25300-36 breather valve and gear

[1950Panhead]

Harley parts book list 25300-36 for 36 to 54 (54 parts book).
Vtwin list different breather for knuckle and pan.
Any difference?

[RUBONE]

The early breather gear has the thrust surface built in as one piece. In '50 the gear changed to one with a spacer on the end to set up thrust and end play. That continued for many years, basically up to the plastic one!
Robbie

[JR JOHNSON]

The early breather gear has the thrust surface built in as one piece. In '50 the gear changed to one with a spacer on the end to set up thrust and end play. That continued for many years, basically up to the plastic one!
Robbie

hi,Robbie,did the knuckle breather have a extra hole in it for the tappet blocks ,for vacuum in the push rod tubes,just seem something different in my thinking.just a crazy question ,have a good new year guys............with respect.JR

[Panacea]

Here's a pic...

[RUBONE]

The hole does not matter for a Pan as it does not line up with anything so it remained in the gear after Panheads began. It doesn't exist in the '50 up gear which will not work in a Knuckle.
Robbie

[1950Panhead]

Spare parts must have had the hole at least through 54 as they were still using the 25300-36 part number.
So knuckle needs the hole or drill one in a pan breather.
Jerry

[JR JOHNSON]

hi,i may be wrong,but the early pans that drain into the case,before they drill the hole in the cylinder,that drain from the heads,they must used vacuum to bring the oil to the breather ,like the knucklehead,that must the reason for the hole tell 54. just a wild guess...................with respect.JR

[Hog54]

Well I dont have the hole and I have a 54.

[RUBONE]

hi,i may be wrong,but the early pans that drain into the case,before they drill the hole in the cylinder,that drain from the heads,they must used vacuum to bring the oil to the breather ,like the knucklehead,that must the reason for the hole tell 54. just a wild guess...................with respect.JR

JR,
No vacuum return on the Pans, gravity does most of it. The oil drains into the scavenge cavity on the rear of the cases. Knuckles drain down the pushrod tubes and into the breather itself, a different deal.
Hog54,
The hole only exists in the early one piece gear, despite the part number.

1950panhead
The parts catalogs show that number for much longer than '54!!
Robbie

[JR JOHNSON]

Robbie,thanks for the info,have a good one......with respect....JR

[1950Panhead]

Robbie,
In June of 54 Joe orders a breather valve and installs it in his 47 knuckle.
What problems is Joe going to have?
Jerry

[steinauge]

The factory made a replacement gear that used a variable washer and had the big drainback hole for the knuck as well as the pickup hole for the vent trap .Thus it would work in both.I have seen several of these over the years.