3779185 Idler arm and tie rod clamps

[Craig O.]

I have a few original 3779185 Idler arms and noticed a slight difference
in the arm configuration..... two have a straight arm and two have a curve in the arm. is there any reference to years of application of each? also I have a slight difference in the tie rod end clamps. It's hard to tell in the photos but 4 have a smaller more defined raised rib and the others have a more rounded rib. are any of these original to the period ? note the last clamp has a flat section where the hole is for the bolt to pass through.

[Alan D.]

Re: 3779185 Idler arm and tie rod clamps

And here's an example of why higher resolution pictures are needed! Unable to zoom into the details on the clamps or arm.
(yes realize NCRS has limited space for photos at present and as storage price comes down things will get better)

Now both my idler arms are flat (no curve to them) Take a look at the boot for a part number, may be 3779190 and also the word "BAY" (mfg name?) and even a "54" which may be a mold number. Of the two that are straight my original does not have any marks on the upright that bolts to frame, again can not see just what those are. In order to get a good picture for comparison try just one clamp, then the other clamp - already zoomed into the details in question.

[Scott S.]

Re: 3779185 Idler arm and tie rod clamps

Now both my idler arms are flat (no curve to them) Take a look at the boot for a part number, may be 3779190 and also the word "BAY" (mfg name?) and even a "54" which may be a mold number.

Craig and Alan,

I have only seen the straight arm, that curved version is a strange looking item, does it have the same 3779185 casting number as the straight idler arms?

The boot from the idler arm on the '67 I'm working on has a raised "KF" for the manufacturer (same company as my dimmer switch grommet), followed by "14-165" and "149".

[Craig O.]

Re: 3779185 Idler arm and tie rod clamps

Scott, all have the 3779185 on the shaft.the boots from top to bottom read....
KF 14-165 137 (placed in 3 equal segments on boot)
KF48 14-165
KF29 14-165

Allen, I will try to get a better photo of the clamps.also the attaching to frame arm has a circle with 135 stamped

[David L.]

Re: 3779185 Idler arm and tie rod clamps

Craig,

My 1963 Chevrolet Parts Catalog (Oct. 1962) lists the following in Gr. 6.895:

63 Ser. 10 (exc. 4/WD).....................(forged 3779185)..............................3817956..... .$6.85
63 CORVETTE..................................(forged 3779185)..............................3779184..... .$5.95

My 1965 Chevrolet Parts Catalog (Oct. 1964) lists the following idler arms for the Ser. 10 trucks:
63 Ser. 10 (1st design)(exc. 4/WD).........(forged 3779185)...............................3817956.... ..$7.20 (part # corrected 9:31 PM)
63-65 Ser. 10 (exc. 4/WD).................(3 longitudinal ridges on support)..............3820387*....$6.25
*NOTE: 3820389 Spacer must also be used.

GM 3817956 is also shown in my 1964 (Oct. 63), 1965 (Jan. 65, May 65), and 1966 (Oct. 65) Chevrolet parts catalogs but is not shown in my 1967 Chevrolet Parts Catalogs (April 67 and July 67).

My Chevrolet & GM Parts History manuals (Jan. 1965-July 1973, Jan. 1973-June 1975, Jan. 1975-Dec. 1975, Jan. 1976-Dec. 1981, and Jan. 1981-Jan. 1990) do not list GM # 3817956 as being discontinued. GM # 3817956 just disappeared off the face of the earth without any record.

The 3779184 idler arm (forged 3779185) is listed in my 1982 Corvette Parts Catalog (Nov. 81) for 63-82 Corvettes.

It's interesting that the 63 Ser. 10 truck and the 63 Corvette had the same idler arm forging number but the truck idler arm cost $0.90 more in October 1962. Apparently there was additional work done on the truck idler arm. Could the "curved" idler arms (forged "3779185") be for the 63 Ser. 10 truck?

When compared side by side do the ends of the "curved" and "straight" idler arms match up exactly? In other words, is the net offset the same?

Dave

[Joe L.]

