2005 G500 build by MG Metalworks

mgmetalworks

Explorer
Apologize for the crude graphic...

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Caster is essentially the inclination of the steering axis relative to vertical. On a radius arm suspension, the axle swings through an arc with the center of that arc being the frame side mount. As the suspension moves up and down, and because there is no rotation of the axle relative to the radius arm, the caster will change by some amount. As the suspension goes up, the caster gets more positive. As the suspension goes down, caster becomes less positive (until the angle passes vertical in which case it would be negative caster).

When I lifted the G, the springs essentially pushed the radius arm down, which in turn rotated the axle forward, which reduced the caster (see diagram). The steering is light (too light) and tends to wander in the lane. Once it starts turning, it likes to really turn in...as if there is no resistance...which is not surprising since the caster angle is so slight. The factory caster is supposed to be 5deg and I'm less than 1.5 now. This small amount of caster really affects how stable the vehicle feels at speed.

Sorry.. no new pictures of the G for a little while. I'm busy putting a Cummins/Allison in my E-series van. :)

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McBride

Adventurer
Great explanation! Thanks. Now I understand it perfectly.

I'll be needing to get a set of the brackets for my G500. It steers light and wanders too much (it has the taller ORC springs).

The camper steers and tracks perfectly - even since I put the portals on - very easy to drive.

Other than the brackets is there anything else needed caster correction?

The van project looks serious.

Thanks for answering my newbie questions - it's a big help.

William
 

mk216v

Der Chef der Fahrzeuge
Hmm, with my ~25mm lift from OEM Mercedes HD springs and 33s/Hutchinson's, my G(fully loaded, ~7000lbs at that point) felt very stable traveling close to triple digits in Utah(in order to make a very important meeting). I don't remember what my caster spec was from our alignment however--will see if I can dig it up.
 

mgmetalworks

Explorer
I'm going to be putting my spare tire cover and stainless ring up for sale on Ebay soon. It's in very good condition. Just going to collect dust and get in the way around here... PM me if you'd like to make an offer. I can also send detailed high res pictures if you leave me an email address.

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autonovice

New member
The idea of making brackets to lower the trailing arms has been done. See postings on P3 and BW. All seems successful and
all requires welding to the frame.

I am willing to try offset bushings on my next front axle rebuild.
1) from Titus ... any reviews?
2) http://www.stockundstein.com/rubrik...-modell7/caster-kit-fuer-mercedes-g-460461463

What I really want is a bolt-on solution using the existing mounts. I am in for a group buy if you have a bolt-on solution.
This way, if I ever want to sell the vehicle, the next owner may want revert back to stock which should be very easy.

The other solution is to use Tibus portal.

If you can solve this, I am sure you can offer a solution to extend the panhard/track bars at the same time.
 
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mgmetalworks

Explorer
Took the G up to a local trailhead today and couldn't resist taking some pics.

I love having the extended door check. Getting the kids in and out of the back is so much easier!
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Life with the G isn't all puppy dogs and sunshine though. The ESP simply HAS. TO. GO. I've done the computer adjustments for bigger tires but It SUUUUUUCCCCCKKKKKKKSSSSS driving this thing on twisty roads. It is so ridiculously sensitive. Add in the almost non-existent caster and it is really only tolerable to drive around town. If I weren't neck deep in Cummins conversion wiring/CAN module trickery right now, I'd be gutting this thing of its overly complex electronic systems and simplifying everything. Every time I drive it I get a little closer to my tipping point. I have a few ideas already for fooling the system, I just need to do some monitoring and data collection like I've done with my other project and come up with a custom module. I'll work on that first and if it doesn't behave like I want it, I'm going medieval on this thing!
 

McBride

Adventurer
Thanks for the update - been wondering how you were doing.

Bummer. I've heard about the ESP issues with the MBUSA models but fortunately haven't had to deal with them. Keep up hope though and you'll get there. My wife drove us to ABQ today and her G is very close to being awesome after a year of LOTS of deferred maintenance and work. Smooth, quiet, tight, powerful, and she's getting almost 17mpg out of a 2000 G500. It is like driving like a new car. She actually sold her Rangerover so I think she must be sold - totally her decision.

I'm sure someone will chime in with some ESP input that will mitigate your issues - hopefully. There's only so many hours in a day and with a project like your other one I can't imagine...

William
 
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mgmetalworks

Explorer
Thanks for the update - been wondering how you were doing.

