Hey all,
I was having some trouble with my 77 F150 4X4 not wanting to start. I later learned the fuel lines running to the frame mounted fuel filter were rotted and kinked. A new filter and some fuel line will have her back on the road.

However, while I was under my truck today, I noticed some new leaks. The frsutrating part is I completed a rebuild/reseal job about a year ago. I removed the engine, transmission and transfer case, completely rebuilt the engine and resealed the transmission and transfercase.

I have a drip pan under my truck right now and can see engine oil, from what looks like the rear main seal area and 80-90w which is dripping from the transmission crossmember.

I have resealed the transmission and transfer case twice. I do not feel I incorrectly installed the parts, since I have several years of experiance and an autmotive degree, which yeiled the experience to know what types of gaskets and sealers go where.

What has been your experience? Has anyone been successful at sealing up a thirty plus year old powertrain? Are they just predisposed to leave there mark? These leaks are not huge, a few drips per week. The truck also sits alot, which does not do any good for the seals.

The truck is old and still sports the origonal engine(300ci 4.9L), transmission(NP435) and transfer case (NP205). My grandfather bought the truck new and I am the third generation to own it, so keeping the truck nice and operational is a must.

What is your opinion of a 351W swap into the above menitoned truck?

Any comments? Suggestions?

Thanks,

Scott

 

It is just marking its territory. I wish I could say my truck leaked a few drops a week. mine is a few puddles a day

 

I think anyone here would be very happy to only leak a few drops a week. These 30 year old trucks just don't seem to seal up completly, gasket surfaces, shafts, etc aren't quite as true as they once were. As for the 300, keep it in the truck, Ford never made a better engine.

 

It could be a number of things...

What were the quality of the seals? I know some seal and gasket manufacturers are substandard. Get original if you can, and stay away from taiwan and china if at all possible.

Also, how often does the truck just sit? And how many miles are on the new seals? Might not have been ran long enough, or often enough to seat the seals.

and finally, any burs or rough edges on components where the seal may ride on other components?

All that I can think of.

 

You have not switched to synthetic oil have you? That can cause old things to leak a bit more than they did sometimes...

 

Leaks should not be tolerated, even from an old truck.
These are easy to fix once they are isolated. Sealing surfaces have to be true and free of scars or grooves.
Rotational items such as harmonic balancers, transmission seals, etc have been turning for many many miles, and they can develop a groove where the seal rides.
Replacement of the worn component can be very helpfull, but isolating the leak should be first.
I do not buy the synthetic oil leakage theory. Some have said this to be true, but I have not seen a single bit of data to support this theory.
Not picking on anybody, but this is just not logical.

 

I agree with the synth idea. The old days when synth was retivly new, there were issues with gasket and sealing areas. This was due to the fact that the good old Dino has addatives that made some seals and gaskets swell to seal. The old days of Syth didn;t have these and with make up of synth and the more uniform chemical chains allowed synth to leak by because there was minimal or no swelling on gasketed areas.

But todays synth's have addatives and are much better formulated. If you switch to synth and have big leak issues, the leak was theyer but most likely was always there and plugged by gunk and often synth will seep through the plug. Kind of like putting Helium in your tires instead of air. You'll have tires that go flat really quickly with He, rather than regular O2 cause the molicules are smaller with with He and can seep through the tinest holes, and O2 molecules are much larger. Kindof the same thing compairing the base stock of Dino to Synth. But the difference being the Dino base stock has much more varing size of carbon chains, while the base stock in synth is more uniform and the same size.

 

I can find NO drips or puddles from under my truck...........knock on wood !! ....it's a '79 F100 (Australian) 351 Cleveland & C-6

 

1. I use only timken and felpro gaskets and seals.

2. The truck sits for a majority of the year, however, after I rebuilt the motor it was my daily driver for approximately 2000 miles. Lately, I have been experiencing one problem after another and properly addressing each issue as they arise, but it gets expensive fast so I have no choice but to let the truck sit inside my garage.

3. All of the sealing surfaces were prepared by throughly cleaning the surface and making sure the surface was at a proper RMS with the use of machining a suface preperation tools.

I have yet to own a Ford car or truck which has a rear main seal that does not at lest seep, causing a mess on the bell housing. Gear lube seems to be quite avasive, I successfully stop one leak and another starts, like some kind of sick game.

I think the rear main seal is the culprit in this scenario. However, the transmission and or transfercase leak is evasive. I can clean the cases, but when the truck is driven the wind blows the oil all over the trans and transfer, making it difficult to detect.

I have also been batteling with my new core (freeze, expanision) plugs. A couple of them have been seeping. I was very careful to install them at the propper depth and use a sealant to aid in their installation. I have heard of people using a cooling system treatment to seal up minute leaks and prevent future ones. Any opinons on this?

I wish I could post some pics, so you guys could see exactly what I am dealing with, but I think I need more posts.

 

I use convetional 10/30w motor oil.

 

I agree, but the NP 435 and NP 205 are extremely heavy and I would rather not take them out to repair leaks if I do not have to. I have yet to find a suitable trans jack which will accomidae working on a garage floor and a lifted truck. The last time I removed and installed the transmission and transfer case it was a interesting experience.

 

I have found with my '78, that it was weeping fluids. Oil and tranny fluid. I have found that oil pan bolts and tranny pan bolts were all loose, not wobbly loose but as in 1/2 to 3/4 turn loose. I first noticed this when I saw drops of tranny fluid forming on the bolt heads kind of like condensation drops. But the pan and other stuff was clean and dry. I need to thuroghly clean my Married NP205 and see where it is weeping.