Replacement engine rear main leak

Greetings All,
Epic long story synopsis: Trying to figure out why a new long block install is leaking out the back. I'm not familiar with the dreaded 3VZE, but is it common for the rear main seal "retaining plate" to warp or something if overheated previously? The shop that performed the work is relating that the original seal supplied by the vendor that sold the motor was leaking, so they replaced the seal with a Fel Pro unit. This one resulted in an 11 hour labor charge to replace it with the final outcome having it still leak. The consensus I get from those in the automotive world (not 3VZE specific) seems to point towards that plate (used off the original overheated motor) either cracking or warping. Any ideas?
THANKS,
Chuck

 

I too have been struggling with this issue. Right after my engine rebuild I couldn't believe the new seal was spewing so I pulled the the t-case and transmission and put on a seal saver and a new rear main seal. This has made no difference seemingly and I am now suspecting the seal saver is leaking between its self and around the crank shaft. Or perhaps the seal carrier is a reject and is not machined properly and is not putting the seal in the correct position so that the lip can get even pressure on the crank shafts surface all around. I remember looking at the seal and crankshaft carefully before I pulled the seal and it looked perfect around the crank. But this darn carrier part is pinned to the block with bushings and I can't believe Toyota would manufacture a part this is so poorly matched up in positioning the seal in the correct location. I can tell you that removing the seal carrier does bugger up the seam with the wind-age tray and the oil pan as this carrier is part of the mounting surface for the bottom of the engine. So I am loathed to remove it unless I pull the motor and redo the oil pan and wind-age tray again. I have another seal saver I got from LC Engineering which looks a better fit than the generic one I have now. But a drive train pull is a big weekend!...

The other thing that leaks really badly are those horrible CAM cover caps at the back of the heads. If they are spewing, the oil will look like its coming from the rear main as it gets well heated up by the crossover pipe but stays on the heads and drips down the back of the block. I had that going on at first but then after I fixed it the rear main was still crap.

 

Andrew thanks for the reply. I figured that this engine just leaks out the rear main no matter what. Just disheartening the amount of time and money that went into it for such a horrible end result.

 

Yes I think your right. My youngest Son's 1990 T4R does't have this problem nor does my oldest Son's 1990 2WD Extra cab. But mine which has about 10,000 miles on the rebuild is a leaking mess. Maybe it has something to do with the boost in oil pressure I managed by installing a washer under the spring in the oil pump of the relief valve plunger? Second guessing now!

 

I have had this same issue after I rebuilt the 3RZ in my 2000 Tacoma. The first time I pressed the rear main seal with tools I had available in my garage at the time. The end result was a leak. The next time around I have bought the OEM Toyota tool to press the rear main in. The tool was around $120 or so, BUT I have not had my 3RZ leak a drop of oil since I installed the rear main seal using the correct tool. This was 30k miles ago...

Point to the story, use the correct tool and you won't have leaks...

 

The inside of my bell housing in my truck was awash with motor oil when I purchased this vehicle in 2018. I rebuilt the engine and paid particular attention to the end play in the crankshaft and the position of the seal in the seal carrier housing to be sure the seal was not falling off the edge of the flange on the crankshaft. When the new seal didn't work I pulled the gearbox and t-case a week after the rebuild and put a seal saver on the crankshaft and replaced the seal again with a new part. Getting the seal in straight with the bore of the aluminum carrier housing is important which i am sure a tool would help with but this seal with the saver isn't working either. So living with the leak till the clutch is done and then I'll do this all over again with a different seal saver that I got from LC-Engineering.

 

This is relatively timely - found this thread in search as I have a friend/client with a '93 4Runner 3.0 that certainly appears to have a rear main leak.

He wants me to work up a quote for replacement and so I'd welcome any guidance on procedure, gotchas, pricing or anything else related to the topic.

I see post #1 says 11 hours, is that about right?

I don't entirely blame him for wanting it done as the leak is quite bad, and we're already running 10W-40 in it primarily because of the leak. If it weren't winter in CO I'd bump him up to 20W-50, although honestly I doubt it'd slow the leak much.

