Head bolt torque? 94 LC

[EagleCap]

I'm not comfortable with the 90 degree thing. Just seems that the torque can be to different on each bolt. Does anyone have a specific ft/lb number? It's just to much work to replace a HG to depend on something so subjective.

Otherwise I'll pour Steel Seal in and pray.

Thanks
Don

 

[Ebag333]

(As per my '97 FSM)

The first set is 29 ft-lbf.

The second and third are to turn 90*.

 

[Chaldaean]

Does anyone a specific ft/lb number?

If you are looking for a final torque value, there isn't one.

It's just to much work to replace a HG to depend on something so subjective.

To lessen the subjectivity, you can use one of these to get precise 90 degree turns (it was really useful for me for the bolts near the firewall as you can't get a full 90 degree sweep): Amazon.com: Lisle 28100 Torque Angle Meter: Automotive

 

[IdahoDoug]

Here's what I do. Do the tightening per the FSM (29 ft lbs, 90 degree, 90 degree). Then check the torque on all the bolts and bring them all up to the torque setting of the tightest one. Uniform tightness, no screwing around (heh). Be sure to clean the threads with a tap and ensure the bolt holes are dry (no oil/water in bottom).

DougM

 

[EagleCap]

Close enough. Thanks Idaho.

 

[jlg32281]

I would replace the stockers w/ ARP studs and torque them to 85 in three stages. This comes from the Supra world.

 

[EagleCap]

I saw the supra thread. Where did the 85 ft/lb number come from?

 

[Snowrun]

I think the bolts torque at about 92ft/lbs if you follow the FSM method.

 

[IdahoDoug]

I wouldn't use a specific torque figure that Toyota did not provide for the 4.5L.

 

[jlg32281]

On the Supra's, if you use ARP hadware and the ARP lube, 85 is the number. I finally found it in all my Supra info. This is the way mine will be when I do mine.

 

[VanGo]

EC-

Trust the FSM. I completed my first (ever) HG repair back in January of this year, and thanks to IdahoDoug's HG DVD, MUD and my own determination I am enjoying the benefits of this DIY 10K later. After having the OEM head bolts spec'd to the FSM standards I completed the 2-90* final torque values this scared the snot out of me, but it worked. Take the advise given to chase threads, remove any containments, etc... and move forward with this repair. The knowledge you gain from this repair is invaluable and frankly your comment about "....Otherwise I'll pour Steel Seal in and pray." has me more concerned then the fear of shearing one of the head bolts off!

Good luck!

 

[EagleCap]

I followed the FSM. 29ft/lb, 90*,90*.

Then followed the suggestion from IdahoDoug. Found the top torque and made them all equal. That at least satisfied my OCD for a number.

105 ft/lbs was the final number. Max movement on any bolt was maybe 1/8 turn.
Seems to have worked.

Thanks again all

 

[green73]

I just got done with my HG. Here was my mistake. I thought the block was dry, and went with the 29 ft/lb, 90/90 settings. HG still leaked. I hit up search here and found that the threads have to be dry for this to work, and the threads cleaned. So, I took the cams back out and the head bolts as well. I then blew air into the holes to dry them out. Well that didn't work as it seems that the bolts are into water jackets. I had coolant coming out of the throttle body coolant lines as I blew air into the head bolt holes. So, I put it all back together as per the torque specs again and threw another 1/4 turn on them. Fired it up and no leaks or smoke out the tail pipe. I know this isn't per spec and the torque ratings are probably not equal, but it is working so far.

 

[IdahoDoug]

You are mistaken that the head bolt holes go into the cooling jacket. I suspect you were using an air hose with a large outlet, not the small 1/8 inch metal tip that will go down into a bolt hole to blast it clean? If so, you were blasting a column of air that was also going down into adjacent block holes and pressurizing enough to push water out the throttle body hoses. I did the same thing while generally blasting the block deck off with air.

Not to put too fine a point on it, but if you had HG leaks then either coolant or oil or both was migrating under the gasket and the gasket should have been removed and everything recleaned and dried before you retorqued. The gasket should be put down onto dry and clean surfaces to seal optimally. YMMV

DougM

 

[green73]

I put a length of 1/8" tubing on my blow gun and ran that down to the end of the bolt hole then blew air in.

I do agree with the clean surface deal for seating the HG before torquing it down. I got frustrated and in a hurry and it didn't even cross my mind till now. Great something to sit in the back of my mind and bother me. Oh well I am not taking this thing down again till something breaks or blows!

 

[Midgainc]

I should have my head off tomorrow. what is the spec on re-using oem head bolts? my rig has 347k miles, 96 model. I have been replacing everything in sight under the hood and elsewhere. Does the ARP studs allow you to get it tighter?

 

[BILT4ME]

I should have my head off tomorrow. what is the spec on re-using oem head bolts? my rig has 347k miles, 96 model. I have been replacing everything in sight under the hood and elsewhere. Does the ARP studs allow you to get it tighter?

Go to the "Resources" section above and download the correct FSM for your truck. It's very important.