Doing HG Now, Service Bolt Won't Fit/Thread in (Pics) (1 Viewer)

[hadji_85]

It has been a while since I've been here but I am scrambling to get my HG done. I tried to thread a service bolt as suggested by the FSM into the exhaust side gear on the camshaft but there are no threads and the hole only goes through about the halfway. I had set the hashmark on the timing gear and chain to the top center and the notches on the camshaft gears facing each other. What am I missing? Do I really need to put the service bolt in?

Pics attached. It shows how the whole only goes about halfway through the gear and doesn't have any threads.

Thanks ahead of time!!

 

[robertaleon]

That's not the right hole , there are three. Make sure you follow the fsm and rotate the exhaust cam to the respective degrees. The instructions and illustrations are vague and they swap directions on the images (at least on mine) where one pic is from front and other is looking from behind.

 

[hadji_85]

I did the
1. Move crankshaft to 0 degrees
2. Make sure Timing Chain Gear has the notch at the top
3. Make sure the Gears on the Camshafts are side by side when looking from the back.

I must have missed something, thanks for the heads up!

 

[Jacques Villeneuve]

Yes, you need the bolt in there otherwise the two gears will not coincide (pushed by a coiled spring) and you will not have any fun lining them up afterwards.
So in my FSM, page EG-26, you turn the exhaust cam until the hole with the threaded main gear hole is near the top (from what I recall, there is another hole without threads that can "fool" you). That's all in step 35 A (a). The bolt is a 6mm with 1mm pitch, length of 16-20mm.
After the bolt is in you then turn the cams to the 35 degree position mentioned in the FSM.
Don't forget to take it out before you button it back up later.
Good luck.

 

[ybhc]

If its lined up properly and that's the correct hole, then the last time the camshaft was removed, someone skipped this step, and the split camshaft gear desprung, so the holes do not line up.

you need to remove the camshaft as is then re-spring it while its off the head.

 

[86tuning]

if you don't bolt the scissor gear together you'll get a knocking noise when you re-assemble.

As it's mentioned above, there is a clock spring inside the gear halves, and they scissor so the gear clearance stays at zero lash.

Turn the cam around until you find the hole with threads.

Don't forget to remove the service bolt after you're all back together.

 

[hadji_85]

Ugh, Now I am confused.

Should I put the bolt back on the timing chain gear and then get it in the proper position so that I find the hole with the threads or do I just move the camshaft (with the timing chain gear off) until I find the exhaust gear with the threads?

 

[rove_mcanus]

Ugh, Now I am confused.

Should I put the bolt back on the timing chain gear and then get it in the proper position so that I find the hole with the threads or do I just move the camshaft (with the timing chain gear off) until I find the exhaust gear with the threads?

Just rotate the cam with the chain off. There is plenty of clearance between the piston and valves.

 

[kirkm76]

timely

This was timely advice...I have the same issue. The threaded hole on the main gear doesn't line up with any of the holes on the sub gear.

 

[Jacques Villeneuve]

There should be three holes from what I see in the FSM. Once the main gear is removed (the one with the chain) the cams can be spun with a crescent wrench as the system is non interfering. Only one of those three holes lines up with one on the back gear having a threaded hole (I think it goes right through the rear gear). Look on the next couple of pages of the FSM where they show how to pull the two gears apart if you are changing out the cam. There is a picture of the front gear having three holes and the back gear has only one.

 

[pkelly72]

I'm reading the FSM and getting ready for my tear down.

FYI: this is from concretejungle.

I was able to find the service bolt to hold the cam gears together at lowes. Think it was around $1.48

IIRC it was a 8x1.0x12mm

 

[alia176]

Ugh, Now I am confused.

Should I put the bolt back on the timing chain gear and then get it in the proper position so that I find the hole with the threads or do I just move the camshaft (with the timing chain gear off) until I find the exhaust gear with the threads?

go ahead and remove the camshafts w/o the bolt attached. This is not going to be a show stopper. Once you have the camshaft on the bench, take a closer look to see what's going on. You can rotate one half of this sprocket manually so that the hole lines up with the other half, put your bolt in there and you're ready for the re-installation phase.

I know people who forgot to put the bolt in and the two halves of the sprocket rotated relative to each other. Their engines are running fine! Toyota did this so that the exhaust camshaft sprocket is always under some sort of a tension with the intake sprocket and any kind of lash is minimized. When the two camshafts are in mesh with each other, this particular hole lines up easily. Once the intake camshaft is removed, the one half of the exhaust camshaft rotates very quickly before you realize what happened! Again, not a show stopper, just "rewind" it on the bench.

Good luck.

 

[hadji_85]

Thank you everyone for your help!!!! You guys are the best.

 

[robertaleon]

go ahead and remove the camshafts w/o the bolt attached. This is not going to be a show stopper. Once you have the camshaft on the bench, take a closer look to see what's going on. You can rotate one half of this sprocket manually so that the hole lines up with the other half, put your bolt in there and you're ready for the re-installation phase.

I know people who forgot to put the bolt in and the two halves of the sprocket rotated relative to each other. Their engines are running fine! Toyota did this so that the exhaust camshaft sprocket is always under some sort of a tension with the intake sprocket and any kind of lash is minimized. When the two camshafts are in mesh with each other, this particular hole lines up easily. Once the intake camshaft is removed, the one half of the exhaust camshaft rotates very quickly before you realize what happened! Again, not a show stopper, just "rewind" it on the bench.

Good luck.

One of those is me. Once on the bench - you have one of those "ah ha" moments along with "that's what they meant" and "I'm an idiot!" shortly after.

 

[kirkm76]

One of those is me. Once on the bench - you have one of those "ah ha" moments along with "that's what they meant" and "I'm an idiot!" shortly after.

Ill second that. Fixed mine yesterday on the bench prior to reinstallation...too easy. Once you have it off it is easy to see how it works.

 

[86tuning]

I'm reading the FSM and getting ready for my tear down.

FYI: this is from concretejungle.

I was able to find the service bolt to hold the cam gears together at lowes. Think it was around $1.48

IIRC it was a 8x1.0x12mm

No need to buy a bolt because that bolt is all over the car. Any of the small screws removed while taking things apart can be used to lock the timing gear. The bolts are usually m6x1.0

 

[Mikesta]

Just for reference - here are a few pictures of it NOT lining up. I think Toyota did this initially without lining it up as this engine doesn't 'need' a head gasket, but While its out, I'm taking care of it anyway. Front to back / back to front.

1 tooth off

 

[jcardona1]

That's interesting. I wonder how they got that way. I knew something didn't look right from the OP's picture because the teeth of the 2 gears were perfectly lined up. Mine weren't. Here's how the teeth from the two gears looked on mine

 

[Mikesta]

oh wow, so the gear shouldn't line up? I'm still a tooth off, but that seems odd that the teeth wouldn't line up when in use.

 

[jcardona1]

Not sure but that's how mine were when I pulled the cover off, and the holes lined up perfectly. I think it may be related to what alia mentioned above; to always keep tension against the intake gear...