2001 2500HD 8.1L Radiator Replacement

toored · April 9, 2019

My radiator has started leaking so I'm in the process of replacing it.

I understand that there were two (2) different radiators installed in these trucks with the Allison 5 Spd: GM P/Ns 15058682 and 21433 (correct me if I'm wrong). While attempting to order a genuine GM replacement radiator, I have found that both of these have been replaced by GM P/N 89018317. This radiator has a core thickness of 1 3/16 inches (2 row). However, my original radiator has a core thickness of 2 1/8 inches (3 or 4 row). I can't find a replacement radiator with a 2 1/8 inch thick core, in GM or aftermarket radiators. I want the extra cooling capacity of the original if I can find one.

Have any of you folks had this issue and do you know of any options available with a thicker core?

Thanks a million for any help.

Grubbworm · April 9, 2019

I use Marietta Radiator for all my Radiator and A/C needs. I see you are in Newnan, Georgia, I am in Acworth. Marietta Radiator, 487 Glover Street, Marietta, GA 30060, 770-428-7120. I have never had any issues with them, they are the best at what they do, and have been around for a very long time. https://www.facebook.com/Marietta-Radiator-326650385071/

toored · April 9, 2019

Thanks for the reply David. I called them and they said if the tanks are cracked, the radiator must be replaced. They couldn't find any aftermarket radiators with a 2 3/8 inch core. That stinks.

Grubbworm · April 9, 2019

That's a shame. If anyone knows it would be them. Possibly you could find one from another type/brand vehicle that would match your dimensions from a junkyard.

toored · April 9, 2019

I already bought the official GM replacement radiator (boy are they proud of them!) but wasn't aware that the core thickness was much thinner than the original. I'm almost finished removing the old radiator. I will see if there's any other numbers on it that may lead me to one identical to the original. Otherwise, I guess I'll be installing this unit.

diyer2 · April 9, 2019

A smaller radiator may lead to cooling problems.

I would find out if this thinner core radiator will work.

toored · April 9, 2019

That is my fear. However, from every search I can find, the thinner core "official GM" replacement that I bought, and all aftermarket radiators have a thin core. Every aftermarket unit I've found have an even thinner core than GM's 1 3/8 core. This is frustrating.

newdude · April 9, 2019

21433 is the short number (ACDelco #) for 89018317. 15058682 was the original radiator.

Per GM:

Quote

PART NUMBER. 89018317. RADIATOR ASSEMBLY. DUE TO A DESIGN CHANGE. WILL BE SMALLER. THAN THE ORIGINAL. ALSO. THE DRAIN VALVE. HAS BEEN ELEMINATED.

Looks to me they revised it a little closer to the 2003-2006 Radiator? The 01-02 still seems larger than the 03-06 though by a bit. But even then, the 2003-2006 radiator changed numbers twice after the first release. I can't find any notes on what was changed though.

2001-2002 Dimensions - CORE SIZE 41 7/8IN X 20 5/8IN X 1 3/16IN

2003-2006 Dimensions - CORE SIZE 37 13/16IN X 19 7/16IN X 1 5/16IN

toored · April 10, 2019

Thanks Newdude,

You are correct. My original part number is 15058682. It's a beast of a radiator with a 2 3/8 inch thick core. I bought the GM P/N 89018317, which is GM's official replacement. I wish I could find a 15058682 new somewhere. I would pay handsomely for it.

txab · April 10, 2019

I would think there is a larger aftermarket radiator out there somewhere.

newdude · April 10, 2019

Perhaps this would work????

https://www.rockauto.com/en/moreinfo.php?pk=3762852&jsn=294

OSC'S site has the same specs. http://showmetheparts.com/osccooling/

Looks to show over a 2 inch core thickness. Its for 2001-2002 8.1 Allison trucks.

Edited April 10, 2019 by newdude

toored · April 11, 2019

Thanks Newdude,

It does appear to be a viable option. Although the core width is only 37 13/16" which is 4 inches narrower than the GM radiator. I may give them a call and inquire why.

Thanks to everyone for the help.

newdude · April 12, 2019

On ‎4‎/‎11‎/‎2019 at 7:17 AM, toored said:

Thanks Newdude,

It does appear to be a viable option. Although the core width is only 37 13/16" which is 4 inches narrower than the GM radiator. I may give them a call and inquire why.

Thanks to everyone for the help.

What is the width on the old radiator from your truck? That one I linked could be based on the original spec designed radiator, and GM could have widened the replacement while making it thinner.