fan shroud question/update

[larry linkous]

I think I have figured out that the NOS fan shroud I bought in the original GM Box is a 3938940 (service shroud) although it has at least two of the original shroud numbers stamped in two pieces. As I stated earlier it has what looks to be sanding marks on the two corners where they attached the two bottom sides to the top piece, with a couple pop rivets in each side. I noticed in E-Bay auction Number 4632066430 you can see the sanding marks (the light gray area on each side) on the top also. Is this original and should I leave it alone or at least take out the pop rivets?? Thanks

[Joe L.]

Re: fan shroud question/update

larry------

The 3938940 fan shroud, although supplied as a 1 piece unit, is made up from the original pieces; it's not like it's a piece that's manufactured as a 1 piece unit from the get-go. However, it's my understanding that it's made up of the 68 pieces and not the 66-67 pieces. In fact, I have an NOS example of one of these things but I'm not energetic enough to go out and dig it out and look at it.

So, what are the part numbers on the component pieces of the shroud you have?

[Wayne W.]

Re: fan shroud question/update

That is the 68 style. Note the angled cut on the RH side. Just as Joe and I had said all along.

[larry linkous]

Joe and Wayne

The top part of the shroud for sure match's the 67 part number and the left side seems to but where the last part of the number is there is a factory hole taking out the last two numbers. I am concered about the rivets. Should they or should the not come out. Even if it is a service replacment did they have the area's cleaned up for glue and rivet's?/ Thanks Larry

[Wayne W.]

Re: Joe and Wayne

I think the proper preparation would have been sand blasted at the bonding joint. As I stated before, originals typically did not have rivets, but some did. Just why, I dont know. Perhaps some did not fit well and they decided to rivet for better holding. Who knows? The ones that I have observed only had one rivet in a location and may or may not have had a rivet at more than one location. The joint typically shows some ooze out of the bonding material, but the material is retained by the fixture and the ooze out is flattened.

[larry linkous]

OK Wayne...........

I am going to leave the rivets for now. Maybe that is sanding blasting marks. I will look closer tonight. Thanks Wayne and Joe!!!!

[Wayne W.]

Re: OK Wayne...........

Larry. I checked out a couple of originals today, and I am going to back up a couple of things. The preparation seems to be by grinding at least on some of them. The rivets are done in at least two ways, some with, and some without washers. The flatened areas of the seams show signs of being cut off to flatten at the upper bonds. Here are some pictures of a small block shroud with one rivet in the left side.