Engine Rebuild.... Rear Main Leak

[motobrad14]

OK guys so I'm turning to the pros again for some questions
I've searched the forums on t4r, toytec, and pirate4x4 for a rebuild thread on the Toyota 3.4l engine. I need diagrams of rear main seal, the plate that mounts to the transmission, and any other helpful diagrams. Also a rebuild thread would be great. If there isn't one I'm going to make one.

Anyways I have a bad oil leak. The oil runs out of the rectangular hole in my bell housing above my rack and pinion.... Rear Main seal right? Any advice? It dumps about half a quart of oil in fifteen minutes. Running the oil just flows out of the rectangular opening between the bell housing and the plate between the engine and transmission...
Any suggestions?

My rig:
98 T4R 3.4 Manual R150F

 

[BrianSD_42]

The rear main seal is Not really my knowledge area but I think you will get more responses if you include pics. The community is pretty much powered by pics.

 

[motobrad14]

Pictures

Heres a few pictures of whats going on, I'm sure that its not the oil pan, as the leak is behind the plate. you can also see that between the bell housing and the plate, oil is seeping out from between the two.

 

[LittleCaesar]

I'd have to ask why you want to do a rebuild on this engine. Does it have low compression? I'd run a compression test first before jumping to conclusions.

That is a lot of oil. The seal must be non existent in one area.

Ever replaced the valve cover gaskets?

 

[motobrad14]

If I pull the motor i might as well rebuild it. I work at an auto parts store and a complete rebuild kit is around $499 my cost. Machine work i can do. I just figure if i need to pull the motor to replace this seal ill rebuild the motor, it does have 265,000 on it. Runs great still, doesn't burn oil.
Interesting thing this morning though, I'm a full quart low, and it quit leaking. I can't drive around like this. Im wondering is there any plugs or gaskets behind that block other than the rear main? Valve gaskets were just done, and have used a mirror to look around the cross-over exhaust tube and there is no leaking from head gaskets, or valve cover gaskets.

 

[steezemcqueen]

Yep that would be the rear main seal. My is leaking a bit too after i replaced it with a cheap one when i did the clutch.

You don't to pull the engine to do the RMS. Just pulling the trans is all you need to do.

 

[audiness]

If you search around on these forums, you will find links to the full service manual for our trucks, all the info you could ever want.

 

[Kurtis]

I believe the service manuals were taken down.

OP: If oil is coming from this rectangular hole in the bottom of the transmission then yes it is your Rear Main Seal.

The reason I ask is because that is an ass ton of oil to be coming out of your truck in 15mins. If you are loosing that much oil from the Rear Main Seal, your clutch and flywheel will be soaked in oil and you should definitely notice the clutch slipping or chattering on take off. If your clutch is soak with oil, you will have to replace it. Your flywheel can be cleaned with brake parts cleaner or even resurfaced or replaced if you want. I would take a look at the valve cover gasket as well. Oil from the valve cover gasket can leak down and behind your engine and look just like your photos.

We have a saying at work. "If it ain't broke, don't fix it." If it is your Rear Main Seal, I would in your situation, drop the transmission, replace the clutch, flywheel, throw-out bearing and RMS. But I would not rebuild an engine that runs great already. A Haynes of Chilton manual will tell you how to replace the RMS but the FSM is always better if you can get your hands on one.

 

[Kurtis]

OK guys so I'm turning to the pros again for some questions
I've searched the forums on t4r, toytec, and pirate4x4 for a rebuild thread on the Toyota 3.4l engine. I need diagrams of rear main seal, the plate that mounts to the transmission, and any other helpful diagrams. Also a rebuild thread would be great. If there isn't one I'm going to make one.

Anyways I have a bad oil leak. The oil runs out of the rectangular hole in my bell housing above my rack and pinion.... Rear Main seal right? Any advice? It dumps about half a quart of oil in fifteen minutes. Running the oil just flows out of the rectangular opening between the bell housing and the plate between the engine and transmission...
Any suggestions?

My rig:
98 T4R 3.4 Manual R150F

If you need the FSM, shoot me a PM with a gmail (or another email that accepts 25MB attachments) email address and I'll compress and send it to you.

