Timing Cover Leak

[Kuda]

Hey yall, as the title says my timing cover is leaking. The engine is freshly rebuilt so I am still breaking it in. But the leak is mostly coming from the Timing Cover Plate (location is highlighted in red on the pictures). I am mostly writing this to see if others have had a similar issue and what the main problem for them was and to see what you did the fix it. I am guessing I am going to have to replace the plate.

 

[Kuda]

I should also add this is a 2F engine in a 1975 FJ40

 

[Pighead]

Sometimes, someone has screwed the oil squirter in too far. Bottoming it out. That pushes the plate away from the block causing the leak...

 

[Kuda]

Sometimes, someone has screwed the oil squirter in too far. Bottoming it out. That pushes the plate away from the block causing the leak...

Once I take the Timing Cover off would this be easily noticed? And how far should the oil squirter be screwed in? I'm guessing the FSM will tell me more info but just trying to gather as much as I can here

 

[Pighead]

IIRC, you thread the squirter in a bit and point the line/squirter hole at where the gears mesh. Then you peen the base of the squirter to the plate to keep it from unthreading.

 

[John McVicker]

Also there are several different length bolts for the cover. 5 different size as I recall. If not installed properly it WILL leak.

EDIT: According the the diagram @73FJ40 just put up, it appears as if there are 3 different lengths.

 

[Kuda]

IIRC, you thread the squirter in a bit and point the line/squirter hole at where the gears mesh. Then you peen the base of the squirter to the plate to keep it from unthreading.

That would make sense. I will dig throught the FSM more to see what it says about that oil squirter. Thanks @Pighead

Also there are several different length bolts for the cover. 5 different size as I recall. If not installed properly it WILL leak.

Yeah I remember see that somewhere. The bolt heads are mismatched I'm guessing because of the engine shop having to order different ones which means they might have used the wrong ones. Definitely need to look into that. Thanks @John McVicker

 

[John McVicker]

Can’t tell from your picture, but if those bolts on your cover are not JIS bolts you can almost be certain they are the wrong length.

Not that they ‘can’t’ be the proper length, but they probably aren’t. I forget, those bolts s/b either 10m or 12m heads. If not…these could be your issue.

 

[73FJ40]

Here is a diagram of the screw designations for the timing cover.

1's I think are shorter and 2's longer (maybe the other way around) You should get them from a dealer.

3's need to have thread sealer. The ones I got from the dealer came coated with blue thread sealer.

 

[73FJ40]

Once I take the Timing Cover off would this be easily noticed? And how far should the oil squirter be screwed in? I'm guessing the FSM will tell me more info but just trying to gather as much as I can here

The gasket between the plate and the block provides a passage for oil to reach the squirter. If the engine rebuilder touched the squirter (no need to) then you can imagine more than the thickness of the gasket would then start to buckle the plate.

 

[zerotreedelta]

I had similar very light weeping after my rebuild - for some reason, it was wanting to weep from under the head of the two bolts in the area you point to. A dab of sealer on the threads for those two bolts sealed it up...they aren't supposed to need it, but guessing there was some sort of fitment quirk on the inner lip of the gasket and the tin where the gasket is punched, causing that slight weepage.

A good cleaning then run should point to the exact leak area (gasket to block, gasket to tin, or the bolts).

 

[Kuda]

Here is a diagram of the screw designations for the timing cover.

1's I think are shorter and 2's longer (maybe the other way around) You should get them from a dealer.

3's need to have thread sealer. The ones I got from the dealer came coated with blue thread sealer.


View attachment 3220353

That helps a ton. I will look into the bolts I have now on the rig to see if that is my issue. Like I said before the bolt heads are mismatched so they definitely aren't JIS

 

[Kuda]

The gasket between the plate and the block provides a passage for oil to reach the squirter. If the engine rebuilder touched the squirter (no need to) then you can imagine more than the thickness of the gasket would then start to buckle the plate.

Well the shop did have to touch the oil squirter because the engine was a basket case so this might be another issue as well. Thanks @73FJ40

 

[Steamer]

My oil nozzle/squirter has a lock nut on it. It was nice to just turn it in gently till it touches the block, back it out till it’s aimed right, then lock it down. Can’t remember where I got it back in 09 when I had the cam out. The new timing gears came from Toyota, so I assume the nozzle did also if it was available but not sure.

 

[John McVicker]

@Steamer now that’s a good idea.👍

 

[73FJ40]

That helps a ton. I will look into the bolts I have now on the rig to see if that is my issue. Like I said before the bolt heads are mismatched so they definitely aren't JIS

I don't see any mismatched bolts in your picture. The red ones appear to be M6 (10mm hex head) and the two bottom silver ones are intended to be larger (likely M10 with a 14mm head). The issues are length and position for the M6 and thread sealant for the M8 (and length if they aren't the original ones.)

 

[Steamer]

The five short M6s protrude out the back of the plate and exposed so longer ones will not hit anything. The three short M6s on the right will hit the block if they are too long. The two longer M6s go through the plate and thread into the block.

 

[Kuda]

I don't see any mismatched bolts in your picture. The red ones appear to be M6 (10mm hex head) and the two bottom silver ones are intended to be larger (likely M10 with a 14mm head). The issues are length and position for the M6 and thread sealant for the M8 (and length if they aren't the original ones.)

The picture with the red bolts isn't my engine. It's just a random picture from the internet. I wasn't able to take a picture of my own because I have the radiator in. But the issues with length do make sense and definitely worth looking into

 

[Kuda]

The five short M6s protrude out the back of the plate and exposed so longer ones will not hit anything. The three short M6s on the right will hit the block if they are too long. The two longer M6s go through the plate and thread into the block.

View attachment 3220509

This helps a ton. Thanks @Steamer !!

 

[John McVicker]

@Steamer gave you some great info & it matches where you say you are having a leak. The three M6 x1.0 x8 on the right.