850 T3 head bolts

[bobra5037]

Any engineers out there?

The 850 engine (Eldorado and T2/T3) has a short engine stud bolt with a hex socket nut.  The nut sits under a screw in cap.  So, my questions:

1.  Why is this not a regular hex nut like all of the other studs?

2.  How do you get the nut off? 

It is frozen tight and I'm not sure if it's fused to the head or fused to the stud.  I suspect the former because it will not budge under extreme torque and I would have thought the stud would unscrew if it was just the nut seized to the stud.

I've tried force, lubricant, heat (albeit rather gentle), a toque wrench and percussion but neither of them will budge.  No problems with the other head nuts.

Cheers

Rob
 

[Antietam Classic Cycle]

Any engineers out there?

The 850 engine (Eldorado and T2/T3) has a short engine stud bolt with a hex socket nut.  The nut sits under a screw in cap.  So, my questions:

1.  Why is this not a regular hex nut like all of the other studs?

2.  How do you get the nut off? 

It is frozen tight and I'm not sure if it's fused to the head or fused to the stud.  I suspect the former because it will not budge under extreme torque and I would have thought the stud would unscrew if it was just the nut seized to the stud.

I've tried force, lubricant, heat (albeit rather gentle), a toque wrench and percussion but neither of them will budge.  No problems with the other head nuts.

Cheers

Rob

1. Because there's no room for a regular hex nut?

2. It'll probably need more heat and a good penetrating fluid. I like to heat the offending nut up, then spray it with CRC Freeze-Off. The thermal shock helps loosen things pretty well.

Put the other head nuts back on and torque them down to alleviate any stress on that nut.

[Moparnut72]

If you have a rattle gun set it on low and let the vibration work on it. Soak it with something like Liquid Wrench for a few days prior.
kk

[TOMB]

I would agree with the other comments here.However, just a thought the head has probably been off sometime in the past.And somebody forgot to put the washer underneath that hex bolt or excuse me, hex.Nut, so do these suggestions from the people above when you get it off.There should be a washer underneath it.It's not your regular diameter, washer.The hole is the same as the other bolts.However, the outside diameter is smaller and it may or may not be a wave washer.Take your time work at it.It will come loose with a big snap, and your arm will probably hurt.When it happens
TOMB

[n3303j]

Can't emphasize enough that you have the stiffest wrench combination possible so that no shock input is lost into winding up the wrench arm or hex key.