Heavy Equipment Forums Heavy Equipment Community

5.2k vs 6k axle

Joe Mahlik · 2023-05-08 19:46

I usually hang out in the skid steer section but now I have a question regarding the trailer I recently purchased to haul my 1835c skid steer. I've read many threads on many different forums on the differences between 5.2k and 6k axels and I have yet to come across a clear concise answer so I'm hoping someone here can clarify for me. I've recently purchased a 1997 Holt Trailers 18ft car hauler. This trailer has 12" 6 lug hubs, with 15in wheels, two 6k axles(per the tags on the axles) and brakes on all 4 wheels. Axels have #42 spindles which when I search the web it's says #42 spindles and are used on 5.2k to 7k axles, along with the size wheel bearings I have. The trailer has 6" C channel for main frame and toungue. Crossmembers are 3" C channel on 16" centers. Springs are 2" 5 leaf springs 25" center to center of eyes which I see is a common size on 5.2 to 7k axels. All that said... the trailer had no data tag so I contacted Holt Trailer and gave them the vin and they confirmed that my trailer left manufacturing with 5.2k axels. My question...what kept Holt from rating this as a 12k trailer. Between the 6k axels and all the axle hardware/components being compatible with 5.2 to 7k axels, can I use this trailer as a 12k trailer? The construction of the trailer also mirrors that of most 14k trailers I see, less the 6 lug hubs. Is there a very good reason Holt didn't rate this trailer for 12k? Am I missing something? The axels are original BTW as the dates on the axel tags very closely match the manufacture date of the trailer. Any insight is much appreciated. Thanks.

Replies33
  1. #1cfherrman2023-05-08 19:54

    Idk but did you compare the hub diameter and brake size?

  2. #2Joe Mahlik2023-05-08 20:09

    Hub diameter is 12" common to 5.2k-7k axels. Brakes size also are common between 5.2-7k axels.

  3. #3OzDozer2023-05-08 20:30

    I'd have to say your local DOT is the final authority on what you can haul on that trailer. In my neck of the woods, if you want to upgrade a trailers hauling ability, you need to present engineering documentation to the DOT, and have it inspected and uprated in hauling capacity by a competent inspector. Get all your paperwork in order for the registration, because you sure don't want to find out after an accident that your insurance was void, because what you were carrying, and what you were registered to carry, were vastly different.

  4. #4Joe Mahlik2023-05-09 14:40

    Good point on the legal side of it. I'm mainly trying to get down to the physical/mechanical differences, if any, between a trailer rated at 12k and 10.4k when they both have axels rated at 6k. The purpose of figuring this out is that I would like to start hauling an 8000lb skid steer. This would be borderline overloading a trailer rated at 10.4k but a 12k trailer would be perfect. Legalities aside, I don't want to create an unsafe condition for me, or other people.

  5. #5gwhammy2023-05-11 19:44

    Take two trailers rated the same from different companies and one will be crap and the other way overbuilt. I like a heavy trailer for skid steers the weight is so concentrated basically on the rear set of tires.

  6. #6PeterG2023-05-12 17:58

    Over 10,000 GVW you need a class A CDL commercial license. I have an old hertz equipment rental trailer built by Best Trailers. It has 7000 lb axles and is basically a 14 GVW trailer. However, the vin plate list it as 9,900 lbs and its surge brakes. That way anyone could rent it and tow it, and if it was overloaded, it was likely safe. Not that many 12 gvw trailers. Yours might have been a 10,000 gvw trailer, overbuilt a bit. The trailer may have an empty weight of 2,500 so legally you can tow 7,500 lbs or so, if your tow vehicle can tow that much. I would assume it's not more than a 12 GVW trailer. What is the weight each tire can hold as stamped on the tire?

  7. #7Joe Mahlik2023-05-12 19:34

    3000lb rated tires

  8. #8cfherrman2023-05-12 19:36

    Not true, if you are under 26k you do not need and CDL at all. Basically 3/4 ton pickup and you can pull anything.

  9. #9_Weldman_2023-05-13 08:59

    Unless the 3/4 ton pickup and the trailer combined GVWR exceed 26,001 lbs

  10. #10cfherrman2023-05-13 09:09

    Only if you get pulled over

  11. #11Steve Frazier2023-05-13 09:10

    I agree with OzDozer, your DOT will be the agency you have to satisfy. Manufacturers rate their trailers in different manners, some list the total weight that can be on the trailer while some take into account the tongue weight as part of the total capacity. It can get confusing.

