• 1 Vote(s) - 5 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Idler Arm question
#1
So engine from my 73 vert is still at rebuild shop so decided its a good time to remove the gear box and send back for rebuild hoping to fix loose steering. At the same time I'm replacing the idler arm. I'm a little confused though. After looking at multiple websites for idler arms, in the details it states "for manual steering". I have power steering. Is there a different idler arm for a 73 mustang with power steering or are these interchangeable?
  Reply
#2
Blmeis;253620 Wrote:So engine from my 73 vert is still at rebuild shop so decided its a good time to remove the gear box and send back for rebuild hoping to fix loose steering. At the same time I'm replacing the idler arm. I'm a little confused though. After looking at multiple websites for idler arms, in the details it states "for manual steering". I have power steering. Is there a different idler arm for a 73 mustang with power steering or are these interchangeable?

That is a good question, are they the same or different for PS v MS? Nobody has been able to tell me either. I bought part #3355-1 from NPD. BUT I had to hand slot the top hole considerably. The angle of the arm is different to the original, but the end point is the same if you get what I'm saying. I read that the top hole may need to be slotted on some applications. Anyway it fitted OK and the drag link lined up well. I too am rebuilding my PS box and overhauling the steering completely. I won't know if that idler arm is good until I get the car back on the road in Spring. If not, I guess I'll be changing it again.
  Reply
#3
the arm and bracket is different between the manual and power steering.
the bracket has a slightly different kick out and the arm itself has a shallower angle and is longer on the power steering version.

when i replaced mine i made sure the replacement part looked 100% the same as the original i had.

now you could use either on the car but if the car was on a lift and you looked at the geometry of the steering cross bar it would not be straight.
the angle of radius would be different between the driver and passenger tire when turning.

an alignment shop would not pick that up because they never test for tire angle left to right full lock.
it would pass all the camber, caster, toe measurements. i guess if you raced the car you would notice a difference in steering left to right in curves.


now i did mine years ago and it was a FORD NOS part, so i matched part numbers and compared my original to the new one.
  Reply
#4
Great feedback! I will continue to research and look for a part that is, like you said, "looks 100% like the original". I really want a 100% OEM part and don't want to risk screwing an aftermarket part up because I need to "modify" it to make it fit.
  Reply
#5
OMS shows them as fitting both:
http://www.ohiomustang.com/store/order_p...temid=3028



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
  Reply
#6
Blmeis;253625 Wrote:Great feedback! I will continue to research and look for a part that is, like you said, "looks 100% like the original". I really want a 100% OEM part and don't want to risk screwing an aftermarket part up because I need to "modify" it to make it fit.

I forgot to mention that my original idler arm was for manual steering. I added PS a couple of summers back and I didn't notice any problems in steering control. However I do agree that it is best to get what's right. I have nothing to compare the PS idler arm to, so like I said, I may be changing it again. If someone knows the exact part number and supplier for a PS idler arm, please let us know. As Blmeis said, they all seem to be listed as for Manual Steering!!

Don C;253627 Wrote:OMS shows them as fitting both:
http://www.ohiomustang.com/store/order_p...temid=3028

That's interesting Don, Worth looking into.
The one I bought from NPD is listed as PG (professional Grade) and has grease fittings on both bushings.
  Reply
#7
Stanglover, I think I'm going to try the one Don suggested from Ohio Mustang. I'll provide feedback after I get the product (compared to original), when I get the product on the vehicle (fitment), and then again after I take her for a test drive. No need to wait for Spring here in TX, just need my engine back first!

Brian
  Reply
#8
Blmeis;253632 Wrote:Stanglover, I think I'm going to try the one Don suggested from Ohio Mustang. I'll provide feedback after I get the product (compared to original), when I get the product on the vehicle (fitment), and then again after I take her for a test drive. No need to wait for Spring here in TX, just need my engine back first!

Brian

Lucky bugger!!
Yes, please let us know how it compares to your original. I took a look at mine, but was still a bit too cold in the garage, despite a record high temp today, to spend any time crawling into the engine bay.
Keep in touch on this as others will no doubt be interested.
Geoff.
  Reply
#9
I took a little time to compare my two idler arms, the original MS and my aftermarket USA made replacement. The math shows that they are both very similar. I'll admit without removing the new one, it was a bit of a guess as to accurate dimensions. Here's what I found: the axis line through the centerline of the mounting bolt holes to the axis line through the centerline of the draglink (D/L) bushing measured almost the same at 5.25" + / - and are parallel to one another . The old bushing in the MS arm is badly worn, so I can't be sure if the my centerline measurement of 5.315" is accurate, but close enough for this. The top surface of the D/L bushing insert to the center of the bottom hole in the mounting post looks to be the same. Therefore it matters not what the lower bushing dimension ( location) to the center of the bottom hole on the mount post is, the arc scribed will be the same. This means that there will be no effect on the steering. If I had access to CAD I could illustrate what I'm trying to explain, so I hope people can make sense of this.
Bottom line is as long as the centerlines are the same, the arc travelled will be the same. I just know someone will question my "theory" , but I wanted to do this for myself mainly to satisfy my own curiosity.
Geoff.
NOTE: I added " and are parallel to one another"
  Reply
#10
I understood what you were saying

but I are a genius Wink

[Image: 1_01_07_15_8_53_18.png]

"I love my Hookers!" and "Get some Strange" probably have a different connotation to non automotive enthusiasts!
  Reply
Share Thread:  


Possibly Related Threads…
Thread Author Replies Views Last Post
  Idler Arm Rebuild, pressing in bushings, Is this OK? andy72 14 574 11-10-2019, 08:51 PM
Last Post: andy72
  Moog Idler Arm, Holes don't match and Geometry andy72 12 510 10-14-2019, 08:30 PM
Last Post: andy72
Magnum Wheel question waterlife 5 297 10-12-2019, 09:35 AM
Last Post: waterlife
  Rag joint question vintageman 42 1,437 07-03-2019, 02:46 PM
Last Post: vintageman
  Rear Suspension Staggered Shocks Question 73pony 11 645 06-25-2019, 01:46 PM
Last Post: 73pony



Users browsing this thread: 1 Guest(s)