Fox T-Bird/Cougar Forums

Technical => Drivetrain Tech => Topic started by: 86cougar on September 15, 2012, 09:01:53 PM

Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 15, 2012, 09:01:53 PM
My axle is still on my car still hooked up to my drive shaft. Shocks, control arms, springs, tires, and rims are all off. My bushings are old and hard. How do you take them out? Is there a special tool I can buy for this operation? Putting them in is not bad, taking them out is another story. The front ones I had to drive the sleeve out then cut the bushings out. Thanks, in advance for your help!
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 15, 2012, 10:17:24 PM
I saw where one guy uses a hole saw to cut them out, then files down what is left.
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 15, 2012, 10:22:34 PM
Simple you burn them out. Best way but it makes a lot of SMOKE!!! This of course if the instructions says use the original sleeves. If toy have new sleeves what you do is use a cold chisel and collapse them in to each other and they come right out.


Then you install the sleeves if required. Some dont use new ones they use the originals. Then lube the poli ones with dialectic compound and press them in like this. Simple!!!

(http://i740.photobucket.com/albums/xx46/proguns/007-13.jpg)

(http://i740.photobucket.com/albums/xx46/proguns/008-9.jpg)
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 15, 2012, 11:03:30 PM
Tom,
 I have a propane torch and a brand new hole saw that's the perfect size. One way or another they are coming out. I'll try the torch first on the ones I have removed and see how that goes. I've been trying to decide if I should take the gas tank out and flush it. I'm sure it has never been done in 26 years. Then I can feel safer using the torch on the differential. Thanks!
Title: Rear upper control arm bushings on differential.
Post by: Thunderbirdz on September 15, 2012, 11:53:03 PM
This worked great for taking the bushing off and back on.

 http://www.maximummotorsports.com/store/index.php?main_page=product_info&cPath=514_21_99&products_id=190
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 16, 2012, 06:51:40 AM
You have to be careful with tools like this. You need inserts in between the A arm center section so you dont crush them in. People use an arbor press without supporting the ends and they sometimes crush the outer portion of the arms in. I use the C clip inserts to avoid this. You can make a set of supports from some angle iron cut to length that will support the arm when installing bushings. Once you burn out the bushings with a torch they will be able to be pushed out with ease. Then the shells van be cleaned if they are to be re-used. If the kit has new shells the old ones can be collapsed with a cold chisel and removed very easily. All you do is use the chisel on the open side of the shells and beat them in. They shrink then come out in 2 seconds. But remember ehen installing the arms open ends must be supported with C clips or cut to size angle iron. I really should do a write up on this as it is very easy to install and remove the bushings with my method. I have changed litterly hundreds of bushinge in my life and this is the best and easiest way.
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 16, 2012, 07:38:30 PM
The tool posted is good for the axle side of the job. Or you can use a beater sleeve. The axle ends are basically beat out and beat back in. Or you can use an OTC Ball joint press to do the job. I thought you were talking about the trailing arms sorry!! Here is a set of stock lowers i modified. I totally boxed them and installed POLY BUSHINGS. Then JR shot them with Water Born Porsche Gray. Sorry for the mix up.

(http://i740.photobucket.com/albums/xx46/proguns/001-130.jpg)
Title: Rear upper control arm bushings on differential.
Post by: bigbada1 on September 16, 2012, 11:52:06 PM
I didnt have a regular tourch when I did mine so I set them in a vice and left my burnzomatic tourch on them untill they slid right out.
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 17, 2012, 07:46:29 AM
That is how it is DUN!!! Once the center sleeve gets hot it will melt the rubber enough to slide the rubber out like hot butter. Then the outside casing if it has to be removed can be crushed in with a cold chisel. Then the new bushings can be hammered in. Normally i do not use a press for this as hammering is better because of the shock factor when driving them in.
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 17, 2012, 12:06:24 PM
Well, today I will try my luck at turning petrified rubber into hot butter. When I did my front control arms and I figured out how much pressure would be needed to press them out, I could visualize crushing the control arms. That"s why I did it the hard way by cutting them out with a hammer and screw driver. NOTICE! I asked before I attempted the rear ones... that's progress, and as usual you guys came through again! I'll be on the back porch sending up smoke signals (remember I live in Arizona, that's what we do). Thanks!
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 17, 2012, 12:17:54 PM
Be careful that rubber sometimes POPS and will stick to your skin. Wear eye protection and be careful!!!
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 17, 2012, 01:00:58 PM
Safety glasses and gloves. Will do.
Title: Rear upper control arm bushings on differential.
Post by: Chuck W on September 17, 2012, 01:12:06 PM
Those bushings on the axle come from the dealer with new sleeves. (Don't put poly in there)

Do you have an air compressor?  Air chisel?  I've removed several sets of the differential bushings from the housing with an air chisel. They drive out pretty easily, and then installing the new ones just takes a hammer and a piece of pipe that mates up to the .  Alternatively, you can use the B-joint press like Tom has shown above.