Now after reading this I'm concerned I might charge him a bunch and still not resolve the issue. Also, does anyone have pics of this retainer plate? This is obviously a design with which I am not familiar.

edit: I did find this, is this also what a '93 would look like (the OP here seems to suggest '90 to '92 changed)
https://www.4runners.com/threads/rear-main-seal-housing-oil-pan.10511/

 

My 1991 was a rear main leaker when I acquired it in 2018. Rebuilt the engine and immediately had oil pouring out of the cam covers I thought and re did them only to find the brand new rear main was pucking too. Pulled seal put seal saver on crankshaft and replaced with new seal, still leaking and suspect seal saver has moved on crank shaft due to axial thrust movement from the pressure plate and clutch. Got a better seal saver from LC Engineering and have new seal hopefully third time is a charm and I find success when I get around to pulling the drive train again!...

 

The rear main seal R&R on this '93 3.0 is a go.

Is there actually a specialty driver to install the seal? I haven't been able to find anything searching the web.

 

Ok so I think the tool would be a
09223-78010-01

Looks to be a KM (Kent Moore) part #

However I'm not positive this is for the 3VZ/5VZ so don't take my word for it.

There's one on eBay right now for $174 but can't say I'm excited about the price.

 

Andrew, were you able to install the seal saver without a specialty driver? When I've installed Speedi-Sleeves in the past they typically come with a cup driver.

I now have the one from LCE and the packaging says to use the appropriate installation tool but no hint of what that might be. I left a VM for LCE tech support yesterday (12/24) but unknown if they'll actually return my call.

Merry Christmas everyone!

 

Ok so I think my seal driver part # in post #10 may very well have been wrong. I think it may be 09223-15030, but once again not positive this isn't for the 4 cylinders like 3RZ's rather than the 6 cylinder engines. Many of the 6 cylinders appear to use the same RMS but the 4 bangers apparently use a different seal, so I'm guessing the tools would be different.

Does anyone have a factory svc manual and can verify they spec SST 09223-15030 for the 3.0?

 

The 3.0 FSM lists the same tool.

 

Thank you so much for taking the time!

 

D60, JustTheMechanic,

I very much appreciate the added information on this thread. I just got back from a three day jaunt out near Borrego Springs and had just given the 4Runner its 250K mile oil change prior to the trip. It has been spewing oil out of the bell housing vent hole with aplomb and I was sure it was a quart low after several tankful's of gas had been burned on the trip. But aside from the seemingly massive oil stain on the driveway while I unloaded it after the trip the oil level is still good on the dip stick each time I check it. But the added custom made cross member is dripping with oil and it is time to get that new seal and LC-Eng seal saver onto the engine as the rear axle and undercarriage are getting splattered with oil drops at this point. I am dreading the transmission/t-case removal and need to make a tool to attach the transmission/t-case rear mount to my floor jack then the job will get easier in keeping it upright and I can get the pitch of the thing adjusted with my Toyota bottle jack. With every year that passes that garage floor just gets harder and harder on the old skin and bones.

As for the seal saver LC- Engineering recommended heating it up in the oven, then setting it on the crank shaft, let it cool down and you will get the press-fit to take hold as the crank and seal saver normalize in temperature. Hopefully this provides an oil tight seal between them. I am thinking I might try to coat the crank shaft seal surface with 515 Loctite before I place the heated seal saver on the crank shaft. Then as this cools off and clenches the crank shaft the 515 should be able to go anaerobic and start to cure and give me a great oil tight seal between the metal parts. I just hope the darn lip seal will work and seal this time? I am not too concerned with getting the lip seal set correctly as I am fairly good at tapping it in with my trusty ball peen hammer. But this technique may be my entire problem as this thread has touched on using a tool to set the seal and then the problem does not reoccur. These tools are expensive, so I might try and see if I can get a college at work to turn me a piece of aluminum to facilitate as a seal installation tool?

