Welch Plugs

Revision as of 08:03, 1 January 2015; view current revision
<-Older revision | Newer revision->

Welch plugs (core plugs) are circular discs that fit into, and seal the casting and machining holes in the Engine block, Cylinder Head and Transmission. You may hear them called "welsh plugs". They are often called "freeze plugs" because if the engine coolant freezes they'll be pushed out of the casting. However, the purpose is not necessaryily to solve freezing problems but rather to seal the holes left by the casting or machining process. Those that are designed for freezing safety are called "expansion plugs".

Set

DORMAN 557-031 A12 & A13 engines

MAFCO 437 120Y 1969-1972

MAFCO 441 Sunny 140Y 1980-1982

MAFCO 438 1972-1980

Cylinder Head

One Welch Plug:

• 00933-14000 PLUG-WELCH (1) head, rear [reportedly 40 mm]

Engine Block

B110

Five Welch Plugs

• 11019-32200 PLUG-WELCH 44 CAM BEARING (1) block, rear (44.425 mm)
• 00933-15000 PLUG-WELCH 50 CORE HOLE (1) block, rear prev. 01648-00084
• 00933-13500 PLUG-WELCH 35 CORE HOLE (3) block, right side

  

  35mm brass core-plugs

B120

35 mm Expansion Plug 00933-13500 / 11021-E3000 / 00933-1351A
Nominal Dia.: 35.21mm
Steel
Height: 0.380"

プラグ (35mm - 3 required)
7510-8506 00933-13500
8506-8706 11021-E3000 [11021E]
8706-     00933-1351A

Transmission

Three Welch Plugs

• 00933-11400 PLUG-WELCH TRANSMISSION CASE (2) inside bell, northwest of mainshaft
• 32102-18000 PLUG-WELCH TRANSMISSION CASE (1) inside bell, below mainshaft

  Can be seen in photo, just below throwout bearing

  

Removal and installation

Removal: tap one edge with a punch or chisel, then grab it with vice-grips and wiggle it out.

To install, fit squarely into bore, and tap gently and evenly into place. No sealer is used.