Upper Control Arm/Thrust Arm

[athflying79]

I've run across many different names but basically it's the upper arms I'm referring to. Today I started on changing all the front suspension/steering links. Started on the passenger side...succesfully changed the sway bar link and tie rod...then I moved on to the upper control arm. Bottom 22mm nut came out no problem. Then moved to the upper 22mm bolt and nut. That thing would not move!!! I ended up using a 22mm open end wrench and a jack to slowly turn the nut. The bolt was not moving, so I know I made some progress. After almost two hours, I gave up. It was Red Loctited on and just would not free up. Every turn was like the first!! All the parts had BMW stamped on them, so I'm assuming this was all original equipment (91 with 120,000 miles). Like I said, I gave up and will try again in a few days. So far I have learned lots and the other side will be so much easier.

[632 Regal]

the bolt that goes through the arm at the crossbar?

[Zeuk in Oz]

I've run across many different names but basically it's the upper arms I'm referring to. Today I started on changing all the front suspension/steering links. Started on the passenger side...succesfully changed the sway bar link and tie rod...then I moved on to the upper control arm. Bottom 22mm nut came out no problem. Then moved to the upper 22mm bolt and nut. That thing would not move!!! I ended up using a 22mm open end wrench and a jack to slowly turn the nut. The bolt was not moving, so I know I made some progress. After almost two hours, I gave up. It was Red Loctited on and just would not free up. Every turn was like the first!! All the parts had BMW stamped on them, so I'm assuming this was all original equipment (91 with 120,000 miles). Like I said, I gave up and will try again in a few days. So far I have learned lots and the other side will be so much easier.
I did both of my thrust arms yesterday - I agree that top bolt can be hard to budge but keep at it - perhaps get some more leverage - I found that putting a 22 mm ring spanner on the nut allowed me to attack the bolt end with my socket and an extension.
I had more trouble freeing the lower ball joint with a pickle fork but managed after I raised jacked up under the control arm.
Keep trying - the difference is amazing ! Had to laugh though, took me almost 4 hours to do the 2.

[athflying79]

the bolt that goes through the arm at the crossbar?

Yup. I seriously thought it was cross threaded. That puppy would not budge. Like I said, I ended up putting the jack on it to push the wrench up. It has taken the same amount of pressure every turn to move it as it did the first. It does not look like it is destroying the bolt, so I'm guessing it's just the loctite that is keepin it on so well. Hopefully the other side will be easier. I can't wait to get everything on though...the parts I have taken off were in pretty rough shape, so I'm expecting a pretty big difference in handling and ride quality.

[Bill R.]

deactivate/release the loctite when taking red loctite fittings loose...not too hot but it doesn't take much...a couple hundred degrees.



Yup. I seriously thought it was cross threaded. That puppy would not budge. Like I said, I ended up putting the jack on it to push the wrench up. It has taken the same amount of pressure every turn to move it as it did the first. It does not look like it is destroying the bolt, so I'm guessing it's just the loctite that is keepin it on so well. Hopefully the other side will be easier. I can't wait to get everything on though...the parts I have taken off were in pretty rough shape, so I'm expecting a pretty big difference in handling and ride quality.

[athflying79]

deactivate/release the loctite when taking red loctite fittings loose...not too hot but it doesn't take much...a couple hundred degrees.


I was going to...we have a MAPP torch....but the underside of the car was quite wet from a mystery leak that I finally solved. Might clean it up and give that a shot...just didn't want to ignite the car.

[athflying79]

I have a couple questions that I forgot to ask earlier. The three bolts that hold the strut at the bottom...they appear to just be threaded into the strut mount...just re-torque them after taking them loose??

The 22mm nut and bolt I am having such a problem with, as long as I don't beat the crap out of it, it's ok to re-use. The nut on there now is not a Nyloc nut, so just a dab of loctite and I'm good to go??

[Bill R.]

apply it sparingly.




I was going to...we have a MAPP torch....but the underside of the car was quite wet from a mystery leak that I finally solved. Might clean it up and give that a shot...just didn't want to ignite the car.

[BigKriss]

I have a couple questions that I forgot to ask earlier. The three bolts that hold the strut at the bottom...they appear to just be threaded into the strut mount...just re-torque them after taking them loose??

The 22mm nut and bolt I am having such a problem with, as long as I don't beat the crap out of it, it's ok to re-use. The nut on there now is not a Nyloc nut, so just a dab of loctite and I'm good to go??

yep, just retorque the 3 lower strut bolts. as for the control arm bolts, I would just loctite them also. Have you tried a breaker bar on the 22mm nut. I did them recently, and they come off pretty quickly as long as you have some leverage meaning the car is high enough on jack stands.

