2008 HHR SS 2.0. I need part numbers for the two timing chain guide bolts and the balance chain guide bolt. They look identical, yet dealership is giving me different part numbers. 11588522 & 11518828

 

The front guide upper bolt is replaced by one of these

https://www.rockauto.com/en/catalog/...ide+bolt,12016

Improved guide and a new bolt for the bottom

https://zzperformance.com/products/z...ng-chain-guide

Like this

https://zzperformance.com/products/z...ain-guide-bolt

 

They don't look identical to me. The one on the top has a thinner washer/shoulder.

 

Lots of theories on the front guide upper bolt. Does a broken guide make the bolt come out, or does a loose bold cause the guide to break, or something else? There are different improved bolts, from a socket head cap screw with a sleeve (stronger,) to a shoulder bolt that looks more or less the same as the original, but made of better steel, to the “problem solver” design that tosses the bolt from the original design and instead uses a stud on a replacement for the access cover to position the top of the front guide.

I wonder what GM’s official supersede list looks like, and if it’s the same for all Ecotecs. Confusion is sure to continue, though.

 

Then there’s this kit from OTTP

https://www.overthetopperformance.co...olts_p_88.html

The bolt for the tensioner shoe doesn’t have the thick shoulder

The upper replacement bolt design was because of the broken bolt problem and having to remove the head to get the bolt out.

 

My concern with these “problem solver” designs is that there is absolutely no reason to assume that the access hole is precisely in the same position as the bolt inside, either by design or by manufacturing tolerances, nor would there be any effort to precisely control the height or parallelism of the mounting surface; it’s intended to be nothing more than an access hole. So, we have no idea where the part ends up in any of the x,y,z axes, or even how straight it is. Seems to work out OK, though.

 

The holes are pilot drilled at the same time then C&C machined to specifications, no reason to think that they are going to be out of whack. I’ve installed several from different manufacturers and had no issues


This Melling bolt has been in the BlackSwan for two timing chain sets since 2019. Has 125,000 miles on it ! I also installed the ZZP front guide last timing chain set and it has 45,000 miles on it , no issues.

 

So cloyse says to torque both black shoulder bolts on the black chain guide to 89 in/lbs. but DMMworks says 106 in/lbs. which is it?

https://www.ddmworks.com/assets/imag...uild%20Kit.pdf

 

I do the 106 , however I don’t recommend that black guide anymore

 

… Instead, this on from ZZP, right? (Both shown for comparison.)