Slant Six Forum
https://slantsix.org/forum/

Idler arm problem
https://slantsix.org/forum/viewtopic.php?t=45443
Page 1 of 1

Author:  wjajr [ Mon Jun 27, 2011 3:42 pm ]
Post subject:  Idler arm problem

The other day I had to get the Dart’s annual state safety inspection done. Car passed, but mechanic said idler arm is showing a bit of slop, or movement. This makes sense, as there has been a bit of a flutter in the steering when following a crack in the pavement with right wheel. I was never able to identify where the problem was.

I ordered a new idler arm for the 67 Dart, and waited until it arrived before disassembling, and removing the old unit. Oddly it all came apart quite easily, too easy, I thinking previous owner did not fully torque inner tie rod, and both ends of idler arm.

What I discovered is that the idler arm is fine, on the new side in fact. The sloppiness is coming from the poor fit of the idler arm in the K member. It is egged out so the arm can wallow fore & aft, this is what the inspector found, and what I can feel at times..

Does anyone know what taper reamer would be needed to bring back correct profile, needed to correct the problem? I know that upper ball joints are 7.5 degrees, and I wonder if the rest of the holes are the same taper in the front end.

Bill

Author:  WagonsRcool [ Mon Jun 27, 2011 9:15 pm ]
Post subject: 

You can try fixing that if you have pretty good welding skills & equipment. Every mopar-head I know would view your problem as a good excuse to go to a 68-up thru-bolt idler K-frame. (or a 73-up spool mount K-frame with BBP discs)
If you want to figure out the taper - measure the change in diameter of the stud (with calipers) & measure the length between your 2 diameters - divide the first number by the second & plug the result into the TAN function of a scientific calculator (or similar web app) to get your degrees.

Author:  wjajr [ Tue Jun 28, 2011 9:20 am ]
Post subject: 

Today brain is in gear, test fit an upper ball joint, and it’s the same taper for idler arm. I know where to get a ream for that application.

Bill

Author:  SlantSixDan [ Tue Jun 28, 2011 10:08 am ]
Post subject: 

Please let us know how things go with this repair.

Author:  Dart270 [ Tue Jun 28, 2011 12:28 pm ]
Post subject: 

I think Seymour (Exner Geek) reamed his '62 Valiant idler arm hole but then the idler arm bottomed out. I was up there one time and we made a ~0.040" thick metal shim out of sheet that slipped in there and dropped the idler arm down a little. I think it's still holding.

Lou

Author:  Exner Geek [ Tue Jun 28, 2011 5:53 pm ]
Post subject: 

Ya, Lou is right, I had the same problem but it had gotten so oblong that by the time the hole was round again the idler arm bottomed out. A friend tried to make a spacer by heating up a piece to tubing and pounding the shaft into it. It wasn't really uniform in thickness so it never tightened up in the hole. Lou made one by just wraping a piece of scrap metal around the shaft, I think it was quite a bit thicker than .040". We trimmed it to the shape of the tapered hole and the arm seemed to tighten up with no wobble. I haven't checked it lately but I believe it was a successful repair. If the top nut is tight enough it should never be a problem.

Author:  Dart270 [ Tue Jun 28, 2011 8:35 pm ]
Post subject: 

Fabrication times at Seymour's shop... :)

Lou

Author:  wjajr [ Fri Jul 08, 2011 7:00 pm ]
Post subject: 

I got the idler arm remounted today. 1967 is a one year only for a tapered shaft idler arm attachment to “Kâ€￾ frame. All other years through bolt at the “Kâ€￾ frame, and utilize a tapered shaft & nut at drag link.

What I did was order a [url=http://www.speedwaymotors.com/Tapered-Ball-Joint-Reamers-7-Degree,2918.html]7 degree ream[/url] from Speedway Motors which arrived promptly within a few days. It fit into a ½ inch drill motor, and I reamed the wallowed out mount in the “Kâ€￾ member over sized by about twenty thousands of an inch.

Once K member bracket was reamed, the idler arm bottomed out making it imposable to tighten its stud. I than made a template out of some card stock from a [url=http://www.nextag.com/Avery-Dennison-Manila-G-690876104/prices-html?nxtg=49f70a50050a-4E59312371A3DF2A]Dennison string tag[/url] that formed a conical shape with seam meeting points forming an angle of about 60 degrees. My thought was having a non vertical seam would provide a stronger bearing area once bolted up.

I than got several different gages of sheet metal scraps and duplicated the paper cut-out in 22 gage (which is about 0.020â€￾ thick) sheet metal forming a conical bushing that slid up into the tapered hole in the K member. It took several trial fittings & light reaming to get it to fit just right. I than installed the bushing and idler arm, and tightened it all up as best I could due to the close quarters leaving no room for a torque wrench in that spot.

I have a set of combination open end and ratchet wrenches where the ratchet can be angled, and that type of wrench worked nicely.

Time will tell if this repair will last, but for now it is nice and tight with no movement.

Author:  Dart270 [ Sat Jul 09, 2011 10:40 am ]
Post subject: 

Should be fine. Nice work. Seymour's has 10-20k on it by now.

Lou

Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/