Turbo bolts missing?

[Banshee365]

Doing alot of work on my buddies truck that required removing the turbo. I've got it off to finish the work in the morning. I spent quite a bit of time looking for the 3 mounting bolts. I didn't have any trouble with the rear bolt. I simply removed the v-band clamp on the downpipe and was able to scoot it over a little and send a 3/8 drive 6-pt socket straight down on it and break it loose without a problem from the top. The 2 front bolts next to the pins were not there and there isn't any evidence that they were ever there. I also checked my truck which recently came from the dealer with an oil cooler rebuild and EGR cooler replacement under warranty, and it also doesn't have the front bolts. What's going on here? I havn't read anywhere that the turbo can be held in place by only the back bolt. Has anyone else seen this?

[powerhoghp]

I'm fairly certain there should be bolts in all 3 holes.....

[m-chan68]

It's very common for the front bolt to fall out for some strange reason.

[powerhoghp]

Originally Posted by m-chan68

It's very common for the front bolt to fall out for some strange reason.

Surely not both?...... Shouldn't they be torqued in enough to resist vibration unless under constant idling for years on end?

[TooManyToys]

The turbo and it's pedestal have a high degree of harmonic vibration. Bolt torque is not an answer to preventing the bolts from loosening.

There are a few ways to preventing a bolt or nut from coming loose. While a common method is to use an adhesive compound on the threads, it can be counter productive when it comes time to disassemble the parts for maintenance. The rear bolt is a good example of when things go bad and using thread locker would just make it worse.

A decades old method used before the ease of thread locker compounds and still used in military and aviation is to use safety wire ties to prevent the bolt or nut from unscrewing. It's not that hard to do once you learn the basics and using wire to retain these bolts would be the best choice IMO.

Here is a good write-up about using the techniques:

Safety Wire Techniques

[Banshee365]

After pulling the turbo I found one of the front turbo bolts laying against the HPOP cover. It looked like it has been there a LONG time as it is covered in grease and dirt. Would using split lock washers help at all or is safety wire the way to go? My truck just got out of the shop for a warranty repair involving removing the turbo. I'm wandering if I should take it back and ask where my front turbo bolts are and expect them to replace them. How crucial are these bolts to have installed? Thanks for the replies!