I think it's fiberglass. I would use an epoxy product plus some mechanical fasteners, like flathead stove bolts, countersunk.

You would be doing yourself a favor by getting a new two piece fan shroud as sold by several of the GMC Vendors (I got mine from Applied GMC)

Carl S. wrote on Wed, 07 September 2022 17:21

I think it's fiberglass. I would use an epoxy product plus some mechanical fasteners, like flathead stove bolts, countersunk.

You would be doing yourself a favor by getting a new two piece fan shroud as sold by several of the GMC Vendors (I got mine from Applied GMC)

Believe me, I've thought about it. I split the OEM shroud, removed the horse collar, and added a 3" aluminum extension and with a this centering adjustment it will fit the Mercedes fan with 1/2" clearance. I'm concerned that I might have to add to the aftermarket flange to center it as well and I will have to trim it to accept the Mercedes fan, but I certainly like the full coverage and I may switch over when I relocate and replace part of the transmission cooler(s) piping. They're in series, and the external cooler is fed with hose and clamped to the OEM steel pipe with hose clamps. Need to add proper fittings and routing to let the shroud drop straight down; at that point it will be much easier to change out the shroud.

I removed the horse collar and did that modification when I installed an aluminum radiator 17 years ago. Worked fine until the aluminum extension started to fall apart recently.

This year, I removed the rest of the aluminum extension and ran that way for a while. I found the fan clutch seem to engage more often without the extension. Rather then reinstall the aluminum, I got the split shroud from Applied thinking that it would work better. I found that it was a bear to install as I had to trim it in several places and it didn't quite fit as the bolt holes didn't line up. No instructions of course were included. My experience with the new shroud was that it didn't work any better than the OEM shroud without the extension. Also, it is in my mind a bit on the flimsy side as compared to the OEM.

I would have been better off repairing my OEM shroud, which I may end up doing. I'm glad I didn't get rid of the OEM shroud.

I do want to get the Mercedes fan to run with my EFI-EBL. Is that conversion documented anywhere? I don't need the controller that Applied sells just the fan and mounting hardware.

Hello Bill, Hello Carl, Hello Richard !!
And from the previously provided Dynamic EFI diagrams (Thank You Bill) - I figure that the PWM feed is in the terminal E to fan+ connection. How does this map to the 5 connections on the Mercedes Fan ?? (I'd go and look at my V1 but the coach isn't with me - it's over in storage).

Looking forward to any collaboration !!

Thanks again,
Steve W