Suspension issues

[Dpboofay]

Update on situation- Talked with GD, they offer nothing. Talked with Lippert and they are willing to send out 4 new springs and 1.5 hr coverage on labor. Decision: ordered upgrade on the springs but staying with the original axles. Time crunch as we have 2 big trips coming up and didnt want to risk waiting for the Dexter 44K axles to come in and get on. Lesson: check your suspension along with all the other trip checks.

[dbphillips]

The weight of the axles themselves are also not weight on the axles either. 2020 2600RB, 2017 Silverado Crew Cab 1500, 6.2L

Weight capacity of the axles? Simple math is combined weight capacity of double axles > GVWR of trailer. And for our 2600RB, I'm happy to pay an extra $50 an axle for the ~15% "over" capacity. Realistically, one axle can easily be subjected to the full weight of the trailer in certain modes, so 8000# axles wouldn't be crazy overkill. And of course, the trailer manufacturer needs to mount them correctly.

[Chewwi]

Weight capacity of the axles? Simple math is combined weight capacity of double axles > GVWR of trailer. And for our 2600RB, I'm happy to pay an extra $50 an axle for the ~15% "over" capacity. Realistically, one axle can easily be subjected to the full weight of the trailer in certain modes, so 8000# axles wouldn't be crazy overkill. And of course, the trailer manufacturer needs to mount them correctly.

I’m thoroughly confused as to what you are trying to communicate in response to the quoted post.

Are you thinking that two 8000 lb capacity axles are appropriate for an RV with a GVWR less than 8000 lbs?


2020 2600RB,
2017 Silverado Crew Cab 1500, 6.2L

[dbphillips]

I’m thoroughly confused as to what you are trying to communicate in response to the quoted post.

Are you thinking that two 8000 lb capacity axles are appropriate for an RV with a GVWR less than 8000 lbs?


2020 2600RB,
2017 Silverado Crew Cab 1500, 6.2L

Ha! Yeah, I read the emphasis incorrectly. I thought he meant that just because an axle is rated for a certain weight doesn't mean that's the weight it sees, but I was wrong.

So, what I mean by 8000# axles is think about what happens with a major expansion joint mismatch. Essentially, much more than half the weight of the trailer could hit one axle. Ostensibly, a 4400# axle could take a hit that damages a bearing or bends the axle at the hub.

You can imagine if you were going to take your trailer off road (extreme), you'd at least want each axle to be able to handle the weight of the whole trailer. Similar to towing with a F-350 when an F-250 is perfectly adequate.

So, at retail, a 3.5k Dexter axle assembly (D35) with brakes is $450. A 5.2k (D52) is $600. Call it half that for the trailer manufacturers and there is about $75 cost difference. For the D44, it's probably $50 more than the D35. Personally, I'd rather have paid the difference and gotten more readily available D52 axles, and Torflex, but then I'd want to go up to D60 for the disc brakes... Gotta stop somewhere.

[Dpboofay]

Ha! Yeah, I read the emphasis incorrectly. I thought he meant that just because an axle is rated for a certain weight doesn't mean that's the weight it sees, but I was wrong.

So, what I mean by 8000# axles is think about what happens with a major expansion joint mismatch. Essentially, much more than half the weight of the trailer could hit one axle. Ostensibly, a 4400# axle could take a hit that damages a bearing or bends the axle at the hub.

You can imagine if you were going to take your trailer off road (extreme), you'd at least want each axle to be able to handle the weight of the whole trailer. Similar to towing with a F-350 when an F-250 is perfectly adequate.

So, at retail, a 3.5k Dexter axle assembly (D35) with brakes is $450. A 5.2k (D52) is $600. Call it half that for the trailer manufacturers and there is about $75 cost difference. For the D44, it's probably $50 more than the D35. Personally, I'd rather have paid the difference and gotten more readily available D52 axles, and Torflex, but then I'd want to go up to D60 for the disc brakes... Gotta stop somewhere.

My ultimate goal after reading so much that has been posted here, I am trying to match a friends rig that is the same floor plan just 1.5 yrs newer. He has the 44K Dexter axles, 2200# springs. For right now - The new Lippert 2200# springs have arrived, a 2” lift kit for the Lippert tandem axle, new service kits, and bearing kits. That should get me through the next 2 trips. Certainly I will be weighing the rig before we head out!! Once we are back, the upgrade to the axles will commence.