  12. #12PeterG2023-05-13 13:53

    From the FMSCA web site. Of course there is the argument of not having a DOT number and not really driving for Commercially purposes despite insurance companies requiring you to have commercial insurance such as for a vehicle over a certain GVW weight. Not much may apply to a Farmer. I'm not familiar with Class A motorhomes etc.. Classes of License and Commercial Learner's Permits (CLP)​ Pursuant to Federal standards, States issue CDLs and CLPs to drivers according to the following license classifications: Class A*: Any combination of vehicles which has a gross combination weight rating or gross combination weight of 11,794 kilograms or more (26,001 pounds or more) whichever is greater, inclusive of a towed unit(s) with a gross vehicle weight rating or gross vehicle weight of more than 4,536 kilograms (10,000 pounds) whichever is greater. Class B*: Any single vehicle which has a gross vehicle weight rating or gross vehicle weight of 11,794 or more kilograms (26,001 pounds or more), or any such vehicle towing a vehicle with a gross vehicle weight rating or gross vehicle weight that does not exceed 4,536 kilograms (10,000 pounds).

  13. #13Tyler d4c2023-05-13 14:11

    This is state dependent on the class A bit in pa you can pull a trailer over 10000 with a regular license as long as your combo weight is under 26000 but the truck needs a combination tag to pull a trailer over 9999 But reading the bit you post off the feds makes it conflicting I got a A it makes no difference to me personally

  14. #14cfherrman2023-05-13 19:04

    100% So a 3/4 ton pickup can pull anything

  15. #15gwhammy2023-05-14 07:59

    It's the combination of gvw of the truck and trailer. Say your f250 is rated at 10,000 gvw. You can pull a trailer rated at 16,000 but not one at 18,000 without a commercial license. Unless you are a farmer then you can pull a barn down the road sideways and they will let it slide in Mo.

  16. #16cfherrman2023-05-14 08:44

    Only if you get pulled over. Farmers are exempt from everything

  17. #17Drag racer2023-05-14 11:15

    Yea even good weather to grow our food.

  18. #18cfherrman2023-05-14 20:04

    When it rains, it rains too much, same with snow

  19. #19Tyler d4c2023-05-14 21:16

    I just buy my food at the store just cut the farmer out of the deal. It's a joke ok don't go getting all worked up

  20. #20cfherrman2023-05-14 22:20

    Problem is people don't know that's a joke

  21. #21Entropy12023-05-16 21:32

    The Washington State Highway Patrol have portable scales they haul around in their SUV patrol cars. They look like boards of wood. They can weigh you right on the side of the road - multiple axle vehicles, no problem. The troopers know the various tractor sizes and what they weigh. When they see a 12,000 lb Kubota being pulled by a 1-ton truck, they're getting pulled over and asked for their CDL. If no CDL, they're getting weighed. And when caught pulling a trailered load exceeding 10,000 pounds without a CDL, the ticket is 5 grand. The GVRW rating of the vehicle is completely irrelevant. It doesn't matter if your 1-ton diesel dodge is rated to pull 26,000, and your trailer is rated to pull 14,000. It doesn't matter how much your trailer is titled and/or registered to tow. It doesn't matter if you've got trailer surge brakes, electric brakes, air brakes, etc. You MUST have a Class-A CDL if you're pulling one pound over 10,000 lbs on a public roadway. Naturally one might challenge said $5,000 dollar ticket in court. In Kitsap & Mason County the judge will typically agree to cut the ticket in half (pay only $2,500) if the person also obtains his/her CDL. Last time I checked the cost to obtain a non-hazmat CDL in Washington State was $4,600 (school classroom & driving fees). The hazmat endorsement was a few hundred dollars extra. Again, the WA State Patrol is all over this issue. On any given day about half the people attending CDL school in western Washington are doing so because they're fighting a $5,000 dollar ticket (for pulling over 10k with no CDL). Troopers will also stop and weigh 10 yard dump trucks whenever they can see the load from their car (aka the mound of crushed basalt rock visible from the SUV's driver's seat is a pretty good indication the 10 yard dump is overloaded). The troopers in possession of these mobile scales like to hang out around the rural highways - where there's no weigh stations between the quarries & the customers. And lots of non-CDL drivers hauling tractors, loaders, mini-excavators (over 10-k) with their 3/4 & 1-ton trucks.

  22. #22cfherrman2023-05-16 23:31

    If total gvwr is under 26k you can pull over 10k trailers, all day every day. This is why I say a 3/4 ton truck because 10k gvwr + 14 gvwr = 24 k, legal with no CDL. I would never do this with a truck gvwr 10001+ however for reasons I can't quite remember perfectly. There are some combined gvwr ratings I'm sure you could get in trouble with but irc they are high enough with a 3/4 diesel pickup. I have a class b CDL and pull trailers all the time and have had dot compliance training a couple of times.

