Morryde IS 7K or 8K

[Sauced Hog]

Hi all, We decided to upgrade our rig to the Morryde IS w/ disk brakes hopefully mid 2022 if we can get scheduled. Everything I've seen and read about them is quite impressive, and since we plan to travel extensively and do an Alaska trip, the IS seems to be a worthwhile upgrade. I really just need to decide if I should go with the 7K or 8K? Our 376THS is triple axle rated at 20,000 lbs. Seems the 7K IS would do the job to 21K, but the cost difference is minimal between the two? I also understand the bearings and brakes are bigger? Can anyone tell me if they had the choice between the 7 and 8K and why they went with the one they chose? My gut says just go with the 8K, but there is also the additional weight to consider. Thanks
-Mike

[Hoopy Frood]

Personally I would stick to the 7,000 lb. axles, 8,000 lb. axles/spring rates are going to give you a harsher ride due to the stronger springs, maybe too harsh with a triple axle. This may be one of those times when bigger is not necessarily better.

[Second Chance]

MORryde has a range of rubber sheer springs and they select the springs according to the wheel weights regardless of whether the suspension units are the 7K or 8K. Choosing the 8K suspension units will not result in a harsher ride. At the GVWR for your rig, definitely go with the 8K units.

Rob

[Hoopy Frood]

Good idea to match springs to actual weights. I didn't know they customized them that way. Thanks for the heads up.

[Second Chance]

Good idea to match springs to actual weights. I didn't know they customized them that way. Thanks for the heads up.

It's a pretty interesting process, Howard. The first thing MORryde does when you arrive is to weigh and measure the height (off the ground) of the rig. Everything done after that is calculated from those numbers. They even ask how tall you want the rig. In most cases, one wouldn't want it any taller than stock due to overhead clearance issues. On our previous Reflection, I had them add two inches since I had overhang-to-bedrail clearance issues with the truck. When we ordered the Solitude, I asked for stock height since the Solitude is so tall, anyway (and our current truck isn't as tall as the previous one). On our Reflection, we got to watch as much (or as little) of the process as we wanted. It was fascinating to see them fabricate the sub-frame and fit it. I watched the night shift guy assemble the bearing and hub assemblies on the suspension units. Finally, they used a Hunter laser alignment system to adjust caster, camber and toe before a tech and I took the rig for a road test. It was an extremely positive experience.

Rob

[Hoopy Frood]

Rob, that's very interesting, thank you for the insights.

[geotex1]

If you are going with disc brakes, the only difference between 7 and 8K is the larger outer bearing and 9/16" studs. Everything else is same. I would go 8K just for the oil baths.

[traveldawg]

My appointment is for October '22. I asked MorRyde what they suggested and they said for my rig 7,000 lbs is fine.

Have you asked MorRyde for their recommendation?

[Second Chance]

If you are going with disc brakes, the only difference between 7 and 8K is the larger outer bearing and 9/16" studs. Everything else is same. I would go 8K just for the oil baths.

Although it is available, MORryde recommends against the oil bath hubs (I have had a conversation with one of their engineers regarding this). It has to do with the smaller internal volume of the hubs compared to the hubs and axles on tractor-trailers.

Rob

[Hoopy Frood]

I have heard that the oil bath works best with hubs that are in motion frequently, so not such a great fit for RV's that may sit for months at a time. Just what I've read and heard anyway.