Explorer DT12 Allison Victron In-Depth - Mike Mas

[Idleup]

Explorer DT12 Allison Victron In-Depth - Mike Mas

Hello IRV2 Renegade Members - After studying Renegade’s Cascadia Explorer, with its powerful Detroit DD13 engine & Allison 4000, last year I finally pulled the trigger on a 2025 Explorer ERB. Having owned almost every type of RV and bus chassis made, the Explorer with its aggressive looking Cascadia semi cab and million mile chassis, is the pinnacle of my nearly half century of owning motorhomes.

After a Number of Excursions - To feel out the Explorer, and its differences from my Class 8 L9 Verona 34, the following 8 months were spent carefully documenting and imaging to create this 2 Part - 88 page, Non-Sponsored personal In-Depth review of the Explorer’s, chassis, engine, transmission and coach body. This review also includes a comprehensive review and tutorial on the operation of the Explorers Victron dual inverter system. Enjoy - Mike

Please click the link below:

https://www.rotory.com/coach/explorerf

[Idleup]

Hello Explorer Owners - Just a few extra notes on the Allison’s new 5th generation control module. 2025 Explorer’s now include a new 5th generation Allison transmission control module and sensors. While the new 5th generation tranny’s offer a number of features such as “Prognostics” and improved “Diagnostics” which keeps track on every aspect of the transmissions health, wear, component life, fluids, etc.

The 5th generation with its massive 40 quart capacity, now offers totally new “Driving Protocols”. Thanks to an included inclinometer, the Explorer’s 4000 can now better predict shifts for inclines since it now gathers vehicle loads with incline for improved shift sequences.

In plain English, the first thing you’ll notice is unlike before when you were in 5th gear and and reached an incline, where before you had to floor the pedal to downshift to 4th, with the inclinometer feature, it knows there’s an incline and downshifts (most all the time) automatically as it encounters the additional loads to climb the hill.

Regretfully, all Allison transmissions shift schedules (regardless of make or model) use shift schedules designed fuel economy. With that said, either with or without Fuel Sense, every Allison will “over-shift”. This means it’s not uncommon for it to shift all the way up to 4th gear, when doing only 35 mph in an ill attempt to save fuel causing you to bog a hill.

The best (and only) fix for this is to shift your coach manually when in hilly terrain. Any time you’re loaded, manual shifting makes any motorhome much more powerful and easier to negotiate mountain inclines. Keep in mind that 4th gear is really the top gear, 5 and 6th gear are overdrives gears. There’s only “200 RPM” difference between 5th and 6th gear.

Since our Allison’s actually have 8 different true speeds, using manual is the only way to take full advantage of the extra speeds provided in 1st and 2nd gear and prevent over-shifting of higher gears. While Allison transmissions will use all 8 speeds in drive, regretfully it “quick shifts” in 1st and 2nd, losing performance when compared to manual shifting. Another major advantage of using manual, is the driver prevents over-shifting to 3rd and 4th gears, keeping the engine in its power band to easily negotiate hill climbing.

I supplied a clip from my Freightliner build sheet and Allison's 8 speed shift sequence and video below.

Enjoy - Mike

ALLISON 8 SPEEDS VIDEO

https://www.rotory.com/coach/8speedsmikemas.mov

[Idleup]

Hey guys - Just as a reminder if you install shutoffs on your Explorer be sure to shut off the solar panels to prevent voltage from remaining in the system. The solar shutoff is pretty much hidden from view behind some cables on the compartment roof. The shutoff is also a resetable fuse as well which doubles as a shut off.

Regards Mike

[lslblues]

I was driving through Indiana today and hit a bunch of stop lights, so I took Idleups challenge - manual shifting vs full throttle acceleration. The difference was maybe 1/2 second improvement at best. The only change in behavior is the transmission hit 1st gear lockout. This is with a 47,000 pound Classic, DD13, Allison, flat-towing 6,000 pound Jeep on level ground.

I timed 3 tests
1. WOT Performance Mode (S5) - 28 seconds
2. WOT manual shifting at just over max HP RPM - 27.5 seconds
3. WOT Economy Mode (S7) - 34 seconds.

Manual shifting had no appreciable improvement whatsoever over Performance Mode WOT. I'm being generous to say it was even 1/2 second improvement. With S5 and WOT, it holds the gear just past max HP (1625 RPM) before it shifts. If you held that gear longer, the torque/HP drops off dramatically.

The slight improvement was hitting 1st gear lockout, which is from about 8-10 MPH. Non manual shifting results in going from 1st gear TC to 2nd gear TC until 2nd locks out at about 22 MPH.

