Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-24-2010, 07:03 PM   #15
3 Rivet Member
 
tvanwave's Avatar
 
1991 34' Limited
Tyler , Texas
Join Date: Feb 2010
Posts: 201
Forgot to ask... the pin hole to center of ball hole on current shank is 15.5 inches. Some drop shanks I've seen are 10-14 inches long in that same measurement. Will I lose turning ability or risk bumper crushing with a shorter shank length like these?

Tim
__________________

__________________
Air Cid
2000 F250SD Crew Cab 4x4 V10
Reese WD Hitch
tvanwave is offline   Reply With Quote
Old 07-24-2010, 07:32 PM   #16
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
keep look'n

is the one you've included rated for W/D?

looks 2 me, mehbe knot.

here's another example that IS rated properly.

Click image for larger version

Name:	anotheroption.jpg
Views:	71
Size:	299.0 KB
ID:	107389

yes shorter=less clearance 4 turns.

but shorter also = less influence from tongue mass on drive axle (yaw)

cheers
2air'
__________________

__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 07-24-2010, 07:49 PM   #17
Rivet Master
 
Dave Park's Avatar
 
2005 22' Safari
Hyde Park Place , Ohio
Join Date: Jul 2010
Posts: 972
Quote:
Originally Posted by 2airishuman View Post
a 2 INCH difference front/2/back may be golden...

but it is significantly UNLEVEL and will result in UNeven loading of the tires and brakes...

and the axles which may have already settled significantly in 20 years.

looking at the profile of a 34 a 2 inch variance is obvious and too much.
A 34' A/S has a 31' body, and three axles on 30" centers. with 60" from the front to back axle (5 feet) the axles cover 1/6th of the length of the body of the trailer. Therefore, the maximum 2" difference across the entire body represents a 1/3" difference from the front to back axle (or 1/6" difference between adjacent axles). Remember, a 2" variance means the nose is up 1" and the tail is down 1" from level.

With 7000 lbs dry weight, minus 800 lbs tongue weight, 6200/6=1033 lbs per wheel. With this low loading, a 1/6" difference between the axles is a non-issue, given the axles will take half the difference. A back of envelope calculation shows the rearmost axle would be taking about 2.6% higher load than the front - less than the difference induced by running on wet road. The difference in braking effort - less than that. In this application, uneven brake effort requires either lack of traction or a different rotation speed - certainly greater than the likely difference of a new tire next to a partially worn tire - which is the sort of height difference we're talking about. This worst case is about 12 lbs load difference from the front to back axle, and assumes very very stiff suspension.

Remember, I said "up to" - I'm guessing it'll end up with an arrangement where you have less than 1/2" difference front to back. On that length of trailer I'd be looking for less than 1" front to back. As I said in my previous post, I'd consider it "safe" to tow at 2".

This raises the question why this trailer has three axles instead of two when two would carry the weight and three axles introduce tire wear problems? Distributing shock loads across three more lightly loaded axles reduces transmission of shock energy to the very long frame by one third, allowing them to keep the frame weight down, and to use the standard shell design without heavy reinforcements, while also keeping the center of gravity low. Plus the lovely handling characteristics.
__________________
TX-16
Dave Park is offline   Reply With Quote
Old 07-24-2010, 08:28 PM   #18
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
lotza good math there.

now if ONLY my 34 showed that loading at the wheelz (it doesn't but it does weigh more) or tongue.

Quote:
Originally Posted by Dave Park View Post
...Distributing shock loads across three more lightly loaded axles reduces transmission of shock energy to the very long frame by one third, allowing them to keep the frame weight down, and to use the standard shell design without heavy reinforcements, while also keeping the center of gravity low. Plus the lovely handling characteristics.
i like this notion TOO, but leaving OUT 'reinforcements' has created issues...

http://www.airforums.com/forums/f36/...ion-35237.html

http://www.airforums.com/forums/f36/...oor-54952.html

cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 07-24-2010, 08:46 PM   #19
Rivet Master
 
Dave Park's Avatar
 
2005 22' Safari
Hyde Park Place , Ohio
Join Date: Jul 2010
Posts: 972
*grins* You know what they say...

In theory, there's no difference between theory and practice.

In practice, there is.
__________________
TX-16
Dave Park is offline   Reply With Quote
Old 07-24-2010, 10:14 PM   #20
3 Rivet Member
 
