welsh plugs c 15a

[colin morley]

I have a water leak in the rear of the motor I believe it is welsh plugs. Is it easier to take the motor and gear box out the front or to remove the gear box with the motor still in there. Thanking you for your help Colin

[Phil Waterman]

Hi Collin

Before you pull engine or transmission, check for a leak at upper radiator connection. Twice I've suspected the rear plug but on closer inspection found that a small leak up front manages to dribble down on valve cover and follow the ridge on the driver side to the rear of the engine down end of the block into the bellhousing and then out the drain hole in the pan. I think I have photos of the leak trail if so I'll post.

Now to your question of pull the transmission or the engine? If you are set up to pull the engine I would go that route and replace the side plugs as well. If you are not set up to easily pull the nose and engine unit, then pulling the transmission and removing the bellhousing is probably the route to go.

Either way keep us posted what you find.

Cheers Phil

[Grant Bowker]

Originally Posted by Phil Waterman

Hi Collin
Now to your question of pull the transmission or the engine? If you are set up to pull the engine I would go that route and replace the side plugs as well. If you are not set up to easily pull the nose and engine unit, then pulling the transmission and removing the bellhousing is probably the route to go. Cheers Phil

The main issue I see to removing the transmission and bellhousing with the engine still in the truck is that the rear mountings for the engine/transmission assembly are on the bellhousing so an alternate support would be needed.

[Phil Waterman]

Hi Colin

Grant is correct if you go the remove the transmission and bell housing in the truck route you will have to support the engine carefully to remove the bolts from the engine mount.
MLU 216 Engine Mount Rear NOS 003.jpg
This is not really a big issue just takes planning. One other thought is getting everything back in place and correctly aligned. If the engine and bell housing are original or paired set you won't have to worry to much about alignment of the bell housing to the engine as they will have alignment doles if they are not a paired set then you will want to check the centering of the crank to the bell housing, see the manual on this.

Here are the photos I was talking about, because of the slight angle of the Chevy engine in CMPs often makes it so a leak up front may drip on the floor far back on the engine. There is a lip on the front of the bell housing shield that sticks out and catches anything flowing down the front of the bell housing.
Coolant Leak front.jpgCoolant Leak path.jpg

Until I carefully followed the leak path, I thought there were two leaks one front and one rear. In all my years of playing with these engines I have actually only heard of one of these plugs rusting through and that was on a CCKW that started loosing water/coolant ant the rate of gallons to the mile. Friend made it home with the truck by refilling the radiator several times.

If you have confirmed that the leak is positively coming from the rear plug then I'd go with pulling the whole unit.

Cheers Phil

[colin morley]

thank for your help i will take it further after holidays . i would like to wish you all a merry cristmas and a happy newyear regards colin joy morley