Now you will see a big improvement if you are either in economy mode or are using performance mode and not mashing the pedal. Both S5 and S7 change the shift points based on throttle position.

[lslblues]

I'm also surprised that there is all of this focus on acceleration and climbing mountains. It's much more important that we can safely go down the mountains rather than how fast we can go up. I didn't see anything in your review about engine braking and probably my favorite mountain feature - Descent Control.

[Uncle_Mike]

Originally Posted by lslblues

I'm also surprised that there is all of this focus on acceleration and climbing mountains. It's much more important that we can safely go down the mountains rather than how fast we can go up. I didn't see anything in your review about engine braking and probably my favorite mountain feature - Descent Control.

I could not agree with you more about Descent Control. In fact, I deliberately stayed out of this debate because I felt like it became too focused on the wrong things - academic/theoretical aspects of truck driving rather than the practical ones. But I've extolled the virtues of Descent Control in other IRV2 posts, and
didn't want to sound like a broken record...

An old timer OTR trucker once told me that amateurs talk about getting up the hill fast, but pros talk about getting down the hill safe, and I have come to believe the wisdom of those words.

When using cruise control, the Cascadia maintains speed within a range band, which is configurable, of about +/- 4mph. So if you set CC to 70, the truck will maintain speeds in the 66-74 band. This is actually a pretty wide band. But if you engage Descent Control at 70, I swear the truck holds 70 dead on, and I've gone down 10-mile 7% grades with DC engaged. It's really amazing and makes long steep grades effortless to deal with. DC will upshift/downshift, adjust the throttle to keep the right rpms, and modulate the engine brake as needed to hold the set speed. It's magic.

[Idleup]

Thanks for the reply - Where you’ll see major 0-60 results and 10 second advantages is when pulling a good load. The light weight of an Explorer for a DD13 is like bob-tailing, the chassis thinks its an un-loaded semi!

Another point is you’re not going to be perfect at manual shifting the Cascadia’s 8 speeds doing it a few times, things happen quickly in the lower gears, it takes years to shift by ear and keep the engine off the governor. What I’m saying is, if you have to look at the tach, you won’t be shifting it right, especially when shifting thru the 4 speeds of 1st and 2nd gears which happens very quickly.

Keep in mind, the Cascadia is spec’ed from Freightliner at 72-80,000 pounds. With that said, a jeep is not going to load the Cascadia you won't hardly know its there. Where manual shifting makes a major difference is when the chassis is loaded close to gross. I have properties in Va and occasionally move equipment to and from Georgia. (16,000-24,000 lbs) I can tell you there’s an easy 10 seconds advantage using manual.

As I mentioned in my article, both the M2 and Cascadia over-shift to save fuel and if you're loaded you can easily lose 5 seconds on both 3rd and 4th gears, before the engine gets back on its step.

Talking about pulling heavy loads, here’s a great shot from the 80’s, it's all in balancing the load LOL!

Regards - Mike

[Idleup]

Originally Posted by Uncle_Mike

I could not agree with you more about Descent Control. In fact, I deliberately stayed out of this debate because I felt like it became too focused on the wrong things - academic/theoretical aspects of truck driving rather than the practical ones. But I've extolled the virtues of Descent Control in other IRV2 posts, and
didn't want to sound like a broken record...

An old timer OTR trucker once told me that amateurs talk about getting up the hill fast, but pros talk about getting down the hill safe, and I have come to believe the wisdom of those words.

When using cruise control, the Cascadia maintains speed within a range band, which is configurable, of about +/- 4mph. So if you set CC to 70, the truck will maintain speeds in the 66-74 band. This is actually a pretty wide band. But if you engage Descent Control at 70, I swear the truck holds 70 dead on, and I've gone down 10-mile 7% grades with DC engaged. It's really amazing and makes long steep grades effortless to deal with. DC will upshift/downshift, adjust the throttle to keep the right rpms, and modulate the engine brake as needed to hold the set speed. It's magic.

Thanks for the reply - The 0-60 mph is only a reference to performance, not drag racing. By keeping the DD13 engine on its power band on steep grades heavily loaded, works the engine less, allows it to operate cooler and provides additional performance and more importantly better economy.

The information in my in-depth review is keyed on the Cascadia chassis, the coach body, electronics and the until now, the hidden and misunderstood differences between a DT12 and Allison's 8 speed transmission. The operation of these two transmissions has been one of the least understood features of Renegade coaches. The article is also geared towards those who use their coach for work who pull "heavy" loads, in an attempt for those owners to better understand their how the Detroit engine operates with the different transmissions. There's nothing to debate here its all facts.

