928n997

'87 AUTOMATIC transmission radiator requires replacement. As is common these days, the mechanic is suggesting a newly constructed aluminum. A friend has an '89 GT MANUAL transmission OE radiator. Assuming it works just fine, does anyone know if it can take the place of my '87 OE radiator?


Thanks in advance.

dr bob

The Automatic box needs the auto trans fluid cooler in the passenger side tank, something that won't be in the original GT radiator. Your options include pulling the heat exchanger from the old radiator and swapping it into the GT radiator. The plastic tanks are suspect if they are original, so you should probably plan on replacing both, include the trans cooler when you change, and of course new o-ring seals for all the connections. Tanks are readily available from our Usual Parts Supply suspects, including 928 International, 928SRUS, and our forum sponsor 928 Specialists. All will get you the stuff you need. Any good radiator shop will disassemble, clean the core, and install your new tanks and pieces for you.

928 International has been offering a very well reviewed all-aluminum replacement radiator. It's a great option, especially if you are buying the old radiator for more than scrap value plus those tanks and seals plus assembly. Call them and get one shipped, you'll be impressed. Get new mounting bits too, whichever option you choose. IIRC, Roger at 928SRUS is also carrying the 928 International aluminum radiator if you are closer to him (DFW area) and want to pick one up instantly.

And... Welcome to the group! Share some info about yourself and the car. Lots of enthusiastic and supportive members are scattered around the world.

SteveG

Rennlist Log Book: 928n997 gives first post, a question: 33 minutes later dr bob posts comprehensive answer. Amazing.

alex70

Although I had the 87 manual, when I was having some work some I had what dr bob describes as tank, tab, etc replacement. Worked well. I think I paid mid $200's for tank, tab rework at a very reasonable rad shop in Santa Ana, CA

New radiator would be nice too if it's in the budget.

dr bob

Should I have waited longer since the OP is "new"?

Red Flash

OK, so other than price or stock look, why would one not want a new aluminum radiator? Do I need to know something?

Chalkboss

Nothing at all, they seem to be very well-built radiators so far. Drop right in with no fuss. I have one on my S4, and after putting on the 3 repro stickers from Roger it looks stock to the untrained eye! I still have the old Behr it just needs to be gone over and a plastic side tank repaired, but I have always loathed radiators with plastic tanks...

dr bob

Plastic tanks add a reliability that's hard to duplicate in a metal tank welded on. The core goes through some pretty amazing distortions as the flow and temperatures change both inside and outside of the radiators. Torque from the odd differential expansion and contraction are easily handled by the plastic tanks and the rubber seals. Aluminum tanks on the ends need to be stress-normalized after welding, and even then the differential heating conspires to break the welds every time the heat load changes. In automotive service, you'd be hard pressed to find a more forgiving radiator end tank than the plastic.

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We look at some of the 928 technology from the position of 30+ years of use and abuse, and how some pieces just don't seem to hold up. We compare that with the old copper or brass radiators we think we remember as lasting forever in [pick your dad's family hauler]. News flash: They really didn't last that long. Regularly the radiators would be un-soldered and "boiled out" or "rodded" to descale them. They'd get a chemical wash in a mild acid to try to dissolve out remaining mineral scale, hoping the scale would come loose before the metal tubes gave way to the acid.

I'm happy to say that I still have the original radiator in my car. Coolant has been swapped religiously since new. Borescope and mirror inspections show that there is no significant plating in the bottom tubes where scale normally appears first. Still, I did grab one of the last bulk-deal Behr radiators from Mark before they turned to solid gold, at least price-wise. The system was pressure-tested when I did the coolant swap last fall, and holds fine. At some point I'll put new tanks and seals on the current core as PM.