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$98.00

123 126 124 Chassis with 722.4x Transmission - Upgraded BLACK Modulator Valve

Fits late 1985 123 and other models listed in description from 1986 to 1993 - Check the color match

If you are experiencing very hard or less than perfect shifts, a failed transmission modulator could be the problem. New Genuine Mercedes part. This unit is an upgrade over the original. It has a better thrust pin design which is less prone to cause pressure variations in cold weather.

$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.

$123.50
Currently out of stock.

722.3x Turbo Diesel Transmission Vacuum Modulator UPGRADE Green - Instructions Available Separately

For 1981 to 1984 Turbo 300D, 300CD, 300TD, and 300SD. Also fits 1984 and 1985 190D and 1984 to 1993 190E 2.3 Only

This is the new Mercedes O.E.M. replacement for the GREEN transmission vacuum modulator found on most of the models listed above. This unit has been upgraded from the original for better shifting performance (you will note it looks quite different).

$3.20

Transmission Modulator Valve Rubber Cap

Fits Late 123 107 126 201 and 124 Chassis 1981 to 1993

NEW Genuine Mercedes Modulator Cap. Check to see if yours is cracked. Cap removal is required for modulator adjustment.

Typical old and cracked rubber cap:

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.

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.

$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.

$19.75

1981 to 1984 722.3 Transmission Pesky Leak Fix Kit

For 5-cylinder turbo diesel engined 300D 300CD 300TD and 3000SD. Tool not included ( purchase separately below).

These transmissions are now 40+ years old, and with age comes hardened o-rings and seals, leading to what I call "pesky" leaks.

$328.00
Currently out of stock.

1980 to 1984 Diesel Transmission Vacuum Shifting Valve ( VCV ) -Refurbished

Low time. Very hard to find ones now that are even repairable. LAST ONE available. Critical for proper transmission shifts on 1980 to 1985 240D 300D 300CD 300TD - 1981 to 1985 300SD. Free video instructions included.

Not all units are repairable. These are no longer available new. This is one of the best we have seen in recent years.

On Demand Video
$14.99

Diesel VCV Valve Installation and Linkage Adjustment Instructions - On Demand Video

Applies to OM617 Turbo Diesels from 1978 to 1985 and OM616 and OM617 Non Turbo engines 1980 to 1983

In this 17 minute instructional video Kent will walk you through removing and installation a VCV valve off the back of the injection pump and the proper way to adjust the linkage travel for best performance.  A number of tips will be shared to reduce frustration and prevent problems.

$39.50

1978 to 1985 Diesel VCV ( Vacuum Control Valve ) Internal Inspection and Service Kit

Poor shifting. Try fixing yours. The kit includes three detailed on-demand videos to remove, test, and service the VCV, which can be purchased separately below!

The VCV valve controls the critical shifting patterns of most diesel automatic transmissions from 1978 to 1985. This includes the 1978 to 1985 300SD, the 1980 to 1985 W123 300D, 300CD and 300TD and the 1980 to 1983 240D.

$242.00
Currently out of stock.

OM617 Turbo Diesel Automatic Transmission Bowden Cable w/Tool - USED

NLA hard to find like this. Very good condition ---- Fits 1981 to 1984 Turbo 300D, 300CD, 300TD and 300SD with tool and free video instructions

ONLY ONE AVAILABLE. Very good used working Bowden cable with good plastic threads on the adjuster. No longer available new.  This will not fit the 1985 transmissions with the black modulator. It comes with installation instructions and Kent's specially made removal and installation tool.

$28.00
Currently out of stock.

Diesel Automatic Shift Control Valve Vacuum Orifice Set - USED

Original color coded vacuum restrictors for 1980 to 1985 240D 300D 300CD 300TD and 300SD

No longer available new These orifices are used to restrict the QUANTITY of vacuum being delivered to the vacuum control shift valve (VCV). This is the valve on top of the injection pump that sends the proper vacuum signal to the transmission modulator.

On Demand Video
$8.99

Fixing 1981 to 1984 Turbo Diesel Auto Transmission Pesky Leaks - On Demand Video

Applies to W123 and W126 turbo 300D, 300CD, 300TD and 300SD

These transmissions are now 40+ years old, and with age comes hardened o-rings and seals, leading to what I call "pesky" leaks. They are not bad enough to flow on the ground, but they do leave wetness around the transmission and drips on the garage floor.

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.

$9.95

Ultimate Oil Resistant Hi-Temp Reinforced Vacuum hose - 3 FEET

For 1/8 inch vacuum hose connectors on 240D 300D 300TD 300CD 300SD

I have never been impressed with the rubber vacuum hose found on older Mercedes diesels. I don't think the engineers ever anticipated how much abuse or how long these hoses would need to last!