  23. #23Entropy12023-05-18 23:21

    So I just went back and reread the federal law for Class A CDL. It does say trailer over 10k "and" truck over 26 GVRW - implying that it's ok (legal) to pull a 20,000 pound trailer-load with a 5500 pound pickup. The problem is that I personally know a guy who was ticketed in Kitsap County for doing just that. Just for **** chat - a few years back I purchased a tilt-bed trailer that had a manufacturer's GVRW of 24,000 lbs. The trailer itself weighed about 4500 pounds. I originally had the same idea - in that if the weight of my trailer with load, plus the weight of my truck, remained under 26,000 lbs, then I'm golden. Problem - Washington State mandated that I register the trailer as commercial. The State issued me zero-cost permanent plates for my trailer (no annual tab fees). The trailer's registration paperwork stated in bold text that I must pull the trailer using a commercial vehicle which has an adequate GVRW registration to cover the combined weight of the commercial vehicle + trailer & load. I tried to obtain normal registration/plates where I paid an annual registration. The DOL was pretty clear - that trailers registered under 10,000 GVRW get fee-plates, and over 10,000 GVRW get non-fee commercial plates - unless the trailer is titled as an RV (the only exception). I openly acknowledge that the State of Washington is known for blind verbatim compliance with written instructions (sometimes vindictive verbatim compliance is a better description). They could very well be over-interpreting & enforcing Federal DOT requirements. Nonetheless, what should I have done in the above situation? Registered the trailer for 10,000 GVRW by obtaining normal annual fee-plates, then load it over 10,000 pounds and hope I don't get a CLD ticket? Or keep the commercial plates on the trailer and put 26,000 GVRW registration on my 1-ton truck - ignoring the obvious stated requirement that the trailer be pulled by a commercial vehicle. I wasn't going to risk either option. I never got around to getting a CDL, so I sold the trailer. The $4,600 cost to obtain a CDL wasn't the problem. The problem was taking almost two months off work to attend CDL school. . . . Another interesting tid-bit - the minimum acceptable registration for commercial trucks in Washington State is 1.5 times the scale weight, rounded up to the nearest 2000 pound increment. I was told you're always welcome to purchase additional GVRW from the State, if/as needed. . . . .

  24. #24cfherrman2023-05-19 07:36

    States make their own laws with licensing and roads but the feds have been pushing them around on it for a long time. With the feds requiring class time now on cdls in every state really sucks and does not make any better drivers, actually I think they are worse from schools. What you should do is move out of Washington! My trailer is tagged for 14k and no big deal to the state of Kansas. You could have talked to a local dot consultant and they would have told you how it is, the one I've used before was a highway patrol for like 30 years so he knew the Kansas dot laws pretty good. Any truck pulling that trailer you wanted is definitely CDL a territory as it goes gvwr and not by actual weight, you would need to get a trailer that is 14k gvwr.

  25. #25Entropy12023-05-20 10:57

    The problem with moving right now is that the US dollar is currently worth 30 cents on a construction site - driving the cost of new & used homes out of reach. My house is worth triple what I paid. The problem is that where I want to move (Florida) houses are worth 5-fold what people paid. I don't want to assume a large mortgage this late in life, and I don't want to move my family into a shack either. If I didn't have a lot of equity in my current house, buying a house would not even be an option. Things are getting pretty bad in WA State. I know we're not supposed to talk politics on these boards, so I just leave that topic alone. . . . For ****-chat, I had a M923 (military 5-ton 6x6, purchased from US Army at DRMO Fort Lewis). The scale weight was 23000 pounds. The minimum registration Washington state would let me put on the truck was 36,000 GVRW (1.5 times the scale weight, rounded to the nearest 2000 lb increment - which were 400 dollar per year tabs). So - 36,000 GVRW with air brakes certainly sounds like Class B CDL territory, does it not? Washington State DOL and State Patrol both told me that if I wasn't using the 5-ton for commerce, I didn't need a CDL. I asked them what their definition of commerce was, they said for conducting business. Well, ok - they happily accepted my 400 dollar fee for tabs, and I never got a CDL ticket driving the truck. And to pull the tilt-bed trailer with my army truck (original intention). I could only pull 8500 pounds on my trailer before I pushed over 36,000 GVRW at the truck scales. Thus I would need to increase my GVRW on the 5-ton to 48,000 pounds in order to get the full load capacity out of my tilt-bed (even more if I desired to have a load in the truck bed also). Problem - the moment I connect the trailer to my army truck, my non-commerce status automatically changes to commerce in the eyes of the State (CDL becomes required). There's no arguing with these people. In hindsight I probably should've taken 2 months off work, spent the 4600 dollars, and obtained my CDL. However between the GVRW registration & the commercial truck insurance premiums, I would've been paying between 2 to 3 grand per year for the privilege of using my truck and my trailer - to occasionally transport my equipment - mainly to friends' houses. It's understandable why contractors charge so much to move equipment. . . . .

