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Phrunes · 04-03-2013, 04:39 PM

Quote:

Originally Posted by jquayle

Just received my suspension upgrade today from UpScaleAutomotive.

I ordered front struts, rear Koni shocks and their rear anti-sway bay. Should have it installed by Friday. Really looking forward to seeing how much of an improvement this makes in both sway and ride comfort for the rear passengers.

As much as I'd love to go with the full 4 airbag Glide-Rite system, $11k for suspension isn't on the foreseeable list of possible expenditures for my family.

I'll update with results soon.

I always thought that "rear airbags" was accomplished by placing the in-laws in the backseat?

hamiltonmj · 05-28-2013, 05:00 PM

We bought a new 2013 Interstate last month and I was wondering if anyone else has noticed that on an uphill section when the Interstate downshifts, RPM at about 2700 and speed about 60-65 mph, there is a loud noise/vibration in the rear seating area coming from the rear end? It's enough to keep you from sleeping in the back while the wife drives...

73shark · 05-29-2013, 09:14 AM

I have never noticed any rear end noise on mine. Since it happens on down shifting, are you actually hearing the engine at a higher rpm? If it is actually rear end noise then you should probably get it checked out by the dealer.

hamiltonmj · 06-12-2013, 01:55 PM

Comes from the rear end. We were driving down the interstate in the Interstate and I put my ears to the place above the rear differential and the noise/vibration seemed to come from there...not that noticeable from the front...taking it to the dealer tomorrow for rear hub leak and will note it with them then.

joemikeb · 06-13-2013, 05:12 PM

Quote:

Originally Posted by jquayle

Just received my suspension upgrade today from UpScaleAutomotive.

I ordered front struts, rear Koni shocks and their rear anti-sway bay. Should have it installed by Friday. Really looking forward to seeing how much of an improvement this makes in both sway and ride comfort for the rear passengers.

As much as I'd love to go with the full 4 airbag Glide-Rite system, $11k for suspension isn't on the foreseeable list of possible expenditures for my family.

I'll update with results soon.

So what are your results? I just ordered the Koni struts and shocks and I am wondering if I should have gone ahead and ordered the enhanced sway bar aw well.

jquayle · 06-13-2013, 11:15 PM

I don't ride in the back myself, but I've had 4 family members state that its a very marked improvement. My wife was a bit reluctant spending about $2k to upgrade the suspension, but after riding in it now she thinks it was money well spent.

Honestly I don't notice much difference with the front struts.

I do notice the reduction is body sway and would recommend the sway bar.

Hope that helps

russ240 · 06-14-2013, 09:43 AM

I did only the rear Koni's and was shocked

by the transformation. The amont of sway resulting from uneven roads and driveway approaches taken at oblique angles was vastly improved. Unfortunately I can't really comment on the improvement to the ride in the rear seat as I have not had a rear passenger, but the body motions in general were so much better controlled that it would have to be better. The improvement from this one change was so dramatic that I did go ahead and order the front Konis to match. They will be installed next week along with the camber bolts that should allow me to get rid of the the small amount of positive camber the front suspension has now which should improve front tire wire and steering response.

joemikeb · 06-14-2013, 01:51 PM

Quote:

Originally Posted by jquayle

I don't ride in the back myself, but I've had 4 family members state that its a very marked improvement. My wife was a bit reluctant spending about $2k to upgrade the suspension, but after riding in it now she thinks it was money well spent.

Honestly I don't notice much difference with the front struts.

I do notice the reduction is body sway and would recommend the sway bar.

Hope that helps

Thanks for the feedback, I will probably go ahead and add the sway bar and maybe the camber bolts mentioned by russ240 as well — as I said before the Koni's are already enroute. The cost does not seem out of line, but I wanted to be sure they could deliver what they promise before I invested more.

73shark · 07-04-2013, 03:27 PM

Did you get the Konis on yet?

joemikeb · 07-04-2013, 07:33 PM

Mutter, Mutter, grumble, NO, I have not yet installed the Konis.

I neglected to swing wide enough pulling into a filling station and got a minor (I stress the word MINOR) crease just behind the sliding curb side door. Between the insurance company negotiating with the body shop, ordering a small panel from Germany, and a smaller chrome trim piece from Airstream (all seriatim of course), my Interstate has been in the body shop for a month tomorrow and I still don't have an estimated completion date! In the meantime the Konis are sitting in my garage at home waiting for a vehicle to be installed on.

When I get my Interstate back from the body shop the Airstream dealer will still owe me a repair on the back door that occurred before delivery and reattaching the water tank sensors that have taken to falling off.

Sometime this summer, I hope to get my rig back, get the Konis installed, and have the chance to take our baby out on the road again.

73shark · 07-05-2013, 08:34 AM

Man that sucks big time. Hope you get it back on the road this summer.

Ripple · 07-09-2013, 06:42 AM

Quote:

Originally Posted by hamiltonmj

Comes from the rear end. We were driving down the interstate in the Interstate and I put my ears to the place above the rear differential and the noise/vibration seemed to come from there...not that noticeable from the front...taking it to the dealer tomorrow for rear hub leak and will note it with them then.

This is considered a "normal noise by Mercedes". This noise is so annoying and loud and you are correct that is tied to RPM. When you go up a slight hill is whites loudly from the rear. They replaced a bunch of parts in the rear end and after 2 weeks in the shop, we got it back with the same noise and a "normal" explanation from Mercedes. It is related to the engine rpm and I think is is a resonant sound that the engine creates at certain RPMs. They worked the diff and the driveshaft with no luck. I was so bummed at that point, I told them I'd believe it was normal if they could show me the sound in another rig. So went down there and took another brand new one out on the road and sure enough, same noise.

