3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order?

[Scott S.]

This Idler arm has the correct casting number (3779185) and the straight lever (not offset, as the idler arm with same casting number for trucks). The rubber boot has the "KF" logo, same as my original. It has the GM sticker with the 3779184 part number, but it's torn, so the sticker could have come from anywhere.

All of the correct markings are present, except the "B" that is stamped into the flat bottom surface on the end of my original where the lever attaches. It has grease filling up one of the bolt holes (just seemed an odd place for grease), and generally grease all over, same color (dark brown) and consistency grease is under the boot as well. Grease looks old, with organic matter (hair, seeds, fragments of leaves) mixed in with the grease in places, like it was stored on the floor in the back of a woodshed.

Is there a way to tell whether this is really NOS, or just used? My original has grooves in the bolt holes from the bolt threads, this one does not. It probably wouldn't be difficult to hone the bolt holes smooth, but these aren't smooth either, they have a slightly rough swirling type of machine marking inside the bolt holes.

The other question, is there a way to determine whether the idler arm is in good working order, without installing and testing it on a car?

[Rich C.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

I would vote NOS! I have a NOS one that I haven't installed yet and it has that grease-like cosmoline smeared on it, including the mounting holes.

'73 LS-4 454 owned for 21 1/2 years

[Scott S.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Rich,

Thanks for the reply.

My original idler arm has the casting number on the bottom side, this (presumably) NOS example has the casting number on the top side. Does your NOS Idler arm have the casting number on the top side, or is it on the bottom side where it would be visible from under the car?

[Joe L.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Rich,

Thanks for the reply.

My original idler arm has the casting number on the bottom side, this (presumably) NOS example has the casting number on the top side. Does your NOS Idler arm have the casting number on the top side, or is it on the bottom side where it would be visible from under the car?

Scott-----


I would say this is NOS, but it looks like it's spent a lot of time in poor storage conditions. Functionally, it's probably fine, though. The parts label almost guarantees it is NOS. Such a label would not be found on a PRODUCTION part and it's unlikely it would have survived in such good condition if this idler had ever been installed as a SERVICE part on a Corvette.

As far as the location of the forging number on the arm section, all that I have seen have had the number on the bottom. However, that certainly does not mean that all were made that way. I'd say that this arm is proof that all weren't made with the number oriented downward as installed on the car.

[Scott S.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Scott-----


I would say this is NOS, but it looks like it's spent a lot of time in poor storage conditions. Functionally, it's probably fine, though. The parts label almost guarantees it is NOS. Such a label would not be found on a PRODUCTION part and it's unlikely it would have survived in such good condition if this idler had ever been installed as a SERVICE part on a Corvette.

As far as the location of the forging number on the arm section, all that I have seen have had the number on the bottom. However, that certainly does not mean that all were made that way. I'd say that this arm is proof that all weren't made with the number oriented downward as installed on the car.

Joe,

After checking, it looks like this will be yet another issue with the Judges:

1966 JG: "The idler arm is a natural finish forging with the part number embossed into the surface facing the ground." (p. 169)

1967 JG: "The idler arm is a natural finish forging with the part number 3779185 embossed into the surface facing the ground." (p. 135)


Clearly they were made both ways, but that's not what the book sez...

[Alan D.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

And naturally that brings up another question - "The idler arm is a natural finish forging"
From previous discussion on the natural v black goop on the arm I believe it has been accepted that the unit came all black goop on standard steering, but natural on power steering (not sure of reason) Perhaps Joe or Hinckley can enlighten us (or back to a link?)

And as a side note; the 64 boot has a GM part number on it, as all the rubber front end boots do, not the "KF" which must be a latter feature.

[Gary B.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Joe,

After checking, it looks like this will be yet another issue with the Judges:

1966 JG: "The idler arm is a natural finish forging with the part number embossed into the surface facing the ground." (p. 169)

1967 JG: "The idler arm is a natural finish forging with the part number 3779185 embossed into the surface facing the ground." (p. 135)


Clearly they were made both ways, but that's not what the book sez...

Scott,

Maybe all of the Production parts had the number embossed on the surface facing the ground. But service replacement parts had the number either on the bottom, as Joe reports, or on the top, as in your NOS example. So, the '66 and '67 TIM&JG could be correct when describing all Production examples.

Gary

[Scott S.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

And naturally that brings up another question - "The idler arm is a natural finish forging"
From previous discussion on the natural v black goop on the arm I believe it has been accepted that the unit came all black goop on standard steering, but natural on power steering (not sure of reason) Perhaps Joe or Hinckley can enlighten us (or back to a link?)

