Switch to 8K Axles?

[kowbra]

Originally Posted by allenclme

$7500. They offer a seasonal discount if done in Dec-Feb but I don't know what that is. What was explained on another thread that 2800# of my GVW is on the pin, so with the two 7000# axles (14000#) that's how the total GWV was determined. Mine is about 168xx but it's at CW getting work done so I can't look to get the exact number. MorRyde didn't say I couldn't do the 8000# axles, just that it was not necessary and would make the suspension stiffer.

Thanks Craig!

I do understand the math but that seems right on the edge. For example, to use your numbers, there is exactly 14000lbs on the RV and exactly 14000lbs of axles to carry it. If all is level side to side and front to back all ok. Except it never is. For example, the fridge slide is going to weigh much more than the dinette side.
So, I guess that's where I've been wondering if 7k suspension is enough. From factory that's all that's available, but if I was to upgrade, I'd sure be wondering if 8k upgrades would give more of a buffer.

Or maybe I have it wrong; I'd sure trust the experts but still curious why they recommend 7k when it seems so close to the edge. Any further thoughts appreciated.

Brad

[McRod]

Originally Posted by steiny93

When I read this thread I come away with the following 3 points

1) 8k axles are better then 7k axles
2) Non IS axle setups have problems which are not typically axle specific (having an 8k axle wouldn't necessarily mitigate the common issues over a 7k axle).
3) IS is a good but costly option

8k is not "better" than 7k. Each has their own appropriate application. 8k can have the opposite effect of a "smooth" ride if your pulling a 12k trailer. Like a dually has a rough empty ride until weight is put on it.

Both IS and Leaf spring suspensions can and do have maintenance failures. Both have required maintenance parts and both have limits on how long the wearable parts will last prior to needing to be replaced. Its not "IF" it's "when" for BOTH systems. Outside of the shock absorber and the shear spring, the spindles, hubs, and brakes are identical on leaf spring systems.

If you have a Montana that has a LRE 4000 center hanger (OEM) with shear springs, I would not upgrade to an IS - just add shocks and cross bars and your good to go for ride quality - if weight is the issue then you have to go with IS to keep ride quality AND increase weight to 8k because LRE 4000 is only rated to 7k LIC. If you have other center hangers then it may be worth it if you are having problems that an IS can resolve. But you really need to know what the problem is to address it correctly.

The OPs question wasn't about IS vs LS suspensions. It was about moving to an 8k vs 7k suspension. If your at or close (within 500lbs) of your weight limit (>13,500 lbs on the axles), I would say to upgrade to the next higher axle weight. If you decide to upgrade to resolve that issue, that is time to determine what type of suspension will meet your needs. IS suspensions are nice, but maybe adding shock absorbers is all you need! Or go with air bags!

[Texan]

Originally Posted by allenclme

$7500. They offer a seasonal discount if done in Dec-Feb but I don't know what that is. What was explained on another thread that 2800# of my GVW is on the pin, so with the two 7000# axles (14000#) that's how the total GWV was determined. Mine is about 168xx but it's at CW getting work done so I can't look to get the exact number. MorRyde didn't say I couldn't do the 8000# axles, just that it was not necessary and would make the suspension stiffer.

The seasonal discount is 10% off for the brakes and I.S. This is whether you do one or both. At least this will pay for the fuel on your trip.

[Texan]

Originally Posted by McRod

8k is not "better" than 7k. Each has their own appropriate application. 8k can have the opposite effect of a "smooth" ride if your pulling a 12k trailer. Like a dually has a rough empty ride until weight is put on it.

Both IS and Leaf spring suspensions can and do have maintenance failures. Both have required maintenance parts and both have limits on how long the wearable parts will last prior to needing to be replaced. Its not "IF" it's "when" for BOTH systems. Outside of the shock absorber and the shear spring, the spindles, hubs, and brakes are identical on leaf spring systems.

If you have a Montana that has a LRE 4000 center hanger (OEM) with shear springs, I would not upgrade to an IS - just add shocks and cross bars and your good to go for ride quality - if weight is the issue then you have go with IS to keep ride quality AND increase weight to 8k because LRE 4000 is only rated to 7k LIC. If you have other center hangers then it may be worth it if you are having problems that an IS can resolve. But you really need to know what the problem is to address it correctly.

The OPs question wasn't about IS vs LS suspensions. It was about moving to an 8k vs 7k suspension. If your at or close (within 500lbs) of your weight limit (>13,500 lbs on the axles), I would say to upgrade to the next higher axle weight. If you decide to upgrade to resolve that issue, that is time to determine what type of suspension will meet your needs. IS suspensions are nice, but maybe adding shock absorbers is all you need! Or go with air bags!

Adding shocks will do very little for the rv unless they can be mounted straight up and down and very few rv's can do that unless you have I.S. My axles weighed 12,720 pounds and i was loaded what i considered pretty heavy and i was recommended the 7,000 pound axles. I am sure i have added a few more pounds through the years but it has been mostly in the front storage area so most of what ever i have added has gone to the pin weight. It's always best to let Mor-Ryde weigh the rv to give you an accurate weight so as you can see why they recommend what they do. They will sell you what ever you want but if you want a good ride then you don't want to oversize the axle. Some rv's need the 7,000# axle and some the 8,000#. I can agree that if you are within 500 pounds then i would probably go with the 8,000# axle and i feel pretty certain Mor-Ryde would recommend that also.

