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Old 02-16-2015, 06:11 PM   #85
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Nope, those items were placed back there just for the weigh-in. I put everything back where originally installed an hour after taking the pictures.

My batteries weighed 92 lbs.
My propane tanks weighed 110 lbs.
The cover plus regulator was 21 lbs.
the spare tire/wheel was 55 lbs.
The tire bracket was 18 lbs.

All weighed with a cheap walmart scale.
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Old 02-17-2015, 04:51 AM   #86
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Hi
The Grand Cherokee has a very robust suspension. It handles the stock hitch weight quite easily. From a handling perspective the hitch weight is good on the GC.

Do you have Air Suspension? Which hitch system are you planning to use.


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Old 02-17-2015, 05:51 AM   #87
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Quote:
Originally Posted by jdthor View Post
Nope, those items were placed back there just for the weigh-in. I put everything back where originally installed an hour after taking the pictures.

My batteries weighed 92 lbs.
My propane tanks weighed 110 lbs.
The cover plus regulator was 21 lbs.
the spare tire/wheel was 55 lbs.
The tire bracket was 18 lbs.

All weighed with a cheap walmart scale.
It's been my experience that the most important TW is the actual weight on the receiver after proper WD has been set.

Our unhitched TW is a very helpful guide.....only.


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Old 02-17-2015, 06:46 PM   #88
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Update - Batteries Moved

Thought I'd better provide an update for anyone interested in the outcome. Apologies for the lengthy post! First a quick shout out to Phil Tippler at Can-Am RV for his expert advice. He provided several email responses to my various questions relating to TV and AS selection, ideas on receiver modifications and finally on tongue weight weight reduction which was what initiated this post. Those guys are great and offer advice freely even to those that are not customers. True enthusiasts.

Anyway, a few photos attached plus a few comments / weights below. The tow home with the Cayenne Diesel was uneventful even for this novice wheel man. It pulls very well and was stable with no hint of sway (I'm using an Ea-z-lift and 2x husky sway control units). I did notice a very subtle porpoising motion occaisionally. The trailer was slightly nose down and a quick stop via a scale on the way home revealed the front axle weight was not quite restored which may have contributed some. I suspect some fine tuning of the setup would have improved an already good combination.

Some data on weights : -

Existing batteries were Interstate Class 24 and weighed 44 lbs each.
New batteries are 2 off 6V Lifeline AGM GPL-4CT batteries that weigh 62 lbs each.

I looked at 3 different possible positions for the batteries. Position 1 (where they are installed in the photo) is as far to the rear as possible - first picture, Position 2 just forward of the furnace under the bench and Position 3 under the fridge. Removal of the rear partition would be required to install here but there appears to be room.

The factory tongue weight was stated to me by Airstream as 844 lbs (catalogue for this model is 770 lbs but it does have the twin AC option plus a few other items so extra tongue weight was expected). I emailed the VIN to Airstream with a request for the as weighed data and they got back to me within a few days. They indicated this was the complete "as built" weight with batteries and full propane. Pretty good so far....

I weighed the AS tongue with a Sherline when I got it home and it weighed 900 lbs with everything installed as delivered (batteries, propane etc). A bit disappointed here. Not sure how the Airstream gained weight on the 50 mile tow home

I then set about taking items off and measuring the effect on tongue weight - weights at the ball cup were as follows: -

With factory batteries removed - 845 lbs

With new 6V batteries positioned (factory batteries removed)

6V batteries at position 1 - 770 lbs
6V batteries at Position 2 - 815 lbs (slightly rear of axle)
6V batteries at Position 3 - 845 lbs (batteries approx. on axle)

I'm planning on replacing the Airstream tires with LT's prior to my first long trip and deleting the spare so I then removed the spare to see what impact that would have. The spare was 48 lbs, the carrier remained but would remove maybe another 10 to 15 lbs. I will also be traveling with a full size TV spare (about 65 lbs) so I added 65 lbs of weight under the dinette to simulate this.

6V batteries in Position 1, AS spare removed and 65 lbs of weight under dinette - 710 lbs.

