I am trying to find some replacement big end Connecting Rod bolts for my Mk 2 1987 16v Golf rebuild after £125k miles. VW does not say they are single-shot, but opinions vary on whether I should replace them or not. I think the correct part number that I need is 048 105 425. I cannot find that in stock anywhere, but there are other similar big end bolts available, including: 052 105 525 A, 056 105 525 B and 056 105 525 C - all of these are available. Is it possible to use any other bolt as an alternative to mine like-for-like Can I have my connecting rods machined to take any of the other VW bolts? Should I buy pattern parts? E.g. Febi Bilstein 02126 Or should I just bang the originals back in and torque them up and see if they go cheesy - then decide!?? Views gratefully received.
I had exactly the same issue when I recently re-built my '88 16V (KR). Many people re-use them but the manual indicates tightening at 30Nm + 90° (if I recall correcty). The fact the extra 90° angle is noted, means to me it is a stretch bolt and one time use only. Just like a cylinder head bolt. I read through different VW manuals from different countries and eventually found one where it was mentioned they had to be replaced! As I suspected. This doesn't mean they will break if you re-use them, as proven by many people. But I also preferred to replace them. Be careful if you decide to re-use them, the manual tells you that when tightening the end cap to check the big end bearing play (with plasti-gauge), you can only torque to 30Nm but not apply the extra 90°. This clearly shows it's a strecth bolt and they don't want you to strecth is simply to check the play. But just like you I had a very hard time finding them an eventually found them on a Dutch website: https://www.bolku.nl/Webwinkel-Prod...500-2000cc-8V-en-16V-behalve-D-TD-en-G60.html For your information, the big crankshaft bolt is also a one time use stretch bolt and was also hard to find!
i am in the same situation, i ordered a complete set of my local vw dealer just prior to lockdown and they called this week to say they are now obsolete, i tried finding a new genuine set but no luck. i have just ordered a set of febi bilstein from a web site SPARETO. the cost was £33.86 in total Although not genuine i will see what they are like
Thanks ger16v I think thats where I am too. How easy are they to change? Can I tap them in and out with a hammer in my garage, or do i need to get them pressed out and in by an engine workshop?
Thanks Spyrock, Good logic all makes sense. I'll go with the pattern bolts I think. Sorry if ive duplicated messages. Getting used to the way this works.
Put them in a decent vise with aluminum jaws and clamp them at an angle so the clamping area is bigger. Then tap them out with clean straight blows on the end of the bolt. To fit the new ones I pulled them in slowly by tightening the old nut against a piece of hard plastic. This was to make sure the plastic would deform instead of stretching the bolt.
