Turbo mounting studs broke off...

[dhirocz]

So one of these decided to let go today. I just had the whole thing apart recently. They were torqued with a torque wrench to 75 ft/lbs.

One thing I dont recall when I put the turbo back on was if they were torque to yield bolts. I wouldn't think so, but I could be wrong.

At least it happened unloaded 30 miles out, unloaded, and I was able to keep feather pedaling it home but boy did it not run well under any boost, understandably. Mileage dropped a good bit too. At least it waited until I got out of the mountains... I'll end up replacing all 4 and the gasket for good measure. Is there a service life or anything I need to be aware of, torque to yield, or maybe it was just a bad stud?

[Brock]

Me and 2 of my friends all had bad luck with turbos at the same time and all 3 of us had our turbo studs back off after install and had to be retorqued. I cheaper out and reused my studs but my one friend bought all new and still had the same issue.

[Nilao]

I've personally had my turbo off 4 times in the last year. Used same nuts and studs every time. I anti seized them and torqued to 75 ft-lb and no issues with them backing off or breaking. I torqued mine in a X pattern. Don't know if that makes a difference but it's just what I've been trained to do.

[JMBT]

I did the exact same as Nilao, mine has been off 4 times in the last couple years and only the last time when I replaced the manifold it got new studs and nuts. Always anti seized, but I torqued mine to 80ft/lbs and in an X pattern. Anyway no problems as of yet.

[Rawze]

(09-01-2017 )dhirocz Wrote:  So one of these decided to let go today. I just had the whole thing apart recently. They were torqued with a torque wrench to 75 ft/lbs.

One thing I dont recall when I put the turbo back on was if they were torque to yield bolts. I wouldn't think so, but I could be wrong.

At least it happened unloaded 30 miles out, unloaded, and I was able to keep feather pedaling it home but boy did it not run well under any boost, understandably. Mileage dropped a good bit too. At least it waited until I got out of the mountains... I'll end up replacing all 4 and the gasket for good measure. Is there a service life or anything I need to be aware of, torque to yield, or maybe it was just a bad stud?

Bad stud or mis-alignment. Helped many many people where the turbo had to come off,.. never had one even come close to breaking or having issues at 75 ft-lbs. -- Maybe you should check your torque wrench to see if it is accurate as well?

BTW: for thos who may not know,.. the studs are threaded on both sides and are replaceable even if they were to break.

[Signature620]

I usually tighten the inner nuts first and the top/outer ones last so that the inner ones get a little bit tighter. 75ftlbs isn't really enough for them either, just get a fair size bar/ratchet and do them right up.

[dhirocz]

I'll be bringing the truck home tomorrow to replace them all and the gasket for good measure. Didn't use antiseize, but did clean them very well before torquing. I'll use two of the other nuts and double nut the remaining studs to pull them out.

I'll take a closer look when the turbo comes off. Might just have been a flaw in the old one. Kind of curious now.

Torque wrench is about due for recalibration, but If it's off, it shouldn't be that far off, but I could be wrong. Never hurts to check.

Since it ran 'kind of off' for a little bit, should I unplug the ECM for a bit before I start it back up, like on older cars with older ecm's, or would that be unnecessary?

If this is the worst thing to happen in the last 10k miles after putting it back together, I can live with that!

While I'm at it I may as well check the manifold to head torques too. Those we're all cleaned, tapped and antiseize up. I can't remember the torque spec on them...35 ft/lbs?

[Signature620]

44 ftlb for EGR exhaust manifold / 35 ftlb for cm570 style exhaust manifold.