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Mysterious hole in transmission

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LexTR3 said:
for example, I've heard that good quality synthetic oil has a tendency to leak because it gets into places other oils do not.
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My opinion, that is a myth, brought on by some synthetic oils being somewhat lacking in "seal sweller" additive. I run Valvoline full synthetic in all my engines, and I have never seen it increase oil consumption. In one case, it actually reduced it rather sharply. However, just one change of Mobil 1 in my Buick (with a Chevy 350 engine) roughly doubled it's oil consumption. Fortunately it went back down after adding just a couple of quarts of Valvoline.

As far as the "mysterious hole", the TRs (like most cars with manual transmissions) use a dry clutch. That hole drains the large cavity where the clutch and flywheel reside (commonly known as a bellhousing for its shape). So it is not exactly "supposed" to leak, but it is supposed to let out any oil (or water) that finds it's way into the bellhousing.

As noted above, British cars are fairly famous for leaking oil ("That's not a leak, my car is just marking its spot!") and the rear main seal on the TRactor motor is one of the most common offenders. But since it is really an engine problem, it's generally discussed as such, rather than a transmission problem. Most folk don't even consider the bellhousing to be part of the transmission; even though for the TR2-6 it is incorporated in the casting for the transmission housing. On many cars, it is a separate piece entirely.

The TR2-4 rear main is such a common problem spot that there are actually multiple upgrades available on the market today to "fix" the leak. There have been several recent threads on that topic, You should be able to find them if you are interested in learning more.
 
LexTR3 said:
I've also noticed that I need to top off the transmission with about a cup of oil every -- say -- 500 miles or so. The engine oil level doesn't change much at all.
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Ed,

If you need to add that much transmission fluid in that short of a time and no other evidence of leaks from the transmission I'd have to suspect it's transmission fluid and not oil?

Scott
 
Thanks, Scott.

Randall,

As always, your information is very helpful in understanding what is going on with these cars.

What you describe is what I dimly reasoned-out about the function of the little hole (drain hole) in the bell housing.

My main question remains, however, and that is: Should I have the seal upgraded/fixed, or can I just leave it alone and keep the fluids topped up?
 
Basically live with it unless it is worth a lot of time/energy/hassle and missed driving time. For some owners fixing it is "required" or it will nag at them, most of us just live with it until the drive train has to come out anyway.

Totally your call, and you won't be wrong either way.
 
LexTR3 said:
...Unfortunately, when I had an overdrive added to my car, the old transmission dipstick was eliminated (much to my regret), and now I have to check the level by jacking up one side of the car, putting some oil in the transmission, lowering the car, and seeing how much runs out of the fill hole...
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Some add a hole in the tunnel to have easy access to that fill plug. I sized mine to take a rubber plug like the one above the u-joint, Don E did his to fit a plug like the ones for the jack holes in the floorboard.

Tunnel%20Holes.JPG


I also added the rearward hole in hopes that, if needed, I could service the solenoid with the cover in situ. Of course the cheesy cardboard cover in the TR4 made this pretty easy though the sheet metal version can be holed too.
 
LexTR3 said:
Unfortunately, when I had an overdrive added to my car, the old transmission dipstick was eliminated
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Well, if you do pull the transmission to work on the leak, IMO you should also look into installing a top cover with the dipstick. The early top covers will fit the later gearboxes (even TR6) if you install the shift forks & rails to suit the gearbox. Many of the early covers were already drilled and tapped for the OD switches, but it's not too difficult to add them if required.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
You mention using a heavier grade of oil. I am using Red Line MT-90 75W90 GL4 Gear Oil in my transmission. If I were to switch to a heavier grade of oil, what would you recommend? [/QUOTE]

Honestly, I wouldn't. That was the factory's advice for the engine. IMO a heavier oil will not help the transmission leak very much, and interferes with gearbox (and overdrive) operation to the extent that I just wouldn't do it.
 
