end spanners & 3/8 drive sockets...these days I use high quality 1/4 drive sockets & it seems comparatively easy.

Yes I totally agree, I bet most of us started out with a cheap tool kit and I am fortunate enough to have a large selection of Teng tools now. Unfortunately the last bolt on the RH manifold has already been rounded off prior to my ownership. I have a set of Irwin bolt removal sockets but the gap between the manifold and the head of the bolt is too small.