A post a few days ago about steel cam gears reminded me of this issue. Seems to me my folks did have a failure of a composite cam gear in one of the 144s years ago.

Rebuild reciept on my '70 145S B20B shows new cam but not new gear. Should I spring for a steel cam gear and install it while the radiator is out for repair?
Car has 240k miles w/ approx 20k since engine overhaul.

BTW. I've tried searching this forum and the archives and find it very frustrating. Anyone have any tips on how to search?

Thanks,
Al

I've been driving B18/20/30 Volvos almost exclusively since I got my license 17 years ago...much of that time was spent delivering pizza full time hard miles. Only once have I had a timing gear go out, and that was las February when 4 wheeling in my 164. And it was an aftermarket aluminum gear. My 1800 has well over 250k on its current rebuilt engine... It too has proven to be a most capable 4 wheelin' vehicle...

If I were you, I'd leave it together, and fix it when it breaks. It should give you some warning with a knock. And if it goes, it ain't gonna do any serious damage. What sort of shop was the rebuild reciept from anyhow? And...how much was charged for the cam? Could well be that it was a cam kit or something and included a new gear...

-Matt

Cam gears are prehaps the weakest point on a B18/B20 engine, but they aren't -terribly- weak. Stock cams/valves on engines driven normally shouldn't have too much problem running high miles with one. Double valves, high lift cams, high revs all put more stress on so shorten the life. I'm still not sure if they have a 'half life' per se or just occasionally fail with little predicatability. I personally have only ever had one fail in 20 years of driving around B18 and B20 engined Volvo's, despite rebuilding a couple high mileage engines and reusing the cam gears. The one that failed was in my PV's '63 B18 engine with an 'A' cam. (I got the car with 22,000 miles showing, to the best of my knowledge that is 122,000 miles). It had an older style larger splined metal hub - and the fiber gear separated from that completely. It kept running for about 50 miles - finishing the trip I was on (a couple of hours of fairly high rpms immediately prior to the failure). When I took the timing cover off the gear fell out. My thought on that is that the car sat for 15 years unused, perhaps the fiber gears 'dried out' and slightly shrank away from the hub. They lasted about 1500 miles after I got the car running again.

I'm running fiber gears in both my 2.2 liter PV engine and the B20 1800E engine without losing sleep. If the gear gives way in the future it won't damage anything other than getting some fiber gunk in the pan.

I've heard new steel gears are available from the Volvo dealer. If not new sets are available from KgTrimning for about $180 - both gears, seal, gasket, thrust plate. Actually - that's probably a little more than $180 now - the dollar seems to have been slipping against the Kronor - and those Swedish parts sources are losing some of the appeal pricewise.

Ouch - just checked the current currency conversion and it's now $212... :(

My experience has been a bit different to Chris', so I hope he doesn't take offense :) I had fibre gears fail twice; once in a B20B in a 144 in which the gears had done a low but pretty hard mileage, and again in a B30E in a 164 which had previously had a minor distributor drive glitch which I supposed had caused a fatigue shock to the fibre gear. Both times there was no warning, just sudden silence. They each dumped a load of shredded fibre gear material in the oil pan, which was a b**tard to get out. I vowed after the second time that I would only use steel ones in future. They're expensive (comparitively) and can make a bit more noise, but they are also "fit and forget". You can't change just the cam gear either. They have a different number of teeth to the fibre gear and come as a matched set. I prefer the peace of mind of being pretty sure they're not going to suddenly dismember themselves.
--
Steve.

My 164 blew the timing gear. I'm not sure how many miles the
gear had when it died. It gave me plenty of warning, got me
home okay when it finally let go and did no damage to the
motor when the motor stopped working.

I replaced the timing gear with an aluminum gear set from
napa. I don't remember the part number; I'll post it if I
can turn it up in my records. I couldn't find any reasonable
source for the steel gear set and the aluminum was not too
much more than a fiber gear. I also replaced the water pump
but it was also leaking a little and was kinda noisy.

I've also heard that the aluminum gears can fail. I have
no idea how often or how common this failure is.

I wouldn't bother with replacing the gear until it fails.
I also wouldn't bother with replacing the gear with something
other than fiber unless the metal gear set isn't that much
more expensive than 2 fiber gears. I've gotten lucky and
lucked into 2 steel gear sets (one in the trunk of my $300
145 in the race motor that came free with the other car
and the other on a B30 long block that I got because it
had good pistons -- I didn't even take the gear cover off
prior than getting the motor).

You can tell if a salvage yard B20/B18 has steel gears
with a strong magnet -- you don't need to take anything
apart.
chris