Best driving practice for driving up hill

[Satter]

Hello all. I live in the Texas hill country. Occasionally I’ll take my 4Runner out on the highway. I set the cruise at 80 mph. When I hit a hill the vehicle will start to loose power. So it’ll downshift to maintain speed.

My question is when driving up and down hills should I keep it in cruise and let it automatically down shift and up shift to maintain speed? Should I not use cruise and drive with the OD function off?

I’m just trying to keep my transmission running well for many years to come.

 

[RandyBobandy]

Someone can correct me if I’m wrong but I believe what causes the transmission to heat up is the constant shifting and hunting for the correct gear, so if it isn’t doing that I don’t think I would worry about it.

I like to put OD off or lock it in 2 if I’m going up a particularly steep hill and it’s hunting for gears, but otherwise I leave it alone.

 

[brillo_76]

If its constantly shifting ( like every 30 seconds) to maintain speed when going up the hill I take the OD off and let it climb.

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[tvpierce]

As Randy says, if it's hunting back and forth between gears that's not great -- although it's more of an annoyance than a real concern.
If it's simply downshifting to get up the hill, then upshifting when you reach the top, it's operating exactly as it should: the transmission is reacting to a need for more torque.

If you haven't already, clean your MAF Sensor. (Google it on this site) That made a huge difference on the my '02 in the same type of situations.

 

[Satter]

As Randy says, if it's hunting back and forth between gears that's not great -- although it's more of an annoyance than a real concern.
If it's simply downshifting to get up the hill, then upshifting when you reach the top, it's operating exactly as it should: the transmission is reacting to a need for more torque.

If you haven't already, clean your MAF Sensor. (Google it on this site) That made a huge difference on the my '02 in the same type of situations.

I’m glad to hear this. It shifts fine. It doesn’t jerk when shifting. It’s quite smooth actually. And it manages to stay at speed without too much of a struggle. However, I feel anything over 80mph would be too much. And it’s winter. I’m not driving with the AC on. It struggles considerably more when it’s really hot out and the AC is on.

 

[jgue467]

How do you 'downshift'?

I'm in austin and drive to johnson city all the time on 290.

If in top gear cruising along, see hills coming, I engage OD override button at hill bottom before RPMS jump as they do when the OD has come unlocked and is allowing TC to slip to allow engine to gain torque with higher RPMS, but that comes at a cost, HEAT (and added wear) added in considerable amounts to the torque converter.

It's simple to avoid, just hit the OD button up hills and off at/near the top, both engine and trans will see a much easier life and last longer.

These 5vz barely have enough torque for the hills in high gear so Toyota set the trans OD engagement at a very light amount of additional throttle.

I avoid cruise control Unless I'm on flat roads. I cannot stand how Toyota does CC on smaller 4 bangers and 6 cyls, it downshifts and stays in the lower gear for gar too long.

Luck and enjoy those Toyotas. :cowboy:

 

[brillo_76]

It's because of their weight. They are 2 tons. All Toyotas were underpowered because of their mass. However, if your not a speed demon they have enough power to get you around plus the extra mass is very important in crashes and impacts.

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[Outrider]

I live in northern Georgia. Plenty of hills here, and when going in true north Georgia, we have some very serious hills.

I rarely use cruise control when there are serious hills involved, and I do this technique many times when hills are either long or steep, whether or not I am running cruise control: I anticipate a hill, meaning that just before I start climbing, I give it some throttle, smoothly and in advance. This helps prevent the drastic downshifting (often through multiple gears). It also prevents the cruise (if I am using it) from hammering the throttle.

"Hammering" anything mechanical (engines, transmissions, etc.) is never good. It increases the effect of wear dramatically. Slower, easier and gentler makes things last longer.

edited: Did you know that while using cruise control, you can press the gas pedal to accelerate some, then you can let off the gas later and it will decelerate until it reaches the set cruise speed, then attempt to hold that speed?

 

[phattyduck]

Hello all. I live in the Texas hill country. Occasionally I’ll take my 4Runner out on the highway. I set the cruise at 80 mph. When I hit a hill the vehicle will start to loose power. So it’ll downshift to maintain speed.

My question is when driving up and down hills should I keep it in cruise and let it automatically down shift and up shift to maintain speed? Should I not use cruise and drive with the OD function off?

