Chevrolet Suburban 3500 Questions

[Doubeleive]

Marky, you seem to be asking the questions right before I get to them! I was looking online last night for new hitch units and there are none online that are made for the 3500 Suburban. I will have to upgrade it, but may need to go to the local trailer dealer and have them take a crack at it. I have been analyzing DuraburbInc’s YouTube video showing a frame tear down. I cannot tell if this is an upgraded previous gen 2500 suburban chassis or if it’s the shared chassis from the Silverado 3500.

you might try reaching out to draw-tite they only list one for a 3500 silverado but I bet they have taken measurements for a 3500 suv I used to know a guy that worked for them and his only job was to go around and measure every new vehicle so they could design a hitch

 

[Bigburb3500]

I've spent a decent amount of time in the past analyzing what the true towing capability would be for my 2010 GMC Yukon XL 2500. I went component by component trying to see what the differences were between what was in the Yukon vs what is in the 2500/3500 GM trucks of similar vintage - and comparing the rated tow capabilities out of the GM brochures.

I think you could take a similar approach to your 2018 3500.

For instance, somewhere on Youtube is video by the guy at Duraburb about the frame used under the 3500 Suburban. He basically says: it's the same exact frame that is under the 2007-2013 2500 Yukon XL/Suburbans and the earlier generation 2500 Yukon XL/Suburbans.

The 2000-2006 2500 Suburbans had the 8.1L big block engine option - and with the right gear ratio - that truck was rated to tow 12,000 pounds. So the way I look at it is: that frame is rated to tow 12,000 pounds (at least). - with the right hitch on it.

Now look at the brakes - you can figure this out by going part number by part number and seeing what brakes are on the 2500/3500 trucks vs what is on the 3500 Suburban. I would be willing to bet that there is no difference there - so your truck's brakes are going to be good for whatever tow rating that the comparable year 2500/3500 pickups are good for.

I think the 2500/3500 gas pickups have the 6.0L engine. So look at the tow ratings in the GM brochures are for that engine - in combination with the gear ratio. If you look at the brochures they'll give the tow ratings by engine/gear ratio - and body style. The heavier body styles - have a slightly lower tow rating. Compare those weights against whatever the listed weight is of your 3500 Suburban - and you can probably get a pretty good estimate of what a "factory" tow rating would be for your truck if it wasn't designed to be up-armored.

I would also bear in mind that - you can enhance the tow rating by upgrading components. For instance: I installed a set of the Wilwood huge brakes on my truck because at one point I was commuting with it in rush hour traffic and almost rear ended people a few times.

If I had to take a wild guess - I can't see the towing capability of your truck being any less than the previous generation 2500 Yukon XL/Suburbans - which is like 9700 pounds.

Calsdad,
I have rewatched Duraburb’s video several times and maybe I need to watch it a few more. I am going through exactly what you recommend by checking parts and comparing them to the HD pickups. I need to more closely analyze the frame section because I felt he glossed over the differences. I forget what part he was commenting on and then he said “And that’s how they get the 1ton rating.” I know ratings are based on a number of different factors but I did think the frames from 2500 to 3500 would also be different based on metal thickness.
You make a great point about using a 2500 previous-gen as a base line and going from there. The brakes on this 3500 are right off a 3500HD and same with cooling for trans and oil. The rear leafs are also 3500 not 2500 so I think we are probably past the 10k mark? How far past would be a crap-shoot. Looking at a comparable 3500 it looks like the GVWR is about 10500-10700 and the sticker on my Burb is 11k.

Your methodology is great! Thank you for the input. Do you tow with yours much and have anything you would change/recommend?

Cheers.

 

[Bigburb3500]

you might try reaching out to draw-tite they only list one for a 3500 silverado but I bet they have taken measurements for a 3500 suv I used to know a guy that worked for them and his only job was to go around and measure every new vehicle so they could design a hitch

I am going to reach out to them or there is a local hitch/trailer shop that I might talk to them and see what options they provide.

I’m no custom metal fabricator, so if one of these two places can point me towards a product that works I can run a few bolts.

Really appreciate the responses.

