This project is posted in the auto section.
Suspension Parts Replacement
This project describes an idler arm and center link replacement for a 2 wheel drive, 1998, S10 Chevy Blazer with just over 100k miles showing on the odometer. The truck was taken in to have the oil and filter changed when the problem with the steering linkage was discovered.
Chris is a professional automotive technician for a local automotive service shop and has been a friend of ours for over 25 years. As any good technician will do, Chris inspected the vehicle as the oil change was being performed and noticed that there was a lot of play in the steering linkage – he diagnosed the problem to be a bad idler arm and he advised that it be replaced.
Keeping everything tight in the front end steering linkage will improve drivability, reduce tire wear and it will reduce further damage to other related steering linkage parts. Taking care of the problem now will also ensure that the vehicle can be properly aligned the next time Chris performs that maintenance procedure.
Chris always handles the big repairs in his shop but replacing the idler arm is a job that Jeff and Evan can do in the Dirty Shirt shop so they set about taking care of the problem.
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Evan acquired the new part for about $15 from our local auto parts supplier.
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The front end of the truck has been raised and supported with jack stands. (A) The idler arm attaches to the vehicle frame on the passenger side with two large bolts. (B) This end of the idler arm attaches to the center link of the steering system. The stud that is sticking up is a part of the center-link. This stud is conically shaped and the mating hole in the idler arm is also conical. When the nut is installed it squeezes these two cone-shaped pieces together and creates a pressed-fit connection. A spreader tool will have to be used to get the parts to release from each other.
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Evan has inserted a socket and extension into the frame access holes to hold the idler arm bolts while the nuts are removed with a pneumatic ratchet.
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(C) The nut that secures the idler arm to the center-link has been removed and the spreader tool is being held in place between the two parts. A large hammer will be used to force the spreader between the parts and cause separation.
In hind sight, the spreading operation should probably have been performed before the bolts holding the idler arm to the frame were removed. This would have held everything in place while the spreader tool was hammered between the parts.
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(D) The new idler arm has been installed and the bolts have been secured. When the idler arm was first disassembled, it was discovered that the joint (E) on the existing center-link had a lot of play and the center-link would need to be replaced in addition to the idler arm. We needed to get this truck back on the road and the center-link will be replaced another day.
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The center-link is the heavy steel bar that spans the photo from edge to edge. All of the components have the same conical connectors as the idler arm and a spreader will be needed to cause the parts to separate. The components that attach to the center link are as follows:
- (F) Idler arm
- (G) Right inner tie rod
- (H) Left inner tie rod
- (I) Pitman arm – the pitman is a component of the steering gear box
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The spreader we used to separate the idler arm from the center-link is a cost effective solution but it doesn't do a good job if the joints are very tightly bound together. We did some shopping and came up with this very versatile kit that will allow us to connect the different sized spreader bit sizes to interchangeable handles – one is for hammering and the other enables mounting the tool to an air-chisel and using vibration within the air chisel to cause separation.
The kit was purchased from TheToolwarehouse.net for about $27 plus $10 for shipping and sales tax. We're anticipating future front end work on other vehicles soon so the purchase of the tool was a no-brainer.
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The center-link has been removed using the spreader kit. The inner tie rod ends are lying loose and the idler arm is standing alone. We found that it took a combination of both air chiseling and using the hammer-handle to achieve separation. The tie rod ends, idler arm and pitman joints are different sizes and we used the appropriate spreader fork tip for each joint. With the new tool it took about 15 minutes to remove the center link.
In this short video Jeff reviews the differences between the old and new center-link parts.
There is one correction to this video: Jeff refers to "bearings" in the video but the pivots are actually ball-joint-style connectors.
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The center-link is being installed with a pneumatic ratchet. We found that in some cases the studs that accept the various nuts would spin and prevent the nut from tightening. In these cases we used large channel-lock pliers to squeeze the parts together (a C-clamp would also work). This provided enough friction to prevent the studs from spinning and the nuts would tighten successfully.
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Here's the completed installation. The truck was taken for a test drive after being removed from the jack-stands. The steering has a much tighter feel to it but the steering wheel was a little off center during the test. This indicates the vehicle will need to be aligned by a professional shop and it is probably in need of having a toe-set performed.
Since tie-rods control the alignment adjustment known as "toe" and we made no changes to the tie-rods, the off-center steering wheel is probably the result of variances between the old and new parts. The fact that the new parts have much tighter tolerances would have caused a bit of a shift from the original settings. No problem, we'll line it up with Chris to have the alignment taken care of.