I’m just trying to keep my transmission running well for many years to come.

To start 80mph is a pretty fast for 3rd gen. Yes, I know, everyone drives that fast there. Texas something something Texas. It still is too fast. I suppose as long as you don't complain about poor gas mileage, its fine.

As for the trans - it his highly dependent on how long you are going up a hill and whether the trans just unlocks the torque converter or it actually shifts to 3rd.

If these hills are less than maybe 3 minutes to get up, just let it go and stop worrying. If the hills are longer and the trans is shifting into 3rd (back and forth or just staying there), turn off OD and that will be better for the trans.

The issue here is that the transmission will only lock up the torque converter when it is in the highest selected gear (4th/OD with OD on, 3rd with OD off, never in 1st or 2nd), and heat in the trans is mostly created by an unlocked torque converter under power.

This can also be solved by just getting a transmission cooler.

-Charlie

 

[patkelly4370]

To get home from work (Bullhead City, AZ to Golden Valley) I climb a 12 mile, 6% grade. In summer it is often over 120°f.
I set the cruise to 65(ish) and it rolls along at 65 with the 'eco' light on.
Going down that same grade the speed limit drops the last couple of miles to 55 then 45. That's when I pop it out of drive to 'manual' using mild engine braking.

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[Satter]

How do you 'downshift'?

I'm in austin and drive to johnson city all the time on 290.

If in top gear cruising along, hills coming, I engage OD override button anytime I see the RPMS jump up. When they do the OD has come unlocked and is not slipping to allow engine to gain torque with higher RPMS, but that comes at a cost, HEAT added in considerable amounts to the torque converter.

It's simple to avoid, just hit the OD button up hills and off at/near the top, both engine and trans will see a much easier life and last longer.

These 5vz barely have enough torque for the hills in high gear so Toyota set the trans OD engagement at a very light amount of additional throttle.

Luck and enjoy those Toyotas. :cowboy:

About once or twice a month I’m driving between Kerrville and San Antonio on I-10. Between Kerrville and Bourne the hill grade is between 5 to 7 degrees. However, they’re not long. But there are quite a few. So that was my concern.

If I was doing a daily commute between Kerrville and SA I would be much more concerned.

 

[Dieselchessy]

3rd gear in these transmissions is 1:1 so will run the coolest and strain things the least.
But, holding 80 in 3rd might be a bit much.

 

[jross20]

You can be like me and keep it at 55 mph

:zoom:

 

[brillo_76]

These rigs are designed for lower speeds. 80 mph climbing is really taxing the v6. I mostly drive around at 70mph and dont have any issues.

As W. PA is the foothills of the mountains in the central part of the state. At 70mph low grades will make it shift down a gear. You start getting into the higher % of climb angles it's going to need to shift down. We have many hills around with 5 to 10% grade on them for some shorter distances like mostly a mile or 2 max.

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[mtbtim]

I only use cruise control on flat sections of highway. When hills come, I turn the cruise control off because I want to control when I get the transmission to kick down to maintain my speed. What I've noticed is the cruise control system can get the engine to race with higher rpms than I would have allowed to happen when I "ease" it into the downshift rather than slam it into the downshift like the cruise control can cause.

When hills become steady, overdrive always is turned off and remains off until the road flattens out again and my speed increases. Turning overdrive off can lower your trans temps a fair amount, 20+ degrees, when you're at the speed between around 40 mph and 60 mph, basically in that area between 3rd gear and overdrive. Overdrive off locks up the torque converter reducing the heat generated in the transmission.

The video below isn't the clearest but if you watch my phone carefully, you will see how turning overdrive off can lower your trans temp.

<iframe width="560" height="315" src="https://www.youtube.com/embed/BEZfDOkGVno" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


If you regularly drive in the mountains, I highly suggest you install an external trans cooler to help keep your trans temp down.

<iframe width="560" height="315" src="https://www.youtube.com/embed/2nVbwe2t2T8" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


I also highly recommend you start monitoring your trans temp. Since you have a 1998, you can't monitor your temps by pulling info via a scan gauge or OBD II reader sending info to a phone app like Torque Pro. You will need to install an aftermarket gauge like I did on my 98.

