3 groove or 4 groove pitman arm?

sahls01gmc · March 2, 2016

I'm looking to replace my idler and pitman arm, but there are 2 options. I don't know if I have the 3 or 4 groove.

My real question is, if I'm replacing both at the same time, can I just buy the same corresponding ones, and they will work? What exactly does the grooves line up to?

I suppose I can buy both options, but if I don't have to, I won't.

sahls01gmc · March 2, 2016

Also, do you recommend replacing the Idler Arm Bracket Assembly as well?

newdude · March 2, 2016

I'm looking to replace my idler and pitman arm, but there are 2 options. I don't know if I have the 3 or 4 groove.

My real question is, if I'm replacing both at the same time, can I just buy the same corresponding ones, and they will work? What exactly does the grooves line up to?

I suppose I can buy both options, but if I don't have to, I won't

Depends. If you buy the idler arm with the mount bracket and not just the idler arm, you would have to match up the spline count on the arm you take off. On the pitman, it is based on the pitman splines out of the steering gear. You may be able to see how many splines there are if you remove the nuts off of them, or you may just have to pull each arm off then order the correct match. Its either 3 groove (33 spline) or 4 groove (32 spline). Typically 2500HD are 3 groove, and 1500 are 4 groove from what I've seen.

I'd go as far as to get the idler with bracket yes. If that has never been greased especially. Some people miss that top grease fitting on the bracket.

If the pitman is 3 groove, the idler should be as well, same if it is 4 groove, the idler should match.

Edited March 2, 2016 by 15HDriver

sahls01gmc · March 2, 2016

And that's my dilemma. I have a 2500, non-HD.

Based on what you're saying, if I buy all new pieces that match with each other, it should work?

newdude · March 2, 2016

And that's my dilemma. I have a 2500, non-HD.

Based on what you're saying, if I buy all new pieces that match with each other, it should work?

Correct. I'd start with the pitman first and match the idler to what you find for groove count (they should match already but I'd base it off of the pitman).

sahls01gmc · March 2, 2016

Sounds good! Thanks for your help! I'll keep this thread updated as I go along.

davester · March 2, 2016

The idler arm has neither 3 or 4 grooves, so you can't really go wrong with that one, it has a taper for the 'middle' connection between the idler arm and the idler arm bracket assembly.

The pitman arm SHOULD be 3 groove for your 2500, but if you have the money and don't have a second vehicle, I would get both and then return the one you don't use.

sahls01gmc · March 2, 2016

Thanks davester! The only reason I was asking on the idler arm was because Rockauto lists idler arms that go with either the 3 or 4 groove.

I pulled the trigger on a complete MOOG front end rebuild, and gambled on the 3 groove pitman. In the mail is:

(2) Upper Control Arms

(2) Lower Ball Joints

(2) Outer Tie Rod Ends

(2) Inner Tie Rod Ends

(1) Pitman Arm (3 groove)

(1) Idler Arm

(1) Idler Arm Bracket Assembly

davester · March 3, 2016

When installing the idler arm/bracket, I couldn't find what the torque for the bolt between the two pieces should be [between the idler arm and idler arm bracket], so I just picked a bit more than the torque for the pitman arm [as they are both taper connections...

The service manual for my truck treats it as a single unit.

Edited March 3, 2016 by davester

mjoekingz28 · March 3, 2016

On my 03 you can get to it from under the hood if you have a table or step ladder.

Underneath it can try your patience as the grease hose must make a sharp angle to couple the alamite. There are adapters for this, but .....

sahls01gmc · March 3, 2016

Thanks for the tips guys! Looks like the parts should be here Friday, which means I may start tackling it this weekend. I'm gonna study my Chilton's manual as well and see if that has any other tips.

I'll try to take some pics along the way.

davester · March 3, 2016

Of, yeah, depending on the size of your pitman arm puller, you may find it easier to use if you loosen the bolts holding the steering box, so you can get a bit more clearance for it. And doing this also helped with getting a straight shot with a socket/torque wrench for tightening the pitman arm nut.

vucelick · March 4, 2016

I did exactly what you did, but also added the cognito motorsports pitman idler support bracket to eliminate any future problems and correct the factory issues. I also added their super strong tie rods. My truck is not lifted, and has stock size tires.

http://www.cognitomotorsports.com/pitman-idler-support-kit.html

Thanks davester! The only reason I was asking on the idler arm was because Rockauto lists idler arms that go with either the 3 or 4 groove.

