Camshaft Sprocket Bolt Re-Torque?

neljoshua · October 31st, 2011, 13:40

About one month ago I did a TB change with tools and parts from metalmanparts.com (thanks a ton, btw!). I used the .pdf file here in the How-To section and torqued the bolt on the cam sprocket to 33 ft-lbs.

After reading an old posting today, however, I am starting to wonder if I should go in and re-torque it for peace of mind. I am not at all concerned that my timing is off or that anything else is wrong, but I do not want that sprocket to slip!!!

Here is the thread I was reading:

http://forums.tdiclub.com/showthread...et+bolt+torque

I will be more than happy to re-torque the bolt if it needs it, but I do not want to over-torque it, either.

Josh

dogdots · October 31st, 2011, 15:01

I torque alh cam pulleys to 40 ft lbs.

eb2143 · October 31st, 2011, 15:40

The gist I got from stories of spun sprockets was that if it was going to slip it would do it sooner than later; this is one reason why the PDF has you bump the motor over and then check that everything remains in time at the end of the job. If the surfaces were cleaned I wouldn't worry about it. Although it's easy to get worried, on the other side of the coin is that Drivbiwire has successfully changed thousands of them at 33 ft lbs. I *think* Herm Pasker uses 33 ft-lbs if I remember correctly from the check sheet he included with an early TB change. And hey, even I've changed one and successfully used 33 ft-lbs.

runonbeer · November 1st, 2011, 14:40

I set my torque wrench to 35ft-lbs

The thread in that link is loaded with fail.

neljoshua · November 2nd, 2011, 10:04

Thanks for the info! I may torque it a little more during my next oil change, but I am not worried. I did not want to be in a situation where it is *supposed* to be 40 ft-lbs and I only did 33 ft-lbs.

Josh

Powder Hound · November 2nd, 2011, 13:41

I think if you ensure that the inside of the cam sprocket is as clean as you can reasonably get it, and the nose of the camshaft equally as clean, the surfaces will mate well and not slip at the stated torque. Bare steel on bare steel pressed together - they get a little sticky.

In an online forum such as this, it is nearly impossible to tell if someone had one that slipped and it was not at all from dirt, grease, and/or oil on the mating surfaces, torque wrenches that are out of spec, or who knows what other detail the story teller didn't notice or couldn't determine.

AndyBees · November 2nd, 2011, 20:03

Here is some additional reading for those who are scratching their heads on this one. As Powder Hound said, being clean is important and is stressed in the two links below.

http://forums.tdiclub.com/showthread...=218960&page=2 scroll down to post #23 by Franko6.

Also, this link has a good write-up with reference to the above link.
http://www.myturbodiesel.com/forum/f...que-spec-1048/

The link in the initial post to this Thread is to a Post I made back over two years ago. I've since torqued several Camshafts at 40 lbs with no problems.