Towing question -3.08 axle

ndgregor · April 10, 2019

I have a 2015 Silverado double cab 5.3 3.08 rear end. I don’t tow heavy loads frequently, but need to transport a tractor on an equipment trailer roughly 30 miles each way. I expect the load to be roughly 6900-7000 lbs.

Does anyone have experience with a similar load in this truck configuration? It appears I’ll be slightly exceeding the charted maximum of 6200 lbs. Any thoughts or recommendations?

Jacoby · April 10, 2019

You'll be fine just take it easy

Weight police should be showing up any time

rkj__ · April 10, 2019

Your truck is rated to tow that 6200 lbs up a mountain, into a headwind, on a hot day, at highway speeds. If your towing conditions are less demanding, it stands to reason that your truck likely won't explode. However, you should review the legal / liability implications that are relevant to your insurance policy, and local laws, so you are aware of the risks you are assuming.

Edited April 10, 2019 by rkj__

Donstar · April 10, 2019

You will find this question asked many times on this forum. The responses are varied from one extreme to the other. If you can't decide, or have doubts, rent a 3/4 ton from your local rent-a-truck. It is a small price to pay for peace of mind, imo.

aseibel · April 10, 2019

The only difference between your truck and mine is the axle ratio, yet I can tow 2,000 lbs more.

So you really just need to take it easy when accelerating, allow plenty of stopping distance, let people pass you to not create a jam, etc. Proper positioning of the tractor on the trailer is important to give you enough tongue weight but not drag your bumper on the ground either.

Heck, the tundra can tow the space shuttle at 5 mph. I don't see why you can't pull a tractor.

Edited April 10, 2019 by aseibel

njk4o5 · April 10, 2019

most guys on here are afraid to tow a jetski with their trucks.

just take it easy youll be just fine

LH Lead Foot · April 10, 2019

While the 3.08 final drive is for fuel economy, there other factor to think about for that occasional exercise in towing. First, how is towing rate determine? The brakes determine the majority of the towing rating. Major changes in towing rating requires changes in suspension components by adding simply welded gussets on lower control arms, springs, control arms, etc. Not always but most of the time. The ability to stop a vehicle with a load, within published empty plus 50-80 feet more when loaded depending on the weight and platform.

NMVSS 105 require testing and certification be done by each manufacture for OEM friction, one a voluntary basis. They actually test and provide the government, DOT, EPA all of the information they use to publish, included fuel economy, plus stopping distance.

As an ASE Master Tech, this bothers me when people purchase brake pads or shoes (Used mostly now for park brake only), but certain manufactures uses Greening Labs to test their brake / friction compound for stopping power and 18 other test including wet, noise, dust, fade, etc. You get it.

So what does this mean? When you start shopping for replacement aftermarket brake friction, (other than the dealerships part department) you really need to look for label certification that shows "D3EA". Not all friction material meets this specs, even in a known brand. So cheaper friction material for some, one blend of organic material, copper, brass and ceramic mixture is produced with the idea that "Hey, this stuff is good, so use it on all of our brake pads for the friction choice"

This is true, so using pads that do not have D3EA label does NOT place you vehicle into the FMVSS 105 Specs. So, it may not or will not stop in the same published distance the manufacture publishes. At 60 MPH, the 2012 Silverado / double cab/ 5.3L will stop within 115 feet on average.( I don't know / didn't look it up)

What is D3EA? It is: Dual Dynamometer Differential Effectiveness Analysis. Their is 31 platforms tested and only ACDelco, Napa & Raybestos are currently getting "ONE" friction compound tested and passed. Then it can wear the label. It puts the vehicle back into FMVSS 105 specs.

Now, starting in 2000, new specs are used as FMVSS 135 testing specs are used. A vehicle is placed on a dynamometer under both front & rear axles. An electronic pressure sensor is place in 14 locations (May have changed), but everyone knows that during braking, the weight transfer to the front occurs and 80% of the load goes to the front friction. The contact in square inches for a brake pad is published by some brake suppliers, but also the pressure from the multi-piston caliper determines how well it stops the load. So the differential of rear to front effectiveness is analyzed during the course of several test to reach constant results is recorded. So, buying brake pads just changed if you want your Monster to stop as design, then add some weight as the load, then exceed it with higher towing loads...make sure the calipers slide to float, generally with high temp PTFE grease and the correct friction installed is wearing even, is a visual that will tell you a lot about what to expect. The 3.08 final will give you less mechanical advantage compared to a 4.11 ratio, but if all of the brakes are in good condition, D3EA friction and you do not plan to find steep downhill grades, just remember that lower gears in your 4L60e / 4L80e will lock-up using engine braking to assist the ability to keep the load under control. The addition of trailer brakes, like electric actuated drums (And a few Disc Type), will reduce the overall load experience. Plan on a straight path to avoid jack-knife conditions and the un-used park brake is used by the experience as they can be very tricky...and actually cause jack-knife conditions.

Yes, the manufacture test their vehicles for MPG and not the EPA. It would be impossible for the EPA to check ever model manufactured each year. The manufacture has to be honest and produce documentation for each model to the government.