I am convinced that this can be solved and will keep trying to dive into it when I am not touring these next 4 months. Let me know if you figure anything out.

hamiltonmj · 07-09-2013, 07:51 AM

Quote:

Originally Posted by Ripple

This is considered a "normal noise by Mercedes". This noise is so annoying and loud and you are correct that is tied to RPM. When you go up a slight hill is whites loudly from the rear. They replaced a bunch of parts in the rear end and after 2 weeks in the shop, we got it back with the same noise and a "normal" explanation from Mercedes. It is related to the engine rpm and I think is is a resonant sound that the engine creates at certain RPMs. They worked the diff and the driveshaft with no luck. I was so bummed at that point, I told them I'd believe it was normal if they could show me the sound in another rig. So went down there and took another brand new one out on the road and sure enough, same noise.

I am convinced that this can be solved and will keep trying to dive into it when I am not touring these next 4 months. Let me know if you figure anything out.

I am pretty sure it's resonance. Was thinking of trying Dynamats to absorb the sound and vibration ... Maybe someone else has a solution.

73shark · 07-10-2013, 07:55 PM

It could be that the gears in the differential are not set up properly. If that's the case, then a good mechanic experienced in setting up differentials properly could fix it. Even if another one on the lot exhibits the same noise doesn't mean it's OK. It also might just be a case of sloppy gear tolerances, in which case it can't be fixed.

I'll bet MB cars don't make that noise and if they did, they get fixed.

Protagonist · 07-10-2013, 09:04 PM

Something just occurred to me. I'm only guessing, so a reality check might be in order…

Given the amount of insulation in the floor of an Interstate, the sound should have been significantly attenuated. Yet it's still loud for you guys. Maybe for my Interstate, too, but I never ride in the back to hear it.

So how is that noise being transmitted to the interior? I'm thinking that the least-insulated area back there is the wheelwells, and it sounds like it's coming from the middle because you're hearing it from both sides.

If so, then for a temporary solution until a mechanic can sort it out, you might try lifting up the side-facing seats to stuff pillows, or foam, or some other sound-deadening material in the boxes over the wheelwells.

It may or may not help quiet things down, but it's easy enough to try, and doesn't cost much.

hamiltonmj · 07-11-2013, 06:53 AM

Yes, that was exactly where I was going to try some sound insulation. The RBM folks told me that AS will be making plastic "drawers" to fit in this slot over the dual wheels but haven't had the chance to go to WM and see if something there might fit.

Lawn guys broke my rear quarter window yesterday weedeating...now it's a tape job.

While i was listening to the vibration last week I thought I felt it going up the side walls??? We were on a trip to NC pulling a small trailer...I might try the Koni's ... seemed to ride better with a full trailer being pulled...

Resonance could go from diff to axle to contact points of the body like where the shocks fit...hmmmm...

Protagonist · 07-11-2013, 07:30 AM

Quote:

Originally Posted by hamiltonmj

Yes, that was exactly where I was going to try some sound insulation. The RBM folks told me that AS will be making plastic "drawers" to fit in this slot over the dual wheels but haven't had the chance to go to WM and see if something there might fit.

Since I never ride in the back, I never noticed a noise problem. I use the space under those seats to store my shore power cables and extension cords on one side, fresh water hoses, spare filters, etc. on the other side.

Quote:

Lawn guys broke my rear quarter window yesterday weedeating...now it's a tape job.

If you have trouble getting the window replaced, the manufacturer of the windows, CR Laurence, also sells direct. CRL Sprinter Van Windows

Quote:

Resonance could go from diff to axle to contact points of the body like where the shocks fit...hmmmm...

Which brings you back to the wheelwells.

A question… How much of the sound can be attributed to simple road noise, from the sound of the tires on the pavement— rather than the differential? Big, heavy tires, lots of ground pressure (otherwise you wouldn't need 61 psi) and duals for double the contact surface, can make for a lot of noise that you wouldn't get in a smaller vehicle, even with smooth treads on the tires. One way to find out, try listening while traveling on different road surfaces… asphalt, concrete, sod. If you get the same noise driving across a lawn as you do on the street, it's definitely not the tires, but if the noise goes away on the softer surface, it's the tires.

I thought of that on my way to work this morning, when I was passed by a 4×4 with knobby mudgrip tires, where the sound of tires on pavement was louder than his engine.

joemikeb · 07-11-2013, 10:15 AM

Quote:

I thought of that on my way to work this morning, when I was passed by a 4×4 with knobby mudgrip tires, where the sound of tires on pavement was louder than his engine.

Given recent highway engineering studies indicating somewhere around 70% of environmental noise on highways is the result of tires on the road surface that is certainly a possibility. If it is tire noise it should change with different road surfaces and even with different speeds.

hamiltonmj · 07-11-2013, 04:11 PM

It only happens at certain RPMs regardless of road...I hear a small indication initially in the shift from 3rd to 4th as speed builds but only lasts a second due to shfit...lasts as long as I am going 68mph and 4th gear? One down from drive?? So I don't think it is the road.

Protagonist · 07-11-2013, 04:52 PM

Quote:

Originally Posted by hamiltonmj

It only happens at certain RPMs regardless of road...I hear a small indication initially in the shift from 3rd to 4th as speed builds but only lasts a second due to shfit...lasts as long as I am going 68mph and 4th gear? One down from drive?? So I don't think it is the road.

That's fine. But I would have been remiss not to ask, since if it had been the road noise, you could have possibly saved some repair money.