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Old 08-24-2009, 03:55 PM   #1
Art-n-Marge
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Turn your F-250 into an F-350

... almost!!!!

As some of you know I was investigating how to increase the GVWR of my 2006 3/4 ton F-250, SRW, 6.0L, 3.73 Diff, PSD (GVWR = 10,000, FAWR = 5600, RAWR = 6100) to a comparable 1 ton F-350. Air bags or aftermarket springs have fine print not to exceed your GVWR even with these modifications.

To accomplish I needed 2 things for sure and an optional third thing:

1. Add FORD parts - overload spring, brackets and bumpers to the leaf spring pack. Everything else (shocks, brakes, tranny, engine, other suspension parts are the same for both models).
2. Get larger wheels and tires to support the new weight capacity. This is planned.
3. Optional - Recertify the vehicle to acknowledge the modifications. Since I am not a commercial vehicle this is not required, but I might do this if it starts to bug me.

The first part of the conversion is complete. The overload springs have been installed. As I had promised to some, here's the link for the completed leaf spring work:

http://s658.photobucket.com/albums/u...0installation/

The procedure is simplified for relevance. The work took much longer than anticipated because of heat, learning things as I went on, trips to the store, I didn't want to rush, relatives visiting (and unable to help), etc. The first side I did over three days, but that's because of interruptions. The other side was done within 4 hours! The total cost was about $500 (California prices) for the suspension parts and 1-2 days after knowing about all the surprises.

In summary, I am very glad I did this. I will complete step 2 and purchase new tires when the current ones finally wear out, then I will be able to load up the trailer and truck with all the gear I have had to leave behind because of the pin weight problems many 3/4 ton trucks can have.

If you would like the parts list and detailed cost, just drop me an email.

FINALLY DONE!

For some of you who provided commentary about this, you might ask, why did I do this to myself? I will only say, I was looking for some security, some comfort and some mental relief that if I have a problem, it is not because of being over the weight ratings. I emphasize this was to benefit my rig combination only and I am not passing judgement on anyone if they don't do this. Thanks for your patience, understanding and support.

Art

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Old 08-24-2009, 11:48 PM   #2
Tom S.
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Art, before you spend money for new wheels, do you know what the weight rating on your present wheels are? You may not need to replace them. If you do need to replace them, watch Craig's list. I got a spare set (4) 1 ton wheels for my SRW for $100.
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Old 08-25-2009, 04:47 AM   #3
FLSTS03
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Hey Art, Did you scratch your head a little when you saw the extra bolt in your tire, thinking "was that suppose to be on the trk somewhere?" Steve
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Old 08-25-2009, 11:42 AM   #4
Art-n-Marge
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LOL, Steve.... nope, no scratching needed. All bolts were accounted for, this one was a hitchhiker. Notice the tire you see has 52,000 miles on it so there's a lot of tread left.

Tom, thanks for the suggestion. I will not be looking for anything fancy or too expensive, so that's a good idea. I had posted in another topic, that I needed new wheels to support the heavier rear axle weight rating (was 6100lbs, now is 7000lbs). The current 17" tires (currently 6390 lbs per axle) do not have a vendor that supports the new weight rating. There is a 16" tire but a 16" will not fit my truck because of the large brake calipers), and the 18" wheel has several major tire vendors and the variety means competition keeps availability higher and the tire prices lower. These options support 7,240 lbs per axle. I am looking at the Michelin LTX A/T2.

But I still have enough tread for a while. So until I wear them down, I keep all the extra junk at home.
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Old 08-25-2009, 01:26 PM   #5
FLSTS03
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Art, this is also the time of year where folks that bought new trks are taking them to a Truck Outfitters and swapping allmost new stock tires for those oversized ones. Keep an eye out there as well. Since I discovered a guy localy that watches out for me I've not bought a new tire in the last couple yrs for my Isuzu NPR's. Finding someone to mount used tires can be tuff.

Steve
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Old 10-04-2009, 06:56 PM   #6
RidgecrestDad
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Art, Great idea. I too would like to consider adding some additions to the 5er that will require either an F350 or a similar upgrade. As you do this you mention that the axels are now 7000 lb. rated vice 6100 lbs. Am I correct that previously you replaced the rear axels prior to building up the springs? Did you weigh the truck to determine if the 6100 pound rear axel weight rating would handle the truck and additional weight thrown in the truck/bed, or is that the rating for the F350?? (My guess is you will want/need the 7K rating anyway). What tire rating are you considering? A final consideration, when you buy the larger wheels/tires are you thinking the speedometer may no longer read correctly for either mileage or speed? And can that be corrected easily?
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Old 10-05-2009, 02:33 AM   #7
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If and when you increase the wheel size, what are your plans for adjustments to the speedometer?
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Old 10-05-2009, 10:25 AM   #8
Art-n-Marge
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Hi Barry and bw2 - The answers to your questions are:

- So far I have only changed the leaf spring pack by adding the extra overload spring, a spacer, and some brackets that the overload spring comes into contact to work correctly. The spring pack sits between the axle and the frame.

