Gearbox leaking from pan bolts?

It appears that my trans is leaking from the pan bolts. Has anyone seen this type of leak? Is there any way to prevent this from happening?

 

Gerry, l dug up a old picture of mine.

I'll say it's oil that just seeps out of all the nukes and crannies of the engine/gearbox. Did you try and clean it first to be sure if it's coming from the bolt?
Image Unavailable, Please Login

 

Many of the pan studs do not go into blind holes. They go right through into the crankcase. Hot oil likes to wick around the threads and drip off the bottom of the stud. There are two solutions. One is to remove each nut one by one, clean the threads, and put loctite on the nut. This fills in the thread so the oil can't get past the nut. I prefer the other method - replace all the nuts with acorn nuts. They look great, and positively stop the leaks. There are many sources for these acorn nuts, but my favorite, believe it or not, is from Home Depot. They are stainless, 6mm, and cost about 44 cents each! (You can also polish each one in about 15 seconds on a buffing wheel). I forget how many are necessary. Home Depot only stocks a few, but they will special order them for you. -Steve
Image Unavailable, Please Login

 

The acorn nuts seem a great solution. Did you have to adjust any of the stud lengths?

 

I bet you the oil is coming from higher up. Either valve cover gasket leaking, or the little round thingy with the hose that connects to the lefthand side of the rear bank.

Oil will gravitate down and will appear to be dripping from the nuts that keep the cover on.

Guess how I know?

 

I still like the nyloc aircraft nuts approach. I usually use them on other parts of the engine (cam covers , WP , etc.) but never thought of using them as leak prevention. I guess I'll have something to do this week while it snows. Thanks for the tip.

 

Look for a product called Stat-O-Seal, a washer with an intergal oring attached. I happen to use Bulkhead seals from Boeing (bought 3,000 many years ago and am now down to dangerous stock levels) but they are almost the same thing.

Many consider this a form of Italian self preservation on the Vintage cars as at speed it protects the entire chassis with a film of oil and keeping the rust at bay. In many instances the oil is weaping right through the castings and requires painting the inside of the pan with special coatings

Dave

 

Dave, I like those washers, too. I think someone should try them and let us know how it works. For the acorn nuts, I did not have to shorten any studs. -Steve

 

Thanks for all of the suggestions. I did not know Stat-O-Seal wahsers existed, very interesting. I can only hope to get my undercarrige to look as clean as Ferrari328GT.

 

Gerry,

I've been using Stat-O-Seals on these cars for quite a few years now. They work great and are essential on many of the older 12-cylinder cars in keeping the "oil down the studs" problem in check. Recently, I've used them on two 328's, with 100% success...resulting in completely dry sumps.

David

 

Hey, that's great to hear. Do you have a favorite source?

Steve

 

Steve,

I get them from McMaster Carr, as they have them in 6 and 8mm (stud) sizes. They get a bit pricey, if you use alot of them...

Installation procedure is pretty straight forward:
-Remove old hardware
-Clean stud and surrounding area
-Lightly lube Stat-O-Seal with oil or silicone spray
-Install Seal against pan
-Install new wave or flat washer (I find this step to be important, as now the backside of the Stat-O-Seal has a smooth surface to seal against, as well.
-Install nut and torque to specs. (78 in-lbs for 6mm studs, 20 ft-lbs for 8mm studs)

-Admire "dry", oil free floor and car!

David

 

Good info.

 

about 2500 of them on the road now.....they work

 

Do the stud lengths need to be shorten with the acorn nuts?

 

It is unfortunate that the engine is in back, preventing the rust prevention from spreading the entire length of the car as is employed in the Fiat Spider and virtually every car made in Britain. Perhaps Ferrari needs to issue a TSB to drive in reverse at high speeds periodically to protect the car? Also perhaps some sort of wicking material to the door sills would be helpful.

I have owned a Ducati and Moto Guzzi for many years. When I had the Ducati's motor open I found patches of some kind of epoxy in the cases - porosity sealant of some kind. Mine is a '74, they'd been making the twin for a couple of years and probably figured this one sometime in production. My Guzzi has a porosity problem in one head. Someday I'll get tired of oil spots on my right knee and figure out how to fix it. It would not surprise me for one second that Ferrari also had porous castings. Lock-Tite sells porosity sealant and I looked into buying it a few years ago, but it is stupid expensive. I wonder if Glypcol (sp??) would do the trick.

 

Another way to prevent these leaks is by removing the nut, cleaning off the threads with lacquer thinner, putting a smear of Permatex Ultra Grey on the threads and putting the nut back on/torquing to spec. Don't use the "normal" silicone stuff... Ultra Grey makes even old Britbikes into non-leakers! Formerly the only way you could make them not leak oil was to not put any oil in them!

 

Exactly my point, each acorn nut is a closed inner depth that the protruding threaded stud section must be less than. Otherwise it applies no clamping force to the joint.

Found reasonable sources of Stat-O-Seal easily though. Worth giving them a try out I believe.

 

i like the acorn nut idea ..........anybody know thw torque setting for the nuts cheers

 

Here you go mate.

 

Already answered that one -- no, the stud lengths are all OK as is. -Steve

 

Where is the best place to buy "Stat-O-Seals", Mcmaster's product is not aluminum?

 

The Glyptol works great but you have to get everything PERFECTLY clean and acid etched prior to application. I paint the inside of every Vintage engine prior to assembly. Half the reason is to help end the porosity problems and the other half is to seal in the left over casting sand that after all these years is starting to work its way out. Those pans are only leaking now because the grain of sand that once plugged the hole is now floating around in the engine.

 

I've used the McMaster o-ring washers on my lower pans (engine and transaxle) with good results. The oring is bonded to a steel washer, that is yellow cad plated if I remember correctly. I don't think you will find an o-ring bonded to an aluminum washer. Rubber doesn't bond too well to natural aluminum.

 

Someone should let Boeing in on this.... they have been around for decades.

The steel washer with an attached Oring is for use on nicely machined surfaces with parallel surfaces which that engine/trans sump is not. Might work, but it is being used outside of its design parameters and luck becomes a factor.