One of the things that drives me to drink and could be improved on my truck is the lack of an inspection plate on the lower side of the bell housing. I have an oil leak (probably another rear main seal), but the oil shows up on the bottom of the T19 tranny (always), but there is no way to inspect it to see if it is the rear main or the tranny seal.

Do all the 460 4 speeds of this era have from the factory a block plate that has an extended lower end that covers the inspection hole. A lot of cars/trucks have a removable inspection plate for the clutch area.

Would be nice to inspect the inside of the bell without pulling the tranny, a real PITA on the 4x4s!

 

If it were the rear main seal, I would expect that to drip from the bottom of the bell housing
close to the rear of the engine and not out by the tranny; think of how much oil would need
to leak into the clutch assembly and how poorly your clutch would operate if there were
enough oil in there to be leaking at the tranny junction. I'll bet it's your tranny input shaft
seal...

I have the same condition but it was easier to spot because I had just rebuilt my engine so
everything was freshly painted and clean. I later noticed gear oil (has got a unique smell)
dripping from the tranny/bell housing junction. *sigh* Well, that's OK, rebuilding that T18 is
kinda-sorta on my list, anyway, but more just for fun than anything. My transfer case input
shaft seal leaks, too, although all of that oil (automatic transmission fluid) gets contained in
the extension housing between the tranny & transfer case. Also on the list....

 

I know that my '87 has the one piece plate.
(sorry for the blurry cellphone camera photo)

 

I'm pretty sure it is engine oil and it is dripping from the bell housing. It is blowing back onto the bottom side of the tranny I think. A good tip though ctubutis. I'll swipe off some oil and see if it smells of gear oil at all. Next time I pull the tranny or engine that block plate is going to get a mod to make the bell interior accessible. Shouldn't be difficult to do. ArdWrknTrk, your comment confirms that I have a factory design and not after market. Thanks!

Do you guys also have trouble keeping rear main seals in your 460s?

 

Rear main? no, not really. BUT I did have problems with the oil pressure sender at the back of the block above the bell housing.
Took me a while to figure that out. I thought it was the RMS at first.

 

I have a 400 and not 460, but they both share the same bell housing pattern and a few other
similarities - one of which is that aluminum gasket/spacer thinger that you want to modify to
create an inspection plate.

Another idea for determining the source might be to use the dye that fluoresces under black
light, add a bit of it to your engine oil and then go snooping around the outside of your
engine a bit later to see what glows. NAPA sells it, the following link may work for you,
there are different formulations for different uses:

http://www.napaonline.com/Search/Res...word&Nty=1&N=0

 

Maybe I just have bad luck with them or I peal them a bit getting them in or such. I have replaced mine twice in the last 6 years. They seal good a year or two with minimal leakage and then start to drip heavy. Bummers.

 

Just an idea, have you ever tried polishing the area where the seal rides on the crank with a strip of crocus cloth?

 

Ones mind should be a sponge. I'm always willing to learn something new. Thanks for the suggestion.

 

Jim, you got me going out to climb in the engine compartment and have a look at that oil pressure sending unit LOL My truck "looks" like it has a RMS leak, but with 100,000 miles on the clock it could be the switch... Man that would make me happy!

 

what's crocus cloth??? my clutch is toasted, rear main has been leeking like a siv for years. though oil is running down the front side of the cover, oil is coming from inside the vent slot as well. that sucks the cover is one piece, I will have to modify that! I am in the process of pulling the tranny. It's a 4x4... so it will be tough by myself. I am making a plate for my tranny jack so I can pull the tranny and t-case tegether, then I'll be looking into my pan or rear seal problem. I think the real bitch will be getting the pan off, but I do have a lift so that helps a lot...

Oh and 400 and 351-M have a 390, or FE bell-housing pattern, not the 460. But 2 piece seals leak period, I wounder if staggering the halves so the are not flush with the block, and using some o-ring volkenising (SP?) glue would work??? we sometimes have to make custom o-rings at work for hydtrualic systems of more that 4000 psi. the kit has glue you use to glue the two pieces together... ??? any thoughts?

Scott

 

What Is Crocus Cloth? | eHow.com I've always lined up 2 piece seals with the block/cap and use a small dab of rtv, but saw someone stagger them on one of those sunday morning cable shows the other day. Seemed like a good idea.

 

might be easier said then done, with the crank in the block?? but that's the way they say to do it..

it looks like it is just emry cloth to me??? LOL we have roles of med, cours n fine in our machine shop... does it work? LOL (roughing or polishing the seal with this?) I would think it woud ruin the seal??? curious about this one... I want no leaks if I replae my rear main seal...

 

Crocus cloth is like a very fine emery cloth. It's usually a brick (reddish-orange) color.Last time I had to do the clutch in the truck I just took the sticks and driveshafts off, pulled the gearbox/TC back and hung it on the crossmember. I'm very sure the 335 & 385 series' pattern is the same.
Most of the point of the M's was to put a tougher tranny behind the 351.
List of Ford bellhousing patterns - Wikipedia, the free encyclopedia
IDK, never tired it on a RMS but I have had to make up O-rings in the field using cyanoacrylate adhesive before. It works for static and linear seals but not for dynamic (rotational) ones.
I'd also think that having the seam in line with the block would apply the most clamping force to the seal's joint. But I have never tried it any other way.

 

It can work, but only if the seal hasn't worn a deep groove into the crank.
If I replace a RMS and it still leaks the first thing I check is longitudinal play. If the crank can move forward and back much it acts like a pump and no new seal will work.

The 460 pan is a PITA on a 4x4.
R&Ring the pickup bolts and torquing the cap bolt with the stay is more maddening than trying to get the pan gasket to fit and stay in place.
But I suppose with the bellhousing removed you can lift the engine higher.