Re: 3779185 Idler arm and tie rod clamps

Craig,

My 1963 Chevrolet Parts Catalog (Oct. 1962) lists the following in Gr. 6.895:

63 Ser. 10 (exc. 4/WD).....................(forged 3779185)..............................3817956..... .$6.85
63 CORVETTE..................................(forged 3779185)..............................3779184..... .$5.95

My 1965 Chevrolet Parts Catalog (Oct. 1964) lists the following idler arms for the Ser. 10 trucks:
63 Ser. 10 (1st design)(exc. 4/WD).........(forged 3779185)...............................3717956.... ..$7.20
63-65 Ser. 10 (exc. 4/WD).................(3 longitudinal ridges on support)..............3820387*....$6.25
*NOTE: 3820389 Spacer must also be used.

GM 3817956 is also shown in my 1964 (Oct. 63), 1965 (Jan. 65, May 65), and 1966 (Oct. 65) Chevrolet parts catalogs but is not shown in my 1967 Chevrolet Parts Catalogs (April 67 and July 67).

My Chevrolet & GM Parts History manuals (Jan. 1965-July 1973, Jan. 1973-June 1975, Jan. 1975-Dec. 1975, Jan. 1976-Dec. 1981, and Jan. 1981-Jan. 1990) do not list GM # 3817956 as being discontinued. GM # 3817956 just disappeared off the face of the earth without any record.

The 3779184 idler arm (forged 3779185) is listed in my 1982 Corvette Parts Catalog (Nov. 81) for 63-82 Corvettes.

It's interesting that the 63 Ser. 10 truck and the 63 Corvette had the same idler arm forging number but the truck idler arm cost $0.90 more in October 1962. Apparently there was additional work done on the truck idler arm. Could the "curved" idler arms (forged "3779185") be for the 63 Ser. 10 truck?

When compared side by side do the ends of the "curved" and "straight" idler arms match up exactly? In other words, is the net offset the same?

Dave

David-----


The GM #3817956 idler arm assembly was replaced by the GM #3820387 in October, 1964. The GM #3817956 assembly used the same 3779185 forged arm as the 3779184 Corvette assembly. However, the bracket section was different. The 3817956 assembly had a bracket with double offsets. The 3779184 Corvette assembly had a single offset. I don't know how the 3817956 assembly differed from the 3820387.

I'm convinced that the 3717956 is a catalog error. For one thing, note that only the second digit is different from the 3817956. That's highly unlikely for 2 "real" parts of the same type. For another thing, the 3717956 would have been an early 50's released part.

[David L.]

Re: 3779185 Idler arm and tie rod clamps

David-----


The GM #3817956 idler arm assembly was replaced by the GM #3820387 in October, 1964. The GM #3817956 assembly used the same 3779185 forged arm as the 3779184 Corvette assembly. However, the bracket section was different. The 3817956 assembly had a bracket with double offsets. The 3779184 Corvette assembly had a single offset. I don't know how the 3817956 assembly differed from the 3820387.

I'm convinced that the 3717956 is a catalog error. For one thing, note that only the second digit is different from the 3817956. That's highly unlikely for 2 "real" parts of the same type. For another thing, the 3717956 would have been an early 50's released part.

Joe,

I now see in the back of my 1965 Chevrolet Parts Catalog (Oct. 1964) that GM # 3817956 was replaced in October 1964 with GM # 3820387. I forgot about the parts history in the back on the catalogs.

It makes sense that the 3779184 and 3817956 idler arms use the same forged arm (forged "3779185") but different brackets. Enclosed below is a link of a NOS truck idler arm with "3779185" forging on Ebay.

The 3717956 part number is my typing error, not a catalog error. I will correct my previous post.

Thanks,

Dave

http://www.ebay.com/itm/NOS-61-62-63-64-Chevy-Idler-Arm-SS-409-Truck-Full-Size-/300585004467?pt=Vintage_Car_Truck_Parts_Accessories&vxp=mtr&hash=item45fc432db3