Search | W123 | Transmission

Displaying 1 - 50 of 116
$248.00
Currently out of stock.

1981 to 1984 Turbo Diesel 722.3 Transmission Bowden Cable - USED

For 300D, 300CD, 300TD and 300SD specific to those years and automatic transmission - instructional videos included.

ONLY ONE AVAILABLE. Very good used working Bowden cable removed from a working 1983 300D. No longer available new.  This will ONLY fit the years and models listed.  This cable adjusts the shift points in your automatic transmission.  TWO new O-rings included so you have a spare.

$2.95

123 107 126 201 124 722.3x and 722.4x Transmission Modulator O-ring Seal

For re-sealing green and black modulators on most 1981 to 1993 models.

If your modulator is working ok, but leaking transmission fluid, you may only need to replace the inexpensive oring ( o ring ). You do have to be careful when removing the modulator from the transmission. For instructions (available separately) see related products below.

On Demand Video
280SEL Transmission Service - On Demand Video
$12.99

Older Automatic Transmission Fluid and Filter Service - On Demand Video

Directly covers most 1960’s Automatics - Indirectly covers 1970’s and Early 1980’s Automatics Directly covers most 1960’s Automatics - Indirectly covers 1970’s and Early 1980’s Automatics

Transmission service on these older Mercedes is very often neglected and it is something you can do yourself. It should be done every 30,000 miles or every 5 years (whichever comes first). After you watch this video you will find out why you should do it yourself!

$1.90

1982 to 1995 Auto Transmission Dipstick Tube Seal

Fits all models with the 722.315 and most 722.4 transmissions - see list below

This is becoming one of the common transmission fluid leaks on these older automatics. If the trans is leaking fluid in small puddles while the car sits for longer periods suspect this seal. You can be fooled thinking it is coming from the pan gasket.

$2.95

617 Turbo Diesel Transmission Bowden Cable O-ring Seal

For 1981 to 1985 Turbo Diesel 300D 300TD 300CD and 300SD

Custom ordered for a better fit than original! special Oring seal for the bowden cable housing where it connects to the right side of the automatic transmission. This is a common leak area and you may be fooled into thinking it is leaking out of the pan gasket.

$198.00
Currently out of stock.

617 Turbo Diesel Transmission Bowden Cable

Specific for OM617 mated with 722.3 transmissions - 1981 to 1985 - 300TD, 300D, 300CD and 300SD

A brand New Old Stock OE bowden cable for your automatic transmission. No longer available from Mercedes Benz. This part is critical to proper shift timing. The bowden cable runs from the transmission to the throttle linkage on many Mercedes from the early 1980's up through the early mid 1990's.

On Demand Video
$12.99

Transmission Bowden Shift Control Cable Removal and Replacement - On Demand Video

Specific instructions for 1981 to 1985 Turbo Diesel Automatic Transmissions

The bowden cable runs from the transmission to the throttle linkage on many Mercedes from the early 1980's up through the early mid 1990's. When this cable fails or is out of adjustment the transmission will either shift too early or too late.

$79.50

Automatic Transmission Shift Rod Bushing Replacement Tool Kit - New Bushings Included

For LATE MODEL (70-73) 108 109 and ALL 114 115 107 116 123 126 201 124 129 and 140 chassis 1968 to 1995

The plastic shift bushing is a very common part that needs to be replaced on older Mercedes. Can you believe it is the exact same part that was used on all models for over 25 years! It is an inexpensive part that can cause big problems if it breaks out.

61x Diesel Automatic Transmission Tuning Manual
$28.50

Diesel Automatic Transmission PEAK Performance Tuning Manual by Kent Bergsma

Receive two related On-Demand videos FREE! Covers ALL Diesel Automatics from 1969-1984 220D 240D 300D 300CD 300TD 300SD

I have received so many emails on this topic that I had to sit down and write a very detailed manual over 130 pages in length!  Let's face it! Diesel automatic transmissions can be troublesome, particularly those models that use vacuum to control shifts.

$129.00

W123 W126 OM617 Turbo Diesel Transmission Ultimate Diagnostic and Tuning Kit

116 and 126 1978 to 1984 300SD, 1980 to 1984 123 240D and 1981 to 1985 123 Turbo 300D 300TD 300D 300CD. Does not apply to the 722.4 transmissions found in most 1985 models

INCLUDES TRANSMISSION PEAK TUNING MANUAL.  DO NOT ORDER SEPARATELY. Bonus videos are included free. To properly tune your diesel transmission, you will first need the know-how and then the equipment to adjust your transmission modulator and your VCV transmission shift valve.

$38.95

Diesel Automatic Transmission VCV Vacuum Controls Testing Kit

All diesel Automatic Transmissions with Vacuum Modulator Fitted 1978 to 1993

This unique kit will allow you to hook up a 30 in HG vacuum gauge between your vacuum control shifting valve (VCV) and your transmission modulator to test the VCV for proper function and to tune it for peak shifting performance.

