Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Vintage Mercedes

Reply
 
LinkBack Thread Tools Display Modes
  #61  
Old 07-12-2016, 01:13 AM
Coasttocoast's Avatar
Registered User
 
Join Date: Nov 2015
Location: Honolulu
Posts: 251
Quote:
Originally Posted by Tomguy View Post
I have a center (inboard) mount R&P assembly from my parts car I can measure travel on. Just so you have the option & info, if that's the route you'd want to go. The unit itself is shot, but it'll move (with play) so I can measure its travel. I want to say it's probably more than just 6".
That would be great! What is it out of?

Thanks.
__________________
"In wine there is wisdom, in beer there is strength, in water there is bacteria."
Reply With Quote
  #62  
Old 07-12-2016, 01:35 AM
Coasttocoast's Avatar
Registered User
 
Join Date: Nov 2015
Location: Honolulu
Posts: 251
Was a little anxious to get started on metal fab. Got things set up and made the first set of panels for the firewall. These three panels are ready to trim to fit and weld in.

Using metal just a smidge thicker .041 vs .038.

Will probably fit a little closer and tack in. Until the engine is placed the lower part (tunnel) might need to be modified.

But at least some forward motion.

'69 230 build w/LQ4 swap-image.jpeg

The new engine and trans should be here this Wednesday, I should have by Friday. Then I can start checking everything.
__________________
"In wine there is wisdom, in beer there is strength, in water there is bacteria."
Reply With Quote
  #63  
Old 07-12-2016, 01:59 PM
Tomguy's Avatar
Vintage Moderator
 
Join Date: Aug 2002
Location: Not where I want to
Posts: 4,969
Quote:
Originally Posted by Coasttocoast View Post
That would be great! What is it out of?
I just got a chance to check, imagine my surprise when it turned out to only be 6.75" of travel! It's 34.5" long in total, but center-mount (not end mount) from my 99 300M. I thought it'd be more due to where it was mounted & the tighter turning circle the car has than many other FWD R&P cars... but not that much, apparently.

You might want to consider an "Exploration" trip to the junkyard. Find a car with R&P, and then measure its travel lock-to-lock. My hunch is you'll need a center-mount because you will NOT find a R&P unit that can do end-mount that both offers only 19.5" length from output shaft end to output shaft end (not body length) AND 7+ inches of travel. The engineering to do that is just not feasible for any manufacturer unless you have maybe a manual rack custom-fabbed.

Keep in mind, steering is all geometry. You'll want to keep bump steer to a minimum but still meet Ackerman geometry. You will be able to do so with a R&P unit and you may be able to decrease your turning radius if you do the geometry right. It is very likely the old pitman arm moves nowhere near the 8" you see when going from lock to lock at the tie rod ends thanks to simple trig (ok, somewhat complex, but simple if you dumb it down enough).
__________________
Current:
1999 Chrysler 300M (Click for pic) - 207,xxx - totalled by Nationwide for $1600 in damage. Being rebuilt better.
2014 Jeep Grand Cherokee Limited (Click for pic) - 32,xxx

My Mercedes Benz 108 109 resource site
August 2014 newsletter live.

Previous: 1972 280SE 4.5 "Quicksilver", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
Reply With Quote
  #64  
Old 07-12-2016, 02:27 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 2,025
Quote:
Originally Posted by Tomguy View Post
I just got a chance to check, imagine my surprise when it turned out to only be 6.75" of travel! It's 34.5" long in total, but center-mount (not end mount) from my 99 300M. I thought it'd be more due to where it was mounted & the tighter turning circle the car has than many other FWD R&P cars... but not that much, apparently.
Tom:
Re: center-mount vs. end-mount, is it possible that you are referring to the attachment points of the tie rods? As contrasted with the mounting points of the rack housing.
Would you put up a pic or two? With some dimensions marked.
Reply With Quote
  #65  
Old 07-12-2016, 02:59 PM
Tomguy's Avatar
Vintage Moderator
 
Join Date: Aug 2002
Location: Not where I want to
Posts: 4,969
Quote:
Originally Posted by Frank Reiner View Post
Tom:
Re: center-mount vs. end-mount, is it possible that you are referring to the attachment points of the tie rods?
Yes, exactly what I mean. As he's doing a custom build, I will assume the rack's mounting points/style matters 0% because it will require custom fab to mount either way. Therefore, the style it appears he actually needs mounts the tierods to the center of the rack unit, because there is no end mounting style that could possibly work with such short play without much more major changes to the steering he probably does not want to do.

