CSF 1993-2001 Mercedes-Benz R129 SL600 / SL 70 / SL 72 / SL 73 OEM+ / Performance All-Aluminum Radiator

The R129 SL600 and its AMG and RENNTech derivatives are among the most complex cars Mercedes-Benz built in the 1990s, and the V12 in the nose asks a great deal of the cooling system. Three decades on, the factory radiator is usually the part that gives up first — and replacing it has become a genuine problem.

The OE unit, Mercedes-Benz part number 129-500-10-03, uses an aluminum core crimped onto plastic end tanks. The plastic tanks and hose fittings start to break down after a few years, and the bond between the core and the tanks generally won't last more than 10-12 years of regular use. The 90° overflow pipe is also plastic on the original, and is known to crack — which means replacing the entire radiator. Original factory components are now either extremely hard to find or no longer available at all.

CSF developed this radiator together with RENNTech, the premier Mercedes-Benz specialist in North America, who restore and build these cars in house for clients around the world. The result is a 100% all-aluminum, TIG-welded replacement that removes the plastic tanks from the equation entirely.

The 2-row, 42mm core keeps the same 55 cooling tubes and 56 fin rows as the OE unit, so nothing about the installation changes — but the internals are reworked. CSF's Exclusive B-Tube Technology delivers a 15-20% increase in heat transfer efficiency over regular oval welded tubes, and the 6.5mm multi-louvered fins are taller than the OEM's 6mm for greater surface area contact. The 5-plate transmission oil cooler is built into the left-hand side tank, as on the original.

It drops straight in using the factory mounting points, fan and shroud, with CNC-machined mounting brackets and OEM-style inlet and outlet connections, and requires no modifications. Every unit is individually leak and pressure tested and carries a 2-year limited warranty.

Features

• 2-Row, 42mm ultra-high-performance core with 55 cooling tubes and 56 fin rows
• 15-20% increase in heat transfer efficiency using CSF's Exclusive B-Tube Technology
• 6.5mm ultra-efficient fins with a multi-louvered design for maximum surface area contact
• Integrated 5-plate transmission oil cooler in the left-hand side tank
• CNC-machined mounting brackets and OEM-style inlet/outlet connections
• 100% all-aluminum TIG-welded construction — no plastic end tanks
• Satin black and silver finish for an OE look
• True plug-and-play "drop-in fit" installation requires absolutely no modifications
• Individually leak and pressure tested
• 2-year limited warranty

FAQs

Is this a direct replacement for the factory radiator?
Yes. It is a true plug-and-play drop-in fit using the factory mounting points, fan and shroud, with no modifications required.

Does it include the transmission oil cooler?
Yes. A 5-plate transmission oil cooler is integrated into the left-hand side tank, in the same way as the original radiator.

Why does the factory Mercedes-Benz radiator fail?
The OE radiator crimps an aluminum core onto plastic end tanks. The plastic tanks and hose fittings degrade over time, the core-to-tank bond rarely lasts beyond 10-12 years, and the plastic 90° overflow pipe is prone to cracking — at which point the whole radiator needs replacing.

Is the core larger than the OEM radiator?
No. It deliberately retains the same tube and fin row count as the OE unit so it fits exactly like the original. The gains come from the B-Tube internal design and the taller 6.5mm multi-louvered fins, not from extra core volume.

Applications

OEM Part Numbers

• Mercedes-Benz: 129-500-10-03

📦 Regal Autosport Shipping Policy

Shipping Destinations

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• United Kingdom: Royal Mail for small items; DPD Local for parcels up to 30kg.
  Delivery estimate: 1–2 business days.
  

• International:
  

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Orders placed after 2 PM will be processed on the next business day.

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• Customers are responsible for all customs duties, import taxes, and fees applicable in their country.
  

• Delivery times may be delayed by customs clearance — time is not of the essence for deliveries.
  

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In the rare case of lost shipments:

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📦 Regal Autosport Shipping FAQs

Where do you ship to?

We ship across the UK, Europe, the USA, Australia, South East Asia, and worldwide.
 There are no regions we restrict shipping to.

Which carriers do you use?

• UK orders: Royal Mail (small items), DPD Local (parcels up to 30kg)
  
  

• International orders: Royal Mail (small packages) or DHL Express (larger parcels)
  
  

How long will my order take to arrive?

• UK deliveries: Typically 1–2 business days after dispatch.
  

• International deliveries: Usually 2–15 business days, depending on location.
  

Please note: We do not ship on weekends or UK Bank Holidays.

When will my order be dispatched?

Orders placed before 2 PM are usually dispatched the same business day.
 Orders placed after 2 PM are processed on the next working day.

How much does shipping cost?

Shipping costs are calculated at checkout based on the volumetric weight of your items.
 We do not offer free shipping — instead, we keep our product prices as competitive as possible.

Will I receive tracking information?

Yes!
All shipments are tracked and signed for. You’ll receive tracking information by email and can also track your order via:

• Your Regal Autosport account page
  

• The courier’s own website
  

Do I have to pay customs charges or import taxes?

• UK Customers: Prices include UK VAT.
  

• International Customers:
  

• We deduct UK VAT at checkout.
  

• You are responsible for any local customs duties, import taxes, or fees.
  

Delivery times may be affected by customs clearance, and time is not of the essence for international deliveries.

What happens if my order is lost or damaged?

• If your shipment is lost, we will re-ship your order once the courier confirms the loss.
  

• If your order is damaged, we will work with you to file a courier claim and either replace the item or offer a discount based on the situation.
  

Please inspect your delivery upon arrival and contact us immediately if there are any issues.

What if my item is on backorder?

Orders containing backordered items will be held until all items are available.
We do not split ship orders. If you require partial delivery, please place separate orders for in-stock and backordered items.

Can I collect my order in person?

We do not offer local pickup or local delivery for online orders due to security verification.
However, you are welcome to visit our store and pay via chip and PIN if you wish to purchase in person.