  26. #26cfherrman2023-05-20 15:41

    Yeah moving was mostly a joke, it's never easy. That 1.5 rule is very strange, in Kansas we just need to say how much weight will be on the truck or trailer and then they have minimums depending on the item, like my trailer you probably couldn't get a tag for under 14k on it and probably not get more because of the rating either, but my pickup is tagged at 12 and I think you could tag it up to 20. My neighbors bucket truck for trimming trees is tagged around 22 even though it weighs less and he told me that's the least they let him tag it for since it can carry a lot more, it's the kind of truck that could get tagged up to 30 probably.

  27. #27PeterG2023-05-22 11:20

    I live in WA too. I bought an International 4900 with air brakes and registered it 38,000 GVW with my DOT number. I could have registered it at 25,999 gvw. But the truck has air brakes, which means you need a CDL. But I wanted a true 6yd dump truck. I drove it for quite a few years for business without a CDL! Finally I broke down and got my CDL class A on one November/December. I was the oldest guy in the class at in my late 50's. A waste of money and time to learn to drive an 18 wheeler and split shifting. Way too much time learning the Pre-inspection crap (complete walk around inspection of truck and trailer every time you operate it). Now I also have a Kenworth T800, but that is another story. Just paid the renewal for it ($1500), and it's only licensed up to 70,000 gvw!

  28. #28Joe Mahlik2023-06-11 09:30

    Update**** After much research and cross checking spindle, bearing, tire, and axel compatability between trailers rated between 5.2k and 7k, I have determined what kept my trailer rated for 10.4k is the wheels. I could not find any 15in wheels(which I have) that were rated for 3k or over. In order to be a 12k gvwr trailer I will need 16in wheels and the appropriate tires to wrap them. This has been a very educational experience researching all that goes into why a manufacturer gives a specific trailer a specific gvwr. After installing the appropriate wheels and tires on this trailer I will be entirely comfortable loading a 9000lb machine on it!

  29. #29cfherrman2023-06-11 14:54

    You will probably need 8 lug drums and who knows if you have enough iron in the trailer for that.

  30. #30Entropy12023-06-11 18:16

    The whole axle assembly must be properly rated (aka the size of the axle tube, the spindle size, the weld that's joining the spindles to the axle tube, the leaf springs, the hub/bearing assemblies, the tires & rims. The whole axle assembly is only as good as its weakest link. By installing 7k rated wheels & tires onto a 5.2k rated axle, you'll still have a 5.2k axle rating. Which means you'll simply break something else before popping a tire or bending a rim. Use caution installing a pair of 7k rated axles onto a 10k trailer. A guy I know did this (thinking it would enable him to pull his tractor). He bent the trailer frame. The C-channel was not sized for 7k axles. If you need more capacity, obtaining a larger load-rated trailer is usually the best solution.

  31. #31Joe Mahlik2023-06-21 17:46

    Entropy1, you make valid points. I've compared my trailer to of many 14k rated trailers I have access to and the construction is almost identical. 6in c channel main frame and tounge frame. 3in c channel cross members on 16in centers etc... As for the axels the data tags from the manufacturer are still on them and they say 6000lb rated. I've compared my #42 spindles(not the actual spindle to axel welds), the leaf springs, and the hubs/brakes to parts listed online as rated for 6k( in some cases 7k) axels and they are dimensionally identical. I understand for the average person stretching the limits of a trailers gvwr is not recommended and purchasing the proper trailer is the best move move.

  32. #32Entropy12023-06-21 18:07

    As long as you're actually evaluating the components, you should be fine. I have a 10k equipment trailer. The weak link on my trailer design was the 24 inch spacing between deck supports. I have 2x6 x 20-ft boards for the deck. When I drive a full size 70s vintage Caddy onto the trailer, I'm worried the 2x6 is going to snap from the weight of the car (very visible board deflection under the wheels - between 24" centers). I am sure my forklift would bust through the deck (way too much weight over the small rear tires - sitting on one, maybe 2 boards per tire). I grew tired of laying extra wood on the deck to move my forklift, so I welded in extra deck supports to the trailer. Now they're at 12 inch spacing down the length of the trailer. I can drive heavy stuff on without worrying about loads busting through the deck. I didn't necessarily increase the load capacity of my trailer (I actually decreased it by adding an extra 300 pounds of steel) - however I significantly increased the localized point-loading capacity of the trailer (aka fixed the weak link - of potentially busting through the deck). If you've verified that the weak link on your trailer is the rim & tires, then that's an easy fix (or should be).

  33. #33cfherrman2023-06-22 00:04

    I'll have to look tomorrow but my 14k trailer probably has higher channel frame, maybe 8". I was under it half the day today finishing wiring it.