TC's 2nd Gen - Rear 4Link Swap (Buildup Thread)
07-27-2008, 08:07 PM
#1
Contributing Member
Thread Starter
4Runner 4Link
So, the driver's side link and mount are pretty much trashed and will need to be repaired in some fashion. I don't see much reason to stay with the stock short links.
Would there be any problem with just replacing the lowers and leaving the uppers and panhard bar as-is for now?
I'm not liking the idea of the truck being down all summer reconstructing the rear suspension, and I can't really afford a shop to do it. What I'm thinking is:
- for now replace the forward link mount and the lower links
- later, redo the attachment points at the axle and the uppers, triangulated to get rid of the panhard bar.
Goals in the end:
- link mounts less likely to get hung up on
- more travel
- stretch wheelbase 1-2" towards rear
Would there be any problem with just replacing the lowers and leaving the uppers and panhard bar as-is for now?
I'm not liking the idea of the truck being down all summer reconstructing the rear suspension, and I can't really afford a shop to do it. What I'm thinking is:
- for now replace the forward link mount and the lower links
- later, redo the attachment points at the axle and the uppers, triangulated to get rid of the panhard bar.
Goals in the end:
- link mounts less likely to get hung up on
- more travel
- stretch wheelbase 1-2" towards rear
08-10-2008, 10:24 AM
#3
Contributing Member
For street driving there is not much change in the articulation. But on heavy movements (like rough roads or 4 wheelin) it's not good having bars that are that different. The factory ones are already too different in my opion, changes the pinion angle too much on extreme movement.
08-10-2008, 10:29 AM
#4
Contributing Member
To eliminate the uppers I think you need more than 30 degrees to create a stable center. An angled bar also changes the length on exreme articulations. A straight bar stays true to length, but an angled one only changes a proportion of the length depending on the angle. Thoughs are all things you have to take into account.
08-10-2008, 01:21 PM
#5
Contributing Member
Thread Starter
For street driving there is not much change in the articulation. But on heavy movements (like rough roads or 4 wheelin) it's not good having bars that are that different. The factory ones are already too different in my opion, changes the pinion angle too much on extreme movement.
To eliminate the uppers I think you need more than 30 degrees to create a stable center. An angled bar also changes the length on exreme articulations. A straight bar stays true to length, but an angled one only changes a proportion of the length depending on the angle. Thoughs are all things you have to take into account.
The uppers are 70% of the lowers, which is the recommended ratio... there is 55* between the uppers which is more than the 40* recommended to eliminate the panhard bar...
Yes, the factory ones are WAY different ... the calculator isn't exactly accurate because it's doesn't include the panhard bar, but here is what it says for the stock link setup:
08-11-2008, 06:58 AM
#6
Contributing Member
Sorry I thought you were leaving the uppers and making longer lowers.
I think each angled bar has to be more than 40 degrees, not combined. I not sure, I just have alot of race car guy friends that have almost 45* upper bars.
I think each angled bar has to be more than 40 degrees, not combined. I not sure, I just have alot of race car guy friends that have almost 45* upper bars.
Trending Topics
09-04-2008, 03:09 PM
#8
Contributing Member
TC's 2nd Gen - Rear 4Link Swap (Buildup Thread)
Hey all, some YT members asked that I post up what TC and I are doing to swap out his stock rear suspention going to 4 link. I'll let TC add the images of the link projections... but here is what we've been up to so far!
Looks like we'll be using Johhny joints...
Our friend Layton pounding on something...
Troy using the plasma cutter...
Axle is out...
Troy and Doug ripping off metal!
Still looks like summer to me!
Today I've been grinding off the old brackets... Troy is ordering the new hardware. I'll let him post up exactly what he is ordering!
Looks like we'll be using Johhny joints...
Our friend Layton pounding on something...
Troy using the plasma cutter...
Axle is out...
Troy and Doug ripping off metal!
Still looks like summer to me!
Today I've been grinding off the old brackets... Troy is ordering the new hardware. I'll let him post up exactly what he is ordering!
09-04-2008, 03:37 PM
#12
Contributing Member
09-04-2008, 06:34 PM
#13
Contributing Member
Thread Starter
There are some significant problems with the stock 4Link:
- uppers are VERY short, less than 50% of the lowers (see post 5)
- no triangulation requires panhard bar
- panhard bar causes side-to-side axle shift on articulation
- frame end attachments are below frame = rock magnet
- axle end attachments are below axle = rock magnet
- lowers are straight and not particularly strong
So, my design (post 2) improves on all these weaknesses. I'm really considering using bent lowers for maximum ground clearance. Might stretch the wheelbase a couple inches for better departure and weight distribution while I'm at it...
- uppers are VERY short, less than 50% of the lowers (see post 5)
- no triangulation requires panhard bar
- panhard bar causes side-to-side axle shift on articulation
- frame end attachments are below frame = rock magnet
- axle end attachments are below axle = rock magnet
- lowers are straight and not particularly strong
So, my design (post 2) improves on all these weaknesses. I'm really considering using bent lowers for maximum ground clearance. Might stretch the wheelbase a couple inches for better departure and weight distribution while I'm at it...
09-04-2008, 07:08 PM
#15
Registered User
Join Date: Mar 2008
Location: Temecula Valley, CA
Posts: 12,723
Likes: 0
Received 4 Likes
on
4 Posts
I don't have the software pictured above...
...but what about running the upper and lower links in parallel from near center axle at about 30 degrees included angle (between arms at the same elevation) out to the frame, maybe upper arms on top of the diff, and lower arms about 18" from the diff... so that the pinion angle doesn't change during up/down axle motion....
let the springs carry the load as they should, and locate the axle from near center?
wish I could draw a diagram...
edit- take this:
but considering the lower arms (in red), move the axle mount points in towards the diff, and the same arms chassis mounts out to the frame, as close to parallel as possible with the 'blue' arms in the horizontal plane, meaning the chassis end of the blue links needs raised on the chassis.
...but what about running the upper and lower links in parallel from near center axle at about 30 degrees included angle (between arms at the same elevation) out to the frame, maybe upper arms on top of the diff, and lower arms about 18" from the diff... so that the pinion angle doesn't change during up/down axle motion....
let the springs carry the load as they should, and locate the axle from near center?
wish I could draw a diagram...
edit- take this:
but considering the lower arms (in red), move the axle mount points in towards the diff, and the same arms chassis mounts out to the frame, as close to parallel as possible with the 'blue' arms in the horizontal plane, meaning the chassis end of the blue links needs raised on the chassis.
Last edited by abecedarian; 09-04-2008 at 07:17 PM.
09-04-2008, 07:19 PM
#18
Contributing Member
09-04-2008, 09:04 PM
#19
Why don't you convert to IRS? I hear the Honda Ridgline has flexy set up.
Seriously though, you've mentioned the virtues of a balanced rig in the sense that the rear should flex proportional to the front. With more rear travel, won't your rear do all the flexing now?
I hear the Honda Ridgline has flexy set up.Seriously though, you've mentioned the virtues of a balanced rig in the sense that the rear should flex proportional to the front. With more rear travel, won't your rear do all the flexing now?
