For the suspension experts out there, I have a question

[RV 4 2]

I have a W24 chassis under my 2008 National Dolphin DX35ci. I am curious as to how much distance between the rear frame snubbers and the rear springs should there be. Weight on the rear axle is 14,120 lbs. I know I am below the max axle weight but am curious as to what others see regarding the separation distance as I would think it should be more than what i see of about 1/2 inch.

Thanks,
Mike

[Davel]

RV 4 2,
The "Like Air Springs" you see are not snubbers in the normal sense. They are cushions that are hollow inside that trap air when the suspension is compressed. They smooth out and cushion the suspension travel. I've been told the space beween the them and the spring should be roughly equal on all four corners and fairly close to the spring. While it's not as accurate as getting the coach weighed on all four corners it is a way to roughly judge how evenly distributed your weight is.

Hope that helped,
Dave

[DriVer]

Quote:

Originally Posted by RV 4 2 I know I am below the max axle weight but am curious as to what others see regarding the separation distance as I would think it should be more than what i see of about 1/2 inch.

When you look at your rig from the side, does it appear to be level?

I just went to look at my like-air springs and they are sitting in contact with the top of the leaf spring. If you have a 1/2 inch clearance between the bottom of the air spring to the leaf spring that doesn't mean that anything is abnormal.

[RV 4 2]

Thanks for the replies. Driver, Yes the coach seems pretty level. The strange part is that there is a gap of about 2+ inches gap .on the front 'like-air springs' to leaf spring. I had my coach in for a front end caster adjustment at Redlands Truck and the workhorse rep said I was fine on the rear weights but light on the front. That is why I was asking. It seemed like it was abnormally close on the rear and that I would think there would me more of a gap for more suspension travel.
Now to solve the howling coming from the rear end. I need to get it into a good WH chassis shop for an analysis. It starts to howl noticably about 55 and gets REALLY LOUD at 65mph and gets worse as I go faster. I normally drive at about 60 anyway but drove faster several times to try to analyze it. The pitch gets higher as I drive faster too. The noise goes away when I take my foot off the gas and the load is offf the drivetrain. There is plenty of oil in the diff and when pulling the plug. it does not seem like there is an abnormal amount of metal on the filler plug magnet. All the rest of the drivetrain seems fine. So it is off to a shop for a better analysis. Thankfully I am still under warranties.
Thanks again.

[Davel]

RV 4 2,

A friend of mine had the same issue, to the point he wore ear plugs on the way home from the East coast. It was the ring and pinion and required a new differential. It is not easy to ID as he had it to more than one dealer before it was fixed. Redland's has a terrific reputation for service if they are nearby. As far as being light on the front, you are at the mercy of the body builder for weight distribution for the most part.

Good luck,
Dave

[RV 4 2]

Dave, yea, I know, the weight and design of the MH go to the builder. This past weekend I was comparing a 08 34ft Dolphin to my 08 35ft Dolphin and all the added length was put behind the rear axle. Personally, I think National should have used the 242" wb chassis instead of the 228" wb one that is under my coach. I think it would have made a difference with the axle weights making them more balanced. Oh well, not much I can do about that part.

[DriVer]

Quote:

Originally Posted by RV 4 2 I think National should have used the 242" wb chassis instead of the 228" wb one that is under my coach. I think it would have made a difference with the axle weights making them more balanced. Oh well, not much I can do about that part.

I had a 228" before Winnebago made it a 248".

[RV 4 2]

Quote:

Originally Posted by DriVer I had a 228" before Winnebago made it a 248".

We had a friend who had a 03 Winne Chieftan that had a stretched W22 chassis to that 248" wb. It was a 39ft coach and it was a Loooong coach. With all the stuff he had in it, I am sure it was overloaded but he said it rode very well.
For me, my 36ft coach is just fine as it fits on my driveway with about 2 ft to spare. Basically we bought a coach that we liked that fit in our driveway.

[justimagination]

Mike, the noise in your rear axle will not go away, sorry to say. It is caused from the Pinion Gear depth not being correct from day one. You can also have this type of noise while coasting as well, same senioro, pinion depth not correct. A good shop can replace the Ring & Pinion gears along with the necessary bearings and seal, and when properly set up (meaning checking the pattern) to make sure the pinion is not to deep as well as not deep enough. Good mechanics know how to do this, rest assured it can be fixed, and does not require replacing the complete rear axle housing. If they tell you you need a complete rear axle assy, get a second opinion. Good Luck. Let me know what they tell you, trust me, I know if their blowing smoke, which in turn is more $$$$$.
David G.

[RV 4 2]

David, thank you for the info. I am pretty sure it is the differential. Luckily, I still have 2 years of warranty under Workhorse and 3 under an extended warranty so if they want to replace the whole rear end, it is fine with me since this is a warranty issue.

BTW, cute puppy in your avatar.