BELT BLOWN AT 9K Miles-URGENT READ

[Ready Go]

Please allow me to geek out a bit: A typical alternator is a purely electric generator which receives mechanical torque from the engine through the serpentine belt and replenishes the 12V battery. The mechanical heart of the e-torque setup is a glorified "alternator" which is a single device that allows bidirectional energy flow; Feed it current (from the 48V battery) and it will produce motion, or forcefully rotate it (by the engine) and it will produce current. An old and basic electrodynamic technology, really.

During a restart, the 48V battery feeds current to the "alternator", which produces torque, which gets sent through the serpentine belt, which rotates the crank shaft and starts the engine. Hence my allusion to push-starting.

Here is an illuminating quote from How RAM eTorque Works | Green Car Journal

"Alternators only draw modest power from an engine’s accessory drive. However, eTorque’s motor-generators use their accessory drive belt to slow and accelerate these trucks, so the belt must be larger and stronger, and also must wrap farther around the pulley. It also requires a tensioner on both sides to keep belts tight as the motor/generator transitions from generating to motoring. The eTorque Hemi gets a larger crankshaft pully as well that improves the motor/generator’s leverage."

Edit: Regarding whether there's a traditional starter or not; here is a quote from a Zeigler article:

"Because of its greater efficiency in extreme temperatures, both the V6 engine and V8 engine with Ram eTorque technology will keep a traditional 12-volt starter motor, which is ideal for cold starts and the initial start of the day."

EXCELLENT information, THANKS!

 

[SpeedyV]

Please allow me to geek out a bit: A typical alternator is a purely electric generator which receives mechanical torque from the engine through the serpentine belt and replenishes the 12V battery. The mechanical heart of the e-torque setup is a glorified "alternator" which is a single device that allows bidirectional energy flow; Feed it current (from the 48V battery) and it will produce motion, or forcefully rotate it (by the engine) and it will produce current. An old and basic electrodynamic technology, really.

During a restart, the 48V battery feeds current to the "alternator", which produces torque, which gets sent through the serpentine belt, which rotates the crank shaft and starts the engine. Hence my allusion to push-starting.

Here is an illuminating quote from How RAM eTorque Works | Green Car Journal

"Alternators only draw modest power from an engine’s accessory drive. However, eTorque’s motor-generators use their accessory drive belt to slow and accelerate these trucks, so the belt must be larger and stronger, and also must wrap farther around the pulley. It also requires a tensioner on both sides to keep belts tight as the motor/generator transitions from generating to motoring. The eTorque Hemi gets a larger crankshaft pully as well that improves the motor/generator’s leverage."

Edit: Regarding whether there's a traditional starter or not; here is a quote from a Zeigler article:

"Because of its greater efficiency in extreme temperatures, both the V6 engine and V8 engine with Ram eTorque technology will keep a traditional 12-volt starter motor, which is ideal for cold starts and the initial start of the day."

Yeah, it absolutely keeps the traditional starter. The BSG/MGU is only capable of a “hot” restart, and only when the eTorque battery is at a sufficient state of charge.

In that sense, eTorque might seem a little redundant. But man, it’s a smooth stop/start setup. And when you think of all the little things it does in place of an alternator, it’s a smart concept.

 

[Ready Go]

Yeah, it absolutely keeps the traditional starter. The BSG/MGU is only capable of a “hot” restart, and only when the eTorque battery is at a sufficient state of charge.

In that sense, eTorque might seem a little redundant. But man, it’s a smooth stop/start setup. And when you think of all the little things it does in place of an alternator, it’s a smart concept.

Also EXCELLENT info, THANKS!

 

[barrak]

Yeah, it absolutely keeps the traditional starter. The BSG/MGU is only capable of a “hot” restart, and only when the eTorque battery is at a sufficient state of charge.

In that sense, eTorque might seem a little redundant. But man, it’s a smooth stop/start setup. And when you think of all the little things it does in place of an alternator, it’s a smart concept.

It is buttery smooth. I'm just hoping that the recent PCM firmware update (Official Recall) and the Tazer DT's latest firmware will allow PIN LOCK and Start/Stop to play nice together. They didn't in the past on my '23 Longhorn. Have to wait till my faulty clockspring gets replaced to find out.

I did notice a slight delay speed-wise in onset of auto-Stop (as I slow down to a stop), down from about 5 MPH to around 3-4 MPH, after the PCM got re-flashed last week. Might do the trick.

 

[Ready Go]

Yesterday, I picked up the Mopar stretchy belt and the Gates Green drive belt from Rock Auto for under $45 and also the Lisle stretchy belt tool from Amazon for under $20.
I definitely don't mind spending $65 to have these in my Rambox in case of an emergency.

 

[Mountain Whiskey]

Posting as a public service announcement and to see if anyone else has experienced the following.

SITUATION:
2021 Ram 1500 Laramie 5.7L Hemi WITH E-torque
Current mileage 9,946
Bought brand spanking new.

On July 15, towing a 6k camper trailer, in tow/haul, adaptive cruise control.
60mph, Sierra Nevadas outside Reno headed towards CA.