- The axles didn't need changing nor did the differential when compared between an F-250 versus an F-350 for the weight rating I needed. I made this comparison with at least two other F-350 owners against the Ford database using VIN numbers. One of the owners worked at the Ford parts desk, so I felt comfortable with the info.

- The 7000 lb rating is for an F-350 and the 6100 is for an F-250 right off the VIN database the label on the truck's door pillar. Besides the leaf spring pack and the wheels and tires, everything else was the same (axles, differential, brakes, etc). I do plan to reweigh my truck, to confirm the 40 extra lbs of hardware, plus the extra weight of the larger tires and wheels when I get them (about another 50 lbs). But to gain 800 to 900 lbs capacity in the rear end, it should be worth it and matches the weight problem I was seeing with my particular rig combination.

- For the tires I am looking at E rated tires that support over 3,600 lbs each. The current 17" tire size I have now uses E-rated tires rated to a max of 3195 lbs (over 300 lbs too light).

- After I change out for 18" wheels and tires I will take the truck back to the dealer for adjusting the speedometer and the transmission. The larger tires are offered as an option to an F-250 when you purchase the truck, so I expect the Ford dealer knows how to adjust them accordingly. It is not difficult nor expensive but I have no knowledge on doing this myself so I'll leave it to Ford.

Thanks for your questions. I hope this info helps.
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Old 10-05-2009, 06:46 PM   #9
RidgecrestDad
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Art, This part confuses me. Maybe you can clear it up. If the tires each handle 3195# or 3600# each based on the tire size/rating, then the axel total weight rated capacity needs to be either roughly 6400# or 7200# which matches the rated axel rating of a F250 or F350. So as I see it, you should need a stronger axel if you add more weight to the bed and tires to move up to a F350 rating. Does that jive with your thoughts and your Ford parts guy info? Additionally, the Ford manual suggests that a F350 can handle more load in the bed, yet the combined Gross Vehicle Weight Rating (the trailer and truck weight) for towing is 500# less than a F250. This makes sense to me in that the brakes can only stop so much weight; so if you add more in the bed, the weight translates thru the axel to tires (and the brakes) and hence reduced stopping power. So, though more goes in the bed, you still need to consider the overall weight rolling down the road. Does that make sense, or am I confused even more?
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Old 10-05-2009, 07:18 PM   #10
RidgecrestDad
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Art, A possible misuse of terms in my last post/questions. I used gross vehicle weight rating to describe the weight of the truck and trailer, I believe the correct terminology should have been Gross Combination Weight Rating. Sorry for the confusion.
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Old 10-11-2009, 06:00 AM   #11
Lawman
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You realize, of course, that the subject "Turn your F-250 into an F-350" is technically impossible unless formally blessed by Ford.
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Old 10-11-2009, 10:02 AM   #12
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Art,

Quite an undertaking, me thinks. I learned a lot from your photo presentation. Did you consider having this work done by Ford or other facility? I'm pretty good with my hands but this project appears to be more than I'd want to tackle myself. Obviously, the cost would be more than the $500.00 you paid.

Questions about the wheels you're considering: are they steel or something else? I ask because the 18" wheels I've seen thus far stipulate a rating of 3,200#. They are not steel, as I presume the stock wheels are. What is the offset of the wheels you're thinking of? I only recently learned of this term; it refers to where the tire's center line is relative to the mounting surface and is expressed as +, - or zero. Zero is the spec for stock wheels; - is what was called "reversed" wheels in the 60's.

Regarding a comment about the additional weight of 18" wheels & tires: it seems to me that weight wouldn't be a consideration since it sits on the ground, i.e., is "unsprung" weight; not supported by the truck. Perhaps I'm missing something here.

Cheers,
-Bob
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Old 10-11-2009, 01:54 PM   #13
Art-n-Marge
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lawman - LOL, that's why the first word in the post was "almost". The task I did showed the job was technically possible. To meet the commercial (legal?) aspects a recertification is needed. But for personal use this is not required. So far I have achieved the technical aspects by using Ford parts that meet the increase in weight ratings and I will complete the technical aspects when I acquire the appropriate wheels and tires that meet the weight ratings I seek. According to the Ford databases for my F-250 VIN and a F-350 VIN with the same features I am pretty confident I have done this correctly.

Barry - I understand what you are saying, but the axles are fine. The axles, brakes, etc. were the same according to the Ford guy. Go figure. Please keep in mind we are only talking about my TV configuration.

Bob - When I bought my F-250 in 2006, at the time, the price difference between an F-250 and F-350 was $4,000 because there were some special rebates at the time. It didn't make sense to pay $4,000 for only 1,500 lbs sinced both trucks met the RV weights on paper. Unfortunately, even though the actual weights for the RV were fine, the TV was overweight because of the pin weight and I should have gone with the F-350! I did NOT want to buy a new truck if only adding some things to make my F-250 comparable to the F-350 would do.