For those who are just putting around on vacation, most of this technical information is not be needed, so just push the big pedal on the right side and enjoy your great coach!

Many Thanks Mike

[MemByTheMile]

Descent control - going to go read more about this. I don’t think we have that on our 2014 Ikon.
Cruise control on our Cummins w/Allison will not engage engine braking while in cruise control. When going downhill I cancel cruise and then find the right engine braking setting that roughly maintains our speed at the same speed we were able to maintain on the uphill portion.
Wondering if we have a hidden feature that we have missed these past few years owning this rig.

[lslblues]

Load is not going to change the shift points for S5 shift program. It’s based on RPM and throttle position alone.

Originally Posted by Idleup

Thanks for the reply - Where you’ll see major 0-60 results and 10 second advantages is when pulling a good load. The light weight of an Explorer for a DD13 is like bob-tailing, the chassis thinks its an un-loaded semi!

Another point is you’re not going to be perfect at manual shifting the Cascadia’s 8 speeds doing it a few times, things happen quickly in the lower gears, it takes years to shift by ear and keep the engine off the governor. What I’m saying is, if you have to look at the tach, you won’t be shifting it right, especially when shifting thru the 4 speeds of 1st and 2nd gears which happens very quickly.

Keep in mind, the Cascadia is spec’ed from Freightliner at 72-80,000 pounds. With that said, a jeep is not going to load the Cascadia you won't hardly know its there. Where manual shifting makes a major difference is when the chassis is loaded close to gross. I have properties in Va and occasionally move equipment to and from Georgia. (16,000-24,000 lbs) I can tell you there’s an easy 10 seconds advantage using manual.

As I mentioned in my article, both the M2 and Cascadia over-shift to save fuel and if you're loaded you can easily lose 5 seconds on both 3rd and 4th gears, before the engine gets back on its step.

Talking about pulling heavy loads, here’s a great shot from the 80’s, it's all in balancing the load LOL!

Regards - Mike

[lslblues]

If you have adaptive cruise, the issue using it going downhill, is it will use combo of engine and service brakes. DC only uses engine brake, and I agree it’s magic.

Originally Posted by Uncle_Mike

I could not agree with you more about Descent Control. In fact, I deliberately stayed out of this debate because I felt like it became too focused on the wrong things - academic/theoretical aspects of truck driving rather than the practical ones. But I've extolled the virtues of Descent Control in other IRV2 posts, and
didn't want to sound like a broken record...

An old timer OTR trucker once told me that amateurs talk about getting up the hill fast, but pros talk about getting down the hill safe, and I have come to believe the wisdom of those words.

When using cruise control, the Cascadia maintains speed within a range band, which is configurable, of about +/- 4mph. So if you set CC to 70, the truck will maintain speeds in the 66-74 band. This is actually a pretty wide band. But if you engage Descent Control at 70, I swear the truck holds 70 dead on, and I've gone down 10-mile 7% grades with DC engaged. It's really amazing and makes long steep grades effortless to deal with. DC will upshift/downshift, adjust the throttle to keep the right rpms, and modulate the engine brake as needed to hold the set speed. It's magic.

[Idleup]

Originally Posted by lslblues

Load is not going to change the shift points for S5 shift program. It’s based on RPM and throttle position alone.

IslBlues thanks for the reply - Regretfully, you're totally confused thinking an Allison or DT12 transmission shifts exactly the same loaded or unloaded. The problem is you've never pulled a load with your coach and therefore fail to understand how the engine and transmission react when loaded. First off, both the DT12 and Allison TCM’s change shift protocol and shift points based solely on load. (Also road incline on Gen 5 transmissions.)

See if you can follow this simple example to better understand why shift points change.

Let’s say an un-loaded Explorer could reach 60 mph in just 30 seconds.

Next, we add a trailer and the Explorers weight now doubles from 38,000 lbs to 76,000 pounds. It would be almost pointless to think the transmission is going to shift exactly the same, since it’s now impossible for the Explorer to reach 60 mph in only 30 seconds when loaded.

Let’s say the loaded Explorer now takes 60 seconds to reach 60 mph. This means the shift points and the time each gear is engaged would have to double. Therefore both the shift points and gear engagement are now a full 100% longer for each gear.

Regretfully, this is why your “loaded test post” was meaningless and your coach shifted the same. In error you thought you were loaded, when in fact you were not. A tiny jeep a weighting 4-5,000 lbs (not 6,000 lbs) floating in the vacuum behind the coach, does not “by any means” load the Cascadia chassis. In fact, when I pull my Gladiator (4600 lbs.) I hardly know its behind the coach.

