What is the real torque value for the front crank bolt without special tool?

[Grubby]

I have read 425 ft lbs somewhere on the web. I am wondering how will I achieve that torque accurately without the volvo special tool 5188? Or should I just invest in that tool? I have a 3/8 torque wrench, is the volvo tool for a 1/2 torque wrench?

Also, it looks tight trying to get to that rear cam sprocket. Can it be done without a special tool?

How about a "sticky" listing good tool sources for the timing belt jobs on this motor?
Thanks!

[Jason]

332lbs


Jason

[piper109]

Originally Posted by Grubby

Also, it looks tight trying to get to that rear cam sprocket. Can it be done without a special tool?

How about a "sticky" listing good tool sources for the timing belt jobs on this motor?
Thanks!

I usually use a 19 mm box end wrench that has slight bend in it. Face the bend forward.

Steve

[Grubby]

Originally Posted by piper109

I usually use a 19 mm box end wrench that has slight bend in it. Face the bend forward.

Steve

How do you torque it to spec with the box end wrench?

[Jason]

Get the front torqued and get a feel for it. If your torque wrench doensn't have a head that pivots, just get the rear bolt tight. Worst that can happen is your timing could get off. The front sprocket is whats important!

Jason

[v8volvo]

You don't really need that much torque. The really key thing is making absolutely sure that the mating surfaces are super clean and dry. If you really get them cleaned up well, they hold just fine without all that much torque.

No need to break out the sandpaper, just carefully wipe all the oil away with a clean rag, make sure the rear cam seal is not leaking, make sure you use the good 1-piece neoprene valve cover gasket to ensure the valve cover won't leak everywhere, then put it together. I use just a clean paper towel to clean the surfaces then wipe down with alcohol or brake cleaner, whatever you prefer, to ensure everything is perfectly dry. I clean the bolt threads with a brass brush, then lightly oil the threads with synthetic motor oil. I also lightly oil the contact surface between the bolt head and the thick washer that goes between it and the cam pulley. By doing all this you ensure that all the torque you apply goes towards achieving max possible clamping force between the pulley and the cam, rather than fighting against friction. That way you can achieve plenty of squeeze where you want it without having to put a ton of torque on the fastener.

Make sure you have a counterhold tool to hold the sprocket with as you tighten the bolt -- you don't want the front timing belt doing all the work of holding things still while you apply torque, it is not good for it. The torque you are able to apply with a box end 19mm wrench will be enough to hold it if everything is clean.

The tools you really need for this job are the cam counterhold (9995199) and the crank counterhold (9995187 or 5188, I forget which). These are the essential tools that you cannot do the job without -- you need them to achieve sufficient torque on the crank bolt and to tighten the front and rear cam bolts without hurting the main belt and disturbing the engine's position. Rotunda Tool sells both of these tools. You also, of course, need the cam locking plate and the pump timing tools (dial indicator and holder), but you can make do with the VW style units on that front if that is what you have available to you. They aren't as nice as the Volvo ones (require removal of the rearmost valve cover studs for using the cam plate, and removal of the vacuum pump for using the dial indicator, both of which are not necessary with the real Volvo tools)... but they suffice to get the job done.

Don't forget to unhook the cold start device when you are timing the motor -- and also take the opportunity to ensure that the CSD is operating properly, giving full travel and release, etc while you are in there.

[Grubby]

Thanks for the level of detail you provided. This helps alot. I am surprised that you add synthetic oil. I mean, your explanation makes sense, but I have heard that was a no-no because the torque values took into account that the surfaces were free of oil, so that by adding oil you run the risk of over-torquing. I'm obviously no expert here, so maybe I have some learning to do.

[v8volvo]

The point is to reduce friction by using the oil (only on the threads and under the bolt head -- don't let any get on the surface between the cam and the sprocket, for obvious reasons...). If you reduce friction, then you can get the same holding power with way less torque on the fastener. The idea of my advice is to use *less* torque than the engine manual advises. The torque spec for that bolt is 85 ft-lbs, but if you use the above method, 40 or 50 lbs will be just fine, and it will be MUCH easier to get it back apart in the future. It also means you can do the job without requiring the special tool that you would need in order to actually get 85 ft-lbs on that fastener -- it is an S-bend wrench with a 19mm box on one end and an attachment for a 1/2"-drive big torque wrench or breaker bar on the other. If you are using oil and getting the mating surface super clean and dry, you can just use a regular 19mm box wrench (or better yet, a ratcheting box wrench with a flexible head -- makes the job even easier) and use much less torque than the book calls for, and have faith that it will hold just fine and not slip. Then you won't be cursing yourself the next time you need to take it apart, either.

[RedArrow]

This is very good advice for the diesel brickers, worth refreshing after ten years.

[Jimarilo]

Are the four bolts and the main bolt in the crankshaft pulley .......stretch bolts ???

Do they have to be replaced once they are undone ??