artemyk

I'm in the middle of putting on a new head on a 22RE. The cam comes from my previous head, and the rest is from a (different) rebuilt Toyota head

While tightening one of the bolts on the middle cam journal, I partially stripped the thread. To be honest, I wasn't even tightening it, it must have "sat" wrong or something -- it stripped with no warning or force whatsoever. I put a longer bolt in and it seems to be holding fairly well , though it won't torque down too tight. Is this going to cause me problems down the road? Should I drill it out , put in a helicoil, etc.? The rockers and headbolts are already in.

Also, how crucial is it to check tolerances between the cam and the journals? Things seem to be rotating OK. If its too tight, will it just wear down until it gets a good fit?

wyoming9

iTrader: (1)

Well a little late now .

Just like any bearing fit then mixing and matching the clearance can be to tight or to large

You did dress the cam followers ??

This is pretty much going to have to be like a new cam install it will need to be run in

Your messed up threads should be fixed This is a New Head like Brand new ??

Call who you bought it from see what the return policy is Machining Defect !!

Then it is your vehicle

4RunnerFreak12

Yeah definatly warranty issue! That's crazy

If they won't cover it helicoil would be your next option

It is certainly not "good enough" with longer bolt it is a critical component and must be torqued

artemyk

Ahhh ok, that does not sound promising.

This is a rebuilt head. I do have a warranty on it, but I'd prefer to pay for a helicoil kit (or whatever) than take the head off, drive an hour away, and put another one back on again. The intakes and exhaust are already on there.

To be honest, I did not have torque wrench that goes down to 15 ft lbs, so I just hand tightened them. Is it crucial to torque these down to spec? It's a bit late but I think I could take the head bolts and rockers back out (I assume this would be ok without swapping out the the head gasket and all? I installed a new head gasket and haven't run the engine at all yet). I could then retorque and helicoil the stripped one. Is there an easier solution, such as tapping a slightly larger size?

artemyk

P.S. What does dressing the cam followers involve? Sorry, really a newbie here

wyoming9

iTrader: (1)

Cam lobes and the cam followers (rocker arms) wear in together .

When you install a new cam(Different ) the Rockers need to be dressed so they are flat and smooth

osv

how much longer? it didn't bottom out in the hole did it?

you still have the old head? see how deep the bolt hole is, if there is room left you might be able to put in a longer bolt.

artemyk

Hi @osv

Those are great ideas. Unfortunately I don't have the old head --- traded it in when I bought the rebuilt one. Maybe somebody here knows how long of a bolt will go down there?

The whole issue with the bolts was strange. All of the bolts that came with the rebuilt head were a certain length, I would say around 3.5cm. However, two of the bolts were shorter, maybe around 2.5cm, looked to be the same thread and everything. The one that stripped was one of the shorter ones. So I just swapped it for a longer one. The longer one definitely didn't bottom out and tightened fairly well. However, if I put enough force on the socket wrench, it would continue turning very slightly though... I didn't push it.

Any idea of how bad it would be to undo the head bolts and then retorque w/o changing the head gasket?

scope103

This happened to me on the cam cap at the back of the driver's side. That cap has a locating collar that mates to a depression in the head, so using a larger bolt was not an option. The factory bolt is about 10mm shorter than the depth of the drilled hole, so I got the idea of using a taper tap followed by a bottoming tap to extend the thread far enough to put in a longer bolt. As I started with the tap, I discovered why the bolt was loose; the hole already had a helicoil in it! It's tempting to too many to think that you can prep for a heli-coil with a hand-held drill. The hole ends up a little elongated, and while the helicoil "works," it will only work for a while. Because the head had already been drilled sloppily (for the helicoil), I absolutely could not use a larger bolt, OR another helicoil.

But using a LONGER bolt worked. I measured the depth of the hole so I knew when to stop turning the tap. I used the taper tap, then the bottoming tap. The replacement bolt was exactly the "depth" of the hole, so I ground it back about 2mm to make sure I didn't hit the bottom of the hole before I had clamping on the cam cap. So far, so good.

15 ft-lbs is less than you think. There are enough of these low torque bolts on the Toyota (e.g., the valve cover) that I finally sprung for a 3/8" drive, then a 1/4" drive torque wrench. The HF torque wrenches are just fine for me http://www.harborfreight.com/14-in-d...nch-61277.html , and they go on sale all the time for half that price!

So learn your lesson; get a 1/4" drive wrench.

Very bad.