Hello, I'd like to introduce myself to the forum. I am in the process of buying a 1985 308 from a friend. I'm a long-time 911 owner and currently have a 1988 that I have rebuilt the engine, suspension, transmission, etc. so I have some mechanical skill (or more likely a pathological lack of reasonable fear). I make plenty of mistakes, but try to learn from them. I also appreciate the wisdom of those that have gone before me. I recently helped my friend fix a coolant leak on the 308. Finding the leak involved removing the air plenum. The nuts holding the plenum onto the intake runners were a challenge. None our wrenches fit well, and I ended up using an open end wrench that in same cases could only partially fit on the nuts. In anticipation of future work, I would like a better solution. Any recommendations for a 13 mm wrench that properly fits?
I would be inclined to replace the nuts with flange type nuts with a 10mm hex. Same bearing surface as the 13mm hex nuts, but more 'working room'. Looks like this: Image Unavailable, Please Login
Word of caution - watch out for the location dowel's as you remove it - don't let them fall into the inlet ports! People tend to loosen the nuts then slide something between plenum and inlet manifold to stop this happening.
Was the 13mm wrench too large or too small? If the 13mm was too large, did you try a 1/2" wrench ? Yeah, I know it's all metric... but did you try a 1/2" ?
Buy a couple of good quality 13mm 12-point all enclosed wrench (not open ended). Take one of them to a bench grinder and thin out the wall of the 12 point wrench so that it will fit the challenging nut. Then keep that wrench ONLY for that purpose. Use the non-modified one for everything else. Dump the loose washers on the way back. Use the M8 13mm flange nuts (above picture in post 2) so that you don't fight the falling away washers next time. Even better, use M8 12mm flange nuts.
Thanks for all the replies! The 13 mm wrench was too large on the outside. We tried grinding it down, but gave up (maybe too soon). I like the flange nut idea best.
Ah - you were referring to the interference of the outside of the wrench with its surroundings. I misunderstood! I thought it meant the wrench was not compatible with the hex on the fitting.
Do any tool manufactuerer actually just make a suitable wrench? Did Ferrari mechanics have to make their own tools in period? Seems like removing the intake plenum would not be an uncommon task.
Triumph motorcycles, amongst others, need thin wall spanners for maintenance work and are readily available. This one is 1/2" AF.... . Image Unavailable, Please Login
Professional mechanics actually end up having to make specialized tools all day long. Sometimes it's a thin wall 13mm wrench, sometimes it's a longish 13mm open ended wrench with a twist for the F1 slave flange, sometimes it's a very thin 17mm open ended wrench, sometimes it's a ground down socket for a ring nut on the steering wheel, sometimes it's a seal puller on a water pump, and that's just some of the Ferrari cars. Let's talk about Porsche some other times.
Most of the times when I end up making a tool, it's because I cannot wait for a factory tool to arrive in 2 days, or to chase down a Snap-On truck, so it's just more effective to grind down a wrench and continue with the job. There are a few times when only a factory tool or only a specific Baum tool will work. Then there is no choice but to wait and order it. Front main seal on an N54 BMW engine comes to mind.