61x Diesel Automatic Transmission Modulating Pressure Test Kit
$75.50
Currently out of stock.

61x Diesel Automatic Transmission Modulator Pressure Test Kit

Updated 11/20/25 - Purchase revised kit with video instructions and speed adjusters listed below.

Applicable to 114 115 116 123 and 126 Chassis, years and models listed above. Troubleshooting an annoying shift problem must first start with the vacuum modulator.

On Demand Video
$7.99

Troubleshooting Older Diesel Automatic Transmission Shift Problems - On Demand Video

Knowing where each component is located and what it does is the start of solving externally caused shift problems

I don't think there is any owner out there who has owned a 1978 to 1993 diesel automatic for any length of time and who has not had some sort of shift problem with the transmission. Maybe it was just a little jerk or a slipping shift. Maybe the rear end clunked hard when you came to a stop.

$98.00

1981 to 1995 722.3 722.4 722.5 Transmission Vacuum Modulator Valve

Only black is currently available, but it will work in 722.3 and 722.4 transmissions. This is the easy-to-adjust upgraded version with the new style pin included.

9/2025 Update: Green and Red Modulators are NLA, and we have been informed that they will not be remanufactured. But, do not panic! You may have heard that you must replace your 1981 to 1995 transmission modulator with the correct color top.

$224.00

1981 to 1990 722.3 Transmission B2 Brake Band Assembly - NEW

This is the one that almost always wears out due to binding of the B2 piston. Just plan to replace it if you are opening up your transmission

Only one available. This is a quality aftermarket part. Study the picture carefully to make sure that you know which band you are ordering.

SaleOn Demand Video
$19.95

Diagnosing Shift Problems Inside the 1981 to 1995 722.3 722.4 Transmissions - On Demand Video

Kent will take 30 minutes to fully explain the internal workings going on during the shift sequence.

This is a 3-part series combined into one 30-minute video. If you can understand how the transmission works, you will be better able to diagnose your shifting problems. Kent will explain the 5 key elements in the transmission that control the shift sequence.

$68.95

Early 722.3 Transmission Valve Body Overhaul Kit

For 1981 to 1990 722.3 valve bodies only. Includes new sealing rings for all the accumulators.

Why rebuild a 722.3 valve body? Some may have told you just to "leave it alone." It can be a little intimidating, especially if you have visions of all kinds of springs, balls, and little valves flying all over the place when you take it apart. Watch the video below for a short overview.

$46.00

722.3 722.4 Transmission System Pressure Tester - FULL Pressure

Measures "line" pressure from the "tap" on the right side of the transmission.

Why have a separate tester just to measure the full pressure running inside the transmission? For this test, the pressure can reach up to 240 psi and can go higher if there is a restriction. This requires a special gauge and hose that can handle the pressure.

$11.49

722.3 722.5 Automatic Transmission Pan Gasket

Fits the larger displacement engine transmissions from 1981 to 1995 Check to make sure which transmission you have.

ALWAYS replace the pan gasket when pulling the pan for any maintenance. No need to change the filter if it has been recently replaced.  WILL NOT FIT the 190E, 190D, 300E 2.6, or the 1985, 1986 and 1987 300D and 300TD.

On Demand Video
$3.99

How to Install a New B2 Piston Sealing Ring - On Demand Video

Bonus: Kent demonstrates and cautions installing the small split sealing rings in the gasket kit.

B2 REPLACEMENT PISTONS ARE NO LONGER AVAILABLE NEW. But you can repair your old B2, unless it is the very early type with the narrow circumferential ceiling ring.

$69.95
Currently out of stock.

722.3 B2 Piston Repair Kit

New Pistons are NLA. This will only work if you have a piston with the wide seal around the outside edge. Inspect you B2 BEFORE ordering

Since new B2 pistons are no longer being made, repairing your old one is your only option. The very early version with the narrow sealing ring on the outside of the piston is not repairable. You piston MUST have the wide ring as shown. Video installation instructions are included.

$39.80

722.3 722.4 K1 K2 Clutch Drum Spring Compressor

A must have to replace the clutches or seals inside these drums

If you try to open up those clutch drums without this tool you WILL be frustrated!  You may get them open, but trying to put them back together is something else! If you need instructions or other parts see related products below.

$325.00
Currently out of stock.

Early 722.3 Transmission Valve Body - Used

For 1981 to 1989 722.3 Automatic Transmissions.

This was removed from a recently rebuilt transmission that was removed from a 1983 300D. I do not know what work if any was done on this vavle body but it was in very good working conditon when removed. SPECIAL PRICE.

On Demand Video
$18.99

How to Repair 722.3 Automatic Transmission Hard Line Leaks and Chaffing - On Demand Video

Do not wait for leaks to develop. Lines are NOT available new.