[Rustam]

I had more trouble freeing the lower ball joint with a pickle fork but managed after I raised jacked up under the control arm.
Keep trying - the difference is amazing ! Had to laugh though, took me almost 4 hours to do the 2.

I found very easy to work with pickle fork with rubber boots off the ball joint. The reason why it takes so much effort with pickle fork is because much energy of the bang goes against the rubber cusion developed by the boot compressed by the pickle fork. Remove the boot completely using a blade such that no rubber gets to go between the fork and the parts separated. It shall take no more than 10 bangs to get things separated. And brand new boot in case same ball joint must be used (bmpd.com has replacement polyurethane boots). Saves time, frustration, and energy!
But best tool is the separator that consists of two arms and a bolt that is placed across in one to press against another as turned - this one works like a charm - saves yet more time, yet more frustration, yet more energy

[Russell]

I want to change my upper thrust arms. However, all the different advice recently posted and the archives confuses me a great deal. Some people say easy job, others have more than their share of issues.

I have only hand tools (read no air tools), floor jack, ramps and jack stands. Now how can one person do this job lying on the floor with minimal hassle? Show I buy any special tool to make it easier or is there just a technique that will work? Is there an "easy button" :)

I really do not want to pay my indy about $500 to do this. BTW, last year I did replace the bushing inserts with Brunos inserts. They are a bit harsh. Even so, they were not overly difficult. It is the other end with the pressed in tie-rod like joint that seems to be a big issue for most people.

I appreciate any help/clarification. TIA



I've run across many different names but basically it's the upper arms I'm referring to. Today I started on changing all the front suspension/steering links. Started on the passenger side...succesfully changed the sway bar link and tie rod...then I moved on to the upper control arm. Bottom 22mm nut came out no problem. Then moved to the upper 22mm bolt and nut. That thing would not move!!! I ended up using a 22mm open end wrench and a jack to slowly turn the nut. The bolt was not moving, so I know I made some progress. After almost two hours, I gave up. It was Red Loctited on and just would not free up. Every turn was like the first!! All the parts had BMW stamped on them, so I'm assuming this was all original equipment (91 with 120,000 miles). Like I said, I gave up and will try again in a few days. So far I have learned lots and the other side will be so much easier.

[Zeuk in Oz]

I did both of mine on Saturday with no special tools apart from a pickle fork and a 22 mm ring spanner.

I jacked up 1 side at a time and put a stand underneath.

Straight forward, but I found the hardest job was getting the pickle fork into the right position. I found it easier to release the lower ball joint after I had put a jack under the control arm ball and raised the axle / strut a little.

I didn't locktite but used new nuts.

Well worth the effort !

[athflying79]

I have not successfully completed doing it, but I think anyone can change the arms. The biggest problem I would say is having patience and the time to do it. It is taking me awhile to do them all, but if I had to do it again, it would certainly go much faster.

Just read the guides and make sure you have the tools necessary.

[stu1]

WRT the balljoints, a separator and blowtorch makes it _MUCH_ easier. First I tried a pickle fork - nope. The I tried a separator and that just bent. So, had to go a buy another separator. When this one started to bend I applied some heat from a torch and it just popped off. (OK, it went bang but it felt good :))

[632 Regal]

Ditto
WRT the balljoints, a separator and blowtorch makes it _MUCH_ easier. First I tried a pickle fork - nope. The I tried a separator and that just bent. So, had to go a buy another separator. When this one started to bend I applied some heat from a torch and it just popped off. (OK, it went bang but it felt good :))

[Hector]

took me 2 hours on one side and 1 hour on the other. I guess, it's a matter of using the right tools and method of approach. Everyone has their own theory to replace thrust arms. My method, as discussed here before, is to remove the steering knuckle plate with thrust arm, apply some heat (sparingly) while using the tool below. It pops pretty easily.

[kyleN20]

pretty nifty, where did ya pick that guy up? and how much?

[Hector]

to this one but mine looks like it is better made, and it's a cast iron color. It was about 30 bucks. Look up ball joint separator.


pretty nifty, where did ya pick that guy up? and how much?

[Russell]

where & how to appy heat?

[Hector]

degrees C (or a bit more) to get the steel to adequately expand. The through-hole DIA of the steering knuckle plate will expand from about 0.5 mil (0.5/1000th of an inch) to 1 mil. I used one of those butane bottles, and heated up the side of the plate opposite to the rubber bushing. Stay away from threaded stud of the ball joint while applying heat. Make sure your working area is clear and watch that you don't get hit by the thrust arm when the thing pops off if you're using the ball joint separator I used.


where & how to appy heat?

