4.0l Camshaft Bearing Question

Are there only 2 cam bearings on the 1GR-FE? (1 upper and 1 lower)

At first I thought I had misplaced the other bearings, but after reading through the FSM I’m only seeing it mention installing bearings on the intake cam of the RH head.

Only having 1 out of 4 camshafts with bearings seems odd, so thought I’d check here to make sure I didn’t miss anything.

 

@Torspd ?

 

Yes, only the exhaust cam on the RH side has a bearing.

Jeff

 

Looks like it's the RH intake cam, but it's the only cam that has bearings from what I can gather from the FSM.

Now I can't find an intake cam sprocket bolt. The part # is proving difficult to find too. 2 steps forward, and then wait a week for random parts to arrive is how it goes over here.

 

I’m more confused now than when I started looking.

The parts catalog clearly shows two bearings on the exhaust cam for the RH bank.

The repair manual clearly shows a single bearing on the intake cam for the RH bank.

I haven’t personally assembled one, so I can’t comment beyond that. I’ll probably look into it more later.

As for the bolt, it’s 90119-12370.

Jeff

 

I am pretty sure it’s only one on the back passenger exhaust cam that does that, it’s been over a year since I’ve had one apart but you are correct there’s one goofy one.

 

How did you find that part #?! I’ve been looking all over for parts diagrams, but I haven’t found any that shows that bolt.

 

Only one bearing on the RH head.

 

What about in that cap? IR1?

Jeff

 

No, all 8 bearing caps on each of the heads are just bearing caps. The caps go right on top of the camshafts on both heads. No bearings in between. There is just one bearing under I1 (IR1) on the intake cam of the RH head.

 

That’s the cap he’s pointing to. Intake Right #1

 

There are no caps in the photo, that’s why I asked.

I’m still a bit confused, but at least it seems like the repair manual matches the engine, but no idea what’s going on in the parts catalog. (Why is PNC 11811 shown, and why are both shown on the exhaust cam?)



Jeff

 

I hear ya. It is not there. That is incorrect.

 

Do you have any pictures of the cap? I don’t even know how they would bore for a bearing just on one side.

I’ve sorted out why the catalog shows it on the wrong cam, it’s just an error from when the diagram was updated at some point and the bearings stayed pointing at the same spot, but the cam moved in the diagram.

It feels impossible there wouldn’t be a bearing in the cap though.

Jeff

 

Unfortunately no. I just have a picture of all of the caps in a box after being removed. I edited my prior post and added it. Keep in mind the caps themselves, are the bearing surfaces that ride on the top of the cams. The bottom of all the cams, with the exception of IR1, ride directly on top of the journal surface milled into the heads themselves.

 

Yeah I’m aware.

I did look at a few pictures of 1GR RH heads and it definitely looks like there’s going to be a bearing shell in the cap. It’s not stepped and the intake bore is larger than the exhaust.

Only the lower has a thrust surface though.

Jeff

 

is this the case with the 2rz as well?

 

No idea.