One question out there is currently I have the 205/75 -15 tires on. With the new springs and lift kit I am thinking of uping the tire size to 225/75 - 15 like my friends rig.

Any assistance on this part would be appreciated.

Happy trails!

[GeoffnCheri]

I started doing some calculation and if I have 3500# axles x 2=7000# Unladened weight is nearly 6400#, and yet on the sticker it says you can carry up to 1149# over. Huh! My pencil just broke! Over 500# over what those axles should carry. GD has to explain this one to me.

You have to remember most manufactures likely estimate axle rating for a particular model with the presumption that approximately 10% to 15% (travel trailers) an 22% to 25% (5th wheels) of the trailer weight will transfer to the tow vehicle. Using your numbers (6400 + 1149 = 7549) minus 12% (as an approximate 905.88 transferred to the tow vehicle) would leave 6643 on the trailer axles. You are correct that is a pretty tight margin but would technically be within their specs. I suspect the multiple failures in the earlier units resulted in GD increasing the axle margins.

[Dpboofay]

You have to remember most manufactures likely estimate axle rating for a particular model with the presumption that approximately 10% to 15% (travel trailers) an 22% to 25% (5th wheels) of the trailer weight will transfer to the tow vehicle. Using your numbers (6400 + 1149 = 7549) minus 12% (as an approximate 905.88 transferred to the tow vehicle) would leave 6643 on the trailer axles. You are correct that is a pretty tight margin but would technically be within their specs. I suspect the multiple failures in the earlier units resulted in GD increasing the axle margins.

You are correct Geoff. It is a tight margins that surprise me. GD told me it was built within their specs yet 3 months later they increased their specs. Hmm! I am exciting to get the upgraded equipment on and roll down to the scales. I still can’t imagine I have consistently overloaded our rig. We shall see!!

Thanks for your input.

[dbphillips]

My ultimate goal after reading so much that has been posted here, I am trying to match a friends rig that is the same floor plan just 1.5 yrs newer. He has the 44K Dexter axles, 2200# springs. For right now - The new Lippert 2200# springs have arrived, a 2” lift kit for the Lippert tandem axle, new service kits, and bearing kits. That should get me through the next 2 trips. Certainly I will be weighing the rig before we head out!! Once we are back, the upgrade to the axles will commence.

One question out there is currently I have the 205/75 -15 tires on. With the new springs and lift kit I am thinking of uping the tire size to 225/75 - 15 like my friends rig.

Any assistance on this part would be appreciated.

Happy trails!

If I were upgrading my rig, I'd be looking at the next logical step and consider the incremental cost. I'd at least look at the D52 setup and maybe D60. And then there are the Morryde options, especially wet bolts. No point doing it twice.

[geotex1]

If I were upgrading my rig, I'd be looking at the next logical step and consider the incremental cost. I'd at least look at the D52 setup and maybe D60. And then there are the Morryde options, especially wet bolts. No point doing it twice.

A very easy way to look at it - any possibility you may want disc brakes? If so, skip the 44s and go straight to 52s.

[Chewwi]

My ultimate goal after reading so much that has been posted here, I am trying to match a friends rig that is the same floor plan just 1.5 yrs newer. He has the 44K Dexter axles, 2200# springs. For right now - The new Lippert 2200# springs have arrived, a 2” lift kit for the Lippert tandem axle, new service kits, and bearing kits. That should get me through the next 2 trips. Certainly I will be weighing the rig before we head out!! Once we are back, the upgrade to the axles will commence.

One question out there is currently I have the 205/75 -15 tires on. With the new springs and lift kit I am thinking of uping the tire size to 225/75 - 15 like my friends rig.

Any assistance on this part would be appreciated.

Happy trails!

A previous posted topic, can’t seem to locate it right now but it involved tires rubbing on the RVs underside, included a conversation with GD indicating that when the axles were upgraded from 3.5k to 4.4k, there were some associated modifications needed to also strengthen the frame.


2020 2600RB,
2017 Silverado Crew Cab 1500, 6.2L