Building A bolt in spring compressor for your early Mustang is easier than you might think

The step by step process of fabricating bolt-in spring compressor or ball joint tool for an early classic Mustang

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Bolt-in Spring Compressor / Ball Joint Removal Tool
When working on a classic Ford, many repairs/modifications can be done using basic tools, however, sometimes a specialty tool is required for said repair or modification to be done correctly and/or safely. Many front suspension modifications may require the use of two such specialty tools: a non-damaging ball joint removal tool or a spring compressor.  Both of these tools can easily be built at home using just a few basic tools and skills.

Spring Compressors  101, Why use a bolt-in type?
When removing a coil spring, it is required to compress the spring to free it from its designed location. Failure to safely deal with compressing the spring can result in serious injury or even death.  There are three main ways to compress a coil spring to remove it: external claw type spring compressor, internal claw type spring compressor or a bolt-in type spring compressor.
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An external claw type spring compressor consists of two separate pieces that clamp onto the outside of the coil spring.  As the nuts on the two pieces are tightened down, the spring is compressed.  There are three main issues with this type of compressor.  First, both sides need to be tightened an equal amount and, since each piece has its own tightening nut, this is easier said than done.  Second, this type of compressor REQUIRES that the two separate pieces be opposite of each other.  Unfortunately, the shock towers of a classic Ford do not allow the two pieces to be positioned completely opposite of each other, which creates an unstably compressed spring.  Third, the claws of the compressor are held to the spring by tension from the compressed spring.  If the claws slip, the spring can decompress violently.  Many chose to use this type of compressor because they are inexpensive and can be purchased for less than $30.00. 

The second type of claw spring compressor is an internal unit, which has four claws (two at the top and two at the bottom) that grab an upper and a lower coil of the spring.  One tightening nut pulls the two sets of claws closer together and compresses the spring.  This compressor is much better for a Mustang than the above mentioned external claw type, however, it is still not the best option.  There are two main problems with this type of system.  First, often times on a classic Ford, a 3 to 4 inch spacer (usually a piece of pipe) is required to be positioned between the upper claw assembly and the tightening head to keep the compressor from bottoming out in the UCA.  Secondly, as with the external claw type, the tension of the compressed spring is all that holds the compressor in place and, as before, if those claws slip, the spring can decompress violently.

It was an internal claw type compressor that sent me to the emergency room in June of 2005.  After already removing the passenger’s side spring, I was working on the driver’s side assembly, had compressed the spring and was in the process of removing it when the compressor slipped, the spring decompressed and pinned my right hand by the three middle fingers, palm side up, between the bottom of the coil spring and the spring perch.  Engaging this type of compressor requires using two hands and, of course, I was alone, the garage door was down, my cell phone was on the passenger’s side fender out of reach and most of my tools, at least any that could have been effective in freeing my hand, were on the floor next to the passenger’s side where I had already pulled the suspension apart.  All I had within arms reach was the 1⁄2” box wrench (no more than 6” long) that I had just used to remove the shock.  I jammed the wrench in between the spring and the perch and was able to pry the spring up enough to get the finger next to my pinkie free.  I then pried on the opposite side and got my index finger free.  To get my middle finger out, I pried again with the wrench and pulled as hard as I could with the trapped arm and got my hand out. To make a long story short, I still have all my fingers and they still work, however, I occasionally feel some stiffness in the middle finger joints.  I was lucky!!!!!  Needless to say, it is my personal mission to convince everyone to use a bolt-in type compressor.

The third type of spring compressor is the previously mentioned bolt-in type compressor.  This compressor bolts to the spring perch and the top of the shock tower, just like a shock.  Once the spring has been compressed, there is no way for it to come loose unless you intentionally decompress the compressor.  The “down side” to this type of compressor is that in order to completely remove the spring, the UCA needs to be removed to get the spring out.  This adds about 15 minutes to the task of changing springs, however, that 15 minutes is well worth the improved safety factor. 

Before you start this project you need to evaluate your welding skills. 

Before you start either of these projects, you need to evaluate your welding skills.  The following is the process for constructing a tool that will be holding immense amounts of pressure and, if your welding skills are not sufficient for the task, the tool could fail which could cause harm or even death.  NOTE: If you have any doubts AT ALL about your welding skills, DO NOT ATTEMPT TO BUILD A SPRING COMPRESSOR!!  One option for the non-welder is to prep the parts and then take them to a certified welder for assembly.

