TR2/3/3A driver side on the trans-cover?

[sp53]

What is the 1 inch hole for in lower center of the driver side onthe trans-cover?

 

[trglory]

Access to the transmission fill plug. Probably doesn't line up, but anyway, that's what it's for.

 

[TR3driver]

Funny thing is, that hole is present even on earlier cars with no fill plug (only the dipstick hole, which has its own hole in the trans cover).

 

[Geo Hahn]

Many (including me) have added a hole about there for that purpose -- but to be practical it will probably need to be larger. I made mine to use the same rubber plug above the U-joint, others made it even larger and use a jack-hole plug.

 

[titanic]

Could it be for the OD wiring? It would have contained a rubber grommet to protect the wires. I agree it is probably too small for a trans. fill plug access.
Berry

 

[TR4nut]

Bonus points for Berry I believe. Pretty sure that was the factory location for routing overdrive wiring.

 

[TR3driver]

Could it be for the OD wiring? It would have contained a rubber grommet to protect the wires. I agree it is probably too small for a trans. fill plug access.
Berry

Lots of folks think so, but I don't know of any evidence that the factory did it that way.

TS39781LO came to me with a solid plug in that hole and what appeared to be original OD wiring routed through one of the grommets in the firewall. Of course one of the previous owners could have re-routed the wiring, so that doesn't prove much.

Also, if you look closely at the photo of the OD relay in the workshop manual (in the section about adding OD), the wires appear to run forward from the relay towards the firewall instead of off to the side towards that hole in the tunnel.

 

[titanic]

Here is an illustration from the Moss catalog. Oddly enough the hole was on both OD and non-OD cars, but with different part # for OD. Maybe a solid plug for non OD and a grommet for OD? The plot thickens. https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29158#top
Berry

 

[TR3driver]

Yeah, you can go really crazy trying to make sense out of the Moss website. For example, that page lists 680-630 as a "plug", but there are some 50 other pages where it is listed as a "grommet".

Also, that page shows no part number for the "non-overdrive" condition, but an older PDF catalog lists 682-510 as plug, non-overdrive. And 682-510 is still listed as available on roughly a dozen other Moss web pages.

My guess is that they tried to remove the listing for the grommet (after learning it wasn't used for OD wiring), and didn't do a very good job.

As a counterpoint, the factory parts catalog gives a very detailed listing for the overdrive kit (used to add OD to non-OD cars), including the wiring harness, clips, etc. No mention of a grommet.

 

[Chuck Murphy]

That hole is for the OD wiring, and it does have a grommet to protect the wiring as it passes thru the tunnel. My 1957 TR3 came with OD and the OD wire went thru that hole (with a grommet). There are connectors on the OD wire that you can disconnect if you have to remove the tunnel.
Chuck

 

[CJD]

That is where the OD wire came through on my TR2.

 

[bnw]

That hole is for the OD wiring, and it does have a grommet to protect the wiring as it passes thru the tunnel. My 1957 TR3 came with OD and the OD wire went thru that hole (with a grommet). There are connectors on the OD wire that you can disconnect if you have to remove the tunnel.
Chuck

Mine too. 57 TS19909 LO