All good advice, and as usual I really appreciate the input.

TDSKIP: The amount of leaking going on doesn't seem to warrant the hassle, time, and cost that it would require to "fix" it, so as long as I feel confident I'm not doing any irreparable damage, I believe I'll go ahead and live with it.

George: I do miss the old fill hole and dipstick, but I'll probably stick it out with checking the level by jacking up the left side of the car from time to time. Thanks for the infomation, however, and the idea.

BTW -- Just ran into some folks from Tucson who have come to Lexington to teach at VMI. Small world!
 
On the off chance that some miracle fluid might help with the transmission leaks, I drew off about 10 oz. of transmission fluid and added 10 oz. of Lucas Transmission Fix. Doubt that it will make any difference, but worth a try.

Any idea how long this stuff takes to begin working on leaks.... if, indeed, it does work on leaks?

Some people swear by it... others swear at it.
 
According to the lable, the Lucas Transmission Fix is appropriate for "light duty manual transmissions." There is another Lucas transmission product for "renewing" transmission fluid, and it seems to be exclusively for automatic transmission.

George: My hopes are up, because of the company's claims for the ability of this stuff to fix leaky seals, but I will be pleasantly surprised if it actually works. I put the "transmission Fix" in today and drove for about an hour, however,the leak was still there when I parked the car in the garage. But somewhere in the back of my mind I seem to recall seeing that these products don't work immediately... We'll see. I'll let you know.

I should have said earlier that we are not talking here of a few drips, but a little "pool" of fluid under the car, probably as much as two tablespoons of fluid under the parked car. This occurs within the first 15 minutes of parking the car in the garage. After a couple of hours, however,there is almost no leak at all.
 
I'm still with those who suggested the drip was engine oil, most likely from the rear main seal. The dark colour indicates the oil is doing its job of collecting burnt carbon particles.

Gearbox oil leaking into the bellhousing tends to show in its natural light color.

A flattened brown carton makes an absorbant and easily disposable drip catcher. Or an upmarket solution I've seen is cat litter in an old oven tray.

Viv
 
Now we're getting into the area of the leak subject I have more experience with -- what to drip on.

For those who shop Costco (a US warehouse-type store) their display of paper towels always has a bunch of large flat sheets of cardboard that divide the layers of packages. My dear wife brings home several each visit for me to use on the garage floor.

I agree the color of the oil suggests the engine. Gearlube (depending on what you're using) will be more the color of honey.
 
The only problem with the engine oil thesis is that my engine oil level hasn't fallen, but I have lost about 6 to 8 oz of transmission fluid over the course of somewhere around 1000 miles of driving.

As for catching this fluid, I use an old galvanized metal tray that once fit into a dog cage, and newspaper. I can change the newspapers often so as to monitor the amount leaking: immediately after parking, several hours later, and days thereafter. The leaking falls off considerably after the first 15-30 minutes of parking the car.
 
Poolboy,

If I don't solve the problem of leaking oil and fumes resulting from cleaning fluids, I may have to remove my Triumph from the garage in the house!
 
LexTR3 said:
If I don't solve the problem of leaking oil and fumes resulting from cleaning fluids, I may have to remove my Triumph from the garage in the house!
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Have you considered adding an exhaust fan to the garage? I have one of those "powered attic ventilators" mounted in the side wall, which seems to help a great deal with odors getting into the house.

On the "which fluid is which" front, you can add a fluorescent dye and then shine an ultraviolet light on the leak. That is also a good procedure for when you're not certain where the actual leak is (like the thin film running down the block and dripping from the bolt heads scenario). Your FLAPS should have the dye for not too much (different dyes for different fluids), although the ultraviolet light might be more expensive.
 
Randall,

Yes, indeed, I have an exhaust fan in the garage, but it doesn't do enough for the "sensitive nose."

Also, oil leaking down on the exhaust system gives off an oven-baked odor. Another reason for stopping some of these leaks.
 
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