Whats the meaning of that bolt?

[Eminent]

Somebody tell me...
Whats the meaning of the bolt in the attachement?

[wwheeler]

Is that the banjo bolt for the fuel injection pump oil line?

[Eminent]

No, it.s a bigger thread i believe.

[ja17]

Hello,

Good question Eminent

This is a special bolt. It has a hardened end that is rounded. It is exactly the correct length to keep the timing chain from jumping off the main engine sprocket which drives the injection pump and distributor. This bolt is a different length if your car does not have power steering.

Since the bolt length is critical, a longer special bolt is used on Power steering cars since the bolt also attaches part of the PS fluid tank. An aluminum seal or seals are used to seal the bolt since it enters the oily chain gallery. It is important to have the proper number of seals since too many or too little will change the distance the bolt enters the chain gallery. If the bolt enters the gallery too far it will lock up the sprocket and possibly damage the chain.  If the bolt does not enter the gallery far enough, it may allow a loose timing chain to jump!

This would be a good subject to dissect. Seal quantities and part numbers for these special bolts would help save a lot of mistakes. I've seen all sorts of wrong hardware used in place of the correct special hardware.

[Eminent]

I thought it must be something special. This because it's very close to the chain in the drawing. If it's just to keep, in my case, the PS tank in place they wouldn't use a bolt that is so close to the chain, i guessed.
Thanks for clearing things up, Joe.

[wwheeler]

That was a great question Eminent.

As soon as I saw Joe's answer, I ran outside to check mine. I just recently took off the p/s reservior but didn't notice anything special about that bolt. I did document it and put it back exactly as it was. Since the engine has been rebuilt by the PO, I don't know if it was put back correctly before.

Mine has a large flat washer maybe 1/16" or so thick between the bolt head and the p/s reservior lower bracket. The bracket is up against the block. There was not a seal ring on there, only the washer. Since I knew that the bolt was in an oil gallery, I used thread sealant on the bolt. It doesn't leak and has no horrible noises like from the chain. I wonder if it is OK?     

[JimVillers]

I would add a comment on the seals.  These seals have a larger than normal diameter; the seal we used  did not fully cover the slot in the power steering bracket.  It leaked a fair amount of oil that took a while to track down.  We solved the oil leaking problem by putting a little thread sealing compound on the threads.

[wwheeler]

According to the EPC, there is a bolt (length depends on if you have power steering or not) and (1) large diameter seal ring as Jim noted. With only one seal ring which is presumably mounted between the block and P/S bracket, there is still a chance the oil could seep in the bolt threads and out by the bolt head. Seems like you should always have to add thread sealer to the bolt.

My washer is much larger in OD than the bolt head, which leads me to believe it is just a plain washer and not a seal ring. SLS shows a picture of the seal ring, and mine doesn't look like that. So it was probably added incorrectly during the PO rebuild. It looks like the washer thickness is about the same as most seal rings and it doesn't leak, so I think I will leave well enough alone.