Bummer. I've heard about the ESP issues with the MBUSA models but fortunately haven't had to deal with them. Keep up hope though and you'll get there. My wife drove us to ABQ today and her G is very close to being awesome after a year of LOTS of deferred maintenance and work. Smooth, quiet, tight, powerful, and she's getting almost 17mpg out of a 2000 G500. It is like driving like a new car. She actually sold her Rangerover so I think she must be sold - totally her decision.

I'm sure someone will chime in with some ESP input that will mitigate your issues - hopefully. There's only so many hours in a day and with a project like your other one I can't imagine...

William
I've calmed down a little since yesterday. My wife loves her G and we're never getting rid of it (and according to her, we need a newer one some day too). I drive a small sedan over a twisty mountain road for a commute each day so once I get in the G and have to slow down to a crawl to make it around a corner, I get annoyed quickly.

I'd rather have a way to disable the system vs. ways to make it suck less. I envision putting some serious calories into this once my other project is done. Anything is possible if you want it bad enough. :)
 

mgmetalworks

Explorer
Any update on the castor correction brackets?

Do you still have the spacers?
I haven't finished the bracket design yet. I plan to soon though so I can order laser cutting at the same time I do a batch of Cummins conversion stuff.

I still have the 40mm spring spacers available for sale.
 

mk216v

Der Chef der Fahrzeuge
I've calmed down a little since yesterday. My wife loves her G and we're never getting rid of it (and according to her, we need a newer one some day too). I drive a small sedan over a twisty mountain road for a commute each day so once I get in the G and have to slow down to a crawl to make it around a corner, I get annoyed quickly.

I'd rather have a way to disable the system vs. ways to make it suck less. I envision putting some serious calories into this once my other project is done. Anything is possible if you want it bad enough. :)
Left foot brake, right foot throttle. :)
 

mgmetalworks

Explorer
Oregon is beautiful in the fall but one thing it is not is dry. Certainly not dry enough to go without wipers...

Wife pulling out of the driveway this weekend asks me: "Why won't my wipers work?"

My answer...preceded by a huge sigh that only someone who's owned a modern European car can understand: "It is probably not something simple nor will it be inexpensive."

The problem:
Wipers will go from down position to up position but not back down. Sometimes not going up either.

My thought process:
Bad connection, intermittent power to the motor...OR...some mechanical interference/drag on the wiper mechanism

Diagnosis:
-I checked the relay first. No issue.
-I pulled the cover off of the wiper motor and saw that the connector was not fully seated. Great success! I found the potential problem (but seems kinda odd the connector would slide off given how tightly packaged everything is...).
-I fully seat the connector but take note of how crazy sloppy the fit is. That ain't right...so I pull the terminals from the connector body and give them a little squeeze to tighten things up a bit. Connector goes back on TIGHT, partially assemble the mess under the hood and test...
-NOT Great Success! Still same problem.
-Head scratch
-I grabbed onto the wiper arm and moved it back and forth. Seemed to cycle just fine...then I noticed something strange.
-Why does the wiper motor move so damn much? Isn't it bolted to the firewall?
-Upon closer inspection, I see this:

wiper motor.jpg

The motor housing has a broken mounting boss, likely from all of the bolts being loose and the motor working itself into oblivion. Now the sloppy connector makes sense, it was being worked back and forth like crazy.

Of all places, Amazon had the best price and availability (prime eligible too).

It turned out to be something relatively simple and inexpensive to fix but only because I'm doing it myself. I'd love to know what a dealership would have charged for this. :Wow1:
 

otiswesty

Regular guy
The ESP simply HAS. TO. GO. I've done the computer adjustments for bigger tires but It SUUUUUUCCCCCKKKKKKKSSSSS driving this thing on twisty roads. It is so ridiculously sensitive. Add in the almost non-existent caster and it is really only tolerable to drive around town.
The ESP is awesome for driving in icy and super slick conditions. You have an ESP off switch good for up to 35 MPH or so. Our friend Fernweh and a few others have put in an additional switch for a non-speed limited ESP off as well as another for ABS off using the blank switch locations on the center console. The 3 switch locker pack has outputs to turn off ESP and ABS when the center diff lock is activated.

http://www.pointedthree.com/disc/forums/showthread.php?tid=14929&start=1
http://www.pointedthree.com/disc/fo...d=12135&start=1&highlight=esp&highlightmode=1
 
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NYCRover

Observer
lucky it was a simple fix. Two months into my G ownership my wiper assembly broke. Whole dash had to come out and needless to say it wasn't cheap...
 
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