The oil leak saga continues

[Basil]

Ok, in a previous post I told you that I have the motor out of my Spitfire in hopes of figuring out a persistant oil leak that has been happening for a long time. Despite changing the rear seal twice it continued to leak. Now that I have the block on a stand and the gearbox on the floor, I'm even more puzzled that ever. If the oil leak were coiming from the rear seal, as I've long suspected, then it seems the back (engine) side of the flywheel would show oil, would it not? However, the back of the flywheel shows no hint of oil - just a bit dusty, but no oil. So does this eliminate the rear sear area? It doesn't seem to leak much when the motor is running, but pours out several tablespoons full when you shut it off. Another possibility is that the oil dis coming from the gearbox. Someone mentioned the possibility that the input shaft seal could be bad. Only problem is, according to the pictures in the Haynes manual, this particular gearbox on teh later Spitfires does not have a seal...just a bearing with an "oil thrower" on the shaft behind the bearing (the side of the bearing facing the inside of the gearbox). When I look under the car it sure seems as if the oil is leaking from the engine. I suppose it still could be from the seal...maybe too much crank case pressure? But I'd think if that were the case I'd see oil all over the engine side of the flywheel - but I don't know that for a fact.


As long as I have the motor out I am going to have the crank inspected and sleeved if neccessary and I will probably chenge out the bearings in the tranny too, but does anyone familiar with these later Spitfires have any other thoughts our suggestions?

Basil

 

[sp53]

Hi Basil I owned a spitfire back in the 70’s but this happened on a tr3. Anyways, I had an engine that would loose oil when it was not running and the oil leak would lessen when I drove it. One day I had the vehicle jacked up, and I noticed a hair line split in the sheet metal of the oil pan. I thought what the heck. I could actual push on it and it would leak, but for some strange reason the leak was less almost stopped when it ran. I thought maybe the tin got hot and sealed itself or perhaps the vehicle was haunted.I replaced the pan and no more puddle on the garage floor.
Steve

 

[Brosky]

Basil,

If either were leaking a lot, you would be adding oil to both or either one or the other. Which one was using a lot of oil and needing refilling more frequently?

 

[2wrench]

Hi Basil I owned a spitfire back in the 70’s but this happened on a tr3. Anyways, I had an engine that would loose oil when it was not running and the oil leak would lessen when I drove it. One day I had the vehicle jacked up, and I noticed a hair line split in the sheet metal of the oil pan. I thought what the heck. I could actual push on it and it would leak, but for some strange reason the leak was less almost stopped when it ran. I thought maybe the tin got hot and sealed itself or perhaps the vehicle was haunted.I replaced the pan and no more puddle on the garage floor.
Steve

Do I hear a possible exorcism on the horizon? Most
I'd have to offer on this one.

 

[DrEntropy]

If the back side of your flywheel is dry, the seal ain't leakin'. The input shaft of the trans is the next "usual suspect". That would have oil all thru the bell-housing over time. As a black soot layer. If profuse you may even see a "track" or trace of clean metal at the point where the shaft exits the case. A 'sloppy' crank pilot bush can allow enough movement to cause that leak too. It allows the shaft to wallow around off center. Won't leak profusely, but over time a small amount of oil accumulated can appear to be a larger leak.

 

[RonMacPherson]

Another way to isolate the leak source. go put in some "purple" oil, either in the engine or the trans. Forget who it is but one of the major oil companies sells purple oil at most parts houses(years ago, at Union 76 we used to sell Royal Purple also). This is very good to isolate a leak when first installed.. It takes a while for the oil to change color.

 

[Basil]

If the back side of your flywheel is dry, the seal ain't leakin'. The input shaft of the trans is the next "usual suspect". That would have oil all thru the bell-housing over time. As a black soot layer. If profuse you may even see a "track" or trace of clean metal at the point where the shaft exits the case. A 'sloppy' crank pilot bush can allow enough movement to cause that leak too. It allows the shaft to wallow around off center. Won't leak profusely, but over time a small amount of oil accumulated can appear to be a larger leak.

Yep - inside of the bell housing seems like it's coated with thick goo - almost like tar. But what's puzzleing is, this input shaft on this tranny has no seal...(not shown in the book parts break down). It just has a bearing and an oil thrower (or it's supposed to). I wonder if the PO had the tranny apart and didn't re-install the oil thrower? (Part# 103 in picture) Or could it just be that the bearing is shot? (But there was no noise to indicate such). I may pull it apart just for the experience and put new bearings (if I can find) and make sure the oil thrower is there and ready for duty. Also, I will change the pilot bearing in the flywheel...etc etc. Any other thoughts?

Basil

 

[RonMacPherson]

Another solution to your problem is to take the front bearing, no 102 to a bearing supply house. They should be able to provide you with a bearing that is sealed on one or both sides. If the only one they have is sealed on both sides, you can pry one seal off. But sealed bearings usually have sufficient lube installed where they last a loooooong time.