[Russell]

Hector, Thank you

[Akhil]

http://www.heartlandamerica.com/browse/item.asp?PIN=12160&SC=WIG20001&DL=GAW1#

I bought it from Walmart for $20 and its like magic for hard to open bolts it you have right size of sokets and proper extensions. Its says its for changing tire but I used it for any hard to open bolt. You just have to have a good charged battary or let engine running while using this tool.

Akhil

[ryan roopnarine]

russell, i was going to refrain from making comments towards you, well, just because i didn't think that you would respond to any questions i posed to you, but then the fire brigade came out with their blow torches and swamped the thread.

if there's any chance that this might be your only mode of transportation immediately/day after, i would not take the torch to it. the torch, and to a lesser extent the pickle fork will kill a little of the boot. the amount of strength necessary to break the balljoint will vary from very little to herculean. if you find yourself in a situation in which the fork simply cannot get the job done, you can simply bolt the car back together and travel to/from work until you have another opportunity. i doubt that anything other than big tank gasses (ie, not propane) would have broken my thrust arm ball joint free. my advice would be...obtain a pickle fork and sledgehammer, plus sockets, but be prepared to go and get more tools. if the fork does not achieve the desired result, go to advance autoparts (i believe that they have them in kentucky), and put down the $89 rental deposit on their front end service kit. the kit contains the cantilever puller pictured earlier in the thread plus two or three other joint pullers. this is the way to go if you have to pull the strut plate because you will need to disconnect the tie rod to get it free, and you probably don't want to use a picklefork on a tierod boot that is worth saving--you can use the cantilever puller in the kit on the tierod instead. once the strut plate is free, you can use the Bill R method on it. in my case, i had to depart from the bill r method here because it didn't have the OOMPH necessary with the sledgehammer to get the balljoint out of the hole. this is where the rental kit saved my bacon. simply use one or two of the supplied pullers on the strut plate, aaannnnddd....... POW (a crack sounding similar to jesus speaking), the assembly will seperate. you can use the same puller to pull the lower control arm out if you need to change the balljoint boot on it or such. a vice might be helpful at this point to retighten things on the plate, but it isn't necessarily necessary. a plumber's wrench will also stop things from spinning on you. much less frustration than using the fork for hours and getting nowhere.

my suggestion to you, if you need to use the car for transporation anytime soon after removing the arms, DON"T use the destructive methods outlined here.

ps, in case you didn't know, the $89 rental fee is completely refunded once you return the kit to them.

[Russell]

Thanks for your reply. Not sure why you would think I would not respond.

Yes, I have another car to use if the car is down. I also have AAA service to tow and an Indy you can fix my "repairs". I plan to completely replace the arm with new bushings so damage to the existing arm is not a concern. However damage to other componets is. Your advice to get the front end service kit from Advance is exactly what I may do.

Thanks again.


russell, i was going to refrain from making comments towards you, well, just because i didn't think that you would respond to any questions i posed to you, but then the fire brigade came out with their blow torches and swamped the thread.

if there's any chance that this might be your only mode of transportation immediately/day after, i would not take the torch to it. the torch, and to a lesser extent the pickle fork will kill a little of the boot. the amount of strength necessary to break the balljoint will vary from very little to herculean. if you find yourself in a situation in which the fork simply cannot get the job done, you can simply bolt the car back together and travel to/from work until you have another opportunity. i doubt that anything other than big tank gasses (ie, not propane) would have broken my thrust arm ball joint free. my advice would be...obtain a pickle fork and sledgehammer, plus sockets, but be prepared to go and get more tools. if the fork does not achieve the desired result, go to advance autoparts (i believe that they have them in kentucky), and put down the $89 rental deposit on their front end service kit. the kit contains the cantilever puller pictured earlier in the thread plus two or three other joint pullers. this is the way to go if you have to pull the strut plate because you will need to disconnect the tie rod to get it free, and you probably don't want to use a picklefork on a tierod boot that is worth saving--you can use the cantilever puller in the kit on the tierod instead. once the strut plate is free, you can use the Bill R method on it. in my case, i had to depart from the bill r method here because it didn't have the OOMPH necessary with the sledgehammer to get the balljoint out of the hole. this is where the rental kit saved my bacon. simply use one or two of the supplied pullers on the strut plate, aaannnnddd....... POW (a crack sounding similar to jesus speaking), the assembly will seperate. you can use the same puller to pull the lower control arm out if you need to change the balljoint boot on it or such. a vice might be helpful at this point to retighten things on the plate, but it isn't necessarily necessary. a plumber's wrench will also stop things from spinning on you. much less frustration than using the fork for hours and getting nowhere.

my suggestion to you, if you need to use the car for transporation anytime soon after removing the arms, DON"T use the destructive methods outlined here.

ps, in case you didn't know, the $89 rental fee is completely refunded once you return the kit to them.