Help! 283 unidentified oil leak
 

I have a question regarding my '66 283 engine.
Last weekend I swapped my th350 for a 700R4, which bolted right in.
I started it for the first time and shut it off after a few seconds, just to do a double check on the oil cooling lines and such.

To my suprise engine oil was running out on the side of the oilfilter (screw on type btw) and I mean gushing..so going over my steps I suddenly realised when taking the th350 out, 1 bolt was missing from the belhousing on the bottom left, right behind the oilfilter. Luckily I found one roughly the same length and the right thread. (the one on the left)
https://myalbum.com/photo/gxtYHsrxQGzY/360.jpg

with the car back on the lift, I suddenly realised what a rookie mistake I made, by not first checking whether the bolt wasn't to long. and see here why
https://myalbum.com/photo/9Sj2RdyRDsVL/360.jpg

I couldn't believe my stupidity and took off the oilfilter to asses the damage I had done.
https://myalbum.com/photo/TFBs8fsYQnyJ/360.jpg
https://myalbum.com/photo/fQyXVWVqQwwP/360.jpg

but after cleaning it up, I could't see a crack and then thought there must be a hollow space behind it.
45min later the transmission was out again, because I wanted to have a look in the thread holes to see if I can see the damage i'd done. here are the close-ups of the holes
https://myalbum.com/photo/p8zQHHUaUgb2/360.jpg

https://myalbum.com/photo/ZDa7q4fxRd2n/360.jpg

https://myalbum.com/photo/RXQdppW99gHS/360.jpg

https://myalbum.com/photo/NCipUgUHunPJ/360.jpg

https://myalbum.com/photo/ZgfG6tM6AtcH/360.jpg

https://myalbum.com/photo/52YfZWPe7wbT/360.jpg

https://myalbum.com/photo/qEaQxSbCMbtY/360.jpg

https://myalbum.com/photo/tcCbTebmvA62/360.jpg

https://myalbum.com/photo/CKAwzELozkcB/360.jpg

to my opinion, the holes all look intact, but I have no idea how it should look like when I screwed in a bolt thats to long.

I read that the filter mounting plates are notorious for leaks, but I didn't touch it during the tranny change..
https://myalbum.com/photo/BmYEqtUYqwQA/360.jpg


so my friends, what could possible be the problem?

Re: Help! 283 unidentified oil leak
 

The oil sending unit line is right at the top of the engine block just behind the surface the bellhousing hooks to. O bet you kinked it or pulled it loose when removing the vacuum line for the modulator.

Re: Help! 283 unidentified oil leak
 

I think you are missing the nut that clamps the lower filter plate to the upper plate....

Without the nut, the plate will leak....

see pic

Re: Help! 283 unidentified oil leak
 

Neither one of those bolts is correct. The bell housing bolts should be 1-1/4'' long. The short one is only going to grab about 3 threads

Re: Help! 283 unidentified oil leak
 

No the oil sending line is fine, and the oil was leaking on the side of oilfilter..but I'll double check.

I was thinking the same thing..but it's never been there as far as I know and has worked fine, besides you tighten it down when screwing on the oilfilter right?. what would cause it so suddenly leak, just by replacing the transmission?


Thanks, thats definetly something to look at.

Re: Help! 283 unidentified oil leak
 

I had a 305 once that I literally sealed and re-sealed everything twice chasing a leak, later to discover that a longer than normal bellhousing bolt in that same position had broken through a thin part of the block casting at the bottom of the hole and had become pressurized. It appeared as a leak similar to yours. I got the correct bolt, thread sealed it and bingo, fixed.

Re: Help! 283 unidentified oil leak
 

You can use the newer style adapter
I did this on my dads 283 a long time ago

I have not used the style with a center nut but i can see with it missing that it may be a leak issue by not properly sandwiching it to together

Re: Help! 283 unidentified oil leak
 

Looking at the pictures, I'm not so sure anymore that I actually puctired it..but I got some JB Weld just to be sure

Well, there doesn't seem to be a problem with the adapter, picked up a central nut for it yesterday and a new rubber seal..which is not OEM, but if fits and is slightly thicker, so I hope will give a better result.

Re: Help! 283 unidentified oil leak
 

Hey there...How did you go with the oil leak issue?

Trust you are doing ok....

:chevy::chevy::chevy:

Re: Help! 283 unidentified oil leak
 

I'm a bit ashamed to say, but all's well. so I didn't puncture the engine, I found all the correct lenght bolts and found a bolt to tighten the oilfilter plate..that did the trick. so you were right ;)

But.. I have other issues now, which I'll write up in my C10 cleanup thread
(spoiler allert: the 700R4 I bought is a lemon)

Re: Help! 283 unidentified oil leak
 

Put the post for the 700R4 issues in the Driveline section for quicker feedback...

Here is the link...

https://67-72chevytrucks.com/vboard/...splay.php?f=24

Glad you figured out the oil leak...

:mm::mm::mm:

Re: Help! 283 unidentified oil leak
 

Thanks, but I'm going to have it rebuild, not attempting this myself