The manufactures even have to test for hydrocarbon leakage over 24 hours in a sealed room, cleaned with washer solvent removed on new vehicles. The room is evacuated with a slight vacuum and filled with nitrogen mix to meet atmospheric readings for the altitude. Then testing begins. They have a net on the ceiling with heavy balloons filled with nitrogen that expand & contract during the test. Sensitive equipment results are provided to the EPA & DOT. Also, this test is done at low altitude and high altitude. GM has the only high altitude test facility in North America.

Other than the actual cost of labor, materials, hand made wire harnesses, are not all of the cost of doing business. Just make sure your brake system is in peak condition before finding out the hard way.

Best of luck. ASE Master Tech since 1978 / ACDelco MASM / Retired

Edited April 10, 2019 by LH Lead Foot
I hate computer with jumpy touch pads / hello mouse

Gagliano7 · April 16, 2019

If you seen what my buddy towed with a 1989 S-10 2.8 six cylinder back in the day you wouldn't think twice. My buddy would laugh for even asking this question. Take it slow it will be a piece of cake. If you were towing it all the time i would say change those gears but 2 times easy peasy.

Jacoby · April 16, 2019

On ‎4‎/‎10‎/‎2019 at 11:11 AM, njk4o5 said:

most guys on here are afraid to tow a jetski with their trucks.

Yes!!!!!!!

On ‎4‎/‎10‎/‎2019 at 12:22 PM, LH Lead Foot said:

While the 3.08 final drive is for fuel economy, there other factor to think about for that occasional exercise in towing. First, how is towing rate determine? The brakes determine the majority of the towing rating. Major changes in towing rating requires changes in suspension components by adding simply welded gussets on lower control arms, springs, control arms, etc. Not always but most of the time. The ability to stop a vehicle with a load, within published empty plus 50-80 feet more when loaded depending on the weight and platform.

NMVSS 105 require testing and certification be done by each manufacture for OEM friction, one a voluntary basis. They actually test and provide the government, DOT, EPA all of the information they use to publish, included fuel economy, plus stopping distance.

As an ASE Master Tech, this bothers me when people purchase brake pads or shoes (Used mostly now for park brake only), but certain manufactures uses Greening Labs to test their brake / friction compound for stopping power and 18 other test including wet, noise, dust, fade, etc. You get it.

So what does this mean? When you start shopping for replacement aftermarket brake friction, (other than the dealerships part department) you really need to look for label certification that shows "D3EA". Not all friction material meets this specs, even in a known brand. So cheaper friction material for some, one blend of organic material, copper, brass and ceramic mixture is produced with the idea that "Hey, this stuff is good, so use it on all of our brake pads for the friction choice"

This is true, so using pads that do not have D3EA label does NOT place you vehicle into the FMVSS 105 Specs. So, it may not or will not stop in the same published distance the manufacture publishes. At 60 MPH, the 2012 Silverado / double cab/ 5.3L will stop within 115 feet on average.( I don't know / didn't look it up)

What is D3EA? It is: Dual Dynamometer Differential Effectiveness Analysis. Their is 31 platforms tested and only ACDelco, Napa & Raybestos are currently getting "ONE" friction compound tested and passed. Then it can wear the label. It puts the vehicle back into FMVSS 105 specs.

Now, starting in 2000, new specs are used as FMVSS 135 testing specs are used. A vehicle is placed on a dynamometer under both front & rear axles. An electronic pressure sensor is place in 14 locations (May have changed), but everyone knows that during braking, the weight transfer to the front occurs and 80% of the load goes to the front friction. The contact in square inches for a brake pad is published by some brake suppliers, but also the pressure from the multi-piston caliper determines how well it stops the load. So the differential of rear to front effectiveness is analyzed during the course of several test to reach constant results is recorded. So, buying brake pads just changed if you want your Monster to stop as design, then add some weight as the load, then exceed it with higher towing loads...make sure the calipers slide to float, generally with high temp PTFE grease and the correct friction installed is wearing even, is a visual that will tell you a lot about what to expect. The 3.08 final will give you less mechanical advantage compared to a 4.11 ratio, but if all of the brakes are in good condition, D3EA friction and you do not plan to find steep downhill grades, just remember that lower gears in your 4L60e / 4L80e will lock-up using engine braking to assist the ability to keep the load under control. The addition of trailer brakes, like electric actuated drums (And a few Disc Type), will reduce the overall load experience. Plan on a straight path to avoid jack-knife conditions and the un-used park brake is used by the experience as they can be very tricky...and actually cause jack-knife conditions.

Yes, the manufacture test their vehicles for MPG and not the EPA. It would be impossible for the EPA to check ever model manufactured each year. The manufacture has to be honest and produce documentation for each model to the government.

The manufactures even have to test for hydrocarbon leakage over 24 hours in a sealed room, cleaned with washer solvent removed on new vehicles. The room is evacuated with a slight vacuum and filled with nitrogen mix to meet atmospheric readings for the altitude. Then testing begins. They have a net on the ceiling with heavy balloons filled with nitrogen that expand & contract during the test. Sensitive equipment results are provided to the EPA & DOT. Also, this test is done at low altitude and high altitude. GM has the only high altitude test facility in North America.

