TR2/3/3A Source of TR3 Gearbox Leak?

[RedTR3]

For several years I have had a gearbox leak at the rear of the gearbox and I just keep topping it up every couple of months (oil is still fairly cheap). But if the fix is easy I should try to do something....in looking underneath, there is a lot of oil at this item that looks like a plug with about 1" across the flats. What is this plug? I do not see it in any catalog diagrams. Is there a gasket associated with it? Thanks!

 

[Moseso]

Re: Source of Gearbox Leak?

Did you know you have an overdrive? That's the drainplug/filter-screen access on the A-type overdrive. Yes -- there is a washer that goes under it. Mine has a fiber washer. Your picture looks like there's an aluminum washer under there. For some reason or another, the socket in my collection that fits it best is the 30mm.

 

[RedTR3]

Re: Source of Gearbox Leak?

Thanks! Yes I know I have the overdrive, it is not working due to (most likely) a bad solenoid and since I drive just on city streets it has not been a priority for me to repair it.

So I assume it is safe and wise to remove this plug and replace the gasket and refill?

 

[TR3driver]

Re: Source of Gearbox Leak?

I would suggest first trying to be sure it's really that gasket that is leaking. Since it's the lowest point on the OD, any other leak tends to run down and drip from the plug. I know I spent a long time and many oil changes trying to get mine sealed, only to find that it was the adapter plate that was actually leaking.

I also use a 30mm socket, but I ground away the tapered portion at the lip of the socket to give it a better grip on the plug.

As Moses said, the gasket should be fiber. Some Hylomar may help it to seal. If you do remove the plug, you should also clean the screen and magnets.

PS, Depending on the vintage of your OD, you may need to remove a bolt to get the screen out. Don't lose the washer and spacer that go on the bolt.

 

[TR3driver]

Re: Source of Gearbox Leak?

The drain plug gasket is available from TRF as P/N 500641

 

[pjsmetana]

Re: Source of Gearbox Leak?

Don't forget RTV!

 

[TR3driver]

Re: Source of Gearbox Leak?

Don't forget RTV!

Please do forget RTV!

That stuff has no place around hydraulic systems, like overdrives. Much too easy for the bead that always squeezes out inside to break off and clog tiny passages, like the bleed hole in the operating valve on an A-type OD. That can literally lead to destruction of the unit (although the odds of that actually happening aren't very high).