I guess if no air comp, then burn the rubber out and crush the sleeves to remove them.
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 17, 2012, 01:30:55 PM
Chuck,
          I was wondering why you say not to put poly on the differential? The kit even comes with them. What would I put in there instead?
Title: Rear upper control arm bushings on differential.
Post by: Chuck W on September 17, 2012, 01:47:24 PM
If you have poly every where else back there, use factory rubber.  You need a point of deflection in the stock splayed 4-link, over wise you get bind, then you get snap over-steer, then you get to skittering off the road into a mess.

If you only drive the car in a straight line, then poly is OK there, but I bet you do plan on turning the car once in a while.
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 17, 2012, 02:59:45 PM
Chuck every one of my cars have poli in all the positions. Absolutely no issues. Just saying. The air chissel can be used with a Snap On adapter. But i have seen people over do it and snap off the ears. I am not kidding. I always use a support sleeve when doing the rear bushings that press in to the upper ears. Just me. I am over cautious on things like this. The service manual does show a ford tool with a plate driver for this purpose. But doing it in the car. NO ROOM to use the tool. Thanks
Title: Rear upper control arm bushings on differential.
Post by: Chuck W on September 17, 2012, 03:25:59 PM
You can run poly at all the RCA locations in your cars if you like, I will not.  The splayed 4-link WILL bind with poly.
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 17, 2012, 05:06:56 PM
Chuck i respect you knowledge on this issue and i am very interested in this issue you bring up. Can you elaborate as i for one have dun many of these for customers. Not only on Fords but on several GM cars as well. Any info you can pass on will be appreciated. I know you are a sereyous guy when it comes to suspension. The 4 link setup on these cars are not designed to be put in a bind situation by design. And most aftermarket bushings are now made from poly. basically the 4 link is in my mind a non binding configuration by design. In the shop we have ran the suspension up and down to check for this. We see no issues. But i am very interested in your info. As we run the 1320 with poly the car normally hook up better and with less wheel hop. Years ago i used to drive finish nails in to the rubber around the permimiter of the joint. This stiffened up the suspension quite a bit. With the introduction of poly it changed the playing field. So with that please explain as i am very concerned with this. Thanks!!
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 17, 2012, 05:15:48 PM
I went back and I am in the process of re-reading "Polyurethane on control arms".  I got a lot of good solid information on that thread. I also notice that Thunderbirdsport302 mentioned that he put aluminum upper axle bushing on his to prevent binding. Thunderbirdsport302, if you see this, please give us more details on you set up. Aluminum I would think would be even less deflection and more likely to bind (??).
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 17, 2012, 05:26:45 PM
Oh, I forgot... I just finished taking all the bushings out of my rear control arms like Tom suggested. Pretty cool! There is a small learning curve (my first one), but then I remember what you said about it "pops". Mine were more like a "sizzle" and sometimes they would act like those old fireworks I used as a kid "snakes". They would ooz out and catch fire. I just treated like a steak, cook it evenly, make it sizzle. Then it would just slide out like you said. That old petrified rubber sure smells awful funky!
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 17, 2012, 09:54:08 PM
86 been doing it that way for many many years. Glad i could help. Like i said sometimes they pop had to throw that in for safety. Glad i could help. I am still up in the air about the binding thing. But i do respect Chucks experience. He is very knowledgeable on these things. I am going to contact the DOG tomorrow he builds custom frames and does a lot of birds. he is a custom chassis builder. I hope Chuck chimes in as i respect his thoughts and experience.
Title: Rear upper control arm bushings on differential.
Post by: Chuck W on September 17, 2012, 11:48:31 PM
Quote from: TOM Renzo;398431
Chuck i respect you knowledge on this issue and i am very interested in this issue you bring up. Can you elaborate as i for one have dun many of these for customers. Not only on Fords but on several GM cars as well. Any info you can pass on will be appreciated. I know you are a sereyous guy when it comes to suspension. The 4 link setup on these cars are not designed to be put in a bind situation by design. And most aftermarket bushings are now made from poly. basically the 4 link is in my mind a non binding configuration by design. In the shop we have ran the suspension up and down to check for this. We see no issues. But i am very interested in your info. As we run the 1320 with poly the car normally hook up better and with less wheel hop. Years ago i used to drive finish nails in to the rubber around the permimiter of the joint. This stiffened up the suspension quite a bit. With the introduction of poly it changed the playing field. So with that please explain as i am very concerned with this. Thanks!!


The splayed 4-link in the Foxes most definitely WILL bind.  The reason it doesn't in stock form are the very soft rubber bushings Ford used to allow things to twist as the axle articulates on bump and in roll. Spherical bearings at all locations would be better for articulation, but lousy for NVH. Big rubber bushings cause wheel hop on launch, so Ford's band aid was to install the Quad-shocks.  These helped dampen the oscillations, but were just that, a band aid. Poly bushings help eliminate the wheel hop issue, but are lousy for the articulation needed as the rear axle goes through its motions of bump and roll.

