Recommended Parts for Rebuild/Upgrade of Harbor Freight Trailer

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Question:

Thank you for answering my questions. I've read your answers and I have a few more questions for you. I was thinking of using the Provider ST175/80R13 Radial Trailer tires, item #A13R45GM. The reason for the switch is these tires have wear indicators and will only make the decision of when to replace them easier like a car. With regard to the axle it seems the smarter way to go would be to mount the springs under the axle using the # CE23000 u bolts you recommended and weld the # APS4 spring hangers to the frame. This raises the question of whether or not it would be wiser to use 15" Provider tires #A15R45GM to keep the axle higher for clearance. I have read that when the trailer rides higher for clearance the trade off is the center of gravity is raised. On the OEM HF parts the trailer axle is 8.5" and the frame is 18" off the ground. I'm not sure if 13" tires with springs under the axle will add to these numbers or subtract but clearly whatever the 13" does to the height of the axle and frame the 15" tires will add even more height. Is 15" tires a wise move or is that raising the center of gravity too high. Again not going anywhere near the 2200lb axle limit, the axle can accept 13"-15" tires ,and I still use the beds tilting feature which would be higher up on 15" wheels but I don't think our friend gravity will mind. Please let me know and thanks again.

asked by: Paul

0

Expert Reply:

The Dexter Trailer Idler Axle w/ Hubs - EZ-Lube - 5 on 4-1/2 Bolt Pattern - 60" Long - 2,200 lbs # 20545I-EZ-60-15 is a great starting point to upgrade your trailer. This will give you a standard size axle with good bearings, hubs, and EZ-lube spindles. This is far nicer than the weird sized stuff that comes on Harbor Freight trailers.

The Karrier ST175/80R13 Radial Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 - Load Range D # AM31994 will be a great addition to these hubs and the radial tires will be much better for highway driving. Make sure to inflate the tires to the max psi of 65 when filling them cold prior to a trip.

The new axle is not square but rather round and has the spring seats which are flat, so you will still want to use the U-Bolt Kit but I recommend the CE Smith U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4" Long U-Bolts - Zinc # CE23000 which are galvanized plates with zinc plated hardware to resist rust and corrosion. There is not an over-under kit we have available for this size axle or that is galvanized, so the leaf springs will need to be installed under the axle or you will need to weld a spring seat like # TRSS175 to the top of your axle and find spacers and longer u-bolts to make your own kit similar to # K71-384-00.

For your springs and hangers to allow you to use the under axle installation, I recommend the Single-Axle Trailer Hanger Kit for Double-Eye Springs - 3-1/4" Front, 1-1/4" Rear # APS4 along with the 3-Leaf Double-Eye Spring for 2,500-lb Trailer Axles - 25-1/8" Long # e66SR which will make your axle or your trailer frame itself the weakest part of your system. The hangers will need to be spaced 24-7/8" on center from each other splitting the distance of your axle. You will appreciate the double eye springs over the slipper springs for the type of traveling you will be doing. This does mean the hangers will need to be welded in place.

expert reply by: Jason S

0

Paul

1/26/2018

Thank you for answering my questions. I've read your answers and I have a few more questions for you. I was thinking of using the Provider ST175/80R13 Radial Trailer tires, item #A13R45GM. The reason for the switch is these tires have wear indicators and will only make the decision of when to replace them easier like a car. With regard to the axle it seems the smarter way to go would be to mount the springs under the axle using the # CE23000 u bolts you recommended and weld the # APS4 spring hangers to the frame. This raises the question of whether or not it would be wiser to use 15" Provider tires #A15R45GM to keep the axle higher for clearance. I have read that when the trailer rides higher for clearance the trade off is the center of gravity is raised. On the OEM HF parts the trailer axle is 8.5" and the frame is 18" off the ground. I'm not sure if 13" tires with springs under the axle will add to these numbers or subtract but clearly whatever the 13" does to the height of the axle and frame the 15" tires will add even more height. Is 15" tires a wise move or is that raising the center of gravity too high. Again not going anywhere near the 2200lb axle limit, the axle can accept 13"-15" tires ,and I still use the beds tilting feature which would be higher up on 15" wheels but I don't think our friend gravity will mind. Please let me know and thanks again.

Reply

Jason S.