Mike

2024 Jeep Wrangler Sport 4 Door: 4,285 pounds
2023 Jeep Wrangler Rubicon 4-Door: 4,449 pounds
2023 Jeep Wrangler Sahara 4-Door: 4,406 pounds
2023 Jeep Wrangler Rubicon 392 4-Door: 5,103 pounds

[Idleup]

Hey Guys - Here’s a few notes on winterizing the Renegade Explorer. While I stopped winterizing my coaches some 7 years ago since I now use electric winterizing, I did winterize my coach once for my review and wanted to share a few tips.

Electric Winterizing - As mentioned I use a “Electric Winterizing System” designed for my Explorer. I’ve installed this system in the last 5 coaches I’ve owned with great success. This method uses 120 volt Marine heaters to control temperature in both the interior and outside compartments. The beauty of electric winterizing is your coach is ready to travel at a moments notice. This is important for us since we use the coach for business as well as recreation. This electric heater method works perfect if you live below the center belt. Our last Winter here in North Georgia was brutal with temperatures dropping to 10-20 degrees for months at a time.

Electric Winterizing - Uses compact all metal marine heaters in the water bay as well as in the interior of the coach. As a word of caution, if you’re already using 120 volt heaters in compartments or in the coach, it’s mandatory for safety reason the heaters are Coast Guard approved and offer all “metal construction”. Keep in mind, should the fan motor fail in a plastic heater, there's a good possibility the heater will overheat possibly melting the case causing a fire. Don’t risk your coach based on the heaters manufacture telling you they have protection, they are most likely in China and exempt of liability.





For nearly a Decade - I use only Xtreme marine Heaters brand. They are available in a number of different wattage's, I purchase mine right on Amazon. While the Xtreme Marine and RV heaters are a bit expensive, they are one of the safest. When you consider our coach costs around half a mill, the extra cost for a good heater is cheap insurance. The Xtreme heaters kick on and off automatically, just plug in and forget them. They kick on at around 38-40 degrees and shut off at 55 degrees. Even thought they use a fan to circulate heat, the heating element uses Positive Temperature Coefficient (PTC) technology which adjust the heat automatically regardless of fan operation.

GFI 120 V Receptacles - As noted in the image below, I added a number of GFI receptacles to my Explorer’s water bay, inverter and battery compartments which operate using the lithium system. This offers freeze protection even when the grids down for a period of time.



Aqua Hot Bay Register - While Renegade does provide an Aqua Hot heat register in the water bay compartment, it requires the Aqua Hot system to be up and running to heat the bay. To avoid all these moving parts, pumps and heating, I simply use a single 300 watt Marine heater in the water bay compartment. Also note that Renegade now removes most of the wall between the water bay and holding tanks, so the heater also heats the holding tank compartments as well. To protect the Aqua Hot system itself, I use the 110 volt element heater.



Liquid Winterizing - Also note when winterizing the Explorer using liquid and the intake system provided under the bed, this does not protect the entire water system and therefore will not winterize the water hose on the reel and many of the lines and valves behind the water bay panel. Therefore, be sure to winterize this portion of the system.



To blow out the Lines - I use my Ryobi tire pump set at 40 lbs. Be sure to winterize the lines going to and from the filter as well, since they are not included using the factory winterizing system under the bed. Finally, I also recommend removing one of the 12 volt power leads on the water pump under the bed to avoid the pump starting up in error when using the phone app, running the pump dry.





Temperature Monitors - I also use X-Sense temperature monitor system in the water and battery bays and interior of the coach. The Wi-Fi X-Sense modules mounted in the compartments allows setting low or high thresholds which will even send text messages to your phone should any of the compartments or interior exceeds your set limits. These temperature monitors are available on Amazon for only $38 and comes with three sensors, you can as many as you need.



Appliances - You’ll also need to winterize and cycle your coaches appliances such as the refrigerator, dishwasher and washer. Be advised some washers only use one water source, so the unused water supply line must be opened and flushed to winterize. I remove both hoses and cap the intake manifold for safety since we don’t use the washer or dryer.



Macerator - Finally, if your coach has a macerator it needs winterizing as well. After draining the black & gray tanks, be sure to leave the valves open to prevent freezing. While the tanks have 150 watt heat blankets, they will not protect the external dump valves. Winterize the macerator by removing the flexible macerator intake hose from the dump outlet and drain the macerator and hose.



Ride Safe - Mike

[Idleup]

Explorers best Friend . . . .