Snapped camshaft at idle.

[Nevadan]

Well.....very stupid and difficult lesson learned. I was recharging the air conditioning system after installing a different A/C compressor and while at idle I heard a sharp clank and the engine died. I pulled the belts to access the timing belt cover and the belt was snapped. Grabbing the front cam sprocket, it just turns and can be pulled out about an inch, therefore snapped cam.

I know I'll need a new camshaft and will know more once I pull the head off next weekend. Anyone who has a cam keep this in mind as I continue the work later.

My error was in not waiting to fabricate crankshaft holding tool so I could replace the belt. That's the stupid lesson learned....patience!!!!

This is my recently acquired '85 745 wagon that is in great condition.

Patience, patience, patience.

[v8volvo]

Wow, that's the second one of those on here in the past week or two. Sorry to hear the unfortunate news.

At least it's in your hands where you'll be able to fix it. As I recall this was for sale at a used car dealer? Hate to imagine what its next fate would be if this had happened to someone who just bought it as a commuter....

Pull the cam and check for lifter damage; since it happened at low engine speed and the cam breaking acts as a safety valve of sorts, you might get lucky and get away with minimal damage.

Anyone who has been running on a belt of unknown age or unknown installation method should be taking heed now, before this turns into a full-scale epidemic...!

[745 TurboGreasel]

Originally Posted by v8volvo

Anyone who has been running on a belt of unknown age or unknown installation method should be taking heed now, before this turns into a full-scale epidemic...!

+1, the crank bolt absolutely must to be tighter than anything most people have ever installed on a car. I think failed cambelt service has killed almost as many cars as cooling system/HG failure.

I weigh 150, so I stand on the end of a 2'3" lever to tighten the bolt, and use threadlocker.

Unfortunately, when a seller claims it was done, there is a real chance it was done wrong.

[Nevadan]

Originally Posted by v8volvo

As I recall this was for sale at a used car dealer?

Pull the cam and check for lifter damage; since it happened at low engine speed and the cam breaking acts as a safety valve of sorts, you might get lucky and get away with minimal damage.

Yes, this was the car at the used lot in Carson City, south of Reno. And it was running soooooooo good!

I agree with you that the cam acts as a sort of shear bolt so I'm thinking there will be minimal damage.

I never thought about just removing the snapped camshaft and testing the lifters to see if the valves all travel as they are supposed to. I was going to pull the head and inspect for bent valves but may take your suggestion and wait on pulling the head. I could replace the cam, which I still need to find and will post separately in the "parts wanted" section, and run a compression test to see if all is o.k.

I did start the tear-down as if I'm going to pull the head and got the injection pump bracket bolts loose to remove the rear belt and they were quite difficult. I loosened the pump timing bolts to move the pump as far out of the way as possible but the 17mm bolts were REALLY tight. Is there a special wrench for this job? I was able to get the rear one loose but only after my top secret method of putting valve grinding compound on the face of the box end wrench to get that little bit of extra grab. I had to use a cheater bar also! I've read the method others are using to time the pump by making the adjustment at the rear sprocket but it still seems there may be minor adjustments necessary.

A few questions:

1. As mentioned above, is there a special wrench for the 17mm bolts that mount the IP bracket to the block, the ones to adjust the belt tension?

2. Is there a special 6mm allen tool to reach the IP timing bolt that's buried back between the mounting bracket and the pump?

3. Does anyone have a cam for sale?

4. Who sells fresh timing belts? Rock Auto and others have them but have they been sitting on the shelf for 20 years?

[ngoma]

Originally Posted by Nevadan

1. As mentioned above, is there a special wrench for the 17mm bolts that mount the IP bracket to the block, the ones to adjust the belt tension?

I use what I have; Craftsman combo boxend wrench. Tedious work, lots of small turns. Maybe a gearwrench ratcheting boxend wrench would help? Once I removed the fuel filter housing and wrenched from below, which seemed easier. Some hoist the IP and heavy bracket during removal with a cherry picker (helps maintain slack on the bolts) (and saves your back when lifting it out).

Originally Posted by Nevadan

2. Is there a special 6mm allen tool to reach the IP timing bolt that's buried back between the mounting bracket and the pump?

Ballwrench?

Originally Posted by Nevadan

4. Who sells fresh timing belts? Rock Auto and others have them but have they been sitting on the shelf for 20 years?

I recently bought a fresh Continental belt from gowestyautoparts.com.


You'll want to cover up those distributor valves on the IP pressure head. Wrap some tinfoil around them if you don't have correctly sized plastic caps. Important to keep foreign matter out of the fuel system.

[Nevadan]

Thanks for the reply. Got it on the IP mounting bracket bolts, that's what I'm doing as well. I might heat, bend and grind a box end wrench to get at them. Mine were either over-tightened or rust/frozen so they shouldn't be as difficult to loosen or tighten in the future.

A ballend allen will do the job on that pump bolt. I will see if I can find a torx bolt to replace it and make it easier in the future.

I've never tried GoWesty, thanks for the tip.

I did cover the IP outlets after the photo, the next day. I was so frustrated with the cam breakage I left a lot of uncovered parts overnight.

[Nevadan]

Originally Posted by 745 TurboGreasel

+1, the crank bolt absolutely must to be tighter than anything most people have ever installed on a car. I think failed cambelt service has killed almost as many cars as cooling system/HG failure.

I weigh 150, so I stand on the end of a 2'3" lever to tighten the bolt, and use threadlocker.

Unfortunately, when a seller claims it was done, there is a real chance it was done wrong.

After standing right next to the engine when it popped I have to agree that snapped cambelts have probably killed a lot of these engine.

I'll post a picture of the tool I made. It worked VERY well! I was able to use a huge crescent wrench that rested against the frame.

[Nevadan]

In my tear-down I found one (possibly two!) missing and one loose bolt on the injection pump head. Just FYI and a comment on the durability of these pumps.