 

Yeah so I meant to update the thread....LCE actually did call me back. Tony in tech left me a helpful and professional VM as I was unable to take the call. He reco'd heating the sleeve in hot water....dunno why i didn't think of such a thing although SWMBO has some theories....many of which seem to center around a closed head injury or excessive paint chip consumption during my early years.....?

Then I thought I can probably just set it on the wood stove in the shop which is presently running anytime I'm out there these days!

Anyway, I just wish I could get my damn hands on the tool to reverse engineer it (that's the fancy term for a hand drawn blueprint scribbled on a napkin). I could then crank one out in my machine shop no problem as it's basically a disc with a counterbore.

I will say I was able to dig up multiple examples of the tool in use in several FSM excerpts I stumbled upon online. Seems this tool is used for a lot of engines including some cars....ANYWAY in some of the fancy Chilton-esque sketches of which the FSM is so fond, they'd clearly show it with one side OR the other being used to drive the seal in question.

Point being, it appears the fancy disc is double-sided 'cause its actually 2 tools in one. We'd really only need the 3.0 side

 

Also in FURTHER time burnt on the web which I'll never get back, I'm 90% this kit includes a copy of the tool in question based upon the part #. It lists it as a puller which I'd say is likely a lost-in-translation error:

Compatible for Master Engine Timing Locking Tool Kit Cam Belts CrankShaft For Toyota & Mitsubishi

https://smile.amazon.com/Compatible-Master-Locking-CrankShaft-Mitsubishi/dp/B07G58NRPM

I just grabbed one from AWD (Amazon Warehouse Deals) for $80, figuring what the hell.....

Also Andrew you just need a 2-post lift and you won't dread such projects! If you can't accommodate one at your present locale....the answer is obvious: MOVE

"We have the technology"....no need to inflame those aching bones!

 

Also from what I can tell 99.9% of the world just drives the seal in with a block of wood or *whatever*. And it seems to work. Most would say all the worry about THE proper tool is time wasted, and by no means am I saying they're wrong.

If I were doing this on my own rig I might take my chances, but since this is on a client's and I definitely ain't doing it for free I'd like to know I used best-practice and have the absolute best chance of a positive end result.

Plus, let's face it: I just like geeking out over TOOLS. It's true.

My investigation started with a single thread on another forum regarding the 3.4 (which, again, I believe uses the same seal) where a user said his first attempt leaked badly, so the second time he used the Toyota tool and the leak was cured. Again, a sample of one ain't convincing and it's possible his first seal was just a dud.

Now, if you wanna waste more time online, I came across this -- it's on a Tundra but the guy (who appears to be a somewhat-professional mechanic) manages to drive TWO rear mains in too deep. It's almost painful but I also give him props for owning up to his mistakes - God knows I mess up GOOD from time to time. He also randomly muses about important things like, "Are the women in California really THAT hot?"....so there's that:
https://youtu.be/fnck0iLR79w

 

Over the years I have replaced a number of this type of seal and have had good results, no leaks. This is how I do it.

Remove the old seal, taking care not to damage the shaft.

Clean and polish the shaft and seal bore with Red 3M Scotch Brite. This will remove any baked on oil film, dirt and surface corrosion. Inspect the shaft for damage. If you find any scratches, corrosion pits or a deep groove from the old oil seal, a seal sleeve will need to be installed. If a new seal sleeve is installed, polish it with Scotch Brite, this will remove any surface coating on the new sleeve.

Degrease the shaft and seal bore. Denatured Alcohol is a safe and readily available solvent. Put one wrap of black electrical tape around the edge of the shaft, as close to the end as possible. This will prevent any damage to the seal lip when installing the new one. Even the smallest scratch or cut to the seal lip will cause a leak.

Apply a thin film of grease to the shaft, seal bore and electrical tape.

I have not replaced this particular seal, but most seals are a double lip type. The inner lip seals the engine oil and the outer lip prevents dirt from getting into the seal area. Apply a light film of grease to the outer metal part of the seal and fill the area between the lips with grease.