The downside of such a rack is that it is inevitably longer than a more "Traditional" end-mount rack, but since it can be mounted "out of the way" it should not matter as much, I would assume.
Album here
__________________
Current:
1999 Chrysler 300M (Click for pic) - 207,xxx - totalled by Nationwide for $1600 in damage. Being rebuilt better.
2014 Jeep Grand Cherokee Limited (Click for pic) - 32,xxx

My Mercedes Benz 108 109 resource site
August 2014 newsletter live.

Previous: 1972 280SE 4.5 "Quicksilver", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
Reply With Quote
  #66  
Old 07-12-2016, 03:38 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 2,025
Thanks Tom; that would appear to be a front-steer configuration (rack in front of axle). Are you able to say what the steering arm length is? (Ball joint center line to tie rod end center).
Reply With Quote
  #67  
Old 07-12-2016, 04:11 PM
Tomguy's Avatar
Vintage Moderator
 
Join Date: Aug 2002
Location: Not where I want to
Posts: 4,969
I would have to measure. The strut itself is the centerline for the (top) of the steering system, I assume you're looking for the length from the strut arm to the center of the strut itself? The R&P is mounted to a crossmember in front of the firewall, and the tie rod ends connect to the steering ends of the front struts.
__________________
Current:
1999 Chrysler 300M (Click for pic) - 207,xxx - totalled by Nationwide for $1600 in damage. Being rebuilt better.
2014 Jeep Grand Cherokee Limited (Click for pic) - 32,xxx

My Mercedes Benz 108 109 resource site
August 2014 newsletter live.

Previous: 1972 280SE 4.5 "Quicksilver", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
Reply With Quote
  #68  
Old 07-12-2016, 04:24 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 2,025
Quote:
Originally Posted by Tomguy View Post
I assume you're looking for the length from the strut arm to the center of the strut itself?
Yes, that would be the steering arm length.

[/QUOTE]The R&P is mounted to a crossmember in front of the firewall, and the tie rod ends connect to the steering ends of the front struts.[/QUOTE]

Is the rack mounted forward of the wheel spindles, or aft of the spindles?
Do the steering arms point forward from the struts, or back from the struts?
Reply With Quote
  #69  
Old 07-12-2016, 05:36 PM
Tomguy's Avatar
Vintage Moderator
 
Join Date: Aug 2002
Location: Not where I want to
Posts: 4,969
The ultimate Intrepid (and Vision, Concord) steering fix
For anyone curious here's info and pics on how a Chrysler LH with R&P is setup. The rack is mounted pretty much on the firewall (on a "Frame" crossmember right in front of it). This is behind the front axle centerline.
__________________
Current:
1999 Chrysler 300M (Click for pic) - 207,xxx - totalled by Nationwide for $1600 in damage. Being rebuilt better.
2014 Jeep Grand Cherokee Limited (Click for pic) - 32,xxx

My Mercedes Benz 108 109 resource site
August 2014 newsletter live.

Previous: 1972 280SE 4.5 "Quicksilver", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
Reply With Quote
  #70  
Old 07-12-2016, 07:47 PM
Registered User
 
Join Date: Jan 2012
Posts: 4,692
Another center tie rod mount rack is a GM J body ( 81 to 05? Chevrolet Cavalier, Pontiac Sunfire , Olds Firenza , Buick Skyhawk , Cadillac Cimarron )
Reply With Quote
  #71  
Old 07-12-2016, 08:01 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 2,025
With respect to the Mopar R&P which Tom has identified, although it is a center take-off type, it is also a front-steer type, i.e., the steering arms at the uprights (struts, knuckles,etc.) are forward of the wheel spindle. To make a right turn, the rack also travels to the right. Given the configuration of the W114/115 crossmember, it is difficult to get the steering shaft in place to use a front-steer R&P.