 

[calsdad]

Calsdad,
I have rewatched Duraburb’s video several times and maybe I need to watch it a few more. I am going through exactly what you recommend by checking parts and comparing them to the HD pickups. I need to more closely analyze the frame section because I felt he glossed over the differences. I forget what part he was commenting on and then he said “And that’s how they get the 1ton rating.” I know ratings are based on a number of different factors but I did think the frames from 2500 to 3500 would also be different based on metal thickness.
You make a great point about using a 2500 previous-gen as a base line and going from there. The brakes on this 3500 are right off a 3500HD and same with cooling for trans and oil. The rear leafs are also 3500 not 2500 so I think we are probably past the 10k mark? How far past would be a crap-shoot. Looking at a comparable 3500 it looks like the GVWR is about 10500-10700 and the sticker on my Burb is 11k.

Your methodology is great! Thank you for the input. Do you tow with yours much and have anything you would change/recommend?

Cheers.

I don't think there is any difference between the frames in the 2500 and 3500 pickups. You could probably figure that out by checking some of the online GM parts sites - if I remember correctly they have the entire frame listed in there somewhere. It's been a few years since I did it, but my belief is that the difference between the 2500 and 3500 trucks pretty much came down to the rear springs. I don't recall there being any other differences that I could find when I looked at all the part numbers.

I'd have go back and find that Duraburb video again - but the 2500 series SUVs ended when the GMT900's ended in 2013. By then - the pickups had already converted over to the "metric" wheel lug bolt pattern. But the SUVs stayed with the "old" pattern. I think the 3500 SUV like what you have - uses the new metric bolt pattern and may use the new pattern front suspension from the equal-year HD trucks. I don't recall there being any big differences that Duraburb pointed out on the frames other than that.

One thing to bear in mind is - the 3500 SUV was a short run vehicle - GM would not have spent much $$ trying to develop a new frame or anything else for it - they part-binned it as much as possible.

 

[Thrust]

https://gmauthority.com/blog/2017/07/chevy-suburban-3500hd-heavy-duty-vs-chevrolet-suburban/

 

[Bigburb3500]

https://gmauthority.com/blog/2017/07/chevy-suburban-3500hd-heavy-duty-vs-chevrolet-suburban/

Thank your Thrust for the link! The 6585 curb weight makes a good bit of sense and I think lines up with its 1ton underpinning. Still funny how this blog says it comes with all the heavy duty tow adds but that hurts its towing capacity
Do we think anyone writes an article like this and says to themself, “ Yes, I’m making sense today.”

 

[15burban]

Just a guess, but since they didn't make very many of them and only sold them new to fleet customers for "upfitting." Gm probably didn't bother going through the j2807 towing tests to determine an actual gcwr for them. They probably just used the regular (1500) suburban gcwr hence the high payload but really low towing capacity.

 

[mikeyss]

I remember the older GMT900 2500 suburbans had a mechanical cooling fan, but I remember seeing a picture of the 3500 Suburban using electric cooling fans. Is this true, or was it a picture showing a normal Suburban?
Also, do the 3500 have beefier torsion bars? I *think* some have the 9.5" 14 bolt rear ring and pinion, and some have the 10.5 14 bolt.

 

[Doubeleive]

Thank your Thrust for the link! The 6585 curb weight makes a good bit of sense and I think lines up with its 1ton underpinning. Still funny how this blog says it comes with all the heavy duty tow adds but that hurts its towing capacity
Do we think anyone writes an article like this and says to themself, “ Yes, I’m making sense today.”

i put that thing on a cat scale and see what it weighs

 

[calsdad]

Just a guess, but since they didn't make very many of them and only sold them new to fleet customers for "upfitting." Gm probably didn't bother going through the j2807 towing tests to determine an actual gcwr for them. They probably just used the regular (1500) suburban gcwr hence the high payload but really low towing capacity.

That actually makes sense - because the tow rating they give for the truck doesn't really add up based on the components they used to put that truck together. For instance, I have the GM brochure for the 2015 HD trucks saved on my computer - and the GCWR (combined weight rating) for a crew cab pickup with the Vortec 6.0L V8 gas , with a 4.10 gear ratio - is: 20,500 pounds. That 3500 Suburban has the same drivetrain and has the 4.10 gear ratio if I remember correctly - so it should have a similar GCWR. Only having a 3500 or whatever it is pound tow rating just makes no sense at all.

I'd have to go back and start digging thru the GM brochures to find it , but GM at one point was selling the HD trucks with either the 3.73 or 4.10 gear ratios available - and 4.10 trucks had a sizeable increase in tow capacity rating over the 3.73.