Replacing Front Coil Springs With Lesser-Rated Ones On Our 2007 E350

Putting the bigger springs from a E250 or E350 seems to be a 'thing' with the off road van community. So maybe the reverse will work also.

https://expeditionportal.com/forum/threads/e350-coil-springs-versus-e150-springs.69931/

But I agree with CalCruiser - the spring length is more the issue than the weight handling, after all it is too light to begin with. Maybe get a stock spring and have a coil cut?

I looked for a while for E350 lowering kits, not much out there. These looked appealing, but I dont know if they need more to work with coils...

https://www.airbagit.com/dropped-lowered-Ibeams-p/ibe-fo07xx-van.htmm

My research continued over the past 24 hours with the E-Series 2007 Ford chassis specs in-hand which states the same front coil spring is used on the E350 van, E350 cut-away chassis, and E450 cut-away chassis, all with a front GAWR of 4600 pounds.

I spent some time on Rock Auto's website which lists Moog springs for the E150, E250, and E350 van.  The E350 Moog spring is CC81366 which would also be the same for the E350 cut-away and E450 cut-away.  I compared the specs of that spring to the E250's CC81368 and the E150's CC81370.  Doing the math with the specs and comparing those numbers to my 2007 spec sheet, my light front suspension should benefit best from the E150 CC81370 spring offering a front GAWR of 3860 pounds which is 600 pounds greater than my heaviest front axle load on a trip.  The GAWR reduction is 740 pounds, I think ideal for the reasons I mentioned earlier.

I also called Moog spring technical support to pick their brain.  The fellow there said that a spring design load times two springs, will be significantly less than the GAWR because of the difference in weight resting on the springs versus the weight of the front axle when driven on a scale.  That made a lot of sense which further supported my "doing math" to determine the best spring to choose.

A pair of Moog E150 CC81370 springs with tax and shipping cost me an affordable $96.45.  They are compatible with my E350 cut-away suspension and seemingly easily to swap, so I ordered them, will install them myself, and try them out.

We won't be taking any big road trips this year due to expenses.  We need tires with plans also for Alcoa wheels.  We also took two lengthy and very expensive over-seas trips to Israel twice, and Greece & Egypt once in the past 6 months.  So it will be a great summer to experiment with front springs.  If the results are poor, I may try spring CC81368 for the E250.  If pleased with the results, I will post an article with pictures in the Tips and Tricks section for the benefit of others with a 2100 and 2350 Phoenix Cruiser.  I feel both models suffer from a poor ratio between wheel base and rear over-hang which I feel lifts and lightens the front axle a bit much.

For those who want to know, the physical differences between an E150 and E350 spring is not much.  They have the same ID, OD, bar diameter, spring rate per inch, and number of coils.  The free height is their only difference, the E150 being 0.627" shorter, hence the 10 coils are a bit closer together.

For those who want to know, the physical differences between an E150 and E350 spring is not much.  They have the same ID, OD, bar diameter, spring rate per inch, and number of coils.  The free height is their only difference, the E150 being 0.627" shorter, hence the 10 coils are a bit closer together.

So the expected result is to have the front end ~1/2 inch lower? (assuming the originals did not 'sag' at all)

GREAT research Ron!!! Following with interest.

Quote from: Ron Dittmer on July 09, 2019, 01:52:04 am

For those who want to know, the physical differences between an E150 and E350 spring is not much.  They have the same ID, OD, bar diameter, spring rate per inch, and number of coils.  The free height is their only difference, the E150 being 0.627" shorter, hence the 10 coils are a bit closer together.

So the expected result is to have the front end ~1/2 inch lower? (assuming the originals did not 'sag' at all)

GREAT research Ron!!! Following with interest.

I hope the front lowers some amount more than 0.627", compressing down a bit more than the E350 springs.  I will take front bumper height measurements with each spring type installed.    If the ride height difference is just that alone, it will still be a success as long as the ride is softer.  We always thought our E350 had an overly stiff front suspension since brand new in 2007, and it is no different with our new Bilstein HD shocks.  For our 2007 2350, the majority of weight is on the rear axle, I feel leaving the front too light for the E350 Super Duty springs.

