722.3 Tools and Hardware Needed to Replace K1 and K2 Drum Seals

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Detailed video instructions included x 2. High-Heat Viton O-rings are included for the bottom rings.

Three seals in each drum need to be replaced.  Only the bottom "hidden" drum seals in Viton are included. The other four seals will come in our complete reseal kit purchased separately (see below).  Of all the seals inside these transmissions, these are the ones that tend to harden and fail first. This is caused by the friction heat created when the brake bands clamp down on the drums. Many do not bother replacing these O-rings because it is "just too much work." Some resealing kits don't even include the two bottom large O-rings. Watch the YouTube video below. Kent will explain where these O-rings are located and what you need to replace them. NOTE: The tools and hardware are the same that you would use on a 722.4 transmission, BUT the seals will not work (drums are smaller on the 722.4)

722.3 Tools and Hardware Needed to Replace K1 and K2 Drum Seals
$99.99
SKU:
TRS-7223K1K2KIT
Free Add-Ons Included:

722.3 Video Class Pt. 6 - K1 K2 Drum Open and Modification - On Demand Video

722.3 Video Class Pt. 7 - K1 K2 Drum Reseal & Reassembly - On Demand Video

Product Details

you will be sorry if you don't replace these

If you already have a press and don't need instructions, the basic kit of seals and hardware can also be purchased. See related products below. 

This kit includes the following small tools and machine screws needed.

  • Adjustable press tool for removing the K1 and K2 piston assembly
  • Small drill bit to drill out rivet heads and enlarge holes in the aluminum ring
  • Large modified drill bit to countersink the holes in the aluminum ring
  • Correct sized tap to thread the holes in the steel drum
  • 6 countersunk heat screws
  • Red thread locker for securing the screws
  • 2 high-heat Viton O-rings 
  • Complete video instructions (two videos)

Here are pictures of the tools in use:

Adjustable press to remove the pistons in the K1 and K2 for resealing (also under heavy pressure)

The small drill bit is used to drill the heads off the rivets without scratching or damaging the drum.

After removing the rivets, the holes are enlarged in the aluminum ring with the smaller bit, then the larger bit is used to countersink the holes for the new screws. The heads of the screws must be flush with the inside surface of the aluminum ring.

The tap is carefully used to thread the three holes in the drum the same size as the new screws included in the kit (6).

These are the O-rings included in this kit. 

Related Products:

$245.00
Currently out of stock.

722.3 Transmission Overhaul Special Tool Set

5 custom tools that can really save you time and frustration when you reseal or completely overhaul your 722.3 4-speed automatic transmission.

New August, 2025. Introductory sale. This transmission overhaul tool set is custom-modified here in our shop at MercedesSource.  We make it to order, and it is time-consuming. Please allow up to 5 weekdays before it can be shipped to you. It contains five tools.

$168.50

722.3 Transmission Overhaul Gasket and Seal Kit

We believe this is the highest quality and most thorough kit you can purchase for the price. Elring Brand. 2 "hidden" rivet sealed O-rings NOT included. See related below.

Take a very close look at the picture. These are all the gaskets and seals you will need to replace if you open up your 722.3 transmission that was produced from 1981 to 1995 for all 6 and 8 cylinder passenger cars that had a displacement of 3.0 liters or more.