In this 27-minute instructional video, Kent will show you how to use our repair kit to prevent chaffing at the clamp locations, and how to actually fix a leak if a hole has worn through the the transmission cooler hard line. Check out the repair kit in the related products below.

$59.50

1981 to 1991 722.3 Transmission Cooler Metal Line Repair Kit

The hard metal lines can develop leaks leading to loss of transmission fluid while driving. This kit will fix leaks and prevent wear leaks from happening!

Introductory special. Full video instructions for both repairing pipe leaks and reducing chaffing are included. This is now becoming a bigger problem as these diesels age. Inspect your cooler lines soon!

On Demand Video
$12.99

1981 to 1995 722.3 Transmission Front Pump Leak Repair Procedures - On Demand Video

Only for the bigger transmissions. Make you know which one you have. Will not work on 722.4 transmission ( parts are smaller )

Kent's highly detailed xx-minute video on how to remove the K3 and pump assembly from the front of a 722.3, take it all apart to gain access to the big pump O-ring, replace it and the torque converter seal, and put it all back together again. 

$69.95

1981 to 1995 722.3 722.4 722.5 Modulation and Governor Pressure Test Kit

Now to both determine the internal health and to prolong the life of these old transmissions. Full video instructions included. 50 psi limit. This will NOT test full 190 psi supply pressure. Bonus speed adjustment video included

Too much pressure and you will blow the seals. Too little pressure and you will wear out the clutch packs.  When installing a new vacuum modulator on your transmission, you most likely will need to adjust it. There are two ways to do this.

$62.75

1981 to 1995 722.3 Severe Transmission Front Oil Leak Reseal Kit w/ Video Instructions

Have a big fluid leak coming out of the front? It won't just be the seal. There is a BIG hidden o-ring at the edge of the pump.

This is one of the most common leaks we have seen on these transmissions over the past 25 years. If you are discovering big puddels of red transmission fluid on the ground at the front of the transmission I can almost guarantee it is the front pump leaking.

On Demand Video
$7.99

722.3 722.4 Transmission Overhaul Checking B1 Piston Release Pressure - On Demand Video

This is very important - Too loose and you will get flaring between 2nd and 3rd. Too tight shift will jerk

When you are resealing or rebuilding, or even just working on the B1 piston, you need to check the release pressure. This is done by measuring the distance the piston has to travel before the brake band clamps onto the K2 drum. This should NOT be neglected.

On Demand Video
$8.99

722.3 722.4 Video Class Pt. 11 - Side components assembly into transmission case - On Demand Video

Part 11 is no longer sold separately. It comes included in Kent’s Full 12-Part Transmission Overhaul Class. See related products below to order.

In this detailed step-by-step 26-minute video instruction, Kent will show you how to correctly install the B1 and B2 piston assemblies, check them for proper operation, and measure the required "free-play." He will also cover other items you will need to install on

On Demand Video
$8.99

722.3 722.4 Video Class Pt. 9 - Transmission Case Prep for Reassembly - On Demand Video

Part 9 is no longer sold separately. It comes included in Kent’s Full 12-Part Transmission Overhaul Class. See related products below to order.

There are several important seals and O-rings that need to be replaced before proceeding with reassembly. In this 26-minute video, Kent will go down both the right and left sides of the case and demonstrate each one. 72234CLASS

 

On Demand Video
$8.99

722.3 722.4 Video Class Pt. 8 - Rear Pump Inspection and Reseal - On Demand Video

Part 8 is no longer sold separately. It comes included in Kent’s Full 12-Part Transmission Overhaul Class. See related products below to order.

In this 19-minute session, Kent will remove a rear oil pump from an early 722.3, disassemble it, and demonstrate some of the challenges associated with resealing it.  72234CLASS

On Demand Video
$8.99

722.3 722.4 Video Class Pt. 3 - Additional Tools, Supplies, and Tech Data- On Demand Video

Part 3 is no longer sold separately. It comes included in Kent’s Full 12-Part Transmission Overhaul Class. See related products below to order.

In part three of his 722.3 video class, Kent will give you his recommendations of some tools and supplies you may need when you go to tackle this job yourself. He will also give you recommendations on additional manuals you should download from the internet. The video is 21 minutes in length.

$23.75

Kent's Speed Adjusters for the 722.3 and 722.4 Vacuum Modulator

Now covers both old and new style Modulators. Install for rapid initial adjustment and fine road test adjustments.

PLEASE NOTE: This should be used in conjunction with our modulator pressure test kit (see below). It can be unhealthy for your transmission to just "guess by feel" where the T-pin should be turned.

On Demand Video
$6.99

Adjusting the Modulator with Kent's New Speed Adjuster - On Demand Video

For the new style modulator that fits the 1981 to 1995 722.3 and 722.4 transmissions. Make it Easy!!!

Out of years of frustration trying to adjust the modulator during a test drive, Kent came up with a better and faster way to make adjustments by just "reaching" under the car. This little device replaces the plastic cap during testing and adjustment.

Pages