Based on the above I went ahead and removed the factory batteries and installed the new 6V batteries in the rear and also relocated the Inverter. I have not weighed the final configuration since the weather here has been uncooperative and the AS has snow on the roof. I also have not towed this configuration yet. I'm a little concerned over the large amount of weight to the rear of the axle and its impact on sway / sway recovery although % dry tongue with this configuration would be 11.6% which seems reasonable. if you are using a ProPride or Hensley sway dynamics with the extra weight in the rear is probably a mute point since these combinations can't sway in the first place.

You may be wondering what my goal is with this exercise, I'd like to get to 850 lbs tongue with a ProPride installed.

Next step is to hitch up, apply WD and go weigh on a scale to see what the actual tongue weight is with WD applied. The weather has prevented me from completing this last step so far - I want the roads clear of snow and dry before I tow so I don't get the AS covered in salt.

A few photos of the install included. Not quite complete yet, some tidy up to do but operational. I opted to run the cable inside under the bench, fridge and shower, along the wall, under the bedside cabinet and then into the front under bed storage area where the 12V bus bars and inverter are installed from the factory. I used 2 runs of 2ga for the battery supply and return with a 100A marine breaker/disconnect on the battery positive line. For the Inverter hookup to the batteries, I used some of the wire used in the factory install and ran a 6ga ground and a phone line (remote switch) back to the under bed storage area to pick up the factory ground point and factory remote switch wire (the remote switch wire runs from the Inverter switch in the galley area to the under bed storage area). The 110A quick blow fuse for the inverter was also relocated to the rear and installed on the positive wire as close to the battery terminal as possible. The hitch jack wire needs to be extended from the battery box (it is connected directly to the battery) into the front storage area and then onto the positive bus bar. This requires carefully digging out some of the sealant where the cables pass through the floor of the front storage area to the outside. I took this opportunity to remove the battery and inverter cables that run from the battery box to the storage area and then resealed the hole.

I plan on covering the cables in the bedroom with a grey rubber trim piece that will be about 2" tall and 3/4" deep and stuck to the wall with double sided tape. It will look similar to the factory grey rubber trim piece that runs around the join between the floor and wall. Need things to warm up a bit before I do that. The only hard part of the install is tapping into the 110V inverter circuit. The inverter outlet local to the TV in the lounge area was "easiest" although getting a wire from the inverter to it is a PITA!

I'll report back when I have the actual tongue weight and some scale weights. I want to collect those before deciding to order a ProPride or not.
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Old 02-17-2015, 07:07 PM   #89
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Try again with photos...
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Old 02-17-2015, 08:45 PM   #90
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Great post, a lot of information to think about in your post Ohiobrits.

I recently installed Group 27's as a hold me over while planning and piecing together my solar build.

Considering I am running my panels down thru the fridge vent, getting the batteries, charger controller and converter/inverter all closer together has been on my mind.

Where you installed yours could really work out well for keeping cable runs short with a solar build.

Keep us posted. And thanks for sharing.
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Old 02-18-2015, 03:51 AM   #91
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From Andrew T: "The Grand Cherokee has a very robust suspension......Do you have Air Suspension? Which hitch system are you planning to use."

My 2011 GC does not have air suspension. I have an Equalizer with 600 lb bars, with an 8 inch drop shank, all used on my 23FB that I traded. The 2015 FC FB twin has not been setup yet as seen in my earlier post when I was playing around with weights and moments. Any advice would be appreciated. I can replace the hitch if another combo makes sense, and can also replace the TV if required, although another GC would be my first choice, probably a 2015 if it is appropriate. (I realize this is about to creep over to another thread topic, so I will note that I am prepared and able to move batteries, if need be).
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Old 02-19-2015, 04:36 AM   #92
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My only concern with the hitch you have is the limited travel of the torsion bars. Whenever you see a spring it is generally tapered, this gives the spring travel or range of motion. With the limited travel they tend to be very hard on the hitch receiver when you drive through dips etc.

We do have a shank that keeps the ball in as close as possible which further reduces the strain on the receiver. Here is a picture of a set up using this.

The spring suspension is easier to set up and make handle well. If your miles are getting up there you might want to consider some new shocks, Bilstein or Rancho. You can also tweak the tire size next time you need a set.

I hope that is not too far off the tread.