[beeje]

I believe the winter discount is 10% off of Parts Only

[McRod]

Originally Posted by Texan

Adding shocks will do very little for the rv unless they can be mounted straight up and down and very few rv's can do that unless you have I.S...

There are plenty of good aftermarket shock absorber kits for trailers. Lippert, Roadmaster, and joy rider all have shock absorber kits. They are widely available. Shocks are typically mounted on a 15° plane. Most high end trailers use them.

[GrahamLock]

Originally Posted by PNW Fireguy

Switched to 8k IS for improved ride and to remove what I consider to be the Achilles heal the OEM suspension. Take note that none of these items changes the vehicle weight limit indicates on the sticker.

What does IS mean?

[GrahamLock]

What does IS mean?

[McRod]

Independent suspension

[beeje]

Independent suspension= IS

[Montana Man]

How does one quantify a better ride by adding shocks? Or IS for that matter. I've read where you can leave a cup on the counter and it will still be there in hundreds of miles. I bet that the crash avoidance maneuvers I had to do today on highway 5 would toss any free standing items.

[beeje]

Originally Posted by Montana Man

How does one quantify a better ride by adding shocks? Or IS for that matter. I've read where you can leave a cup on the counter and it will still be there in hundreds of miles. I bet that the crash avoidance maneuvers I had to do today on highway 5 would toss any free standing items.

If shocks could be installed in a near-vertical position they would help with the balance of the axles up and down but that's nearly impossible to do.

In my opinion the is is simply the best suspension you can buy it has a shock in each wheel and each one operate independently from the other just like most of today's cars.

I had the is installed simply because I had so many suspension problems. Bent with bolts missing wet bolts worn out wet bolts and bronze bushings sagging Springs to the point the tires Were Striking the underside of the camper. I installed an all new suspension four years ago new Springs u-bolts what bolt kit Etc and still had issues.

The IS suspension can be aligned using a hunter laser aligner easily without bending anyting simply add shims by loosening bolts. Camber and toe can be adjusted.

The is along with disc brakes is just simply an amazing upgrade and until you experience it I suppose you'll be second-guessing it.

If you can't afford it or simply think it's not worth that price so be it.

[Montana Man]

Disk brakes are a no brainer. Probably my next upgrade. The discussion on the 8k axles was interesting and for me requires more study. The questions regarding IS are honest questions. They make sense from a logical viewpoint as being easier on a trailer, but have yet to read/research anything factual to support that assumption. I don't mind paying for stuff. I just want to know why I'm doing it.

[beeje]

I personally don't have any problem spending good money for Quality things.
However I hate having to spend money because I didn't do that in the first place. And then you have to spend money on items that are not tangible things like Towing your rig from the middle of nowhere to a shop to have the junk suspension replaced or repaired, ruining your trip

Kind of like trying to get another five years out of the roof on your house and then unknowingly find out but it's been leaking, rotting all your trusses out and your plywood deck then on to this bedroom ceiling which has to be replaced.

[kowbra]

Originally Posted by Montana Man

Disk brakes are a no brainer. Probably my next upgrade. The discussion on the 8k axles was interesting and for me requires more study. The questions regarding IS are honest questions. They make sense from a logical viewpoint as being easier on a trailer, but have yet to read/research anything factual to support that assumption. I don't mind paying for stuff. I just want to know why I'm doing it.

I also have found the discussion interesting, but I feel like I'm in exactly the same situation...
almost like "if a tree falls in the forest, does anyone hear it?" :-)

Brad

[beeje]

For me to spend that kind of money for something like that is very unusual. My wife doesn't call me a penny pinching Miser for no reason. Lol

Just to give you an idea of the quality difference, the old axles were unbolted pulled out of their easily lifted by the skinny young man that was doing it and hauled outside.

I watch them Assemble the new is and it was all done with electric winches cranes and heavy-duty equipment that roll them around. They were rolled over to the camper on to floor jacks and then hoisted into place.

But put it this way I could easily walk over to one of the old axles and bench press it over my head with ease.

I couldn't even get one of the is units off the ground. They are built like a Sherman tank

[kowbra]

Originally Posted by beeje

For me to spend that kind of money for something like that is very unusual. My wife doesn't call me a penny pinching Miser for no reason. Lol

Just to give you an idea of the quality difference, the old axles were unbolted pulled out of their easily lifted by the skinny young man that was doing it and hauled outside.

I watch them Assemble the new is and it was all done with electric winches cranes and heavy-duty equipment that roll them around. They were rolled over to the camper on to floor jacks and then hoisted into place.

But put it this way I could easily walk over to one of the old axles and bench press it over my head with ease.

I couldn't even get one of the is units off the ground. They are built like a Sherman tank

...which is one of the negatives; several hundred less pounds of cargo capacity... still unsure

Brad

[beeje]

I suppose you could look at it like that. A lot of that is unsprung weight.

If I was going to be overweight I much rather have that bearing on the IS suspension than the horse and buggy suspension

[beeje]

The main reason to get the IS was to avoid this from ever happening again. We drove 200+ miles through the MD mountains on 10% grades up and down only to find this the day after we got home. We could have been killed if the other bolt broke holding that that spring on.

[beeje]

Just a few pics of the IS install.