Hello everyone

I am new here to the forum but have been visiting a few times before and found a lot of helpful information. Now I'm having an issue which I can't seem to find any information on :-)

I recently bought a Volvo S80 2001 with the 2.4L 5 cylinder non-turbo engine (B5244S2).

I started out chasing a ECM-640F DTC (camshaft reset valve, faulty signal) along with an oil leak causing the timing belt and housing to be really messy.

After aligning the timing marks and removing the timing belt, I noticed that there was about half a tooth play where the timing gear meets the crankshaft. In order to inspect it further, I took of the timing gear and it appears that the teeth on both crankshaft and the timing gear is severely worn/stripped. I have attached a few pictures of this.

The engine is running fine and I was expecting to just be replacing a cam/crank seal along with the VVT unit. I guess, however, that even if I managed to get the timing right with that play in the timing gear, whatever is left of the teeth would soon wear out and then cause severe damage to pistons and valves.

I can't really think of any way to repair this without replacing the crankshaft - in which case I might just as well swap out the entire engine. But as the engine is running fine it feels kind of ridiculous just because of some stripped teeth.

Any advice on how to move forward from here is much appreciated :-) Also, what could cause the teeth to strip in the first place?

 

this is a first for me - yikes . Hard to see the splines on the crank - are they rounded off? A seized water pump or camshaft is the only thing I could think of that could cause this and I would imagine that the belt would just snap in that case. Weird to say the least.

 

The teeth on the crankshaft is in better condition than those on the timing gear, although they are also worn.

I went to a scrapyard today and bought a new (used) timing gear with good looking teeth. The new gear fits pretty good on the crankshaft - they fit together with an extremely small amount of play which can be felt but is hardly visible to the naked eye.

I have been talking to a couple of specialized Volvo mechanics today and none of them has seen the teeth strip like this. Their only advice was to replace either the engine or the crankshaft.

I think I just have to bolt it back up and hope that the (almost non-existing) play will not get any worse with the new timing gear. Will the center nut on the crankshaft help hold the timing gear and crankshaft together or is it the splines alone doing the job?

 

nut holds the pulley to the gear - splines pretty much do all the rotational work. I would assemble it with plenty of red loctite and make sure that nut is tight.

 

I think that is good advice. My dad was an industrial maintenance mechanic, and I know he would have considered "plastic steel" sort of epoxy in a situation like that. Movement is going to cause wear.

 

I would just weld them on.

 

I'm trying to figure out how your 2001 S80 has a 2.4 when it only came with a 2.8 or 2.9