 

[motobrad14]

I believe the service manuals were taken down.

OP: If oil is coming from this rectangular hole in the bottom of the transmission then yes it is your Rear Main Seal.
The reason I ask is because that is an ass ton of oil to be coming out of your truck in 15mins. If you are loosing that much oil from the Rear Main Seal, your clutch and flywheel will be soaked in oil and you should definitely notice the clutch slipping or chattering on take off. If your clutch is soak with oil, you will have to replace it. Your flywheel can be cleaned with brake parts cleaner or even resurfaced or replaced if you want. I would take a look at the valve cover gasket as well. Oil from the valve cover gasket can leak down and behind your engine and look just like your photos.

We have a saying at work. "If it ain't broke, don't fix it." If it is your Rear Main Seal, I would in your situation, drop the transmission, replace the clutch, flywheel, throw-out bearing and RMS. But I would not rebuild an engine that runs great already. A Haynes of Chilton manual will tell you how to replace the RMS but the FSM is always better if you can get your hands on one.

Im going to tear into it later this week. And I'm going to take pictures. Im not very good at threads but i am going to try to do one on a rear main seal replacement since i cannot find anything.
I know it loses a ton of oil, but here's my question. My clutch is fine, it doesnt slip, smell, or make noise. There is a plate that bolts between the clutch extenstion housing and the engine. I think that this plate shields the clutch in all areas. Its hard to explain but i think the oil drips down the engine side of the clutch between the plate and engine. So it traps the oil on the opposite side of the clutch. Then it is leaking out from between the plate and the engine. I dont think it is leaking from the clutch side. Ill post up some pictures when i do it. In the meantime i found some microfiche but it doesnt show any plate between the engine and tranny.

 

[motobrad14]

I do have another question... Since It looks like i will be dropping the transmission and transfer case i am going to fix a few leaks. Now i am no expert, and hope someone can tell me what to do. Its my only vehicle so i cannot afford to be down more than a day at most. So i need to have all the parts, seals, and gaskets there next to me as i replace this stuff. So can anyone tell me based on my poor picture why i get leaks from the Red Lines, and on the green line should i make sure that is a gasket so it doesn't interfere with any shifting clearance that is necessary, or can i get away with some good ole permatex?

The areas in red that leak must have a bad seal im assuming....can anyone give me a Toyota or aftermarket part number i can interchange at work so i can get the seals? I can always order everything i think i may need and return what i don't.... So give me everything you got.

My Toyota dealer sucks and wont supply me with any information... or part numbers. I made the mistake of walking in with my work shirt on. So i got the snide remark "Can't you get it at your work?"

 

[motobrad14]

Yep that would be the rear main seal. My is leaking a bit too after i replaced it with a cheap one when i did the clutch.

You don't to pull the engine to do the RMS. Just pulling the trans is all you need to do.

I'm so happy to hear this. Thank you for the reply. I am much more excited to tear into this and fix it now knowing that i don't have to pull the engine.
Im going to make sure i get the factory toyota seal. Or a Altrom. I sell fel-pro and magnum at work and am not too pleased about what i see come back through the door. You replace yours with a good one? remember what brand?

 

[Kurtis]

I do have another question... Since It looks like i will be dropping the transmission and transfer case i am going to fix a few leaks. Now i am no expert, and hope someone can tell me what to do. Its my only vehicle so i cannot afford to be down more than a day at most. So i need to have all the parts, seals, and gaskets there next to me as i replace this stuff. So can anyone tell me based on my poor picture why i get leaks from the Red Lines, and on the green line should i make sure that is a gasket so it doesn't interfere with any shifting clearance that is necessary, or can i get away with some good ole permatex?

The areas in red that leak must have a bad seal im assuming....can anyone give me a Toyota or aftermarket part number i can interchange at work so i can get the seals? I can always order everything i think i may need and return what i don't.... So give me everything you got.

My Toyota dealer sucks and wont supply me with any information... or part numbers. I made the mistake of walking in with my work shirt on. So i got the snide remark "Can't you get it at your work?"

Yes, I would use your favorite color of RTV on that green circle. As for the red lines, you don't normally see leaking there unless someone has pulled it apart in the past. Not sure why it would be leaking now.