Lower Control arm replacement. Trouble removing them.

The bolt in the issue is Toyota Part #90105-A0250. The end is screwed into the mail cross member, which is Toyota Part #51201-12442.

The bolt is threaded into a "captive weld nut" in the main cross member. You need to examine the cross member to determine if there is an access point to see the captive nut. There is where the heat and/or penetrating oil needs to be reapplied.

When torqued to a high value, the bolt is under high tension. You might have to cut away the eye of the control arm to relieve the tension on the bolt. This would relieve the tension, resulting in the bolt held to the nut only by friction of the threads of the bolt and captive nut and maybe some corrosion.

The weakest point of the bolt would be at the point of the smooth shank and the start of the thread and the part inserted into the captive nut. This is where the bolt would be most likely to break. Cutting away the eye of the old control arm is likely the best option.

If the bolt is broken, a carbide burr needs to be used to dimple the broken bolt in the center. The hole then needs to be drilled into the bolt with a cobalt alloy high speed streel drill bit to the minor diameter of the threads of the bolt. Then, the hole needs to be re-tapped. if the threads are destroyed, a thread insert like a Heli-Coil or a Timesert needs to be installed. Not having examined the bolt, but my familiarity with Toyota suspension components says that the thread is most likely J.I.S. M16x1.5 or even M18x.1.5.

 

Find out what the shop is using first. The torque on that is 170 something foot/pounds IIRC. To break that loose you want a significant breaker bar (not a ratchet with cheater pipe, if that's what they're using). Also, something like Milwaukee Tool's 1400 foot/pound 1/2" impact might do it.

As far as heating the captured nut, if that's not practical, try to chill the bolt? There's a spray for doing that and applying a penetrating lube at same time, I think?

I appreciate a bolt torqued to 170, then subsequently rusted up for a few years, is going to take some oomph to break loose, much more than 170.

 

Then I think Georgina's ideas are what's needed, lol.

Good luck!

 

They're $600 CDN (with two batteries, charger and case) up here, I just can't justify it. Yet...

 

Yeah tool-only on sale for $250 CDN.

 

Time to get an air impact wrench and try that. I have the equivalent Makita battery powered wrench and find that it does not have the same power as my air wrench.

If that doesn't work, using an angle grinder and an abrasive cutting wheel, cut the end of the control arm through the entire bushing and the a bolt across its axis a little more than half way from the head. Pull off the head end of the bolt. Cut off that end of the control arm loop with half the bushing and discard it. Slide the rest of the control arm off the remaining bolt and remove it. Having relieved the tension on the bolt Using a Vise Grip, remove the cut off stud from the captive weld nut. If it refused to move, use penetrating oil or heat as needed.

 

@mypriuscious I notice some reference to other Repair Manual section, in the previous info I attached. I've attached what I think that is. I haven't read through it that carefully, so if you need more just ask and I'll try to find it.

 

The captive nut is boxed in, inside the cross member? The bolt is the highlighted one?



I just revisited the rust proofing on that area, and kinda looked, got the impression you can't even see that nut, let alone get to it. Isn't road salt just great...

 

That's why early in a car's life, I always spray rustproofing into the hollows of all undercar beam cavities to make sure the places of the welded on captive nut is covered.

 

I would try everything possible before cutting into the control arm mount or the cross member.

As I stated previously, if you cannot remove the bolt, saw the old control arm off at the eye that hold the bushing attached to the mount. Saw through the remaining control arm remnant at least half way past the head of the bolt, pull out the sawed off bolt by its head, remove the piece of the bushing held by the headed section of the bolt, slide the remaining part of the bushing into the space left by the removed bushing half to remove it.

You are left with about half the bolt between the ears of the bushing mount. This allows access to the place where the bolt threads enter the captive nut to be soaked in penetrating oil, while still providing enough of the bolt to hold and to twist it with a locking pliers to remove it.

 

Yes, mine is 2010 with 350k right now and original engine.

 

OMG! ......I need to follow you around! .......