1980 31' Excella II
Drummond Island , Michigan
Join Date: Sep 2007
Posts: 140
Quote:
Originally Posted by tvanwave View Post
I like the reese extra drop pictuted here. Provides 5.75 inches of drop... but if I need more thene not so good. Is your recommendation to look for a 7" drop and if i need less - OK? I'm worried about some fabricated hitches not having the real rating that they advertise. Thanks for the comments.
I have a '05 F350 we tow our 31' with and use a Reese "tall" draw bar with a 6" drop. In our original 1980 Airstream manual it suggests that the ball height and hitch height should be about 1/2 inch of each other. After we replaced the axles on the trailer we measured the hitch height with the trailer leveled at 17 1/2 inches and luckily the ball is about 18 inches high with the drop hitch. I drop the trailer onto the ball until it just settles on the hitch, snap the coupler closed and then install the equalizer bars with two chain links and then fully retract the tongue jack. The truck settles and trailer is level at that setting. We have about 25K miles on the set up now with no problems.
__________________
Ahzmyrah is offline   Reply With Quote
Old 07-25-2010, 10:14 AM   #21
3 Rivet Member
 
tvanwave's Avatar
 
1991 34' Limited
Tyler , Texas
Join Date: Feb 2010
Posts: 201
Thumbs up

Quote:
Originally Posted by tvanwave View Post
I like the reese extra drop pictuted here. Provides 5.75 inches of drop... but if I need more thene not so good. Is your recommendation to look for a 7" drop and if i need less - OK? I'm worried about some fabricated hitches not having the real rating that they advertise. Thanks for the comments.

Ordered this one today. Distance from top of reciever to ground 21" Drop on this hitch is 5.75. Ball platform should then be at 15.25. Add ball height of 3" I should be right at 18.25 unloaded. Depending on loaded squat on truck (about 2" ) I should be able to adjust up if needed, prob no need for lower. I will post pics and response one parts get here and I do the install. Thanks to all the rivet pros for helping me with this question.
__________________
Air Cid
2000 F250SD Crew Cab 4x4 V10
Reese WD Hitch
tvanwave is offline   Reply With Quote
Old 08-06-2010, 05:19 PM   #22
3 Rivet Member
 
tvanwave's Avatar
 
1991 34' Limited
Tyler , Texas
Join Date: Feb 2010
Posts: 201
Quote:
Originally Posted by tvanwave View Post
Ordered this one today. Distance from top of reciever to ground 21" Drop on this hitch is 5.75. Ball platform should then be at 15.25. Add ball height of 3" I should be right at 18.25 unloaded. Depending on loaded squat on truck (about 2" ) I should be able to adjust up if needed, prob no need for lower. I will post pics and response one parts get here and I do the install. Thanks to all the rivet pros for helping me with this question.

Long drop shank came today. Is it an OK idea to use the trim strip on the side of the AS as a measuring point to determine whether ot not the trailer is level? I am OK in the front with the hitch frame but in the rear I cant get to the frame due to sealed underbelly. This could throw measurements of a bit.
__________________
Air Cid
2000 F250SD Crew Cab 4x4 V10
Reese WD Hitch
tvanwave is offline   Reply With Quote
Old 08-06-2010, 08:30 PM   #23
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
yes.

i typically use the MID level beltline trim

since the stream sides curve OUT to this level...



cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 08-06-2010, 08:52 PM   #24
3 Rivet Member
 
tvanwave's Avatar
 
1991 34' Limited
Tyler , Texas
Join Date: Feb 2010
Posts: 201
Thumbs up

Quote:
Originally Posted by 2airishuman View Post
yes.

i typically use the MID level beltline trim

since the stream sides curve OUT to this level...



cheers
2air'

Thanks again 2air--- I will use the mid level beltline trim
__________________
Air Cid
2000 F250SD Crew Cab 4x4 V10
Reese WD Hitch
tvanwave is offline   Reply With Quote
Old 08-06-2010, 09:00 PM   #25
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
a bubble level can also be used

but finding a reliable reference point is tricky.

so one approach is to use the beltline trim in a REALLY REALLY flat concrete location...

and once it's reasonably level MOUNT a bubble level somewhere

(like the tongue) or just inside the entry door or on the SKIN somewhere...

or ?

this will pay off later and each time you seek level for parking, towing and so on...

finding a LONG level strip of roadway is often tricky when REchecks are needed.

with older units getting the FRIDGE really level is important 4 efficient function.

so older rigs (like yours) often have...

a small square/ROUND (target shaped) BUBBLE level in the freezer for this purpose.

cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 09-06-2010, 04:48 PM   #26
3 Rivet Member
 
tvanwave's Avatar
 
1991 34' Limited
Tyler , Texas
Join Date: Feb 2010
Posts: 201
Installed this shank using lowest holes. Everything now matches up!
Thanks again for everyone's help

__________________

__________________
Air Cid
2000 F250SD Crew Cab 4x4 V10
Reese WD Hitch
tvanwave is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
We've finally reached our goal !!! RognChris Member Introductions 10 11-02-2009 01:23 PM
Hitch ball height drop down - dodge ram HD Ag&Au Hitches, Couplers & Balls 2 08-06-2009 04:57 PM
Deep drop WD hitch shank ground clearance? mountainboy Hitches, Couplers & Balls 5 07-20-2009 05:56 AM
Jack Drop WestMichCamp Jacks, Stabilizers, Lifting and Leveling 6 08-26-2007 10:33 PM
Hitch bar drop size for 3/4 ton trucks Silvertwinkie Hitches, Couplers & Balls 20 09-22-2004 02:37 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:33 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.