I pulled the trigger on a complete MOOG front end rebuild, and gambled on the 3 groove pitman. In the mail is:

(2) Upper Control Arms

(2) Lower Ball Joints

(2) Outer Tie Rod Ends

(2) Inner Tie Rod Ends

(1) Pitman Arm (3 groove)

(1) Idler Arm

(1) Idler Arm Bracket Assembly

Edited March 4, 2016 by vucelick

sahls01gmc · March 21, 2016

Well, I finally got it all wrapped up. Some parts were a breeze, and some parts were slightly more difficult. Here's some notes for anyone looking to do this in the future:

Upper Control Arms - Since a complete upper control arm with new bushings only cost about $20 more than just the ball joint, this was a no brainer. Not having to press and ball joints or control arm bushings definitely comes in handy if you don't have access to a press. This also saves time. The bolts on the control arms were kinda trick to get out. They were slightly stuck and took some "convincing" to get out. I had to remove the shock to get enough access to swing the mini-sledge to knock the bolts out. After that, just replace and reverse procedures. Pretty straightforward.

Lower Ball joints - This one was a lil difficult for me. The ball joint press didn't knock these out, so I headed over to YouTube. This video was a huge life saver!

I just followed along and let the 3lb sledge knock the ball joints right out. The ball joint press put the new ones in easy as pie.

Tie-rod ends - I originally wanted to leave the center link in and just replace the inner and outer tie-rod ends. I couldn't get enough leverage to break to parts loose when this was installed. Now, the tie-rod end tool would have easily accomplished this task. However, since I was replacing the idler and pitman arms I knew the whole steering linkage was coming out. At that point, I just put the center link on the vice and was easily able to remove the tie-rod ends. Assembling the new tie-rod ends was easy and I was able to match up the lengths so it would be close to how it was when it came off the truck. My only gripe is the MOOG grease zerks would not go in. I had to use the old zerks to thread the new parts before I could attach the new grease zerks. Not a huge deal, I didn't break anything or lose any time.

Idler arm (and bracket) - Definitely replace both of these at the same time. The new bracket comes with a grease zerk relocation line so that you can make it easy to grease in the future. I mounted mine to one of the bolts on the sway bar where it attached to the frame. Really easy and straightforward. Remove and replace.

Pitman arm - This was the only part I wasn't convinced I could tackle easily. With the differences in parts (3 or 4 groove), I was instantly doubting myself. I bought the 3 groove, and was ready to replace it. When I went to look at replacing it, I noticed I had to move the steering gear box to gain enough access to remove the pitman arm. I was expecting a huge headache fumbling around in that tight space. So I held off and decided to wait until I was going to replace the gear box later down the road. There were 2 gear box options (33 spline or 32 spline), and I was instantly confused again. I shot in the dark and ordered the 33 spline so I could replace everything at once. Turns out the 3 groove pitman arm attaches to the 33 spline gear box. And just for reference, the 4 groove goes with the 32 spline. Makes sense now that I saw how they went together. Replacing the whole unit ended up saving a huge chunk of time versus just replacing one stuck part in tight quarters.

Steering gear box - I held off doing this because I thought it would be a pain to do. But, this needed to be done since it was leaking a ton of fluid. After looking at it further, it's only 3 bolts that hold it on there, and they are right on the frame. Really easy to get to. The steering linkage is held on by 1 bolt, and then it comes right off. Quick tip, MAKE SURE YOU DO NOT SPIN THE STEERING WHEEL WHILE THIS IS DETACHED!!! The wires in the steering wheel can easily get pinched and damaged because there is no stop to keep it from spinning. The power steering fluid lines were kinda tricky to break loose, but I was able to do it without breaking them. Then the whole piece came out really easy with the pitman arm attached (after the bolt on the center link was removed of course). From there I was able to attach the new pitman arm to the new steering gear box using the old as a reference, and then re-assemble. I waited to put the lines back on the new gear box until it was bolted to the frame, which was very time consuming because the 18mm wrench could only move about an 1/8 of a turn at a time. Same thing when I was removing it, but I didn't consider that because I was just excited I didn't break the lines. I would suggest trying to attach the lines before you bolt it to the frame, just be careful about how much play you have with the hoses.

All in all , I spent around $600 for all MOOG suspension pieces and an ACDELCO re-manufactured gear box. RockAuto was my go to on this, and they delivered big time! The local shop quoted me $2,300 to do all of this work. Even if you had to buy the ball joint press and pitman arm puller, you would still come out way ahead. This work was completed with 275,000 miles on the odometer.

Well, off to get an alignment and then hit the road!