720 Lower Control Arm Bushings replaced using hand tools

[matrophy]

It can be done with hand tools but probably the hardest repair I've ever done all things considered.

This is what worked for me and others may have better suggestions. I don't have a large enough compressor to use with an

air chisel which is a suggestion I read somewhere and I was reluctant to do something that may damage the frame

so I took this safer road suspecting that it would be a bitch of a job. And it is...

 

 

Tools used:

Propane torch

7/16"" all-thread -  I used all of two 36" lengths in various cut lengths

Nuts and Washers from the Grade 8 bin at hardware store - I would buy 6-8 each

Washers:

2-1/2" OD - 1" ID

1-3/4" OD - 5/8" ID

1-1/4" OD - 1/2" ID

7/16" nuts - 11/16" wrench - buy 10

11/16" end wrench - 2 ea

3" Pipe nipple

1-1/6" Craftsman 1/2" drive socket -  or a socket that fits exactly on the outer shell

11/16" Craftsman 1/2" drive socket - or a socket that fits exactly inside the outer shell

LockTite

White Lithium grease

Dremel with sanding wheel

 

 

I did the passenger side in a totally different way based on suggestions of burning out the rubber and using a hacksaw on the outer shell and it was a complete mess and took me 2 days to clean out the rubber and hacksaw the bushing out. Below is what I did on the driver's side which still took about 5 hours but was way easier and didn't damage the frame which hacksawing has the potential of doing.

 

 To press the bushing out, start by pressing out the rubber with the inner core still attached  Assemble your press using the 11/16" (or whatever socket fits inside the outer shell) on the rubber inside the outer shell and add the 3" nipple to the outbound side. I used 3 locknuts on the outbound end with locktite on all the nuts. I stacked all 3 sizes of washers on the nipple end and used 2 of the small washers on the inbound end. Cut your all-thread so it is only as long as what you need for tight assembly. I found that extra long all-thread had a tendency to bend. Heat the frame where the bushing is until you see smoke coming from the rubber. For me, this took 7 minutes of heating. Then press out the rubber with the inner shell still attached. You'll have to add another socket behind the first one to fully push the rubber and inner sleeve out. Allow for this extra length when cutting your all-thread here. There is not as much force required to push out the rubber so you should be OK with a long piece of all-thread for both of these setups in this step and you could actually do it with 2 sockets from the start.

 

For the outer sleeve, assemble the press as above but use the 1-1/16" socket. I cut 2 pieces of all-thread for this part. One for the 1-1/16" socket and another long enough for whatever socket you'll add to the first socket to push the sleeve all the way out. Make sure the first socket is perfectly engaged with the outer sleeve all the way around. If it is off center, you could damage the sleeve or the frame. I heated the frame for 2-3 minutes realizing that the rubber degrades and melts at about 6-7 minutes. Lubricate the all-thread real well and crank with your end wrench on one end and hold  the 3 nuts on the outbound end. Crank until it becomes more difficult and stop and reheat as needed. I saw suggestions of removing the crossmember to get fully around the frame to heat it and I didn't do it  that way. It worked fine just heating from the bottom and sides.

 

Once the outer sleeve was out, I ran a dremel sanding wheel in the frame opening and polished it up real nice and chamfered the outer edge of the frame opening so the bushing could be started easily.

 

There were suggestions of putting the new bushing in the freezer which I did but I miked both a frozen bushing and one at room temperature and there was no difference in the OD. I felt that freezing the bushing may have made it more rigid I so used frozen bushings both times. 

 

Assemble your press for the 1-1/6" socket and put 2 of the largest washers flush against the outbound side of the frame followed by 2 medium washers and a small washer so there is room for the protruding inner sleeve to fit through the center of the washers (this is why the largest washers should have an ID of 1"). In case it's not obvious, you won't need the 3" nipple here. You'll need a second length of all-thread once the socket runs out of room and you need to add a socket to continue pushing the bushing in. Make sure at this step that the washers are all centered so there is room for the inner shell to poke out. Add a good amount of white lithium grease to both the frame opening and the outside of the bushing. Lightly tap the bushing in place. Crank and heat as before. Lube the all-thread. You can see the grease bubbling after heating for a while and that's when I decided to stop heating each time. Remember that the rubber degrades and melts at around 6-7 minutes of heating so 2-3 minutes of heating and crank until the bushing stops moving. It gets harder the farther the bushing is inserted. 

 

Have fun!

 

 

 

 

 

 

[bottomwatcher]

Nice write up. That job sucks but every old part has a little play that adds to the whole. Enjoy your fresh tight suspension.

[Charlie69]

That is basically the way I did the lower bushings on my 86 and the 80 720 chassis under my 66 520.  My brother got a piece of hardened all thread and he turned some steel round stock down to fit the outer diameter of the bushing and then machined one end flat and recessed the other end to fit the Inner sleeve of the bushing.  We used grade a nuts and change the out on each bushing.  We also used a torch to get them moving.  only difference is we used the impact wrench to drive them out and drive the new bushings in.  Only use the nuts one time and scrap.

[matrophy]

On 6/12/2020 at 6:28 AM, Charlie69 said:

That is basically the way I did the lower bushings on my 86 and the 80 720 chassis under my 66 520.  My brother got a piece of hardened all thread and he turned some steel round stock down to fit the outer diameter of the bushing and then machined one end flat and recessed the other end to fit the Inner sleeve of the bushing.  We used grade a nuts and change the out on each bushing.  We also used a torch to get them moving.  only difference is we used the impact wrench to drive them out and drive the new bushings in.  Only use the nuts one time and scrap.

I'm curious if the impact tool took it in/out in one pass or did you have to do it in stages and heat in between stages?

[Charlie69]

On the 1980 chassis I had to heat and run the old bushing out a little at a time then reheat repeating this process until the old bushing was out.  On my 86 it took the old bushing out in one continuous push.  We used hardenened all thread not the stuff available from your local hardware store.  Tried the local hardware stuff first and it was to soft and galled. Also using a commercial compressor and 1/2" impact gun.  It took some time to push the old bushing out and the new bushings in.  I also used never sieze on the new bushings.  Also used Moog bushings.

Edited June 15, 2020 by Charlie69

[EDM620]

I used pretty much the same process as well, but incorporated a 2 jaw puller to push it out. One side came out "reasonably" well, the other side ended up having to cut the LCA to finish. The bolt I used was getting really galled and was junk after.