Topic: Rear Main Leak - 22RE 4Runner

[blackdiamond]

I am 99.9% sure that my rear main is leaking on the 4Runner.  Today I did a feel/smell checkon the drips under he transmission and there is no evidence of gear oil.  Also, the engine oil was significantly lower than the last time I checked it.  It seemed to start leaking after I switched to synthetic motor oil (I know it doesn't cause leaks, but can find leak paths that conventional won't) and also when I had the transmission rebuilt.  I have switched to Valvoline Maxlife in hopes of slowing the leak, but I think it is actually getting a bit worse.

The engine is a fresh rebuild so the seal should be ok.  I don't know anything about the configuration of the seal/bearing so I'm wondering what I need to worry about other than keeping the fluid level topped off.  I think the Maxlife might do the trick given some time and I might give auto-rx a try as well before I have someone pull the transmission and fix the problem.

What causes them to leak?  What is the best fix? 

[KDXSR5]

I use the maxlife in a semi-synthetic form, and it must have fixed the small leak I had, because after two oil changes, the oil level doesn't drop like it used to. What maxlife are you using? they have conventional, semi-synthetic, and synthetic. I like the stuff, it is what I have used since I did my engine swap.

[Thomas P]

the rear main could have been damaged at install, you better fix it before it ruins your clutch, its worth getting in there now and its pretty easy once you pull the tranny out

[skyscraper]

The crank could need a speedy sleeve, because the old seal has worn it down.  But most likely it is ok.  The seal sits in a little housing that bolts to the block, thats what might be leaking.  Thats what happend to me, because I used a cheap gasket. 

[kneedownnate]

That seal is super easy to replace, aside from having to pull the tranny out.  I'd plan a weekend around it for peace of mind, but a speedi sleeve is a good idea while you're in there too.  Never know if they knicked the crank, and it doesn't take much to make a leaker   

[blackdiamond [OP]]

I use the maxlife in a semi-synthetic form, and it must have fixed the small leak I had, because after two oil changes, the oil level doesn't drop like it used to. What maxlife are you using? they have conventional, semi-synthetic, and synthetic. I like the stuff, it is what I have used since I did my engine swap.

I'm running the Maxlife Blend.  As an FYI, Maxlife has always been a synthetic blend, but it was not advertised on the bottles.  Now they are marketing it as blend and synthetic, the non-blend is just the old packaging that is still on the shelves.

[79coyotefrg]

Jon,   i dont know if  synthetic gear oil smells like  80-90  but  if it doesnt smell like gear oil i would say its the rear main seal,  and if you dont fix it  it WILL  ruin your clutch

clean the clutch and  flywheel with brakekleen  and it  will be fine  as long  as it hasnt deteriorated  the disc

[blackdiamond [OP]]

Jon,   i dont know if  synthetic gear oil smells like  80-90  but  if it doesnt smell like gear oil i would say its the rear main seal,  and if you dont fix it  it WILL  ruin your clutch

clean the clutch and  flywheel with brakekleen  and it  will be fine  as long  as it hasnt deteriorated  the disc

I put in the Valvoline Blend that I'm running and it had the classic smell and feel.  I'm sure it is the rear main, otherwise it is a seal on the transmission that would require the same teardown to correct.

[KDXSR5]

I'm running the Maxlife Blend.  As an FYI, Maxlife has always been a synthetic blend, but it was not advertised on the bottles.  Now they are marketing it as blend and synthetic, the non-blend is just the old packaging that is still on the shelves.

Interesting...I was unaware of that! Thanks for the new info.

[blackdiamond [OP]]

Interesting...I was unaware of that! Thanks for the new info.

If you visit Bob Is the Oil Guy forums on www.bitog.com you will find that Maxlife is a favorite oil of many for any and all applications.

[KDXSR5]

That is where I got the idea to run it in the first place, but thanks for the link, maybe others will check into it! There is A LOT of good info on that site.

[79coyotefrg]

I put in the Valvoline Blend that I'm running and it had the classic smell and feel.  I'm sure it is the rear main, otherwise it is a seal on the transmission that would require the same teardown to correct.

yea,  but im betting its  the rear main,   pull the trans  and flywheel  to get to it

[blackdiamond [OP]]

That is where I got the idea to run it in the first place, but thanks for the link, maybe others will check into it! There is A LOT of good info on that site.

Based on what I have learned from the forum and a UOA on my Mazda, Pennzoil Platinum is now my oil of choice when I'm not chasing leaks.

[KDXSR5]

That sounds very expensive. I spend like $12 at walmart for 5 qt. of 10w-30 maxlife semi synthetic, and like $8 for a NAPA Gold filter every three months. I don't want to be spending a ton of money on my oil, but I think this set up is good enough for the ol' 22re. Sorry for getting so

[blackdiamond [OP]]

That sounds very expensive. I spend like $12 at walmart for 5 qt. of 10w-30 maxlife semi synthetic, and like $8 for a NAPA Gold filter every three months. I don't want to be spending a ton of money on my oil, but I think this set up is good enough for the ol' 22re. Sorry for getting so

It's my topic so we can discuss whatever we wish.   

My Mazdaspeed 3 destroys oil so it is important to run the best and I believe Pennzoil Platinum to be the best off-the-shelf oil on the market currently.  The 4Runner would do fine on just about anything, but it's nice to use the same oil in everything.

[KDXSR5]

Sounds like a fun little car! I do agree that using the same oil in everything simplifies regular maintenance.

[blackdiamond [OP]]

On Friday I stopped by the shop that I'm having fix the "rear main" leak so that he could "put his eyes on it" ahead of time and he doesn't think it is the rear main at all.  He wanted me to clean up the block really well and let it run watching a few suspect areas along the head gasket, there are also some signs of water leaking as well.  He said that he has seen leaks develop more when the copper shims are used under the head.  He said that it is more prone to heat cycle issues.  My thermostat has been sticking and the water temperature sometimes get farily hot, but never close to overheating as far as I can tell.  I changed the thermostat a while back and the problem happens less, but still happens on occasion.  I'm wondering if this contributed to the leak.

[emsvitil]

The rear half-moon plug in the head/valve cover can seep and it looks like the rear seal..................

[blackdiamond [OP]]

The rear half-moon plug in the head/valve cover can seep and it looks like the rear seal..................

My last toy had that leak, this one seems to be leaking passenger side near the front.  I have it degreased and will start it up tomorrow after work so I don't have to worry about any fumes going up in smoke.

[Thomas P]

my front half moon was leaking i siliconed it and it fixed the issue

[blackdiamond [OP]]

Today the head gasket was replaced on my 4Runner and problem solved.

I have a few less 

[KDXSR5]

Atleast it is fixed!

[blackdiamond [OP]]

Atleast it is fixed!

 

[Plekto]

Good though - it's far better than having the thing go and blowing half the engine up.