I have not had good luck with trying to insert the seal with the type of tool called out in the FSM, it will not start evenly and it usually gets cocked in the bore. I hold the seal in place by hand and lightly tap on the outer rim with a small ball-peen hammer to get it started. Once it is started in the bore the seal tool should evenly seat the seal. If you don’t have the tool, lightly tap the edge of the seal, going around the perimeter until the seal is seated and the hammer is contacting the seal housing. If the front metal face of the seal gets dented, remove it and start over with a new seal, as any dent can distort the seal and the rubber may not contact shaft and it will leak. Remove the electrical tape.

The objective is to make sure the shaft has no damage, all of the parts are super clean, the seal is not damage during installation and to grease the seal when installing.

 

^^yeah even on wheel seals they never seem to start evenly with a seal driver, so I wouldn't dream of starting this one with the tool. Once started, the driver should theoretically sink the seal evenly and squarely to the seal retainer in rear of engine.

Good tips though, thank you! This project begins in 4 days.

 

Received the import tool kit from Amazon. Without an OEM driver to compare, I can't say this is an exact copy but I imagine it is.

Anyway, here's the rundown:
OAL is 2.203"
Major OD is 4.490" (the big end). I failed to record the length of this feature but I doubt it matters. Inside diameter at this end is 3.941", .860" deep

Minor OD is 4.173" (the small end). ID here is 3.785", also .860" deep

There's a center thru-hole which is about 1/2". Really the center hole size is determined by what you'd want to use for a handle.

The seal is about 4.340" OD, FWIW. Last photo reflects seal on driver

 

I gotta say, this was one of the tighter removals I've personally dealt with. Specifically, that upper LH bolt is a b#$!@ and there's an incredibly stupid bolt anchoring wires on the left top of trans (14mm head).

Clearance with the front pinion flange on the way down is near zero - NO WAY I'd do this on my back!

 

Well the back of the heads on this motor look nearly bone dry, so at least I'm not facing a cam bearing cap fake-out!

Funny, the ID of the flywheel was very dry and even rusty, but each flywheel bolt was literally just DRIPPING in oil below the flange head.

Anyone notice the less-than-happy pilot bearing?

Also the clutch is in fairly good shape but not OEM. And the rear main is definitely not seated 100% square to the rear of the engine (carefully calibrated fingernail reveal test), so I'm wondering if someone already botched this once during a clutch replacement.

 

Ok the next saga installment:

I decided I personally wanted an installation driver for the seal saver. I decided on an OD of roughly 3-13/16" and from measuring the crank I wanted a counterbore of 1.660", .350" deep.

I did not have any Al round stock this big but I had some 3/4" flat bar. So I cut a pc about 4" sq, drilled a center hole in the mill so I could mount it on a crude arbor in the lathe, and turned the OD round to ~3.8"

For a handle I decided to just use the handle from my HF seal driver set. The "arbor" portion of my HF handle was .545, so I drilled a thru-hole of 35/64"

I heated the seal saver on my trusty double barrel stove until my IR temp gun claimed it was 160F, but more importantly it made the grease smoke off my favorite all around welding/fab/wrenching gloves: Tilman 48's

Anyway, here's what I can tell you: the driver for the sleeve WORKED F'N AWESOME!!. The c-bore in my disc keeps it concentric and so you just tap until you hear that nice dead thud. I'm confident it's fully seated and square.

The instructions on the seal saver box specifically say not to use any compound (I gotta admit if anything I was tempted to use Permatex "locking compound"), so I decided next best was install it DRY so after it cools it is just metal on metal.

Saver is installed in final photo.

 

This is the seal saver LCE sells, a Micro Seal MS331-1. I don't mean to undercut LCE but I believe in freedom of information. Looks like you can get it directly from Silver Seal for $7.50 but I didn't run thru the cart to see if shipping is reasonable.

The installation tool from them is ~$31 and is an MST331. I haven't been able to get a visual on the tool, would be curious. From looking at FelPro tool examples I think I get an idea, though

https://shop.silver-seal.com/storef...er-uom=EA&warehouse-id=25&item-number=MS331-1

 

Ok, next: above I made a driver for the seal saver (crankshaft sleeve) and I turned the OD to ~3.8"

Well, I should have turned it to the ~3.94 I mention in Post #21 here. Then, it would slip right into the Toyota (import copy) tool I have, and the counterbore would keep it concentric for driving in the seal.