There are steel and aluminum wheels. I am seeking any stock 18" wheels that were available on a new 2006 F-350 with the ratings I seek. The ratings, offsets, etc. will be met. You are right, I might be overestimating the weight differences between the wheels, but they are larger than what I've got, therefore have to be heavier - I will be changing out all the wheels including the spare. The wheels will be part of the scale weight. When Gross weight is measured, the wheels and tire must be considered.

Please note, all this work and information pertains to my truck upgrade. Just like others bring up, other makes and models might require additional considerations including it's not possible.
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Old 11-22-2009, 03:07 PM   #14
Biggjb
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Art, I purchased a 2005 F-250 and was wondering why the ride so hard and it only felt smooth with 2 face cords of wood in the back. However, after looking at my supension and the pictures you posted on your work, I now know why. My truck was modified by the previous owner to have the same GVWR as the F-350...thanks for the post.

I am now concerned on the tires...I have load range E. Is there a higher range?

Greg
Quote:
quote:Originally posted by Art-n-Marge

... almost!!!!

As some of you know I was investigating how to increase the GVWR of my 2006 3/4 ton F-250, SRW, 6.0L, 3.73 Diff, PSD (GVWR = 10,000, FAWR = 5600, RAWR = 6100) to a comparable 1 ton F-350. Air bags or aftermarket springs have fine print not to exceed your GVWR even with these modifications.

To accomplish I needed 2 things for sure and an optional third thing:

1. Add FORD parts - overload spring, brackets and bumpers to the leaf spring pack. Everything else (shocks, brakes, tranny, engine, other suspension parts are the same for both models).
2. Get larger wheels and tires to support the new weight capacity. This is planned.
3. Optional - Recertify the vehicle to acknowledge the modifications. Since I am not a commercial vehicle this is not required, but I might do this if it starts to bug me.

The first part of the conversion is complete. The overload springs have been installed. As I had promised to some, here's the link for the completed leaf spring work:

http://s658.photobucket.com/albums/u...0installation/

The procedure is simplified for relevance. The work took much longer than anticipated because of heat, learning things as I went on, trips to the store, I didn't want to rush, relatives visiting (and unable to help), etc. The first side I did over three days, but that's because of interruptions. The other side was done within 4 hours! The total cost was about $500 (California prices) for the suspension parts and 1-2 days after knowing about all the surprises.

In summary, I am very glad I did this. I will complete step 2 and purchase new tires when the current ones finally wear out, then I will be able to load up the trailer and truck with all the gear I have had to leave behind because of the pin weight problems many 3/4 ton trucks can have.

If you would like the parts list and detailed cost, just drop me an email.

FINALLY DONE!

For some of you who provided commentary about this, you might ask, why did I do this to myself? I will only say, I was looking for some security, some comfort and some mental relief that if I have a problem, it is not because of being over the weight ratings. I emphasize this was to benefit my rig combination only and I am not passing judgement on anyone if they don't do this. Thanks for your patience, understanding and support.

Art

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Old 11-22-2009, 04:43 PM   #15
Art-n-Marge
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First thing you must know is that not all load range E tires are created equal. Sizes and types of tires may affect the actual load limit. For example, my current tires are E rated at 3195 lbs each on my 17" wheels. The larger size I plan to change to are also E rated but at 3620 lbs each for 18" wheels. The letter rating is very confusing and I'll save you from the more dependable number rating explanation for now. email or PM me if you'd like these details.

Just look on the side wall. Besides the "E" rating will be the maximum weight rating (and the inflation to get this rating) for the particular tire.

Throughout all of this I have discovered that F-250s might have F-350 components out of the factory not just from the previous owner. For example, someone orders an F-250 with the camper option - chances are it will get the F-350 leaf spring pack, but they will label it with the F-250 specs because you "paid for" an F-250 and not an F-350 and you don't get the improved label because of it.

Your truck's rough ride might also be caused by your tire pressure. When not towing or loaded down I run an inflation pressure between 62 and 65 lbs. I found this prevents much of the stiffness. I have a pretty good air compressor that allows me to inflate when needed, then I deflate the tires when not needed.

I hear it's not a good idea to just run out and get higher rated tires because the rest of your truck's suspension will need consideration. What is the current tire size and the pillar ratings for your truck? This will help determine if larger tires are needed or can be used. With your F-250 I expect that whatever Load Range E is on there is just fine for it. You might be wasting money for higher load ranges that don't help your truck.
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Old 11-23-2009, 01:33 AM   #16
Tom S.
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To add to the info Art provided, there are "F" and "G" rated truck tires available, but they are hard to find and expensive. If you think the truck rides rough with "E" tires, "F" and "G" will be much worse! To give you a real life experience, we had our trailer and truck weighed at Goshen this year. The loaded weight of the rear of the truck was 2,850 on the right and 2,900 on the left. With our tires, which are "E" rated, we are 500 lbs under the limit.
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