Hooked up the trailer, got on the freeway, literally, from this exit to the very next exit, the truck shredded the main accessory belt.

No cause noted. Sounded like plastic bag in the fan, truck kept towing, no CEL no lights.

Pulled of the next exit, belt had shred from the front of the belt towards the back of the belt. Belt fiber EVERYWHERE.

All pulleys working, nothing seized, no road debris as the cause either.

Here’s the kicker. Not a single auto parts store (Napa, AZ, Oreily *could not cross reference and did not stock) and not a single Ram dealership with in a 4.5 hour drive stocks/Stocked a single Accessory belt for the 5.7 Hemi WITH E-Torque.

So, if you plan to tow. Bring a breaker bar, and order a belt ahead of time. Part # 5281514aa

Truck is currently at the dealership (was able to limp it home with 1/4 of a belt left after having friend pick up the trailer). By the time we got into town, the E-Torq/Alternator had stopped charging or running electronics.

Dealership is “booked out” for the next 8 days. And advised it would take 5-7 business days to ship the belt to them.

Part # from several Ram Parts Depts 5281514aa.
Mopar.com shows a belt diagram with the listed part number, in the correct configuration, but states that this part number will not fit an ETorq 5.7 Hemi.

So, not even Mopar is sure what belt fits what.
Tried to verify if the belt from a standard 5.7 would work, no dealership I called while broke down could verify.

Thoughts: maybe the ETorq seized momentarily caused the belt to shred but continued working.

Will keep thread updated.

Seems like an important fact here is that he didn’t shred the belt until he hooked up the trailer. The added force needed to get the truck moving probably caused the etorque belt to slip and start chewing itself up. I hope that’s just a fluke but it hardly ever is with these mass produced vehicles.

So since this thread keeps coming back to life, can someone explain what towing something has to do with the serpentine belt? I mean hook it to a monster truck sled if you want it's not like the alternator is putting the power to the wheels.

 

[Ready Go]

So since this thread keeps coming back to life, can someone explain what towing something has to do with the serpentine belt? I mean hook it to a monster truck sled if you want it's not like the alternator is putting the power to the wheels.

On the eTorque 5.7L, it quite literally does put the power to the wheels..by powering/turning the crank pulley which eventually turns the wheels..it's round a bout, but that's one of the generators jobs.
Read an article on the eTorque..it's good reading..brilliant design work.

 

[Mountain Whiskey]

On the eTorque 5.7L, it quite literally does put the power to the wheels..by powering/turning the crank pulley which eventually turns the wheels..it's round a bout, but that's one of the generators jobs.
Read an article on the eTorque..it's good reading..brilliant design work.

I did not realize that. I don't deal with these issues not having it. Even with it applying force through the belt, it does not seem like it would vary depending on weight. If you mash on the throttle from a stop with a 5000 pound truck, does the etorque know it is only 2.5 tons and apply only half power as opposed to truck and trailer to apply full power? Doesn't it only kick in for that first half tire rotation?

 

[Ready Go]

I did not realize that. I don't deal with these issues not having it. Even with it applying force through the belt, it does not seem like it would vary depending on weight. If you mash on the throttle from a stop with a 5000 pound truck, does the etorque know it is only 2.5 tons and apply only half power as opposed to truck and trailer to apply full power? Doesn't it only kick in for that first half tire rotation?

I'll see if I can find and link the YouTube video that has a RAM Engineer explaining eTorque..it's enlightening.

 

[barrak]

I did not realize that. I don't deal with these issues not having it. Even with it applying force through the belt, it does not seem like it would vary depending on weight. If you mash on the throttle from a stop with a 5000 pound truck, does the etorque know it is only 2.5 tons and apply only half power as opposed to truck and trailer to apply full power? Doesn't it only kick in for that first half tire rotation?

Aha... eRoll Assist might be the culprit here, when it tasks the poor belt with the first half tire rotation, oblivious to the extra 3-5-ton trailer load.

It's like absentmindedly grabbing your backpack not knowing your boy had put a 16Kg kettlebell in it. True story... he was doing loaded pullups!!!!

 

[theblet]

Yup. First half of the wheel rotation, pretty much before you even have your foot on the throttle. It’s supposed to help with fuel mileage too

 

[Mountain Whiskey]

Aha... eRoll Assist might be the culprit here, when it tasks the poor belt with the first half tire rotation, oblivious to the extra 3-5-ton trailer load.

It's like absentmindedly grabbing your backpack not knowing your boy had put a 16Kg kettlebell in it. True story... he was doing loaded pullups!!!!

I get that. But if the kid can only put 8 pounds of force to his lift, it would not matter if the pack was 8 pounds or 100 pounds, his force would only be 8 pounds.

Much like this belt, it is 16hp for the first half tun of the wheel. I would think that whopping 16hp is the same for a 5000 pound truck or a 5000 pound truck trying to pull a locomotive. It's the same strain on the belt, 16hp.