You need some point of give in the system, otherwise what happens is when the bushing resists the twisting force, it causes the "effective" spring rate at the wheel to increase.  The worst instance is when there is no more give, and things bind (the effective spring rate goes through the roof).  While it's not usually an issue tooling around on the street, and the car usually "feels" better, that "one" time you are giving it hell at the limit in a corner, and the suspension binds, you are headed off the road. "Snap over-steer" is the term you're looking for.
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 18, 2012, 01:04:26 AM
Cool! Thanks, for taking the time to explain that Chuck! I figure that the one time I give it hell around a corner is the worst time for the sh_t to hit the fan! Snap over-steer sounds like a nice way of saying by-by 86Cougar. Here is my dilemma, I have a kit of poly's, and I have two worn out bushings on my differential. Where could I buy just the two rubber bushings that I need? Would I be safer just using the two old bushings and the rest of the kit? Tom has helped me a lot since I've come on board, and it sure sound's like he has a lot of respect for you, so if you don't mind, I'd also like to hear more for safety's sake. Thanks!
Title: Rear upper control arm bushings on differential.
Post by: TOM Renzo on September 18, 2012, 05:42:41 AM
I am lost for words on Chucks answer. As most of the CHASSIS builders in the area confirm that the bushings should be changed out to POLY. Fact is FORD actually changed the arms from OVAL at 2 points to a set of ALL ROUND units on the lowers. They also installed the QUAD SHOCKS to eliminate chassis wheel hop and movement. According to My buddy over at the chassis shop the poly bushings wont bind the BIRD. They are not solid and wont increase spring rate. As posted the inside sleeves on the bushings in fact are not permanently fused to the bushings in the ones we use. Their fore the bushings we use wont bind. With that i am all confused on this subject and i do respect CHUCKS answer. But this opens a whole new can of WORMS. Or should i say POLY???
Title: Rear upper control arm bushings on differential.
Post by: Chuck W on September 18, 2012, 08:57:04 AM
Quote from: TOM Renzo;398504
I am lost for words on Chucks answer. As most of the CHASSIS builders in the area confirm that the bushings should be changed out to POLY. Fact is FORD actually changed the arms from OVAL at 2 points to a set of ALL ROUND units on the lowers. They also installed the QUAD SHOCKS to eliminate chassis wheel hop and movement. According to My buddy over at the chassis shop the poly bushings wont bind the BIRD. They are not solid and wont increase spring rate. As posted the inside sleeves on the bushings in fact are not permanently fused to the bushings in the ones we use. Their fore the bushings we use wont bind. With that i am all confused on this subject and i do respect CHUCKS answer. But this opens a whole new can of WORMS. Or should i say POLY???

First, Ford used the all round bushings in the early cars. They changed in '83 to the big oval ones in front of the RLCA to cut down on harshness.  The only Fox to use them after that was the SVO, which was marketed as a "driver's car", and not just a neo-musclecar.  After they changed to the oval bushings they realized they had an issue and instead of keeping the slap bars the early cars had, they went to the quads to help dampen the diff bouncing up and down on hard launches due to the big rubber bushings.

Second, you and your chassis guy are missing the point.  Yes, the internal sleeves are not bonded to the bushings like the rubber ones are, so yes, when the control arm moves in an arc around that pivot there is no binding.  However, when the body rolls, the rear axle is not moving in that nice up and down arc, it is actually causing those sleeves to twist in the bushing as the mounting points on the axle are now no longer being asked to move at parallel axes.  The motion is actually trying to twist the control arm. The stock rubber allows for that bit of twist, and poly doesn't. When it can't twist, it binds.

Now, using poly in stock un-boxed stock control arms MAY be OK, seeing as how flimsy the stock arms are, but if you have aftermarket or boxed stock arms loaded with poly, not much twist is going to happen there, and there for certain WILL be spring rate increase and bind. I'd rather be twisting rubber bushings than my control arms, though. The stock splayed 4-link in the Foxes is asked to do a lot of things, and is not very good at any of them once you start pushing it.

Quote from: 86cougar;398501
Where could I buy just the two rubber bushings that I need?

You should be able to get those at the dealer.  They were used on Mustangs until '04, so they shouldn't be obsolete...yet.
Title: Rear upper control arm bushings on differential.
Post by: 50tbrd88 on September 18, 2012, 10:23:23 AM
I'm glad I read this...just ordered factory style rubber upper bushings.  I had no idea it was a bad idea to run all poly bushings!
Title: Rear upper control arm bushings on differential.
Post by: Aerocoupe on September 21, 2012, 10:13:05 PM
http://www.maximummotorsports.com/store/index.php?main_page=index&cPath=21_98

Be sure to click on the "Rear Lower Control Arm tech section" link in the third paragraph and read up on that page as well.  Pretty much tells it like it is or should I say Chuck said.  This is common knowledge in the Fox Mustang world if you do any kind of racing that involves turns.

Darren
Title: Rear upper control arm bushings on differential.
Post by: 86cougar on September 21, 2012, 11:10:21 PM
The whole rear end is done. I ended up using stock bushing for the differential and poly every where else. The differential has fresh oil, the rear end has new shocks, springs, anti-sway bar and brakes. I want to thank all of you for you opinions, knowledge, and help. Nice attachment Aerocoupe!