Materials needed:
.625” coarse thread all-thread, 12” long, grade 8 (non-galvanized)
.75” square tubing, .0625” walls, 9” long
1” X .25” X 3” bar stock
1.5” X 1⁄4” X 3” bar stock
.625” coarse thread nut, grade 8
.625” grade 8 washer
two .375” X 1” grade 8 bolts
two .375” grade 8 nuts
two .375” grade 8 washers
shock, spring perch, coil spring to get measurements from
Tools required for the project:
Cutting tool
Drill bits and drill
Bench grinder

Materials needed

Cutting the All-thread

All-thread sand blasted end
Prep the materials:
The first step is to prep all the parts needed to assemble the compressor.  It is good to have a shock and a spring perch on hand to ensure fitment as pieces are being fabricated.  Start by cutting a piece of coarse thread, grade 8 all-thread to a length of 12”.  NOTE:  It is important that you use all-thread that has been treated with black oxide as a rust preventative, rather than galvanized all-thread because as pressure is applied to the galvanized threads during the compression of the springs, the galvanization will come loose and clog the threads in the nut, which decreases the functionality of the compressor.  Once the all-thread has been cut, it needs to be cleaned on the end that is going to be welded.  If you have the opportunity to use a sand blaster to strip it down to bare metal, you will get better weld quality.

The next step is to cut the .75” square tubing to a length of 9”.  For best welding, one end of the square tubing needs to be drilled out for plug welding.  Measure down .5” and then drill a .125” pilot hole completely through the square tubing.  The .125” hole then needs to be enlarged to .5”.

It is now time to cut the base plate. This piece measure out at 1” X .25” X 3” and needs to have two .475” holes drilled with a spacing of  2.125”.  Once the holes are drilled, the corners need to be rounded and the underside on both ends needs to be beveled so that either end can fit easily in position on the perch.  I recommend trying the plate on a perch to ensure functionality.  NOTE:  older perches have a tighter fit than aftermarket ones so use an older original type perch to check fitment and have a more universally functional tool.

The last piece to prep is the shock tower cap.  Cut the cap retainer so that it measures 1.5” X .25” X 3”, drill 2 elongated holes so that the cap can be bolted to the top of the shock tower (the dimensions for these holes can be obtained from the top of a shock).  Then drill a .625” hole in the center of the plate so that the all-thread can come up through the middle. 

Cutting the square tubing

Plug weld hole in square tubing

Base plate with .475" holes
Beveled edges on base plate
Shoct tower cap
Now that the pieces have been prepped, it is time to assemble the compressor. The first step is to thread the cleaned end of the all-thread 1” into the end of .75” square tubing with the hole.  Due to the .5” plug weld holes, the all-thread should actually need to be threaded into the square tubing.  Once the all-thread has been threaded in, the easiest way to hold it in place and square it up is to tighten a nut down onto the end of the tubing.  Make sure you only hand tighten the nut because the metal on the inside of the tubing that causes you to thread the all-thread in is not strong enough to cope with the pressure of tightening the nut down with a wrench.  It is now time to weld the 1⁄2” holes closed.  Once they have been welded shut, the lip of the square tubing needs to be welded to the all-thread.  After welding, you should be able to look at the threads on the all-thread and see penetration where the threads have melted during welding.  NOTE:  If this penetration can not be seen after welding, you may want to question the quality of your welds and reconsider having the parts professionally welded together.  The base can then be welded into place, making sure it is centered, square, and that the welds have good penetration.  At this point, the majority of the compressor has been fabricated and it is a good time to test fit the base to a spring perch again to ensure proper fit.

Once you have a good fit on the spring perch, install the .475” bolts into the holes already drilled in the base.  When I fabricated my spring compressor, I happen to have press-in studs so I used them.  If I had not had press-in studs, I would have held the bolts in place by tightening a nut down onto them.  The heads of the bolts can now be welded to the base.  The last thing we need to do to complete our spring compressor is to finish fabricating the shock tower cap that we have already cut to length and drilled several holes in.  There are two options available to complete this piece.

All-thread inserted in square tubing

Hole plug welded closed

Weld penetration in threads

Base spot welds

Base welded on

Press in studs

Studes welded in place

Completed assembly less the cap
The first (simpler) option is to make a dual washer cap.  This cap bolts into the top of the shock tower, just as the shock did.  Since the cap has already been drilled with three holes, a .625” washer needs to be welded to the middle of the cap over the 5/8” hole.  You can grease the face of the washer, place another washer on top and then the tightening nut goes on top of that.  The two washers then press against each other and slide as the nut is tightened down.

The next option is more complicated but makes a much better functioning tool, which is to use a tapered bearing in the top.  The first step is to obtain a tapered roller bearing and race by either buying one new or removing one from a wheel hub assembly that is not being used.  I got mine from an old disc brake assembly I had removed from a 1984 Mercury Grand Marquees I had parted out some years back.  It was the outside bearing and its measurements were an I.D. just over .75” and an O.D. just less than 1.75”.  The first obstacle to overcome is that the bearing hangs down past the race.  I found a low profile 1.5” washer, cut the ends off to clear the mounting holes and welded it to the cap plate, making sure it was centered over the .625” cap plate hole.  To center it, I took a .5” washer that was snug fit inside the 1.5” washer and drilled the hole out to .625” so that I could bolt it to the cap to center the outer washer.  I then found some exhaust pipe that had an I.D. 1.75” where the race was a nice tight fit inside.  I cut a .575” ring of this pipe and welded it to the top of the washer I had just attached to the retainer cap.  Three holes were drilled along the inside edge of the ring so that if the race needs to be removed it can be tapped out with a punch.  Once the holes are in place, the race can be pressed in.  At this point the cap is basically done but there is one more issue to overcome.  The all-thread for the spring compressor is .625” and the I.D. of the bearing is .75” so, to fix this, I cut a spacer ring out of some .625” steel pipe I had and ran a drill bit through it to clean out the seam so it could slide nicely over the all-thread.  This spacer was the last piece needed.