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Old 02-21-2015, 10:39 AM   #93
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The other day I submitted a photo of my dry weight at 900+ pounds (#81). Like others I wondered how the tongue "gained" weight over the published tongue weight. Today I relocated the trailer to a very level spot, filled the (previously empty) fresh water tank, and weighed again..............850 pounds. Now I am really liking the idea of removing those Interstates, replacing them with AGM's and relocating them back there under the dinette storage. I might even do the full monte and ditch the 15in wheels for 16's with Michelen tires and remove the spare as well. I've already purchased smaller propane bottles. That trailer tongue might be bobbing like a see-saw by the time I'm done!
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Old 02-23-2015, 03:57 AM   #94
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15" Michelins are a better match for your trailer, they will ride much smoother than the 16's and you don't have to change rims.

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Old 03-09-2015, 08:25 PM   #95
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Lightened tongue - towing impressions

I towed the configuration showed above about 10 days ago (new 6V batteries and inverter in the rear under the dinette, 65lb TV spare tire under dinette, 2 full propane cylinders in original position, no spare AS tire at front but spare holder still in place). I weighed the tongue this weekend and got 650lbs. This is down from 900 lbs. For anyone reading this, 650 is probably a bit lower then recommended (close to 10% dry unloaded for my trailer) to avoid sway. So, if you do this mod, feel free to install the batteries a bit closer to the axle (see post #88 and #89 for options) or load up at the front as desired when travelling. My goal is to install a ProPride so I will be adding about 190lbs back on the tongue so this is not a concern for me.

On the original trip back from picking up the AS the tongue was a bit nose down so I thought I'd try one more link on the WD to raise the rear of the TV some. I hooked up 3 link from the top of the chain i.e one link more WD than on the first trip. I measured drop on my TV with WD applied and had 1/2" drop at each corner. Photo attached below. Looking good! I realize the chains are too long (I will need the length for the ProPride).

I then drove about 50 miles to the CAT scale including some state routes and interstate. The combination had virtually no porpoising which was a slight issue on the first tow. The TV however did feel nervous with very sharp steering response. The trailer felt a little "active" also. No sway per se but I could feel small movements from the rear when on a very smooth road. I purposely sat close to the left hand lane marker on the interstate at 60 to let several big rigs blow past. No drama.

Scale weights were as follows with an (almost) full tank of diesel but no passengers or other load in the TV. AS was unloaded.

Hitched with 3 links WD
Steer - 2800
Drive - 2800
Trailer - 5780

Hitched with no WD
Steer - 2320
Drive - 3420
Trailer - 5640

TV alone, hitch in receiver
Steer - 2600
Drive - 2460

Via one of the spreadsheets on AirForums (Ron's?) I believe that puts tongue at 680 lbs (close to the 650 measured) and 140 lbs returned to the trailer axles by WD.

The scale weights above revealed the probable cause of the TV steering "nervousness". It showed I had added 200 ADDITIONAL lbs to the front axle with 3 links of WD applied.....too much WD to the front. There has been much written on this forum about returning too much weight to the front axle of the TV and potentially making the TV prone to oversteer. I think I now know what that feels like

I then reduced the amount of WD to 2 links and ran over the scales again. Result - 100% front axle weight recovery, 40 lbs less weight transferred to the AS:-

Hitched with 2 links WD
Steer - 2600
Drive - 3040
Trailer - 5740

TV wheel drops with this amount of WD were 0 drop at the front and about an inch at the rear.

So how did 2 links WD feel? In a word, better! The steering nervousness was gone. I ran back up the interstate using the same tactics with the big rigs - still no sway. I ran for a while at 65, no issues. There was still a faint sense of the trailer moving around a little but the rig tracked straight and needed no direction corrections. Once off the interstate I really enjoyed making good time on the more twisty roads on the way back to my house. This is a nice handling rig .

I stopped and measured the AS for level on the way back (with 2 links of WD) and it was 1.5" nose down. Handling probably could be improved a bit further if the AS was exactly level. Maybe this would remove the slight movements from the rear - don't know. The AS manual indicates that the AS is prone to sway if nose down.

So whats next? Despite the fact that I really like how it tows in the current configuration, I did go ahead and order a ProPride a few weekends ago. I was snow bound at the time and it was not clear when I would be able to tow and make an evaluation of the handling so I decided to get in the queue at ProPride. Sean indicated they are running 2-3 weeks from order to ship. I will hopefully be delivered by this weekend. The reason why I chose to buy a ProPride is probably a discussion for another thread.

