I just performed transmission service on my ’97 E420 (fluid, filter and electrical connector). In addition to these, I addressed the issue of the transmission slipping during shifts, as discussed here http://www.benzworld.org/forums/w210-e-class/1238434-722-6-transmission-rpm-sensor-problem.html .
I was having the same issue as the other members in that thread, so I replaced the solenoid pressure regulator valve spring in the valve body as noted by Movada in his post (thank you for that excellent information).
I found my spring broken into 2 pieces as shown in the picture.
So far, the transmission seems to shift perfectly, but it’s too soon to say definitively that the slipping issue is fixed, since the slippage was intermittent.
Replacement procedure:
On the side of the valve body, passenger side, there are 2 rectangular steel plates that retain springs in the valve body. The rearmost plate is fastened by 12 torx screws. Under this plate are 4 springs, 2 which are visible and 2 which are covered by caps. The spring closest to the front and the spring closest to the rear are visible. The 2 springs between these are covered by caps. The spring in question is the spring under a cap that’s closest to the rear. In other words, of the 4 springs, it’s the 2nd from the rear, and is covered by a cap.
Remove the cap, and the spring. If the spring is broken, make sure both pieces are removed. Replace the spring with Sonnax part number 68942-01, then reinstall the cap and the retaining plate. Note: in the thread referenced above, it states that this part # is applicable to ’99 and earlier 722.6 transmissions only.
If we continue to hear about failures of this spring, it may make sense to start changing it out as preventive maintenance when doing the normal transmission service in 722.6 transmissions.
I was having the same issue as the other members in that thread, so I replaced the solenoid pressure regulator valve spring in the valve body as noted by Movada in his post (thank you for that excellent information).
I found my spring broken into 2 pieces as shown in the picture.
So far, the transmission seems to shift perfectly, but it’s too soon to say definitively that the slipping issue is fixed, since the slippage was intermittent.
Replacement procedure:
On the side of the valve body, passenger side, there are 2 rectangular steel plates that retain springs in the valve body. The rearmost plate is fastened by 12 torx screws. Under this plate are 4 springs, 2 which are visible and 2 which are covered by caps. The spring closest to the front and the spring closest to the rear are visible. The 2 springs between these are covered by caps. The spring in question is the spring under a cap that’s closest to the rear. In other words, of the 4 springs, it’s the 2nd from the rear, and is covered by a cap.
Remove the cap, and the spring. If the spring is broken, make sure both pieces are removed. Replace the spring with Sonnax part number 68942-01, then reinstall the cap and the retaining plate. Note: in the thread referenced above, it states that this part # is applicable to ’99 and earlier 722.6 transmissions only.
If we continue to hear about failures of this spring, it may make sense to start changing it out as preventive maintenance when doing the normal transmission service in 722.6 transmissions.
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