Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks



Visit the new site at vcca.org

Previous Thread
Next Thread
Print Thread
Rate Thread
#486524 10/26/23 07:39 PM
Joined: May 2017
Posts: 144
Likes: 1
Shade Tree Mechanic
OP Offline
Shade Tree Mechanic
Joined: May 2017
Posts: 144
Likes: 1
My oil pan drain plug drips. The threads in the pan are bad, as I can't tighten the drain plug. Is it possible , or smart, do drill and tap the pan for a larger bolt? I have in the past tried o/s self tapping drain plugs with some success, but I don't want to go that route.

Filling Station - Chevrolet & GMC Reproduction Parts


Filling Station


Joined: Nov 2001
Posts: 5,906
Likes: 8
Former ChatMaster
ChatMaster - 5,000
Offline
Former ChatMaster
ChatMaster - 5,000
Joined: Nov 2001
Posts: 5,906
Likes: 8
I did that many (25?) years ago with my first '31. I used a special oil pan "repair" bolt It worked good for me. Used it for 15+ more years.

The bolt is oversized, naturally. But more importantly, it was tapered, so it got a really good grab on the metal.

If you want to go to the effort to remove your pan (after draining it, etc, and adding a new gasket) then go ahead. There's a metal piece inside which you can easily tap to a larger size. But then you'll have to find a larger bolt that has a large "head".

One other thought, after a few 'minor' leaks I finally bought the reproduction copper washer that goes on the outside. That gives a really snug fit when you tighten the bolt. I recommend it.

Good luck.


Bill Barker
Previous VCCA CHAT Administrator
(VCCA Member: 9802)
1 member likes this: Clement
Joined: Nov 2002
Posts: 7,472
Likes: 26
ChatMaster - 7,000
Offline
ChatMaster - 7,000
Joined: Nov 2002
Posts: 7,472
Likes: 26
I would install a helicoil to be able to use the original plug.


Steve D
Joined: Dec 2007
Posts: 4,024
Likes: 99
ChatMaster - 4,000
Offline
ChatMaster - 4,000
Joined: Dec 2007
Posts: 4,024
Likes: 99
Maybe I am missing something in this discussion.

I am wondering why using an oversized drain plug is not preferred over drilling and tapping oversized. It seems like in both cases the end result is a larger threaded hole in the pan.

A helicoil might not work due to the relative thin length of engagement in the pan. That extra metal piece for the plug is not very thick.


Rusty

VCCA #44680
Joined: Oct 2012
Posts: 119
Shade Tree Mechanic
Offline
Shade Tree Mechanic
Joined: Oct 2012
Posts: 119
I had a similar experience with my 1936 Standard. I ended up using a double oversize drain plug. It worked but is not perfect, but I have come to realize that a vehicle this old will have some minor drips. You know like our bodies as we age.


1936 Chevy Std
1954 3600 Truck
2008 Corvette Z06
Joined: Sep 2002
Posts: 2,323
Likes: 6
ChatMaster - 2,000
Offline
ChatMaster - 2,000
Joined: Sep 2002
Posts: 2,323
Likes: 6
I have used the self tapping plug with good results. On one of my vehicles I use a metal washer that has a soft rubber insert and it works perfectly. Another solution is to use one of those rubber plugs that has a draw bolt in the middle. They work for sure and are reusable. I definitely would not pull the pan if I didn't have to.


My 1951 1 Ton is now on the road! My 38 Master 4 Door is also now on the road .
Joined: Nov 2001
Posts: 19,758
Likes: 63
ChatMaster - 15,000
Offline
ChatMaster - 15,000
Joined: Nov 2001
Posts: 19,758
Likes: 63
No matter what option is used it is critical to make sure that the oil pan drain plug is aligned to the oil pan. If at even a small angle it can have a slow leak.


How Sweet the roar of a Chevy four!

Link Copied to Clipboard
 

Notice: Any comments posted herein do not necessarily reflect the official position of the VCCA.

Powered by UBB.threads™ PHP Forum Software 7.7.5