Anyone ever seen this happen on a rear cover?

Took my truck to the trans shop a couple of weeks ago for a rear main seal. Got it back, it still leaked.

The shop said they thought it was the oil pan gasket, I changed that. Still leaked.

Finally got smart and poured some dye in the crankcase and took it back.

He pulled the rear cover off and found one of the bolt holes broken.

The awesome thing, he didn’t charge me labor to pull it a 2nd time. Just the cost of the cover.

Makes you wonder why the heads on the new bolts are 12mm instead of 10mm.

 

First I have seen it. What's the backstory on the truck?

 

It’s a TMS longblock with 706 heads.

I took it in for an oil leak, got it back still leaked. Took it back and they pulled it apart and found that.

They put a new cover on it. The new bolts have 12mm heads vs 10mm.

Makes you wonder.

 

Did TMS install the cover? Or did you when you received it?

 

It was installed by the shop that swapped out the motor almost 2 years ago now.

I've had it off a time or 2 when I was having multiple 60e failures from late 2017-2018.

I hadn't touched it or even been under my truck in 13-14 months after the 80e swap. It started leaking oil and it goes from there....

And yes, I spent 10 min pulling the intake off to visually verify the oil sending unit/cam sensor. I still swapped out the oil sending unit because I had a new Delco one on my bench and thought just as soon as I put that intake back on, the bitch would start leaking.

 

I am wondering if they over tightened it or some how damaged it while installing it. I Don't believe the bolt head size has anything to with it.

 

It’s possible. I mean an impact and thin cast aluminum don’t mix.

The 2-3 times that I had it off, I started the bolts with my finger and bumped them on with my 20v Porter Cable, then torqued to 18ft-lb.