Stripped Thread Repair? - Large Timing Belt Roller

Working on replacing the timing belt of a non-running 2003 NB that I recently bought. A gorilla must have worked on the car. The large roller bolt is badly stripped as well the small top roller bolt. Since these are critical components that need to be strongly fastened, I want to repair the threads correctly. I am not comfortable with just re-threading using a tap. I've used helicoil before but not sure if it goes deep enough. Thank you for your input.

Could use an insert instead, should be strong enough.

Seatman said:

Could use an insert instead, should be strong enough.

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helicoil or time-sert? i've used helicoil before on a brake caliper and that has held up well. thanks.

Helicoil would probably do just fine.. I'm using them for some larger bolts to attach motor mounts to a much heavier engine that shakes worse than a tdi could ever dream of.. But, since your repair is a single bolt in a critical area, I'd use a time sert with red loctite.

EDIT:Or even better still: http://www.repairengineering.com/keensert.html

sent from my mobile look-at device

Time-Sert...no question what so ever.

Douglas

Can you thread new bolts in there to tell whether the holes are messed up? Might be non-issue. Keep in mind that the large idler pulley's bolt is torque-to-yield [TTY}, in which case that bolt is always going to come out looking distorted, and if it's been reused (don't do this!) then it'll likely look worse. TTY fasteners are supposed to give before the material they're going in to does. The small idler pulley is a concern, though it's at the top so at least you have working room there.

If one has a choice of thread repair devices I'd tend to recommend TimeSerts: I did one of my motor mounts with them (we're talking a fairly high-stress situation).

Helicoil will more than adequate. There will be little stress in the direction of the bolt's axis. Unlike the 18mm motor mount bolt which are holding the motor up. Most of the stress will be on the bolt itself.

Thank you all for your inputs. I re-threaded the large roller hole then installed the large roller using an old bolt just to see if I can torque it to 30 ft lbs. I was able to, so I installed the roller with a new bolt, torqued to 30 ft lbs with 1/4 turn. Upper small roller was also fixed just by re-threading. Also, applied blue loctite in both cases. I was apprehensive about drilling a perfectly perpendicular hole especially for the large roller. All is well. Thanks again.