Local mechanics
- Thread starter Murdoch52
- Start date
scoutdude80
Moderator
I have someone for you. Pm me your email address.
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
I got your email, I'll respond within a few hours. But your description of your problem does not match a rear main seal leak.
Either way, regarding several potential leak points, the transmission must be removed to address this issue. I'll elaborate in my email response so that if you chose to have a commercial shop do this, they will know what to look for and you can come from a "informed" position regarding overseeing the quality of the work.
Thank you. Well I just bought the truck so I am not sure what it is. When I asked the guy I bought it from about it he told me that it was a best guess kinda thing and that was it.
Like I said when I drive it is fine and doesnt leak but when I stop that is when it pours out all over the place. When I got out and looked at it there seems to be a little vent that is right where the tranny and the motor meet, the oil dumps out of there and then gets all over the place. I havent decided if I am going to do this myself yet or not. I was told that the rear main is a rope seal and no one wanted to touch it with a 10 foot pole. I was only told that but was also skeptical on that info and am thinking it is not a rope seal and just a regular rubber seal. If that is the case I was thinking of just buying every seal possible for the lower end of the motor and changing them all out at the same time.
This motor is supposed to only have 20k on a rebuild that was done by anything Scout in san jose. Apparently they build this for one Scout that was totaled and then the guy I bought it off of put it in my current Scout. If this is true then the rear main doesnt seem like a likely problem. I can see damage to the oil pan so who knows.
Thanks for your time.
Ben
Like I said when I drive it is fine and doesnt leak but when I stop that is when it pours out all over the place. When I got out and looked at it there seems to be a little vent that is right where the tranny and the motor meet, the oil dumps out of there and then gets all over the place. I havent decided if I am going to do this myself yet or not. I was told that the rear main is a rope seal and no one wanted to touch it with a 10 foot pole. I was only told that but was also skeptical on that info and am thinking it is not a rope seal and just a regular rubber seal. If that is the case I was thinking of just buying every seal possible for the lower end of the motor and changing them all out at the same time.
This motor is supposed to only have 20k on a rebuild that was done by anything Scout in san jose. Apparently they build this for one Scout that was totaled and then the guy I bought it off of put it in my current Scout. If this is true then the rear main doesnt seem like a likely problem. I can see damage to the oil pan so who knows.
Thanks for your time.
Ben
scoutdude80
Moderator
Ben. I sent you keith's landline number.
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
Might as well respond to ya on the forum so that others May benefit!
A leaking rear main seal system is very common on not only IH stuff but any engine. However...the "seal" system used on the ihc I-4 and sv engines (yours) is a very advanced unit as compared to many chryfordrolets apps. It is a one piece/hi-tek oil seal and also incorporates a very nice "side seal" feature for the rear main bearing cap.
Those "side seals" then interface with the pan gasket to create a oil retention effect.
Up above and behind the flywheel or flex plate there is a large plate that covers access to the rear cam bearing, that point uses a gasket. Adjacent to that plate is a 1/4" npt plug that blocks the main oil gallery. Those are leak points also. You will also see two core plugs that are notorious for rotting, that allows a coolant leak.
The flywheel (flex plate/hub in your case) is retained to the crankshaft hub with bolts. Those bolt threads must be sealed with some type of adhesive, otherwise oil will migrate past the bolts and appear to be a leaking rear main seal also.
As for the transmission, there is a distinct difference in the appearance/smell/feel of transmission fluid as compared to engine oil.
The most common leak point on the 727 automatic is the "front pump seal". That will be exposed when the torque converter is removed. If that seal leaks, then that means the pump bushing is worn behind the seal. That bushing and seal is a very common replacement job, they must be replaced at the same time or it will continue to leak with even a new seal.
Up on the top of the front pump cover you see the transmission vent. There were two possible types of vents used on these trannys. Yours is most likely a round plastic type baffle riveted in place.
That vent point normally will only leak if the transmission is grossly overfilled and the tranny fluid is overheated (it expands/aerates and leaks through the vent).
It will also leak if the tranny fills with water inna water crossing or if the rig goes on it's side or upside down.
