Rear Main Seal

Hey Guys,

My mechanic replaced my rear main seal on 3/20/2020 and today, I think it blew again. I'm trying to figure out what may have caused this to blow prematurely. Any suggestions and ideas to make sure this wont happen again.

My mechanic says he uses only Toyota parts. The more I read about this it maybe be a faulty crankshaft? I won't know until he tears the truck down tomorrow.

Thanks

 

Any photos of the leak? Or did you just have a puddle of oil on the floor?

 

Check all things that can create excessive pressure. I also had new rear main installed and it started leaking. Little did I know, my catalytic converter was done, and all the elements inside were restricting airflow.

 

Could a clogged PCV valve cause this? Let's too much pressure build in the crankcase?

 

@jerryallday No pics, just a few drops in the drive way/
@Chip_Tundra and @bmf4069 I'll call my mechanic. He's going to look it over today and I'm going to stop by to check it out after work .

 

Is he 100% sure it's the rear main leaking and not the valve covers? It wouldn't be the first time someone has found valve cover bolts finger tight, they seem to loosen over time.

 

Yea, he lifted the truck in the air and we saw oil coming where the rear main is. I also tighten the valve covers a few months ago because I saw oil being built up around the top. I should know more today.

 

Got my truck back yesterday. A new rear main seal was installed and new PCV valve. My mechanic says he doesn't know why it failed. The rear main looked fine and it was a Toyota part. I'm thinking it may have been a poor install OR the PCV valve wasn't working properly. He said the original PCV valve didn't look clogged but it was original so we replaced it. IDK, I'm going to drive it and monitor. Hopefully it holds.

 

Did he charge you again? That's typically a really expensive repair.

 

He did. I was hoping he would at least cut me a deal but since it was out of warranty, I couldn't really argue with him. Cost me $400.

 

$400 ain't bad to drop a trans, pull a flex plate, then replace a seal.

 

I was thinking the same thing. When the rear main was leaking on the Rav4 the Stealer quoted me almost $2,000 to replace it.

 

I'm not sure why prices differ from vehicle to vehicle but I assume it must be an easier job to do on our trucks. I just hope I don't see oil again.


What are your thoughts about switching back to conventional oil? A buddy mention, since my truck does call out for 5w-30 conventional, that I should go back because it's thicker, and full syn is thinner and will find a way to leak out.

 

Not buying that. Oil weight is oil weight. Not related to type of oil.

 

Agreed, if 5-30 conventional was thicker than 5-30 syn it would be labeled 10-40.

 

https://www.firestonecompleteautocare.com/blog/oil-change/should-you-switch-to-synthetic-oil/#

Scroll down to the first point of the myths section.

 

Fully synthetic oil in my Tundra, no leak, and it will be old enough to drink beer next year.

 

Update
I had the rear main seal replaced a few weeks ago. After the replacement, I cleaned the area with simple green, drove it to work for a week and noticed oil is still coming from the rear main seal area. It's not a lot, doesn't drip on to my driveway but it's still a leak.
It's back in the shop and my mechanic isn't sure why it's still leaking. He says there some bolts on fly wheel that connect to the crank shaft that may be where it's leaking from. He's going to put some sealer in that area.
He says he's seen it leak from there before and he's put sealer on and it fixes the issue.
He says it's not the rear main seal. Nothing is coming from the valve covers. He's pretty confident it'll work.

Thoughts?

 

Some Toyota crankshafts are drilled all the way through and you need to use a thread sealant (blue loctite) on the crank bolts or oil will leak past them.

 

Fingers crossed it fixes the issue. Thanks for the reply.

 

Still leaks. Not sure where it's coming from. Hoping it's not a bigger issue.

 

Hey, if you don’t mind me asking, where’d you go for the rear main seal
Repair?
It was only $400 ?

 

Woah, I totally forgot to update. The shop is Montero’s Auto Services in Bellflower, CA. He does a good job but isn’t the cleanest mechanic.

The leaked did stop but only after I took the inspection plate off and degreased the area. There was left over oil and that was what I thought was the leak.

 

Is your truck 4wd?

 

No, it's not.