hzjcm8 wrote:
mci7 wrote:
Reference to the 4000MHR transmission, using the Detroit TranSynd oil, What would the max safe temp allowed when decending a mountain using the retarder ?
So far, have not let it go above 220F.
Many thanks
MCI7,
I would say you could let it get to 250F but only intermittently. The transmission will allow a max "converter out" temperature of 330F so 220F sump temperature is not too high. The transmission will go into the "inhibit" mode to allow better cooling once it reaches a pre-set sump temperature but I'm not sure what that point is. I'm thinking it's probably around 250F though.
Tom,
Let's back up a minute. There are three different (very different) location for the transmission temperature senders on RV's I have worked on. I have seen them at the transmission sump, line into the transmission cooler and the line out of the transmission cooler.
Each will have a maximum recommended temperature, with the sump temperature likely being the most "accurate" and critical in reflecting what is happening in the transmission.
If you could share temps for each of these locations, it would be of assistance, as the readings are so different.