A common rear-steer, center take-off R&P can be sourced from GM J-platform cars, and forms the basis for a number of after-market kits, many of them directed at early Mustangs. J-bodies include: Buick Skyhawk, Cadillac Cimarron, Chevy Cavalier, Oldsmobile Firenza, Pontiac 2000/Sunbird/Sunfire.
Reply With Quote
  #72  
Old 07-12-2016, 08:01 PM
Registered User
 
Join Date: Jan 2012
Posts: 4,692
As for " Ackerman " ( toe out on turns ) , that is dictated by the angle of the steering arm relative to the wheel ( when looking from above. ) Look on the net for a drawing of steering arms / center line of the car.

When using ackerman, a front steer car will have the outer tie rod end close to the tire, a rear steer farther away from the tire.

If you move the outer tie rod end closer to the spindle while keeping along the same angle, you won't change ackerman but you will reduce tie rod travel needed to complete a turn. I did this on a car bu drilling / tapering a new hole along the arm. Not sure if your arm will have enough material or not.
Reply With Quote
  #73  
Old 07-13-2016, 02:54 AM
Coasttocoast's Avatar
Registered User
 
Join Date: Nov 2015
Location: Honolulu
Posts: 251
Tom, Frank, and 97,

Thanks much for your conversations today.

Oahu does not have salvage yards like the mainland. I'm not sure if it's for environmental or financial (due to high real estate prices) reasons, but no acreage of salvage cars. So combing wrecked cars is not an option. For both my Jeep/Vortec and Mercedes/Vortec build I've had to buy from the mainland and ship over. Not only no availability, the largest "Salvage Yard" salesman didn't even know what a Chevy Vortec engine was. So trying to get their help looking for steering racks would certainly be futile.

In the many hours I've spent so far reading forums on steering swaps it seems the most prevalent R&P is from the Chevy J-bodies. A few aftermarket companies even base swap kits on this rack.

'69 230 build w/LQ4 swap-image.jpeg

I can buy locally, rebuilt racks for under $100 from OReily. Basically this rack has 2.8 or 2.5 to 1 ratio, 6" of travel, for rear steer, and it's two mounting points are pretty close in width to match the W114 frame rails at the point of installation. This rack, as mentioned, connects to the steering arms from the center of the rack, not each end.

So to keep the same W114 geometry a bar needs to be fashioned to attach to the racks center point with connection points at each end to match the existing inner tie rod bolting locations, approx 19 1/2". So a modified drag link, if I have my terminology correct. Similar idea to the pic above.

I need to re-install my steering box and map out all the existing points, so when I make all the new parts and mounts I can duplicate the existing.

I'm planning on buying one this week and checking to see if what I have read matches my estimations.

The only downside I see at this point is going to be a reduced turning radius. This is the common complaint with the swap. And the fact that it seems that even with all the posted swaps and companies that make conversion kits, no one offers a rack with more than about 6 3/4" travel.

In some swaps I've read they move the tie rod connection to the wheel closer to the spindle, as previously mentioned. I need to measure this out before I cut everything out to see how far inward I would have to go to achieve the same turning radius as stock with only 6" of travel.
__________________
"In wine there is wisdom, in beer there is strength, in water there is bacteria."
Reply With Quote
  #74  
Old 07-13-2016, 01:50 PM
Tomguy's Avatar
Vintage Moderator
 
Join Date: Aug 2002
Location: Not where I want to
Posts: 4,969
FYI it'll also reduce bump steer if you do mount the ends closer to the spindle. Basic leverage principles apply (the lever to push the tie rods is longer when it's further from the spindle, thus bumps more easily can mess with your steering angle). Killing two birds with one stone = good.
__________________
Current:
1999 Chrysler 300M (Click for pic) - 207,xxx - totalled by Nationwide for $1600 in damage. Being rebuilt better.
2014 Jeep Grand Cherokee Limited (Click for pic) - 32,xxx

My Mercedes Benz 108 109 resource site
August 2014 newsletter live.

Previous: 1972 280SE 4.5 "Quicksilver", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
Reply With Quote
  #75  
Old 07-13-2016, 04:59 PM
Registered User
 
Join Date: Jan 2012
Posts: 4,692
The Chevy Cobalt replaced the J body so I'd have a look at one of those to see if the rack is similar.

The late 80's J body could have been had in a 1.8 and 2.0 OHC turbo so there is a small chance of a faster ratio rack.
Reply With Quote
Reply

Bookmarks

Thread Tools
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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 04:36 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page