I will also pay close attention to any changes in handling.

I hope you get more drop than the .6 inches also for all that work!  But once you get the 'in and out' figured on those springs it will be easy to modify as you go.

My race car buddies reminded me there is an engineered way also...



There are variables, but a pair of custom made springs go from $250-$350. I was expecting closer to $500. .   They can tailor them to desired ride height, and 'cushy'ness.  Springs to order!! 

 I told him I was 99.9% sure PC did NOT alter the stock cutaway, so he said either a) the tag on the spring or b) take the vin to a dealer and get the part number. If it is NLA or superseded, its OK. Just get the stock number. (should be 8 digits, with a couple letters he said)

Yes, its a couple hundred bucks more,  but engineered professionally for your specific vehicle.  I like that. Mrs V likes safe too... I will be getting more info to him tonight and see what the final quote is. But for $350 maximum... and 'dialed in' to my exact wants.. I honestly think it is a bargain!

Thanks Ron for inspiring yet another improvement on our 2350.   YOU da man! 

Tag was still on my spring. 

ROLLCALL!        I got 3C245310VA  for a front coil spring part number.                PC model 2350   Year 2006

I have my camper parked 'kittywampus' in the drive, and not inclined to go in the rain and move it. I am guessing I want 1.5" of drop, but think it a good idea to maybe load and check the height before ordering.    Might want lower.   

Tag was still on my spring.  I got 3C245310VA  for a front coil spring part number.  PC model 2350   Year 2006

I got that exact same part number off the internet for our 2007 E350.  The local Ford dealer gave me part number F2UA5310VA.  The common denominator is 5310-VA, not sure of the difference in the prefix.  It could be a change in part numbers for the same part, a common practice in the auto industry.

Neither Ford part number worked with the Moog website, nor were they useful with Moog's technical support.  I had to resort to other methods in determining which Moog spring to order from Rock Auto.  It was a bit of a math and science project.  If I ordered the wrong springs, I'll be out 4 to 5 hours of my own labor and $96, well worth "a try" to me.  It wouldn't be the first time I put effort and a little money into a learning experience alone.  I enjoy doing such with potential for a substantial payoff.  Experimenting with front coil springs, there is no harm in reverting back to what I started with.  It's like experimenting with various shock absorbers.

Ron, my barn has a 10' door, and the airbags had no impact.  I have tested driving it in with the bags inflated up to 75 pounds.  Like I said, they merely cure the sag. They don't INCREASE the height -- which was my entire complaint.  I was hoping to gain a couple of inches clearance, but the only time they help with that is when I've lost 2" from carrying a full water tank. 

Hard to argue with $100, though, if you've verified that it's safe.

As for the road conditions on I-10, it's miserable, but not because of the road quality, which is excellent in Texas.  The only problem in Texas is the constant road work to widen it to deal with the ridiculous amount of traffic.  I drive this route regularly, between Cypress, TX and my kids in Florida.  It's positively a relief when you finally hit Texas and escape all the traffic problems in Louisiana due to the out of date narrow bridges over the Mississippi, Lake Charles, and the Atchafalaya.  If it was as bad in Texas as described, the speed limit wouldn't be 75.

https://grassrootsmotorsports.com/forum/grm/lowering-my-van/43961/page1/

Yeah, thats where I found that link for the airbagit front beam.   Unfortunately, it is a 'one off' product, and only built if you order one. And can be adapted to coils, but is intended for airbags. Its a pretty complicated weldment, which makes me leery that its made to order.... I would much rather it be built in batches, with a weld order and cooling times outlined. 'Order built' can be hurried by its nature...

