Common bolt material and qualities

[CodeWarrior]

I am rebuilding a Liberty that I purchased some time back. When I got it, the engine had been removed to the cargo compartment, and a number of items are missing, specifically in this case, the timing chain cover, engine mounts and bolts, and the bell housing bolts.

Ordering these from an OEM retailer will be expensive. There is a Fastenal just down the road that has the majority of these bolt sizes in stock. I do not however know what material or qualities I should be getting. For instance, the Bell housing bolts are 7/16 - 14 X 2.00 (they are listed in the parts catalog at .437 inch - thanks Chrysler). Fastenal has several, but I am thinking that this Steel with Zinc Finish is the closes that I will come. What are the OEM bolts properties? Steel Hardened?

 

[M38 Bob]

Unless in a particularly high stress application, most automotive bolts are simple grade 5. You can easily cut em with a hack saw. High stress, they will be grade 8. If you buy grade 8 you'll only be out a couple/three bucks additional and be using a better bolt than most original. with the NOTABLE exception of head/crank/rod bolts. For these go OE (or high performance specialty aftermarket) only.

OR, go to a U-pull-it salvage yard and do a bolt scavenge.

Bob

 

[1stdeuce]

I'll agree. Grade 5 is good for all of that stuff. OE bolts are often flanged, so I use a grade 8 washer under the head. Use the next size smaller washer for a better fit. For metric bolts on the engine, 8.8 is usually sufficient, and 9.8 is a bit higher strength. TSC and Big R let you buy by the pound, which you is much cheaper. I've never had a problem with bolts from either.

 

[teeje]

Don't get used head bolts, main bolts, or bolts for the cam. Buy original OEM bolts. You said it was sitting for awhile so I wouldn't trust em. But if you're confident that they're where they're supposed to be, at least replace the head bolts. They're Torque to yield bolts and you never re use them


2002 Jeep Liberty 3.7L with brand new engine
Sent from my iPhone using Tapatalk

 

[M38 Bob]

Don't get used head bolts, main bolts, or bolts for the cam. Buy original OEM bolts. You said it was sitting for awhile so I wouldn't trust em. But if you're confident that they're where they're supposed to be, at least replace the head bolts. They're Torque to yield bolts and you never re use them


2002 Jeep Liberty 3.7L with brand new engine
Sent from my iPhone using Tapatalk

True enough with torque-to-yield.
Bob

 

[ArtO]

Metric 8.8 bolts are equivalent to sae grade 5. Metric 10.9 bolts are equivalent to sae grade 8. As a general rule if its going under the vehicle use 10.9 or grade 8.


I sell hardware for a living. Fastenall is 1 of our competitors. Depending on what there are in your area for vendors, Fastenall might be your best bet. I personally wouldn't go there for anything. I have never heard a good thing about their prices or policies. YMMV

Art