(2005 X model, 6cyl, Stock 4-speed automatic transmission (overdrive), all stock except for 3" lift and 31" tires.)
I’ve written elsewhere about the trip I took this week. I started out at about 500 feet above sea level, got over 5,500 by the time I got to where I was going. This was in less than 50 miles and entailed three or four peaks with drops between them. Ambient temperature was moderate, drove most of the day with the windows down and A/C off.
In the first half of the trip, there is a long, steep climb over some real rough road (rocks-some big, some deep washouts, lots of curves). That part of the road goes from about 450m to over 1500m in less than 20km, so we're talking a climb of well over 3000 feet in less than 12 miles.
This shows my elevation over distance. The steep climb started at about 32km.
This is speed over time (km/h); over two hours to make the 50km (30 miles). The first fifteen minutes were on pavement, then we jumped off. The road was pretty good for the first 40 minutes or so, was able to haul ass. The dirt got rough after the 45 minute mark. I was seldom doing 30kph (shy of 20mph) once I got into the ugly stuff, then I slowed down at the top as we got close to the town. [A trick for converting km to mi: divide by half then add 10% of the original. So, 60kph is (30+6)mph. 50kph is (25+5)mph.]
I’ve never driven that kind of road in this kind of vehicle. Always had manual transmissions before. (My old Russian UAZ 469 was a dream on these kinds of roads.)
Going up, I honestly took it pretty aggressively; probably too aggressively. Kept up a pretty good pace and just left the transmission do its thing in DRIVE. There were times when it did seem like it was straining. I probably should have slowed down. The transmission got really hot before we got to the top.
Once at the top, we stopped to visit some friends for a couple of hours. On arrival, I checked the fluid and it looked OK. Didn’t smell funky, wasn’t foamy or anything. There was one oddity, though; when I put it back into DRIVE to pull up into the driveway, there was an initial short grinding sound – just for a fraction of a second. Every time I'd slip it into drive it'd do this before it even rolled. Once the tranny cooled down and we got underway, it didn’t do that again. Scared the snot out of me, though.
So, my question to those who might be more experienced in driving conditions like this with an automatic tranny is, what’s the best way to make a climb like this?
Should I slow it down, keep it in 1st and 2nd gear and just crawl up at a slower pace? It seems to me that that would have worked better for my transmission.
Also, is there any way to monitor the transmission temperature? Somewhere to plug in a sensor?
And any idea what would mechanically cause that frightening grinding sound?
I’ve written elsewhere about the trip I took this week. I started out at about 500 feet above sea level, got over 5,500 by the time I got to where I was going. This was in less than 50 miles and entailed three or four peaks with drops between them. Ambient temperature was moderate, drove most of the day with the windows down and A/C off.
In the first half of the trip, there is a long, steep climb over some real rough road (rocks-some big, some deep washouts, lots of curves). That part of the road goes from about 450m to over 1500m in less than 20km, so we're talking a climb of well over 3000 feet in less than 12 miles.
This shows my elevation over distance. The steep climb started at about 32km.
This is speed over time (km/h); over two hours to make the 50km (30 miles). The first fifteen minutes were on pavement, then we jumped off. The road was pretty good for the first 40 minutes or so, was able to haul ass. The dirt got rough after the 45 minute mark. I was seldom doing 30kph (shy of 20mph) once I got into the ugly stuff, then I slowed down at the top as we got close to the town. [A trick for converting km to mi: divide by half then add 10% of the original. So, 60kph is (30+6)mph. 50kph is (25+5)mph.]
Going up, I honestly took it pretty aggressively; probably too aggressively. Kept up a pretty good pace and just left the transmission do its thing in DRIVE. There were times when it did seem like it was straining. I probably should have slowed down. The transmission got really hot before we got to the top.
Once at the top, we stopped to visit some friends for a couple of hours. On arrival, I checked the fluid and it looked OK. Didn’t smell funky, wasn’t foamy or anything. There was one oddity, though; when I put it back into DRIVE to pull up into the driveway, there was an initial short grinding sound – just for a fraction of a second. Every time I'd slip it into drive it'd do this before it even rolled. Once the tranny cooled down and we got underway, it didn’t do that again. Scared the snot out of me, though.
So, my question to those who might be more experienced in driving conditions like this with an automatic tranny is, what’s the best way to make a climb like this?
Should I slow it down, keep it in 1st and 2nd gear and just crawl up at a slower pace? It seems to me that that would have worked better for my transmission.
Also, is there any way to monitor the transmission temperature? Somewhere to plug in a sensor?
And any idea what would mechanically cause that frightening grinding sound?
Last edited:
