1966 856 transmission lower fill hole size question

[FLtractor 7]

Afternoon, 

wondering what size bolt this is for the lower transmission fill hole.. and what size extension would I need to fit this as pictured here? (What size wrench too) Orginal post stated that extension is factory but have yet to hear back from poster as thread is at least a decade old. Is there a name for such. 

[Achto 28,586]

32 minutes ago, FLtractor said:

wondering what size bolt this is for the lower transmission fill hole

 

 Not a bolt at all. It's 3 pieces.

 

1 - 1" long 3/8" pipe nipple

1 - 3/8" pipe coupling.

1 - 3/8" pipe plug

 

All pieces should be readily available at any hardware store. 

I believe pipe plug takes a 9/16" wrench. 

 

Edited 16 hours ago by Achto

[FLtractor 7]

7 minutes ago, Achto said:

 

 Not a bolt at all. It's 3 pieces.

 

1 - 1" long 3/8" pipe nipple

1 - 3/8" pipe coupling.

1 - 3/8" pipe plug

 

All pieces should be readily available at any hardware store. 

I believe pipe plug takes a 9/16" wrench. 

 

Poor wording on my part. Thank you. The orignal poster stated that if you fill the transmission full till it reaches the end of that extension hole.. then that is full enough oil for a well oiled transmission. If I did fill the transmission this way with the extension, would I need to tip the tractor anyway to fully fill the transmission? 

Edited 16 hours ago by FLtractor

[Achto 28,586]

8 minutes ago, FLtractor said:

The orignal poster stated that if you fill the transmission full till it reaches the end of that extension hole.. then that is full enough oil for a well oiled transmission. 

 

True. Usually only the 6 & 8 speed trannys had the extension. On the 3 speed tranny the pipe plug went directly into the tranny with out the extensions, like in the pic below.

Edited 16 hours ago by Achto

[FLtractor 7]

22 minutes ago, Achto said:

 

True. Usually only the 6 & 8 speed trannys had the extension. On the 3 speed tranny the pipe plug went directly into the tranny with out the extensions, like in the pic below.

So would the extension be of any real benefit to my 3 speed filling? 

[Achto 28,586]

1 minute ago, FLtractor said:

So would the extension be of any real benefit to my 3 speed filling? 

 

You would gain oil capacity that might be of benefit. Not sure it is necessary though. 

[FLtractor 7]

35 minutes ago, Achto said:

 

You would gain oil capacity that might be of benefit. Not sure it is necessary though. 

Makes sense. I Would much rather fill the transmission thru that hole than having to remove the shifter. 

[SylvanLakeWH 27,190]

39 minutes ago, Achto said:

 

You would gain oil capacity that might be of benefit. Not sure it is necessary though. 

I just filled one with 1/2 quart extra by tipping tractor up on left side, fill, put in plug and lower it... easy peasy... that trick brought to you by @Pullstart...

[FLtractor 7]

4 hours ago, SylvanLakeWH said:

I just filled one with 1/2 quart extra by tipping tractor up on left side, fill, put in plug and lower it... easy peasy... that trick brought to you by @Pullstart...

Ahh that’s where I’ve heard the tipping tractor to side before. Thanks 

[Racinbob 11,665]

I haven't bothered with that 'fill' hole for decades. Figure 1.5 quarts for the 3 and 4 speeds and 2 quarts for the 6 and 8 speeds and be done with it. The only thing that extension did was eliminate the need to tip the tractor to get the proper amount in if you insist on going that route. I think it was only factory installed on the 6 speeds making folks think they required more. Not so. In reality it would be fine to run 2 quarts in all of the Unidrive manuals.