Quote from: Volkemon on July 09, 2019, 05:31:05 pm

Tag was still on my spring.  I got 3C245310VA  for a front coil spring part number.  PC model 2350   Year 2006

I got that exact same part number off the internet for our 2007 E350.  The local Ford dealer gave me part number F2UA5310VA.  The common denominator is 5310-VA, not sure of the difference in the prefix.  It could be a change in part numbers for the same part, a common practice in the auto industry.

Neither Ford part number worked with the Moog website, nor were they useful with Moog's technical support.  I had to resort to other methods in determining which Moog spring to order from Rock Auto.  It was a bit of a math and science project.  If I ordered the wrong springs, I'll be out 4 to 5 hours of my own labor and $96, well worth "a try" to me.  It wouldn't be the first time I put effort and a little money into a learning experience alone.  I enjoy doing such with potential for a substantial payoff.  Experimenting with front coil springs, there is no harm in reverting back to what I started with.  It's like experimenting with various shock absorbers.

The tag was on my spring, surprised yours wasnt still on there. 

I admire your spirit, but I have twisted wrenches too long to get joy in doing the same job several times. Getting the right spring custom made is worth a couple hundred easily in my book.  I checked with my 'alignment guy'  to make sure the front end can still be aligned properly with a 2" drop.  His first reply was 'isnt it kinda high over stock to start with? ' which means I am carrying a tape measure and looking for stock E series vans to measure.     But he did say that a STOCK height can be lowered 2 inches and still be adjusted within specs, so I am looking good. Just with the original height being OVER stock, my desired drop may be more than 2 inches from 'coachbuilt' height, but not more than 2 inches from 'factory designed' ride height.

And the reason PC doesnt spring (hahahahaha see what I did there?) for the extra cost and replace the front coils is because then that WHOLE package must be re certified because they are resellers. As 'end users' we can replace parts without that requirement. 

Be interested in your results.  Right now (from the passenger side) my coach looks like it is 4WD the way it is parked,  so if the rain holds off I am gonna level it tonight and measure.

The tag was on my spring, surprised yours wasnt still on there. 

My tags may still be on my front coil springs as well.  I didn't think of looking until after you had done so on your 2006 2350.  I should crawl under and see what my tags say, though not sure what to do with the information now.

About the idea of air bags in the rear on our 2007 2350, I feel that is addressing only part my goal in keeping the rig level.  Being the miser that I am (most beneficial, lowest cost), I am trying to come up with a very affordable, readily available $96 solution (plus installation).  If successful, no human interaction would be required, and hoping to address a longer list of minor issues.

I imagine PC owners with model 2551 and longer, scanning through this thread may think I am a loon, but if you owned a 2100, 2350, and maybe even 2400 you should find this interesting.  I feel model 2100 would be the best candidate for lower rated front coil springs, given so much weight rests behind the rear axle has the front lifted worse than our model 2350.

I have wondered this.
The Sprinter version of model 2350 has a stock wheel base of 170", the Ford utilizes the stock 158" wheel base.  I wonder if stretching the Ford 158" to 170" would best address the problem.  That would transfer more weight from the heavily-loaded rear axle to the lightly-loaded front axle.  Certainly this could not be retrofitted on an existing rig, but rather included in a brand new special ordered Ford-based 2350.  Moving the rear axle 12" more rearward might make quite an improvement in weight distribution, quality of ride, better front wheel alignment, and better handling.

  The tag on my passenger spring was easy to read in the wheelwell. Took a cell pic of it, no crawling under required. 

Well, no arguing that a $96 solution is initially more economical than a $300 solution.     

We would have saved ~$5K+ if we had gotten a 28 foot Coachmen instead of our 24 foot PC. At the same dealer, it was one year newer (2007). The salesman was kinda confused when we were not even interested in looking, and just wanted to inspect the PC. I was aware of the many advantages that were not obvious with the PC, thanks to Mrs. V's research. He really had no idea why that little coach was at a premium.

I feel the same with parts.  Moog is certainly a respected name, and sells very capable parts. Their $98 springs probably look near identical to the $300 springs.  But after talking with Kevin, and reading up on the company, I am impressed with their process. They can provide me with an alloy datasheet for the metal used, and the test results of the very spring I will install on my vehicle. That they test in house before it ships.   This is 'professional grade' stuff in my book, not the parts you buy from Autozone* or Rock Auto, Discount Auto, et al.

