• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Why would a timing belt crankshaft gear break?

VolvoLatAm

VolvoLatAm

Active member
Joined
Oct 4, 2019
Location
Colombia
In various volvo 240 facebook groups, especially among the "drift" crowd, I have seen them break their crankshaft timing gears...or shear the key off? How does this occur in the first place?
 
It can also happen because the gear is a machined casting. Too much sudden applied torque and it breaks. That's why you are supposed to buy the billet ones if you are racing. I think Yoshifab and definitely KL racing sell them.

The drift crowd needs to spend some time learning how to build a strong performance redblock. Don't they all follow Drifts n Lifts?
 
dl242gt said:
It can also happen because the gear is a machined casting. Too much sudden applied torque and it breaks. That's why you are supposed to buy the billet ones if you are racing. I think Yoshifab and definitely KL racing sell them.

The drift crowd needs to spend some time learning how to build a strong performance redblock. Don't they all follow Drifts n Lifts?
Click to expand...
yes it looks like they do
yoshifab.com

Yoshifab

Volvo performance and fabrication
yoshifab.com yoshifab.com
 
I had some of these made if anyone's interested. TAB LOCK
cranktabinstalled2lo.jpg
 
Last edited:
I've never personally had a bolt loosen. 80% of volvos I've owned we B21 or B23. But from all the loose bolts I've read about over the years, a whole lot of them, it sure seems to me those were all B230s.
 
240 240 said:
the rubber wears out on the b230 balancer, and starts vibrations that eventually loosen the main bolt
Click to expand...

That and people don't know how to tighten the bolt properly.

And or they don't have the special pulley holding tool.

The torque for that bolt is 60Nm plus 60°
 
Radtap said:
ugga till it don't dugga
Click to expand...
There's a reason why torque specs are given.

Too loose, and the bolt won't clamp things tight enough to keep them from shifting around and possibly damaging the parts, or even allowing the bolt to slowly loosen over time.

Too tight, and the bolt could pass through the elastic (stretchy) stage and into the plastic (permanently deformed) stage, where it again won't clamp properly, and the actual strength rating of the bolt (12.9, 10.9, 8.9, etc...) will change.
 
MasterBlaster said:
There's a reason why torque specs are given.

Too loose, and the bolt won't clamp things tight enough to keep them from shifting around and possibly damaging the parts, or even allowing the bolt to slowly loosen over time.

Too tight, and the bolt could pass through the elastic (stretchy) stage and into the plastic (permanently deformed) stage, where it again won't clamp properly, and the actual strength rating of the bolt (12.9, 10.9, 8.9, etc...) will change.
Click to expand...
Does it really matter when we are reusing the 19 year old pulley that has been taken off 6 times and reused over and over to pull 3 dinky china belts using the variable rate 9" long crooked bolt tensioner on mushroom accessory bushings?
 
You must log in or register to reply here.
Back
Top