Head nut re-torque question.

[ESokoloff]

After reading this thread, I decided to check/adjust my 03 RT's (with 42k) cam end play.

The process involves loosening one of the four head nuts to allow for the required adjustment.

I had marked the location of the two nuts (one per side) before loosing & found that upon re-torque, they were now 90º c.w. (farther) then to start.

I decided to re-torque all the nuts for the sake of consistency.

I read some were that the nuts/studs should have oil on the the threads when doing this.

My question is should the M 10 screw also have oil on its threads

 

TIA

[Joe Frickin' Friday]

Manual doesn't say, but since these threads are probably already slicked with oil anyway, I'd say it's expected. I would not worry about it.

[T__]

After reading this thread, I decided to check/adjust my 03 RT's (with 42k) cam end play.

The process involves loosening one of the four head nuts to allow for the required adjustment.

I had marked the location of the two nuts (one per side) before loosing & found that upon re-torque, they were now 90º c.w. (farther) then to start.

I decided to re-torque all the nuts for the sake of consistency.

I read some were that the nuts/studs should have oil on the the threads when doing this.

My question is should the M 10 screw also have oil on its threads

 

TIA

 

Eric, that lube process is on newly installed cyl head nuts.. Those nuts have been operating in & around lubrication since the engine has been run.. There are NO seals on the studs & nuts so trust me when I say they are well lubed by now due to seepage between the nut & stud..

 

No re-lube required of the re-torque process..

 

That 90° extra partial turn on a re-torque is perfectly normal on a retorque & is about what I usually find after some miles go by.. That is why the low initial torque setting then torque to stretch on the 180° additional.. Too darn easy to over torque/over tighten if just using a final torque setting..

 

Twisty

[ShovelStrokeEd]

I wouldn't worry about it for this iteration, Eric. I might be able to provide some insight as to what is going on. It is really one of two things, maybe 3.

 

1. Threads on the nuts are stretching. I would replace them next time you do this.

2. Studs are stretching, a bit worrisome as that indicates that they are going beyond their elastic limit with normal torque. Not good as that means replacement of the studs. Not terrible, if you do them one at a time and double nut them to remove the old ones.

3. The studs are pulling out of the crankcase. Bad juju here. Might be a good idea to pull the studs and replace them prior to another tightening and make sure that the studs are fully threaded into the block. You should be able to get them in by hand almost all the way. Difficulty in threading in a new stud would be an indicator that the threads in the block have become damaged.

[Anton Largiader]

My question is should the M 10 screw also have oil on its threads

No, the oiled threads part is for the angle-torque fasteners. The M10 is a straight torque.

 

And it's perfectly normal, IMO, for the re-torque to need a bit more rotation than the previous torque. If that weren't the case, we wouldn't need to re-torque, would we? The head gaskets compress, etc.

[ESokoloff]

The head gaskets compress, etc.

 

That was my thought (after much pondering) as well as the fact that two different wrenches were used (600 mile/42k mile) so that MAY be a factor.

In any event I now have a base line for any future work.

 

Thanks for the input gentleman