Idler arm length
 

My 64 C10 has a GM power steering box and pittman arm installed by the PO, but the idler arm I assume is stock, as the steering geometry on that side is wrong. A friend says the idler arm length should match the pittman arm length, with the center link parallel to the crossmember. The current pittman arm is 5" c-c in an S shape.

Re: Idler arm length
 

Do you know what year your steering gear is?

Re: Idler arm length
 

I am having the same problem with my truck. Having trouble finding the dimensions for pitman arms and idler arms on the web and parts houses dont seem to want to do the leg work to help out. My steering box is from a mid 80's c10.

Re: Idler arm length
 

Steering box/pittman arm is from PO, looks like 70s/80s power type Saginaw. The rest (center link, tie rods, adjusters) is assumed to be stock 64 C10. This was a bought project. When I move the idler arm mount to where the center link is parallel and clamp it to the frame, it seems to steer correctly. The pics posted by bagger is very like my setup.

Re: Idler arm length
 

Is the steering not acting right with the current setup?

I don’t know for certain if an idler arm from a squarebody has the same taper as the 64 on the center link, but if it does, you could use that one. You would have to drill new holes in the frame.

Or, just use the stock idler arm if it’s in good shape and drill some new holes where it seems to steer the best.

Also, make sure your center link is attached in the correct orientation. If installed wrong, a new idler arm won’t fix your problem.

Re: Idler arm length
 

C10/20/30 Chevrolet - Moog P/Ns

Pitman Arm length (center line to center line)
60-66 all 5.374" K6086
67 all not 100% sure ?
68-72 manual not 100% sure K6130
68-72 power 5.137" K6131
73-89 manual 5.157" K6142
73-89 power 5.059" K6143

Idler Arm length (center line to center line)
60-62 all not 100% sure ?
63-66 all 5.9" K14
67-82 all 5.394" K6096T
83-89 all 5.394" K6247T

Re: Idler arm length
 

After checking RockAuto, it seems the idlers after 66 use a different mounting procedure. I also checked the earlier S10s, that use the L-shaped arms, and they mount to the inside of the frame, not the outside, making them shorter on the center link. As my initial question says, do you need an equal-length idler arm as per the pittman? If they're not, and steering is not hampered, does it matter? What are people using for an idler? Just lining things up and making the existing one work?

Re: Idler arm length
 

That does seem logical but notice that GM never had the pitman length equal the idler arm length, at least not on trucks from '60-'89. So being equal must not be important. The safest bet is to do whatever GM did and make your idler arm match whatever your pitman arm usage was. In other words, if you have an '80 pitman, use the '80 idler. This may also make you change center links.

And yes the center link should be parallel to the crossmember.

Re: Idler arm length
 

Or maybe the idler arms were mounted in different spots on the frame for different years. There's a lot of parts in play here.

Re: Idler arm length
 

That does seem to be a good plan, especially if everything was the same year, etc. But in this case, and many who upgrade to power steering with our trucks, components may not be in the original locations which cause differences in the way things work.

Re: Idler arm length
 

Places like RockAuto sometimes give the dimensions of things like this in their description of parts. I've figured that a idler from a 80s-90s S10 4WD pretty much fits the bill, at least in dimensions. Maybe check out the local UPullit for a looksee.