All of the bolts which retain the front pump have a composition steel/viton washer under each head to seal that point. And a large "square cut" "o" ring seals there perimeter of the front pump body along with a stamped gasket to seal the pump ports to the tranny case. Those are all potential leak points for trans fluid.
Dealing with the tranny stuff (including vent relocation) is covered in this thread so do a review of that to educate yourself:
http://www.forums.IHPartsAmerica.com/transmission-tech/588-torqueflite-727-guapo.html
If you need more info regarding the rear main seal system for the engine, then review the posts in many threads in this sub-forum:
http://www.forums.IHPartsAmerica.com/gas-engine-tech/
If ya don't see what need there then start a new thread and we'll address that issue separately. I have much in the way of pics and such regarding dealing with rear main seal service.
Hint...much oil leakage that is thought to be the rear main seal system...is actually oil leaking from the pcv grommet and valley cover under the intake manifold. It runs down the rear of the engine after pooling in the recesses on the top of the block casting...drips when the engine is shut down....and then quits! In actuality it only leaks when the engine is running!
A leaking rear main seal system is very common on not only IH stuff but any engine. However...the "seal" system used on the ihc I-4 and sv engines (yours) is a very advanced unit as compared to many chryfordrolets apps. It is a one piece/hi-tek oil seal and also incorporates a very nice "side seal" feature for the rear main bearing cap.
Those "side seals" then interface with the pan gasket to create a oil retention effect.
Up above and behind the flywheel or flex plate there is a large plate that covers access to the rear cam bearing, that point uses a gasket. Adjacent to that plate is a 1/4" npt plug that blocks the main oil gallery. Those are leak points also. You will also see two core plugs that are notorious for rotting, that allows a coolant leak.
The flywheel (flex plate/hub in your case) is retained to the crankshaft hub with bolts. Those bolt threads must be sealed with some type of adhesive, otherwise oil will migrate past the bolts and appear to be a leaking rear main seal also.
As for the transmission, there is a distinct difference in the appearance/smell/feel of transmission fluid as compared to engine oil.
The most common leak point on the 727 automatic is the "front pump seal". That will be exposed when the torque converter is removed. If that seal leaks, then that means the pump bushing is worn behind the seal. That bushing and seal is a very common replacement job, they must be replaced at the same time or it will continue to leak with even a new seal.
Up on the top of the front pump cover you see the transmission vent. There were two possible types of vents used on these trannys. Yours is most likely a round plastic type baffle riveted in place.
That vent point normally will only leak if the transmission is grossly overfilled and the tranny fluid is overheated (it expands/aerates and leaks through the vent).
It will also leak if the tranny fills with water inna water crossing or if the rig goes on it's side or upside down.
All of the bolts which retain the front pump have a composition steel/viton washer under each head to seal that point. And a large "square cut" "o" ring seals there perimeter of the front pump body along with a stamped gasket to seal the pump ports to the tranny case. Those are all potential leak points for trans fluid.
Dealing with the tranny stuff (including vent relocation) is covered in this thread so do a review of that to educate yourself:
http://www.forums.IHPartsAmerica.com/transmission-tech/588-torqueflite-727-guapo.html
If you need more info regarding the rear main seal system for the engine, then review the posts in many threads in this sub-forum:
http://www.forums.IHPartsAmerica.com/gas-engine-tech/
If ya don't see what need there then start a new thread and we'll address that issue separately. I have much in the way of pics and such regarding dealing with rear main seal service.
Hint...much oil leakage that is thought to be the rear main seal system...is actually oil leaking from the pcv grommet and valley cover under the intake manifold. It runs down the rear of the engine after pooling in the recesses on the top of the block casting...drips when the engine is shut down....and then quits! In actuality it only leaks when the engine is running!
Rock Tractor
IHPA Tech Moderator
Sounds like blowby in the pcv gromet area.
Check the valve cover and make sure there is a breather there and not another pcv valve, seen this more than once.
Check the valve cover and make sure there is a breather there and not another pcv valve, seen this more than once.