Airhead Engine/Tranny seal exploded and oil spilling...!

[Roy Gavin]

I would check the breather too - you may have had a pressure build up in the crank case.

Some joker plugging one of the mufflers has been known to blow the seal it too , but you wold probably notice that---.

[gspd]

Some joker plugging one of the mufflers has been known to blow the seal it too , but you wold probably notice that---

Blocking (or restricting) the exhaust won't blow out seals.
That's how engine (jackman) brakes work.

[robtg]

Jake brakes work by lifting the exhaust valves releasing compression not by blocking the flow. Oil seals still wouldn't be effected.

[gspd]

Jake brakes work by lifting the exhaust valves releasing compression not by blocking the flow. Oil seals still wouldn't be effected.

My mistake , wrong terminology, I was confusing 'jake brake' with 'exhaust brake'.
Exhaust brakes block the exhaust, jake brakes don't.
Neither will blow out engine oil seals.
http://en.wikipedia.org/wiki/Engine_braking

[Roy Gavin]

Might have just been a coincidence, but I bought a cheap SS 2 in 1 header for the 75/7 at a swap meet.

Wasnt finished , both front pipes had the same , err , backward projection, and the tailpipe was overlong too.

Cut it to size and fitted it , started her up , and after a minuite or so wondering what the xxxx was wrong the header blow off - there was no connection between either side. Presumably the intention was to cut the hole with a in pipe cutter, but they never got that far.

Put the origonal system back on and noticed a pool of oil under the gear box, and automatically assumed that the cause of the blown seal was excessive crankcase pressure, caused by the blocked exhaust port.

But as I say it might just have been a coincidence, or maybe the truck engines with exhaust brakes also have a upgraded breather system to cope with any excess blowby.

[gspd]

But as I say it might just have been a coincidence, or maybe the truck engines with exhaust brakes also have a upgraded breather system to cope with any excess blowby.

That could very well be, I don't think it simply a question of blocking the exhaust.

FTR -
I misspoke in my last post: A TOTALLY blocked exhaust could very well have caused your seal to blow out,
I meant that a partially blocked (as in restrictive) exhaust shouldn't.
Exhaust brakes restrict exhaust flow, they don't totally block it.

[mefrank11]

thought I had read about the crank having to be held from moving forward and something falling out of place?
Frank in florida

[Major Softie]

thought I had read about the crank having to be held from moving forward and something falling out of place?
Frank in florida

Yeah, that's the thrust washer/bearing. That shouldn't cause these symptoms as far as I can imagine.

[Jean]

You have to block the crank (at the front) when you go into the rear-main-seal..as in removing the clutch, flywheel, etc.
BE careful that you notice the location of the flywheel for correct-timing when you put it all back together.

[pkboxer]

Has the original poster made a 2nd post? Or is someone here working with them to fix this?