I'll post a brief update on the "The unofficial PP Users Guide" http://www.airforums.com/forums/f464...ide-57179.html in a few weeks for anyone that is interested in the differences.

So, would I recommend this mod for those who must or want to use a payload challenged TV? Absolutely! Just don't go over the top and remove too much!
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Old 03-09-2015, 10:42 PM   #96
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Nice thing about the ProPride is no links to fiddle with. I set mine up with a tape measure!

You will enjoy the ability to tune the ride exactly as you wish. Just be sure to record your basics setting on the jacks and work from that. I use between 6 and 7 inches of tension on the jacks to get stable steering and no porpoising on the rig. YMMV.

Best thing I ever put on our AS.


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Old 03-10-2015, 10:22 PM   #97
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Nice thing about the Equalizer is no links to fiddle with... once your offset and L-brackets are set properly ... but it does allow for fine tuning if your load changes substantially. I set mine up with a tape measure, too. Record your basic setting as far as L-bracket position and work from that. YMMV

Best thing I ever put on our Airstream! That doesn't mean I wouldn't like to try a PP; but don't buy an over simplification posted on here.
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Old 08-18-2015, 08:39 PM   #98
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Update...change in plan

Thought I'd post an update after having towed about 10,000 miles with the batteries in the rear. I have just this week moved the batteries again this time from under the dinette to under the fridge. Why, you may ask....?

The arrangement with batteries under the dinette worked well from a towing perspective, no issues. The reduced tongue weight was definitely also well appreciated however after about 3 months I noticed what appeared to be a small "distortion" in the skin just to the rear of the wheel well on the side with the batteries. I was not sure at that time if this was just imagination, maybe it had been there all along???? Not sure. I decided to keep an eye on things and see how things developed. I then, very recently, noticed a similar small distortion in the skin at the top left of the window towards the rear. I'm pretty sure this was not there before since I had given the whole AS a good look over when I had noticed the first issue. The locations of the distortions would be where I'd expect to see them if the AS was deflecting due to the battery weight. I have verified that the frame is still true when stationary to the best of may ability by shooting a laser level down the side trim and across the floor inside which shows everything is still straight/level. I suspect the distortion in the skin is due to the dynamic "bouncing" of the load of the batteries as the AS is driven down the road. Admittedly, if someone did not know where to look on the outer skin, they would almost certainly not see these areas. These two areas however were sufficient to persuade me to move the batteries under the fridge which is pretty much on the axle CL (no more "bouncing" at the rear).

I'm still storing my TV spare and a small BBQ under the dinette when in transit. I'm not too concerned about this since this weight (80lbs or so) is centered on the frame.

Some photos of the new install below together with some photos of the skin in sunlight so you can see the "distortion".

Incidentally, this new battery location may be a great option for those looking to add batteries for solar. Looks like there would be room for 2 more on the other side (over the axle) under the oven. The 6V batteries I used (see above) are a very tight fit under the fridge but do fit in....just.

I took the newly configured setup to the scales to reweigh. It still tows beautifully. I added another 0.5" on the PP jacks which was sufficient to handle the extra tongue weight.

For the record, tongue weight with the batteries under the dinette was 740lb (620lb with WD) and with the batteries under the fridge 840lb (720lb with WD). Both with ProPride hitch.

I'm sure I'll get a barrage of "I told you so" but several other people on this forum have asked me about this mod over the last several months so I feel obliged to report back the learning and reasoning for this change of plan.

Photos below: -
First 2 photos - new install with batteries under fridge. There is only room for 2 batteries, the white backboard area covers various hoses and plumbing.
3rd photo - "distortion" to the rear of the wheel well. Rear of AS is to the right. Batteries were installed on this side of the AS (under dinette, far right, out of shot)
4th photo - "distortion" above window on same side
5th photo - so I must be paranoid right...because here is similar "distortion" in front of the wheel well....no reason for this
6th photo - "now you see it, now you don't".......same side with different light - no distortions visible

The "distortion" I'm seeing may be quite normal settling of the frame and structure as it gets used. Don't know. But I'd rather not find out the hard way it was something more serious in the making.

Live and learn.....
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