Alan,

I have read about the pitman arm being painted black for manual steering and natural for power steering, but I had not heard about the natural vs. black goop on the Idler arm yet, I will check the archives.

And as a side note; the 64 boot has a GM part number on it, as all the rubber front end boots do, not the "KF" which must be a latter feature.

Is the part number on your Idler arm boot "3779196"? It's hard to make out the last digit.


"KF" is also embossed on my original dimmer switch grommet, is that the same for 1964?

My presumed original (1967) Idler arm boot has all of the following in raised letters or numbers: KF, 14-165, 149

The NOS Idler arm boot has: KF, 14-165, 70

[Alan D.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

See Idler Arm on Steering linkage restoration above for some good information.
As far as black goop or black paint I just consider them equal (which they are not) so just make black somehow as opposed to natural that was the point of my comment.
The boot pn is 196. Also note in the above link the order which references the boot is INCORRECT!
Do have a nice picture of entire unit with numbers and order shown however it does not load into data base, can send a copy if you desire, but that was not the subject.

[Joe L.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Scott,

Maybe all of the Production parts had the number embossed on the surface facing the ground. But service replacement parts had the number either on the bottom, as Joe reports, or on the top, as in your NOS example. So, the '66 and '67 TIM&JG could be correct when describing all Production examples.

Gary

Gary------


Yes, it's very possible that during the 66-67 period (or, even later) all of the idler arms did have the forging numbers on the bottom. This would include both SERVICE and PRODUCTION pieces since I doubt there was any difference for one or the other as far as manufacture goes.

However, the 3779184 idler arm was used in PRODUCTION through 1981 and available in SERVICE until June, 1984. At some time, the orientation of the forging numbers could have changed for some or all arms. SERVICE arms manufactured during that period would, of course, by applicable to 63+ Corvettes.

[Scott S.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

See Idler Arm on Steering linkage restoration above for some good information.
As far as black goop or black paint I just consider them equal (which they are not) so just make black somehow as opposed to natural that was the point of my comment.
The boot pn is 196. Also note in the above link the order which references the boot is INCORRECT!
Do have a nice picture of entire unit with numbers and order shown however it does not load into data base, can send a copy if you desire, but that was not the subject.

Thanks Alan. I think I found your picture with the Idler arm associated parts in the correct order, last post in this thread: 63 idler arm pics

[Joe L.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

And naturally that brings up another question - "The idler arm is a natural finish forging"
From previous discussion on the natural v black goop on the arm I believe it has been accepted that the unit came all black goop on standard steering, but natural on power steering (not sure of reason) Perhaps Joe or Hinckley can enlighten us (or back to a link?)

And as a side note; the 64 boot has a GM part number on it, as all the rubber front end boots do, not the "KF" which must be a latter feature.

Alan------


The GM #3779196 idler arm seal was available from GM as a separate part. At least, it was until November, 1988 when it was discontinued without supercession.

As far as the asphaltic coating on the idler arm goes, I think the arm was at least partially coated. However, I don't think the bracket section was coated; it may have been masked off or otherwise covered.

[Scott S.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Joe,

I found the thread where Rich Pasqualone describes a method to lubricate the Idler arm, just wondering how stiff they ought to be normally. Both my presumed original and presumed NOS examples seem to be frozen in place.

Should I be able to move either the ball stud end or the lever end of the Idler arm, without the arm being mounted on the car?

[Joe L.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

Joe,

I found the thread where Rich Pasqualone describes a method to lubricate the Idler arm, just wondering how stiff they ought to be normally. Both my presumed original and presumed NOS examples seem to be frozen in place.

Should I be able to move either the ball stud end or the lever end of the Idler arm, without the arm being mounted on the car?

Scott-----


I can usually move them by hand but it takes quite an effort.

[John H.]

Re: 3779184 Idler Arm- Is this NOS or USED? How to tell if it's in good working order

As far as the asphaltic coating on the idler arm goes, I think the arm was at least partially coated. However, I don't think the bracket section was coated; it may have been masked off or otherwise covered.

Joe -

When I was at Buffalo in 1966 on a trouble-shooting visit, steering linkages were hung on overhead conveyor racks for painting (with that gooey black paint) from two hooks - one through the pitman arm hole, and one from the steering idler arm bracket hole, five or six linkages per rack.

Alan -

The pitman arm was part of the steering linkage from Buffalo on manual-steering cars, and at least part of it got painted. On power steering cars, the pitman arm was a separate part, installed to the control valve in an off-line bench subassembly at St. Louis where the control valve was assembled to the relay rod and the system was bench-bled before installation on the Frame Line.