Other than the actual cost of labor, materials, hand made wire harnesses, are not all of the cost of doing business. Just make sure your brake system is in peak condition before finding out the hard way.

Best of luck. ASE Master Tech since 1978 / ACDelco MASM / Retired

Darmichar · April 16, 2019

My boat, fully equipped and fueled weighs around #7,000. I pulled it with my 2014 5.3L 3.08 400+ miles running 75MPH through the hills of Kentucky with no issues whatsoever.

Darmichar · April 16, 2019

On 4/10/2019 at 12:22 PM, LH Lead Foot said:

While the 3.08 final drive is for fuel economy, there other factor to think about for that occasional exercise in towing. blah... blah... blah...

Other than the actual cost of labor, materials, hand made wire harnesses, are not all of the cost of doing business. Just make sure your brake system is in peak condition before finding out the hard way.

Best of luck. ASE Master Tech since 1978 / ACDelco MASM / Retired

So, is that long winded missive a yes or a no?

LH Lead Foot · April 16, 2019

The brakes ability to stop a given load is the main factory in how much you can tow. Now, in the aftermarket and your garage, do what you want...or do nothing.

I am just saying that not all brake pads are created equal. Does that statement not deserve an explanation? Tow what you want. Stop if you can.

Too much info? Can't read it on your $900 phone...Well I don't own a cell phone.

If I am guilty of defaulting to instructor mode, sorry. I will cancel and leave this forum. Some do not want to learn, while others don't want to know. Which one are you?

( My current medical condition does not allow me the chance to talk to gear heads or a younger tech / garage guy to pass on knowledge. Being disabled in severe chronic pain (SUCKS) in 7 joints and after todays procedure, I am now headed for #8, while driving only 14 miles a month to doctor(s), from now on, I will keep it to myself.)

I have properly diagnosed and repaired almost every type of vehicle made, at shops to dealerships from Alpha-Beta Type"B" Roadster, Mercedes, Delorean, Datsun Z, Isuzu, GMs' since 1967 +/- I have learn things and developed skill most will never have, then forget it)

Have you worked on electronic fuel injection in 76 when there was only two on the market? I am not talking about "CIS" systems either. Do you know how to use a 4-gas analyzer to find defective purge valves? Do you know that GM has used 5 types of serial data? Unsubscribed!

I am not sure what some of the post above are saying. Blah, blah or long winded missive means what? Who cares.

Jacoby · April 16, 2019

1 hour ago, LH Lead Foot said:

The brakes ability to stop a given load is the main factory in how much you can tow. Now, in the aftermarket and your garage, do what you want...or do nothing.

I am just saying that not all brake pads are created equal. Does that statement not deserve an explanation? Tow what you want. Stop if you can.

Too much info? Can't read it on your $900 phone...Well I don't own a cell phone.

If I am guilty of defaulting to instructor mode, sorry. I will cancel and leave this forum. Some do not want to learn, while others don't want to know. Which one are you?

( My current medical condition does not allow me the chance to talk to gear heads or a younger tech / garage guy to pass on knowledge. Being disabled in severe chronic pain (SUCKS) in 7 joints and after todays procedure, I am now headed for #8, while driving only 14 miles a month to doctor(s), from now on, I will keep it to myself.)

I have properly diagnosed and repaired almost every type of vehicle made, at shops to dealerships from Alpha-Beta Type"B" Roadster, Mercedes, Delorean, Datsun Z, Isuzu, GMs' since 1967 +/- I have learn things and developed skill most will never have, then forget it)

Have you worked on electronic fuel injection in 76 when there was only two on the market? I am not talking about "CIS" systems either. Do you know how to use a 4-gas analyzer to find defective purge valves? Do you know that GM has used 5 types of serial data? Unsubscribed!

I am not sure what some of the post above are saying. Blah, blah or long winded missive means what? Who cares.

LH Lead Foot · April 16, 2019

(: (: (:

L86 All Terrain · April 16, 2019

Piece of cake. I have a 99 Dually that routinely carries nearly double its GVWR worth of sand on her back on the regular with no issues, (not on public roads of course ). But for reference, your not going to snap a leaf spring, blow a rear end, or snap wheel studs off towing 7,000lbs, which is about the weight I carry in the dump box of my ol' dually. Just make sure the tractor is loaded properly. I would assume your using a tandem equipment trailer with at least 5,000# axles. Make sure you know the heavy end of the tractor depending on your attachments and balance it over the trailer axles accordingly with a slight front bias for tongue weight. The less weight you have on the tongue, the easier it will pull. You want about 10% tongue weight, any more and it will feel like you added 1,000# to the load, any less and it will buck and you risk losing it. If you get it loaded just right, I think you will be surprised in how well your truck will pull that tractor. Everyone here thinks "Oh, I can't accelerate over this mountain pass in overdrive, I better get a Duramax." Take a ride in a heavy haul truck, see how many downshifts they make on a mountain pass...