Cameron707

so first off I read the device manual for torquing down the head bolts on my 91 4runner 3.0 but I'm still a lil confused. I was hoping someone can flat out tell me the order and procedure to tighten my head bolts. How many pounds and what order I should torque then down in. I'm sorry I know this probably bugs u guys being asked over and over again. But I read the link on here and still wasn't completely clear.

scope103

Seriously? You read the Factory Service Manual (device manual??) and you think someone "telling" you how to do it would be simpler than the pictures?

http://web.archive.org/web/201208130...68cylinder.pdf page 77

Maybe if you told us what is confusing you. It can't the the order. The two-step torquing seems pretty straightforward to me. I use a fine point yellow paint marker http://www.dickblick.com/products/el...paint-markers/ to mark the head bolts.

TurboWood

If I could make a guess as to what was confusing it would be the comment about multiple passes. The process is that you want the torque wrench to reach the desired torque, but you don't want to go to that target immediately. This means you start with bolt #1 and tighten it about 1/2 turn after resistance is felt. Then move to bolt #2 and do the same. Do this in the sequence outlined until all the bolts reach the torque target. This will require repeating the sequence multiple times. The goal is to slowly torque the head down. If you do one all the way it will risk warping the head. For the second step where you are torquing to an angle you can do the full 90degrees on each one directly. This is ok because you seated the head in the first step.

I hope that helps.

Daniel

wyoming9

iTrader: (1)

Pray tell what is a Device Manual ??

I am pretty sure I do not have any!!

Look at the picture

RJR

This is not entirely correct. The only time you read the torque from the wrench is to set the initial snugging of the bolts to 33 ft-lbs. From there on it's all angle "torqueing", and you can put away your torque wrench and just use a big breaker bar. As @scope says, put an index mark on each bolt. The first pass you tighten them all 90 degrees (in the order specified), and then you go back and tighten them another 90 degrees, in the same order. Then do the 6-pointed head bolt to 30 ft-lbs and you're all done.

scope103

I think TurboWood is talking about the general process of torquing multiple fasteners. You want to bring them up evenly, so you do it in several passes adding a little torque at a time. (In the factory, they have a device with 10 rotating heads that tighten every bolt at the same time.) It never hurts to follow that procedure.

But 33 ft-lbs isn't very much for a 12mm bolt, so you can apply that small torque all at once in any order you want. It's just to get them to all start from the same place. Then for the head, you will apply two 90° additional turns in the order indicated.

TurboWood

I've not built this engine so I won't make any guarantees, but it's generally a bad practice to go to the full torque spec in one go on a head. I know this head has a 2-step process, but the service manual specifically says to take multiple passes for this reason. The last pass should have all of them at 33ft*lbs. Ideally this would be done with the bolt rotating and w/o multiple *clicks* on the wrench, but that's getting nit picky. Then, as others said, do the 90deg rotation one by one in the same sequence.

What you might find if you go directly to 33ft*lbs immediately is that after doing a full pass the first few bolts are no longer at 33ft*lbs. This happens because of the small angle between the head and block that is created by the uncompressed head gasket. One bolt just wont compress the whole thing.

Short version: follow the service manual.

Daniel