 

[barrak]

I get that. But if the kid can only put 8 pounds of force to his lift, it would not matter if the pack was 8 pounds or 100 pounds, his force would only be 8 pounds.

Much like this belt, it is 16hp for the first half tun of the wheel. I would think that whopping 16hp is the same for a 5000 pound truck or a 5000 pound truck trying to pull a locomotive. It's the same strain on the belt, 16hp.

This analogy is probably sound if the MGU is maxed out when launching an unladen truck. Otherwise...

Force = Mass * Acceleration. If the MGU can provide the same acceleration during the first half tire rotation for a 5,000lb truck as for a 10,000lb truck+trailer, then it would subject the belt to twice the force when the trailer is attached.

A very crude calculation, I admit. I'm sure there are mechanical engineers lurking around who would put me to shame.

 

[Mountain Whiskey]

This analogy is probably sound if the MGU is maxed out when launching an unladen truck. Otherwise...

Force = Mass * Acceleration. If the MGU can provide the same acceleration during the first half tire rotation for a 5,000lb truck as for a 10,000lb truck+trailer, then it would subject the belt to twice the force when the trailer is attached.

A very crude calculation, I admit. I'm sure there are mechanical engineers lurking around who would put me to shame.

But if maxed out at 16hp, it can go no higher no matter what weight it is pulling against. The belt should take the max output.

I mean I can make math say anything we want too, no need to bring engineers in to correct thier methodology.

 

[killerformula]

But if maxed out at 16hp, it can go no higher no matter what weight it is pulling against. The belt should take the max output.

I mean I can make math say anything we want too, no need to bring engineers in to correct thier methodology.

I think the belt should be able to take the output of the etorque motor and apply it to the snout too. But if it’s shredding then that’s clearly not happening. If there is an issue with the amount of tension or slip on the belt, you might be more likely to see it when there’s a load on the truck.

In order to move the truck, the crank has to turn. If the truck weighed 1 pound, the coefficient of friction needed on the belt to turn the snout and move the truck will be very low. If the truck weighed 20,000 pounds, the amount of friction you need to maintain on the pulley is much higher in order to move the truck. I agree the etorque motor doesn’t care, it will send its max output probably in either situation. But as the truck weight increases, you need to have a better grab on that pulley to turn it. If you don’t, the belt slips and it shreds.

That’s one theory as to why this is happening. Nobody else has found an alignment issue, and I don’t see why a belt alignment issue would manifest more often under load.

 

[barrak]

What puzzles me is the Manual-suggested 150,000 miles Replace intervals for this belt, with no heavy use qualifications. In contrast, it suggests just Inspecting the transfer case fluid every 150,000 miles, or if towing frequently, Replace every 60,000 miles.

Seems like an extremely ambitious lifespan for any serpentine belt, let alone one pulling six different MGU duties (not to mention the frequent towing factor). Personally, I would toss this recommendation in the same trash bin I tossed the lifetime transmission fluid bilge.

Question is, when should this cautious old dude sensibly and proactively replace that mighty belt, even if it passes visual inspection?

 

[Mountain Whiskey]

I think the belt should be able to take the output of the etorque motor and apply it to the snout too. But if it’s shredding then that’s clearly not happening. If there is an issue with the amount of tension or slip on the belt, you might be more likely to see it when there’s a load on the truck.

In order to move the truck, the crank has to turn. If the truck weighed 1 pound, the coefficient of friction needed on the belt to turn the snout and move the truck will be very low. If the truck weighed 20,000 pounds, the amount of friction you need to maintain on the pulley is much higher in order to move the truck. I agree the etorque motor doesn’t care, it will send its max output probably in either situation. But as the truck weight increases, you need to have a better grab on that pulley to turn it. If you don’t, the belt slips and it shreds.

That’s one theory as to why this is happening. Nobody else has found an alignment issue, and I don’t see why a belt alignment issue would manifest more often under load.

Once again, it's not more friction on anything. The little electric motor does not make the pulley tighter. It puts out 16hp. It turns or it does not is irrelevant. It just does not turn if the force on it is greater than its power.

More than likely a cheap POS belt used on a system that would benefit more from a decent tune on the 5.7 gas motor than adding a little electric one to it.

 

[theblet]

Once again, it's not more friction on anything. The little electric motor does not make the pulley tighter. It puts out 16hp. It turns or it does not is irrelevant. It just does not turn if the force on it is greater than its power.

More than likely a cheap POS belt used on a system that would benefit more from a decent tune on the 5.7 gas motor than adding a little electric one to it.

Someone said the ET motor puts our 100+ hp during that first 1/2 rotation. 16 sounds more believable tho

 

[Idahoktm]

Someone said the ET motor puts our 100+ hp during that first 1/2 rotation. 16 sounds more believable tho

Maybe you're remembering the torque figure. eTorque can add up to 130 lb-ft of torque.

 

[barrak]

Maybe you're remembering the torque figure. eTorque can add up to 130 lb-ft of torque.

To put this figure in perspective, the 2.0-liter in the latest Subaru Crosstrek maxes out at 145 lb-ft.