Just so no one tries fixing a leaking transmission electrical plug with an inferior product........
After reading posts of the URO transmission electrical plug not being up to par, I got a MB plug to compare with the URO plug previously ordered from AutohausAZ. (Had previously ordered but not installed a URO for the lastest 722.6xx addition to the family, a ML320 with 165,000 mi)
A quick visual did not show any differences. A dimensional comparison of the plug bodies with calipers showed they were the same.
However, a dimensional check of the smaller O ring showed that the URO was thinner than the MB plug by about 20 thousands when installed on the plug. The upper O ring was also thinner.
Once the O-rings were rolled off the plug bodies, the size differences became clear. (see photo)
I speculate that the smaller O ring is critical to keep ATF out of the conductor plate shroud connection (a guess) and that the larger O ring keeps ATF from leaking to the outside of the transmission. A less tight fit of the URO plug may increase the chances of ATF leaking into the connector and wicking up to the Transmission Control Module.
Glad now of spending a few extra bucks on the MB plug. Just changed it out on the ML320 (which has a transplant tranny and heaven knows how many miles). Of course, the connector plug was wet with ATF on the electrical side, and the inelastic rubber O rings were red (factory original?) Also, the new MB connector plug was slightly difficult to get the center 7mm bolt to engage than compared to the last time I changed a plug on our E420 – with a URO. Suspect that the smaller O-rings make for easier seating, but inferior sealing. And, as luck would have it, I had ordered the S430 transmission plug replaced 3 years ago from AutohausAZ, so that (URO) is going to be replaced in during the upcoming tranny service.
After reading posts of the URO transmission electrical plug not being up to par, I got a MB plug to compare with the URO plug previously ordered from AutohausAZ. (Had previously ordered but not installed a URO for the lastest 722.6xx addition to the family, a ML320 with 165,000 mi)
A quick visual did not show any differences. A dimensional comparison of the plug bodies with calipers showed they were the same.
However, a dimensional check of the smaller O ring showed that the URO was thinner than the MB plug by about 20 thousands when installed on the plug. The upper O ring was also thinner.
Once the O-rings were rolled off the plug bodies, the size differences became clear. (see photo)
I speculate that the smaller O ring is critical to keep ATF out of the conductor plate shroud connection (a guess) and that the larger O ring keeps ATF from leaking to the outside of the transmission. A less tight fit of the URO plug may increase the chances of ATF leaking into the connector and wicking up to the Transmission Control Module.
Glad now of spending a few extra bucks on the MB plug. Just changed it out on the ML320 (which has a transplant tranny and heaven knows how many miles). Of course, the connector plug was wet with ATF on the electrical side, and the inelastic rubber O rings were red (factory original?) Also, the new MB connector plug was slightly difficult to get the center 7mm bolt to engage than compared to the last time I changed a plug on our E420 – with a URO. Suspect that the smaller O-rings make for easier seating, but inferior sealing. And, as luck would have it, I had ordered the S430 transmission plug replaced 3 years ago from AutohausAZ, so that (URO) is going to be replaced in during the upcoming tranny service.