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Boater
09-13-2013, 12:38 PM
Just been looking for leaf springs - Looks like the 312D could have a single leaf (up to 3.2t?) or 2 leaf springs (3.5t?).
Mine has 3 leaves (2+1), which as far as I can tell are the ones for the 4t class vans, 412D etc.....
I still haven't worked out if 312D would be a 2500 or 3500 in the US, but the spring choices seem to be the same on all T1Ns?

I know people uprate springs for towing and that the permanent weight of a motorhome/RV conversion can cause issues so people uprate or fit assisters, the question is what is the most sensible thing for me to do?

My van has a pretty spartan motorhome conversion with a large garage space at the back so when it's parked up at home (will only ever be a weekend car) there is little permanent weight over the rear axle over and above the vans own weight.

There is a towbar fitted, although with my current license I can't tow very much with it, and have never towed with it, but might do (up to 750kg/1500lb trailer).

Should I be looking at replacing with the original type of spring, replacing like for like (assuming I have 4XX series springs and not 3rd party replacements) or even going to a 3rd party spring, perhaps parabolic?
Will the springs for the 4t models be too harsh given that I am unlikely to be fully loaded (3.5t) most of the time (I hope).

Also if I use something other than the original type do I need to tell my insurer?

Also recalling threads about downrating 4t class sprinters with spring limiters etc. - would having the springs for a 4t van technically require the van to be uprated to 4t class (my license only allows me to drive up to 3.5t)? That last question is definitely UK specific!

By the way - I have a broken spring so spring assisters aren't an answer, I need to sort out the actual spring, or springs.

Thoughts?

sailquik
09-13-2013, 03:19 PM
Boater.... beyond the spring configuration, the main difference between the 2500 and 3500 in the USA is that the 3500's have a full floater (outer bearing is out side centerline of the outside wheel, and dual rear wheels..2 on each side.
2500's have a regular automotive type rear axle with the outer bearing around the centerline of the single rear wheel, but it's a simple axle shaft with a bearing.
The 3500's have a separate axle that extends through the outside bearing and into the differential, so there is no shear load on the axle, only torque.
On the 2500 single rear wheel Sprinters, the outer end of the axle is what the brake disc mounts on, so they take both shear and torque.
Roger

mean_in_green
09-13-2013, 07:13 PM
I think you might find the 4xx springs harsh if you're not over 3,500kgs anyway, at least that's how my empty T1N 416 felt. Did you know there's a 3.8t spring set available?

CJPJ
09-13-2013, 07:15 PM
Just been looking for leaf springs - Looks like the 312D could have a single leaf (up to 3.2t?) or 2 leaf springs (3.5t?).
Mine has 3 leaves (2+1), which as far as I can tell are the ones for the 4t class vans, 412D etc..... I still haven't worked out if 312D would be a 2500 or 3500 in the US, but the spring choices seem to be the same on all T1Ns? Thoughts?Boater
Charles here! I'm completely satisfied with these springs. They are the softest of the three spring rates that MB offered for the 3500. The van rides good when empty and it rides better then good with 3000lb. in it.

Boater
09-14-2013, 08:26 PM
Thanks guys.

Roger, Charles, mine has single rear wheels - the 3500 seems to correspond to the 400 (and presumably 600?) series sprinters in Europe.

On that basis and because he has over a million miles in Sprinter's I'm going to follow MIG's advice and look for 300 series springs. I didn't know there were 3.8t springs, but I have seen some that claim to be Heavy Duty, a bit more research required yet. Mind you it's taken me all day just to clean the rust off around 1 spring mount so it's going the be a while before I'm ready for springs.

xriss
09-16-2013, 05:43 PM
boater your welcome to pop over and have a spy @ my spring set up on my oberaigner cook...single leaf on 3.5 tonn james cook sporting konie shocks

israndy
09-16-2013, 06:24 PM
I have the 2007 Serenity based on the 2005 3500 and recently replaced the rear wheels, while they were off I noticed that the leaf springs looked pretty flat. I am used to the idea that they are curved and only flatten out on extreme bumps, is that correct? Should I worry? I do get air ride with this conversion but it is one of the heavier conversions and likely uses much of the Sprinter's weight carrying capability.

-Randy

Charliektm400exc
09-16-2013, 08:31 PM
Thanks guys.

Roger, Charles, mine has single rear wheels - the 3500 seems to correspond to the 400 (and presumably 600?) series sprinters in Europe.

On that basis and because he has over a million miles in Sprinter's I'm going to follow MIG's advice and look for 300 series springs. I didn't know there were 3.8t springs, but I have seen some that claim to be Heavy Duty, a bit more research required yet. Mind you it's taken me all day just to clean the rust off around 1 spring mount so it's going the be a while before I'm ready for springs.

My understanding is the 3.8T springs are for the passenger van and ambulances.

Boater
09-16-2013, 09:00 PM
Randy - flattish with with load on, but you should see a curve with the rear jacked up to take the wheels off, unless you air ride conversion has added something which holds the springs up - might be necessary to stop the air bags being overextended?

My colleagues 2008 Nissan Navara didn't even get it's MOT test today, the test centre drove it onto the ramp and noticed that the drivers side leaf spring had a negative bend in it, and the passenger side had the same negative bend and was 'cracked' so gave it back to him without testing. When he showed me I think I would have classed the passenger side as broken with the broken leaf sticking out at a funny angle (away from tyre).

Must be a bad month for leaf springs!

israndy
09-17-2013, 12:30 AM
It was jacked by the differential (with a 3000 lb. jack, YIKES). New tires work great, but the leafs (leaves?) were pretty flat, I'll find a photo and post. Not curved backward, and I do have air ride bags that will catch the RV, and I pumped them up when I saw the leaf springs. Just wanna know if they are OK, if you don't jack by the differential and take off the wheel you would never see them flat.

-Randy

Boater
09-17-2013, 02:41 PM
Ah right, probably just the permanent weight of the RV outfit means they are nearly flat at rest then, that's the main reason for adding assister springs or airbags. Maybe Leisure Travel could tell how flat the springs normally are by the time they finish outfitting?

israndy
09-18-2013, 07:01 PM
Maybe Leisure Travel could tell how flat the springs normally are by the time they finish outfitting?

Sadly, no one from the days of my 2007 Leisure Travel Van still works there as they were purchased by Triple-E. I did get a replacement body part for my T1N based Serenity, so there must be some corporate history, but I have had difficulty finding info about my unique Serenity based on the T1N since I bought it. Thanks for the suggestion though, that is why I post.

-Randy