I worked around this by simply making a Delrin bushing that goes over the longer M8x1.25 bolt I used and threads into the HF handle.

The 3/4" thickness of my custom disc is perfect to not hit the crank (which sits a tiny bit proud of the seal retainer, aka the block) when in the Toyota tool.

I used this setup to press in the seal tonight and it also worked wonderfully.

ONE CAVEAT: This will not work with the pilot bearing installed due to the head of the bolt that threads into the handle. That said, if you're this deep into it and EVEN IF you're not replacing the clutch it'd be wise and inexpensive to replace the pilot bearing.

 

Ok, well, mostly successful test drive tonight.

I only took it out for 4 or 5 miles but it used to be EVERY time it was pulled into my shop it'd leave at least a saucer-sized puddle on the floor, and surprisingly quickly. But several hours after my drive, no puddle!

I did take a look underneath a couple hours later and there were a couple droplets on the bellhousing, but I'm 99% the oil pan gasket (er RTV) is leaking, too. The entire perimeter of the oil pan looks NASTY.

Regardless, I can sleep well because I'm confident I did the best job possible here. The crankshaft sleeve was seated beautifully, flush, and had zero wrinkles. The RMS was seated as square as a human being could do it, period (I checked with a straight edge afterward). I packed the RMS with grease around the spring and greased the crank sleeve. If the RMS is still leaking now I'm confident it ain't my fault.

This is not to say "I'm perfect" but rather that my conscience is clear. I don't have to second guess myself or think "maybe I should have...."

I also installed the Marlin seat and socket at the base of the shifter and filled with Redline MT90 (in addition to a new Aisin clutch). I gotta say, the shifting seems to have improved, specifically the synchros seem happier.

For giggles I'll include a comparison of the aftermarket Marlin shifter seat and the OEM

 

D60, JustTheMechanic,
I greatly appreciate your additions to this thread. The pictures and dialog are first rate. I was planning to do this seal and seal saver replacement last weekend but the Pro Comp rear coils arrived and couldn't get the thought of improved rear suspension out of my head.

It is pricy but have you looked at the Marlin Crawler (MC) short throw shifter kit? I really like mine as the side pins on my OEM shifter were supper loose in the aluminum which added to the overall imprecision and general sloppy gear lever. This MC kit has replaceable turned down machine screws for pivots that are Red Loctite secured in the housing. FYI

Bravo,
ATGP

 

I haven't investigated the Marlin Crawler short throw kit. It's actually a client's/friend's vehicle and so I'm trying to do "practical" upgrades without getting too "aftermarket-ish." He just putts around the local area with it.

This probably ain't the thread but I'll offer this warning to anyone doing the MC seat and socket: I first installed the seat and socket on my trans jack -- merely as a test fit -- and then had to of course pull the shifter handle back out of the trans to, well, actually install the trans back into the vehicle.

The MC socket hung up in the bore in which it lives in the transmission, and I couldn't (easily) pull the handle back out. I could tell that if I pulled hard enough I was likely going to leave the socket in the trans as it would pop off the ball end of the shifter, which is EXACTLY what happened.

Now, fortunately the socket can't go very far in the trans. It would SLIDE up and down in its bore but when it got to the top it's as if it was hanging up on a bur or something .

I tried hooking a right angle pick thru it and pulling up on the bottom of the Delrin/acetal, but that was just not enough contact at the bottom of the socket.

FINALLY, my import blind hole puller saved the day! I then chucked up the socket and added a chamfer to the upper edge, but I never tested if the chamfer solved the problem because I decided the NEXT time I installed it would be the LAST.

TL;DR: 1) don't "test fit" the Marlin seat and socket. Put it in once and be happy. 2) Have a blind hole puller if you ignore #1

 

Also Andrew did you ever pursue PCV? Is excessive crankcase pressure a problem in these 3.0s? I'm wondering if some of these leaking motors are just a faulty PCV valve?