<iframe width="560" height="315" src="https://www.youtube.com/embed/fT_2szdKXRM" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


When 4wheeling, knowing when to switch into 4Lo can also make a huge difference in your trans temp. Anytime the trail starts to climb consistently and my speed is pretty slow, 20 mph or less, I put my transfer case in 4Lo. The difference between 2wd or 4Hi and 4Lo can be huge. In 2wd or 4hi, I could get my trans temp to get into the mid 200's or higher on a sustained grade. As soon as I switch into 4Lo and just resign myself to driving slower, my trans temp will drop to the sweet spot in the 170's. People that don't understand this and don't monitor their trans temps are the ones that will get the trans temp "idiot" to light up on their dash letting them know they cooked their ATF. That light supposedly lights up when your ATF hits 300 degrees. At that point, your ATF is cooked and a prompt flush is in order.

<iframe width="560" height="315" src="https://www.youtube.com/embed/wqxeZvljYGc" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


Heat is the big killer of automatic transmissions and ignorance definitely isn't bliss if it's going to cause you to burn up your transmission. Even with a trans cooler and turning overdrive off, you can still overheat your transmission. Sometimes it's prudent to pull over and give your engine and transmission a break when temps begin to spike. I did this when I was traveling up a brutally steep and sustained road in Death Valley. Better to pull over and let things cool down rather than overheat your engine or trans.

 

[Satter]

Thanks so much Tim. That first video was great information. I’m going to resign myself to switching OD off and keeping it below 70mph when driving uphill on the highway.

However, I think cruising at 80mph on a level highway should be okay. The rpms are at 2500. And I don’t mind the lousy gas mileage. Or is that too much for the engine and tranny?

 

[phattyduck]

However, I think cruising at 80mph on a level highway should be okay. The rpms are at 2500. And I don’t mind the lousy gas mileage. Or is that too much for the engine and tranny?

Shouldn't be a problem. As long as the torque converter is locked, you won't be ruining the trans. With those RPMs, do you have an e-locker 4Runner? It should be closer to 2300-2400 with the normal 4.10 gears (e-lockers got 4.30 gears).

-Charlie

 

[Satter]

I have one of those rare 4Runner LTD 4WD models that didn’t come with an e-locker. &#55358;&#56596; I’ve driven my 4R since it was brand new. Every time I’ve driven it at 80mph the rpms have always been at 2500.

I recently had the tranny checked at the dealership. They told me everything looked fine. The tranny fluid was a bright red. And it shifts very smoothly. The thing is I don’t remember the last time it was serviced. I want to have it serviced by someone who will do a drain and refill. But everyone wants do to a #%!@ flush. &#55357;&#56865;

 

[theesotericone]

These rigs are designed for lower speeds. 80 mph climbing is really taxing the v6. I mostly drive around at 70mph and dont have any issues.

As W. PA is the foothills of the mountains in the central part of the state. At 70mph low grades will make it shift down a gear. You start getting into the higher % of climb angles it's going to need to shift down. We have many hills around with 5 to 10% grade on them for some shorter distances like mostly a mile or 2 max.

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How is 80 MPH taxing the motor? Peak torque occur around 3600 RPM and peak HP at 4800 RPM. These motors want to rev high not languish at 2500 RPM.

As far as the OP's question goes. Just shut OD off when climbing a hill and let the cruise do the work. Also make sure that your throttle and cruise cables are properly tightened.

 

[brillo_76]

How is 80 MPH taxing the motor? Peak torque occur around 3600 RPM and peak HP at 4800 RPM. These motors want to rev high not languish at 2500 RPM.



As far as the OP's question goes. Just shut OD off when climbing a hill and let the cruise do the work. Also make sure that your throttle and cruise cables are properly tightened.

"I was talking about the condition of long mountains and OD."

They are not designed to be held at 80mph up mountains with an automatic transmission in OD. Unless you want to super heat your transmission fluid thus warping the fins in your TC and damaging your transmission. Then by all means go up the mountain at 100mph.

If you want to rering your engine every 100 to 200k then by all means hold it at redline all day long as it's not my engine nor my rig.

However, if you want your engine to last a very long time without having to rebuild it. You can keep the rpms lower thus keeping the heat down as I believe that is what the OP was asking. Or maybe I misunderstood the question.






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