1/26/2018

Flipping your axle to be under your springs will add roughly the diameter of your axle and thickness of your leaf springs at the axle to your height. So this will raise your coupler height slightly and will move your center of gravity. Part A13R45GM has been discontinued, but a similar fit is the Provider ST175/80R13 Radial Tire w/ 13" White Spoked Wheel - 5 on 4-1/2 - LR C - # TTWA13RWS . The one thing that won't change in doing this is your axle height will remain the same even though your coupler height increases slightly. Unfortunately the A15R45GM have also been discontinued but if you were to move to the similar larger tires like the Karrier ST205/75R15 Radial Trailer Tire with 15" Galvanized Wheel # AM32397, you will raise the height of your axle and also your coupler moving your center of gravity. If you do this, I don't recommend flipping your axle as that would really raise your coupler height and your center of gravity giving you less stability. If it were me, I'd go with the larger tires for your highway driving because the larger diameter will help them to run a little cooler and you'll gain a little axle clearance. The trade off with this is ensuring you have enough fender clearance for the larger tires and suspension movement.

Reply

Wookie

3/1/2020

I am liking the recommendations posted here, and I have access to a person who can mount the hangers. Will likely go the 13 tire size, so I wont be flipping the axle.Before I pull the trigger, do you have any idea if anything of this setup will take the folding feature away from this trailer?Do you also have some insight if the OEM fenders can still be used, or do you think I might need to purchase a new set of those too?

Reply

Chris R.

3/3/2020

I don't THINK I see anything in this upgraded setup that would prevent the trailer from maintaining its folding function, but since this is a pretty custom application I really can't say for certain. It's just not been tested. The OEM fenders may cause an issue if you're replacing the axle but keeping the springs beneath it (while also upgrading to larger 13" tires). The same fenders may still work, but they might need to be bolted a bit further up on the frame to allow for enough clearance between them and the tire tread (we recommend at least 3" of clearance).

Reply

Wookie

3/3/2020

Thanks, Chris. I pulled out a tape measure, and the leaf springs mounting doesnt look like it will interrupt anything. Thanks for the recommendation of 3 of clearance.I will post up how things shake down. I ordered my kit last night!

Reply

Chris R.

3/4/2020

Sounds good! Definitely reach back out if anything else comes up.

Reply

Answer 1

We can very likely get this worked out. Can you tell me how far it is from spring center to spring center? This is the distance from the middle of one spring to the middle of the other. We will also need the hub face to hub face measurement. This is…

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Answer 2

From my research on the Harbor Freight 4x8 folding trailer uses 4.80-12 tires on a 12 inch wheel for the 1195 lb capacity trailer and a 5.30-12 for the 1720 lbs capacity trailer. It is a good idea to check your existing tires to see which size they…

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Answer 3

Since you want to change your trailer hubs to the 5-on-4-1/2 bolt pattern I suggest you select a 60-inch axle kit that includes idler hubs, such as one of the two kits shown on the linked page. These two 2K-rated axle kits include 5-on-4-1/2 hubs,…

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Answer 4

While there are stock axles that are close to the measurements you mentioned, there is not one that's an exact match to the existing axle on your Harbor Freight trailer; in order to get an exact match you'll need to special order a…

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Answer 5

Harbor Freight trailers do not typically use standard hubs or spindles. In most of the situations that we have encountered, we do not carry a hub that uses the same bearings and seal that Harbor Freight uses. The best way to determine if we have a…

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Answer 6

For a stake pocket that you could weld to the side of your trailer that would allow you to make your own walls for the trailer you could use the part #HW03-080. The inner dimensions of the stake pocket are 3-1/2" (w) x 1-9/16" (deep). This…

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Answer 7

The Dexter Trailer Idler Axle Beam with EZ-Lube Spindles - 60" Long - 2,200 lbs #T20BTR-EZ-6048 will fit any trailer with spring seats 48 inches on center. If you Harbor Freight trailer has leaf springs that are 48 inches on center then you will…

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Answer 8

Our narrowest 3,500lb axle is going to be the Axle #e65GR which is 89" from hub face to hub face. To mount this and widen your trailer you will need to modify the trailer which will entail new frame and suspension components. We do have a…

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Answer 9

In order to determine if we have an axle that would bolt right up to what you have without welding we need to know the distance between your spring seats on center. We also need to know hub face to hub face dimension of your current axle as well.

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Answer 10

Trailer wheel bearings are specific to the spindle that is installed on the axle that is on your trailer. You will need to safely support the trailer, remove the wheel and tire, remove the grease cap, remove the cotter pin and washer that secures the…

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Answer 11

From what I could find, the Harbor Freight trailers do say not to exceed 45 miles per hour in the owners manual. That being said, the tires they use are not rated very high and may be the limiting factor. The trailer you have looks to use a 5 on 4…

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Answer 12

In order to swap out your 13" wheels and tires with 15" you will need to match up the bolt pattern and make sure there is enough clearance. A wheel and tire like the Karrier ST205/75R15 Radial Trailer Tire with 15" White Spoke Wheel…

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