Like the $5K more for the PC, another $200 to upgrade to 'custom made for my needs and tested to meet specs' springs may seem strange to someone who does not know all the information I base the decision on.  Automotive Geek life. 

Time will tell!  I look forward to following your progress. I know it will be well written and thought out.







* Dont get me wrong - There are many pro shops that use AZ for parts. We did, but not for the quality of the part. AZ was the only supplier that PAID FOR WARRANTY LABOR if the parts supplied were a warranty issue.  We used AZ parts for our cheaper customers, we knew they would squeal the loudest if the part failed and they had to pay for labor again. (Like its OUR fault the part failed...?!?!)   Heck, my front shocks are from AZ, and I love the cushy ride. So are my brake calipers!

My two Moog CC81370 E150 Springs from Rock Auto came today.  Boy these things are heavy.

I failed to mention this earlier.  The Moog CC81370 springs I bought have a variable spring rate where the coils near the top are closer together than the coils near the bottom.  I don't know if my original Ford E350 springs are equally spaced.


I have so much going on in July.  I likely won't get to the project until later this month or early next month.

Looks like July is out for me too. I spec'd a 2" drop on the driver side, and 2.5" drop on the passenger side. 15% lower spring rate for a cushier ride. $325 delivered.

On my 2350, the slide, LP tank, generator and fridge are all on the driver side, and it has always been a 1/2-3/4 inch lower. I would like to see if the front spring can correct that a bit.

I asked about progressive rate. He said they make them, but he does not like to sell them for steering axle use. Since i had been on hold for ~25 min waiting for him, I didnt question it.  I did a bit of googling to try to corroborate that opinion and didnt find much, but did find a mustang page that covered it.

https://www.cjponyparts.com/resources/mustang-linear-vs-progressive-springs

In short, looks like its a performance driving issue, and personal preference. I copied and pasted some off the link above.

Why people might prefer linear:

Handling Feel: We’re not talking about handling capability; we’re talking about overall feel you get from the suspension components working in unison as your car takes a turn. This is how your suspension communicates with your chassis and in turn, communicates with you as you’re cornering at speed. It’s a simple fact that linear springs will communicate better than progressive springs due to the predictability of a constant spring rate.

Not A Daily Driver: Is your Mustang a Weekend Warrior? Great! Linear springs may be a good choice for you since a rougher ride quality won’t be at the top of your list.

Handling > Ride Quality: If you value handling more than ride quality, then linear springs are the way to go for you.

Why people might prefer progressive:

Better Ride Quality: In comparison to linear lowering springs, progressive lowering springs will offer a smoother, more enjoyable ride.

Your Vehicle Is A Daily Driver: If your vehicle is a daily driver and you’re constantly in the driver’s seat, you’re probably not going to want a rough ride.

Ride Quality > Handling: If you’re willing to sacrifice a little bit of handling


So it appears there is merit to him not wanting to put progressives in front. Just oriented towards performance and handling(safety) and not comfort. But as most wont be pushing their PC's to 'extreme handling limits' it looks like progressives are a fine choice for the front.  Especially (In my opinion)  if you have upgraded other components like Ron has - rear sway bar, track bar, over sized front sway bar etc.

So now a 3 week hiatus for that project. 

Volkemon,

One of my primary goals in changing the front two springs from E350 to E150 is to achieve a softer ride up front where the both of us and also our PC would appreciate.  As you say, I think I can afford a little sacrifice in handling (if any is sacrificed) given all the other suspension upgrades I had done.

Progressive/variable-rate springs, or linear was not optional for my choice.  It kind-of makes sense regarding the benefit they offer so I look forward to my test drive.  I do wonder if our original E350 springs today are progressive because Moog only offers progressive across the E-series.  When I take the old ones out, I will take comparison photos.