After lowering engine cradle--need to replace bolts?
#1
After lowering engine cradle--need to replace bolts?
2002 Monte SS 3.8 liter. Need to lower the back of the engine cradle to ease replacing the stabilizer bar and the rack,which is leaking.
Service manual says to lower the back of the cradle by removing the two bolts, and that's all it says. But if you go to the section of the manual where it actually describes removing the cradle, it says specifically that the two bolts must be replaced, not reused. The words DISCARDED and NEW bolts are in caps in the manual.
There's lots of descriptions of people lowering the cradle, but no one ever said they replaced those bolts.
Anyone here know the scoop on this?
Is GM saying that the act of loosening those two bolts make them weaker?
Service manual says to lower the back of the cradle by removing the two bolts, and that's all it says. But if you go to the section of the manual where it actually describes removing the cradle, it says specifically that the two bolts must be replaced, not reused. The words DISCARDED and NEW bolts are in caps in the manual.
There's lots of descriptions of people lowering the cradle, but no one ever said they replaced those bolts.
Anyone here know the scoop on this?
Is GM saying that the act of loosening those two bolts make them weaker?
#2
Technically, yes. If you are one to go with manufacturers recommendations the bolts should be replaced. They are torque-yield bolts, meaning they are stretched when they are at their proper torque settings. To re-use them exceeds those limits and there is some risk of damage if they break or loosen. With that said...the risk of breaking or loosening and causing damage IMHO is not as great as is the case with head bolts or strut mount nuts with the same recommendation to replace. I have lowered the cradle several times without replacing those bolts without a problem, but I'm a bit of a gambler. If you're one to go by the book and don't gamble, replace them because if they do break they might be a real PIB to get out.
Last edited by plumbob; 01-14-2017 at 09:40 AM.
#4
The same goes for me, we have reused the factory ones at least 5 times. But since you bring up this point, were getting ready to drop the cradle again next month, think I will tell them it is about time to use some new ones. Thanks for the heads up...
#5
Thanks guys. Since this is the first time the bolts are being removed, I'll re-use them.
As an aside, since I've never lowered the cradle before, do I need to do anything for the steering gear other than remove the pinch bolt? The manual is vague. Will just removing the pinch bolt let the steering gear come free from the intermediate shaft as the cradle comes down?
As an aside, since I've never lowered the cradle before, do I need to do anything for the steering gear other than remove the pinch bolt? The manual is vague. Will just removing the pinch bolt let the steering gear come free from the intermediate shaft as the cradle comes down?
#6
Support the ISS and don't let the steering wheel turn. Bleed the steering pump by filling the reservoir, start the car and turning the wheel all the way left then right about five times, keeping the reservoir near the full line during the process until there's no more air bubbles in the fluid in the reservoir. Don't hold the steering wheel all the way to the left or right for any length of time to avoid damage.