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Hello people,
In the course of having some welding done, I enquired about the noisier than normal engine. My mechanic warned me that it was probably the fibre timing gear.
It's not a terrible clatter, more like the sound of a older diesel.
Can you tell me whether I should change the part now, before my trip across the channel in June (2000 miles approx)or whether it will happily run, albeit a bit noisily, for longer.
Thanks a lot,
Tom
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Just about every Volvo I have had has done this. The handwriting's
on the wall. Might be tonight, might be next year. I wouldn't drive it
anywhere I couldn't otherwise get back from. Don't be like Belshazzar!
--
George Downs Bartlesville, Heart of the USA!
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Tom: I wanted to show you what can happen if the camshaft gear does disintegrate!
This is more a case of the metal crankshaft gear destroying the much softer camshaft gear. That said, it sounds as if yours is just starting to come apart at the metal spline that fits onto the camshaft itself.
Many years ago, I did buy my first 1965 Amazon for $65 because of this horrible sound. I surmised that the camshaft gear was moving forwards and backwards, hitting the front of the timing gear cover. The helix of the meshed gear kept the car running. At that time, in 1975, expenses being tight, I had a large stainless steel washer made that fit under the camshaft nut, to hold the fibre gear in place. This lasted another 2 years before it was time to buy a new gear set from the dealership.
I understand there are metal camshaft gears that will last a lifetime - I had one on a 1975 164-E. So, as everyone suggests, you are most likely hearing the early symptoms of this problem and you now know the consequences.
--
Cam a.k.a. CVOLVO.COM
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I understand there are metal camshaft gears that will last a lifetime - I had one on a 1975 164-E.
Volvo steel/steel gearsets can be hard to find, and expensive when you do. They also add a fair amount of rotating mass to the motor, and should be lightened for performance applications.
Now I'm using aluminum/steel gearsets made by Cloyes (they make them for UPS trucks and other super-duty use) -- available at NAPA, far cheaper than all steel gears, and lighter than the fibre version.
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"Now I'm using aluminum/steel gearsets made by Cloyes (they make them for UPS trucks and other super-duty use) -- available at NAPA, far cheaper than all steel gears, and lighter than the fibre version."
Do tell! Are they sold as being intended for B18/20/30 applications? or what? What did they set you back? I think many here would be very interested in this cross referenced application.
How'd you find out about this anyway?
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Cloyes part number 2032S, ballpark $160 for the set from NAPA (you must replace both gears). Direct replacement for B18/20/30.
www.cloyes.com
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The hub of the fibre gear may be breaking loose, and becoming less trustworthy every day. When very badly damaged, they can miraculously continue to run, although horribly, and damage other parts, such as motor mounts. I would suggest having the work done prior to the trip.
The steel gear is often provided, but rarely replaced. Good luck!
Al A., '84 245GLT, advanced entropy labrat
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Motor mounts? Other than that, I concur. The original B18 in my PV started making a sound exactly as you describe - sounded like an old diesel engine. It would even fade away somewhat if the revs went up. This was near the tail end of a highway trip, and I pressed on another 30 miles or so before getting home. And then I drove it about another 15 miles back and forth to a shop (who very kindly diagnosed it as a timing gear within about 10 seconds of listening, but was too booked to do the job).
When I took the timing ocver off the fiber portion of the gear was so loose on the hub that it practically fell off. The only thing keeping it working was that the steel hub had some fairly large splines that were still engaging in some grooves int he gear, and the torque of the gears against the tooth angle tended to pull the gear back against the hub. But it was definately on the N-th stage of failure, I would have been lucky to get 10 more miles out of it, best guess, before the abused remnants of the fiber gear decided to not pplay with the hub anymore. I think the most abusive time for the gear, oddly enough, was at idle. When going slow the oil pump has less drag and the valve springs can push the cam forward as they pass 'TDC' on the cam lobes, then the cam yanks backwards as the next lobes starts pushing. This back and forth really exacerbates any slack on the cam gear or the thrust block. When revved up, though, the oil pump makes more drag (my theory) and the cam gear gets into a constant pull - thus the lessened clatter.
My advice - if you don't fix it now at home or you'll be paying for a tow from the side of the road. Luckily enough if the gear totally goes it won't damage the top end of the engine - the pistons don't hit the valves of a B18/B20 that is anywhere remotely close to stock. (Shaved heads, decked blocks, big valve lifts - GOOD LUCK!)
--
I'm JohnMc, and I approved this message.
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Motor mounts? Outlandish but true. The particular 122S ran like a haybaler toward the end, and seperated a mount.
I defer to John Mc's judgement...err on the safe side, don't be stranded at the side of a motorway.
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I guess it jumped a tooth or two and really started shaking? I could see motor mounts breaking when you describe it like that!
I used to break motor mounts in my 122 in high school by doing stupid human tricks. Power-brake burnouts, drag racing friends in Camaros and Mustangs (I'd stay ahead for about 1/8ths of a mile, then inevitable the cubic inch advantage would overcome the old 122). I changed a lot of u-joints too. And eventually the differential decided to self destruct as well...
--
I'm JohnMc, and I approved this message.
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