Non bearing shock tower cap

Low profile washer used to create bearing clearance

Retainer ring

Race removal holes

Installed race and spacer

The final step to finish the tool is to clean it up and coat it with a rust preventative.  This is accomplished by sand blasting the spring compressor parts, except the bearing and race, and then coating them with Gun Bluing.  This simple compound that can be purchased at many sporting good stores and is similar to black oxide.  The compound needs to be heavily applied to the metal and then allowed to dry.  Once it is dry, the metal will have a brown/green look.  I then wipe it down with a dry rag to prep it for oiling.  Oil or grease can be applied with a soft rag and, as it is applied, the metal will take on a blue/black color.  This type of protection will not make the tool rust proof from direct water contact but it will eliminate flash rust.  NOTE:  paint is not used to protect the tool because it will clog up in the threads and will tend to be eaten by anti-seize oils applied to the threads during use. The compressor is now completed and ready to use.

To use the compressor, simply remove the shock and bolt the base of the compressor to the spring perch.  Then slide the cap over the all-thread that sticks out the top of the shock tower and bolt it in place.  Apply a small amount of anti-seize oil to the threads that protrude out of the shock tower.  The bearing, spacer sleeve, cap washer, and tightening nut can then be installed and tightened down which compresses the springs.  The spring should not need to be compressed more than 3” to work on suspension.  Once the spring is compressed, the spring perch can be unbolted from the UCA and the UCA nuts can be removed.  NOTE:  if your car uses shims to do the alignment, remove them and mark them so that they are put back in the same place during reassembly.  The UCA can now be removed and the tension can be slowly taken off of the spring by loosing the retainer nut, making sure that it does not hang up on anything as it expands.  Once all the tension is off, the spring, compressor and spring perch can be removed from the shock tower as a unit.  To reinstall springs, follow the above directions in reverse order.

Gun bluing compound

Here are 4 shots showing the instilation of the race, bearing, and spacer in to the spring compressor cap.

One bolt in spring compressor complete with bearing cap

Ball Joint Tool
Separating Ball Joints 
Separating ball joints from the spindle can be a challenging task, especially when the two parts have been together for a long time or you do not want to damage the ball joint.  For many years, the standard for separating the ball joints from a spindle has been the pickle fork and/or a hammer.  These tools can be effective but can also be very damaging to ball joints.  A much better option is to “press” the ball joint stud out of the spindle using a press tool.  I originally received a picture of this tool from MustangSteve of  Using MustangSteve’s design, such a tool can be easily made using just a few simple tools and a few inexpensive materials.

Materials needed:
two .75” bolts
one .75” coarse thread, all-thread coupler


.75” coarse thread, all-thread
two .75” coarse thread nuts
one .75” coarse thread, all-thread coupler
three .1875” press pins

Tools required for the project:
Cutting tool
Drill bits and drill

Ball Joint Removal Tool
There are two ways to make this tool.  The first is to thread two .75” bolts into an all-thread coupler.  The advantage to this is that you can purchase several different length bolts so that the length of the tool can be modified to work on different spindles.  The disadvantage is that there is nothing other than pressure to hold the bolt heads to the ball joint studs.    A better option IMHO is to attach two nuts to some all-thread, either by press pins or by welding. Using nuts gives you a little cup at the top and bottom of the tool for the ball joint studs.  I fabricated my tool by cutting two 3” pieces of all-thread, threading a nut onto the end of each one, leaving about .125” depression, then drilled and pinned the nuts to the all-thread.  I then inserted one of the all-thread/nut pieces into the all-thread connector and drilled it and pinned it in place.   It is just as effective to weld the nuts and all-thread connector to the all-thread rather than pinning them, however, I chose to pin them for a cleaner looking tool. Once the tool has been built, using it is quite simple.  Pull the ball joint retainer pins, loosen both nuts about .125”, install the tool and begin to expand it by holding the solid end and unthreading the removable end.  As the tool expands, pressure is applied and both ball joint studs should pop out of the spindle.  At this point, the nuts can be removed and the spindle can be removed.

Ball Joint tool

Disclaimer on Daze Tech Tips
      I am not an expert in this field. I have performed these modifications myself with very good results. I am passing along restoration and performance tips for the purpose of education.  If you are concerned about reliability or safety issues, I do not recommend that you or any other individual perform these changes or attempt to modify your cars from stock configuration except under your own volition.  I do not assume nor accept any liability for the use of this information or how it is applied.

2013 DazeCars
The words / logos for Ford, Jaguar, Mustang, Galaxie, etc are used for descriptive and reference purposes only. DazeCars is neither affiliated with Jaguar Land Rover North America LLC, Ford Motor Company nor the manufacturers/distributors of Ford or Jaguar automobiles.