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View Full Version : Thrust arm removal...alternative procedure?



rizal
05-06-2007, 02:31 PM
Please forgive a potentially dumb question, but...
Since it sounds like it can be very difficult to remove the thrust arm ball joint shafts from the plates to which it attaches (the forward end), requiring a puller, etc., etc., could they be more easily and quickly separated by:
1. Lifting car with wheels still on
2. Removing the nuts
3. Placing a jack under each arm
4. Slowly lowering the car, placing its weight onto each arm and jack, until the ball joint shaft comes loose from the plate? (assuming something was tied around the arm to prevent it from slapping up against other parts when it pops off)?

Feasible? Does anyone do it this way? Just checking. Thanks

DanDombrowski
05-07-2007, 06:03 AM
Nope. I actually tried using a jact to support the pin of the ball joint (I think this is what you mean) as it extends past the plate which it mounts to and lowering the car. Held the weight of the car just fine.

Look up on the board for BillR's method on removing the plate and hammering it out.

RallyD
05-07-2007, 06:19 AM
You need a lot of force applied in a brief instant to break it loose as it is a tapered (interference) fit. If not reusing the arm and ball joint the pickle fork/prybar method works but almost always rips up the rubber boot.

I back the nut off until it is flush with the end of the pin. Tap in the pickle fork to apply constant pressure. Heat the steering knuckle with a propane torch, expanding the metal, then give it a sharp rap with a 5lb mini-sledgehammer. Then have a St. Pauli while the parts cool off.

oh and wear safety glasses.

632 Regal
05-07-2007, 07:13 AM
this works very well indeed!

You need a lot of force applied in a brief instant to break it loose as it is a tapered (interference) fit. If not reusing the arm and ball joint the pickle fork/prybar method works but almost always rips up the rubber boot.

I back the nut off until it is flush with the end of the pin. Tap in the pickle fork to apply constant pressure. Heat the steering knuckle with a propane torch, expanding the metal, then give it a sharp rap with a 5lb mini-sledgehammer. Then have a St. Pauli while the parts cool off.

oh and wear safety glasses.

Ross
05-07-2007, 07:15 AM
There is a chance this will work if you give the knuckle a HARD hit with a fair size hammer. The shock will break the interference fit allowing the tapered stud to pull out if it's under load. Perhaps the weight of the car is enough.
This does sound a bit dangerous .

kick7ca
05-07-2007, 07:59 AM
Mine popped out by hand so don't be afraid that it's going to be impossible or something. They were designed to come apart and they will. I don't like your suggested procedure, I'd only do it with car firmly on stands and following your service manual.

icesoft
05-07-2007, 10:47 AM
Seemed to work best to remove the plate and arm from the car and sit the plate on top of some open vise jaws. One quick rap on the ball joint stud with a 3-lb sledge and the joint pops right apart. The whole proceedure isn't too bad with a good impact wrench and a lift, but it can be done on the ground with hand tools just as well (just takes a bit longer).

I've had success on other cars hitting both sides of the area where the ball joint stud goes through whilst applying pressure on the joint to separate it, however there's just no room on the E34 to swing a hammer or get behind it (both hammers need to hit simultaneously for that to work).

kick7ca
05-07-2007, 11:39 AM
Mine popped out by hand so don't be afraid that it's going to be impossible or something. They were designed to come apart and they will. I don't like your suggested procedure, I'd only do it with car firmly on stands and following your service manual.

Oops my bad I just remembered it popped out easily with a ball joint puller I rented from the local autoparts store. With the puller it was 3 turns of a socket and presto. A non issue with the right tool.

Evan
05-07-2007, 12:00 PM
sounds dangerous.. i did it with hand tools in my driveway and had no problem

Blitzkrieg Bob
05-07-2007, 12:08 PM
loosen them up, and leave them on so the arm doesn't go flying around once it breaks loose.

I rather buy the right tool and avoid getting hurt, wasting time or busting up surrounding parts.

spend $80 buck for a front service set from Eastwood.

Ross
05-07-2007, 12:09 PM
Most dangerous method I everwitnessed was as follows. The "mechanic" worked in a pit and the front of the car, my '63 Cadillac, was hoisted by the bumper with a sling and let to swing a foot or two off the ground. After removing the wheels in the conventional manner the lower ball joint nut was removed as well as the shock . Jethro then swung a huge hammer at the steering knuckle where the stud was located. One blow and the spring popped the joint free in dramatic fashion. Both front coils were replaced in a matter of a couple of minutes. I wonder if that guy is still alive.

rizal
05-07-2007, 07:00 PM
Thanks VERY much! I won't risk my life, and I won't try Jethro's Cadillac Ball Joint removal method.
Last question...can these be swapped with the wheels on the car, tires on ramps? (as opposed to removing them and supporting the car on jacks)
Thanks! Great forum!

Blitzkrieg Bob
05-07-2007, 07:06 PM
Thanks VERY much! I won't risk my life, and I won't try Jethro's Cadillac Ball Joint removal method.
Last question...can these be swapped with the wheels on the car, tires on ramps? (as opposed to removing them and supporting the car on jacks)
Thanks! Great forum!


The arms provide the support for the lower end of the suspension and the strut mount is the upper.

best done on a lift or stands

kick7ca
05-08-2007, 08:50 AM
Stop looking for shortcuts! You should get your hands on a Bentley manual and simply follow the instructions.

bsell
05-08-2007, 12:59 PM
Most dangerous method I everwitnessed was as follows. The "mechanic" worked in a pit and the front of the car, my '63 Cadillac, was hoisted by the bumper with a sling and let to swing a foot or two off the ground. After removing the wheels in the conventional manner the lower ball joint nut was removed as well as the shock . Jethro then swung a huge hammer at the steering knuckle where the stud was located. One blow and the spring popped the joint free in dramatic fashion. Both front coils were replaced in a matter of a couple of minutes. I wonder if that guy is still alive.

So where did Jethro's springs shoot off too? I wonder how many fenders got trashed during this operation?