Cadillac CTS-V - Rear Diff Bushing Replacement Help




Bacon
08-07-2012, 07:48 AM
So I set out to replace my rear diff bushing last night because I had a fair amount of clunking - The bushing was pretty much just an oval core floating in the pressed in sleeve at this point so its good that im replacing it.

Im having a hell of a time getting the old sleeve out - didnt get the custom steel tool, but I tried using a puller of my own and i was afraid I was going to deform the aluminum ring it goes in. I think I can get it out tonight, but Im worried about putting the new one in.

Any hints for the install to make sure the thing goes in square? How much force does it take to get it in? Is it going to be a massive load required or is it a light press fit? Does greasing it up help any?

Thanks for any help - this is going to bug me all day at work.


rjoffe
08-07-2012, 08:30 AM
Use a hacksaw and very slowly cut through the sleeve, but not into the diff housing. That should allow you to remove the sleeve.

Which diff bushing are you replacing it with ?

soulja
08-07-2012, 08:42 AM
Yep, a hacksaw should do it. Just cut about a 1/4 inch piece out and you should then be able to pry the sleeve out with a flat head screwdriver.


Bacon
08-07-2012, 08:50 AM
ugh...dammit i knew that was going to be the answer. I spent an hour with a keyhole hacksaw last night doing just that. Its about ready to come out, but like I said Im worried about how the install will go. PLEASE tell me it goes in easier than it comes out?

Im replacing it with a CS bushing. Once this is done Ill post some pics and video - the old one was so bad that the internals fell out and I could move the differential about 1/2" with one hand. I bought it 2 weeks ago so apparently the previous owner learned to deal with it?

rjoffe
08-07-2012, 09:10 AM
You should have no issues with inserting the CS busing.

BudRacing
08-07-2012, 09:18 AM
If anything stick it in the freezer for a couple of hours before installing. That should shrink the metal sleeve up some.

Bacon
08-07-2012, 11:31 AM
Anyone have any idea what the interference or press fit will be for this thing? I called CS and he said he thought it was .020"? That sounds huge to me, especially in thin cast aluminum. Wouldnt a press that tight just dig the aluminum out anyway thus reducing the amount of press?

Might have to try to heat the diff and cool the busing to get it to go in nicely...

Bacon
08-07-2012, 12:07 PM
Sometimes when I kick problems like these around I'm embarrassed to say im an engineer.

So I ran some numbers and this may help people in the future:

coefficient of linear expansion for aluminum is 23x10^-6/C and 11x10^-6 for carbon steel.

If I can heat the aluminum of the diff by even 50*C, then I will have 23x10^-6/C * 50C * .048(diameter of bushing) = .055mm growth in diameter which is roughly .002".

Similarly with the bushing, if I can COOL it by lets say 35*C, then I have 11x10^-6/C * -35C * .048 = -.018mm shrink in diameter which is roughly .001".

So heating and cooling I can gain maybe .003" in my favor - thats not much when I need to get to the .020" they claimed. Looks like ill be borrowing a heat gun from work tonight.

BudRacing
08-07-2012, 01:24 PM
I'd probably use a propane torch, but that's just me.

Bacon
08-07-2012, 01:28 PM
Eh, gas tank near by, some residual penetrating oil...we'll see how daring I get. I may also just turn the sucker down a little in the shop. If it truly is a .020 press fit, you would have to heat the diff to 950 degrees Celsius in theory just to get the press fit down to a 1:1 fit. Since aluminum melts at 660C, I dont see that happening. AKA, I dont see need for such a tight fit.

Fuzzy_Wuzzy
08-07-2012, 01:58 PM
other people have installed these before so i would assume the size is ok. You have the diff and the bushing so go measure and see how much of a press fit it really is. and convert to english units... for temp i have to think about celcius too much to get a feel for how much energy that is...

SSmokd U
08-07-2012, 02:29 PM
A freezer, hammer & block of wood is all you should need. You are over analyzing this big time. I rented the tool to do mine but if I had done a little more research I would have passed on the hassle of waiting then return shipping.

soulja
08-07-2012, 02:36 PM
You are seriously over thinking this. I agree with SSMOKD U. Freeze it, then get a nice heavy blow or smaller sledge and a piece of 2x4 and knock it in. I recall it being very easy putting the frozen bushing in.

lollygagger8
08-07-2012, 02:37 PM
Ya, use a hacksaw blade to get old sleeve out.

Here's my writeup on CF.....

Missing pics on page 7

http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-general/161750-diff-bushing-install-removal.html

Like above, freeze the new bushing and hit with a small hammer. Don't over analyze it.

Bacon
08-07-2012, 02:49 PM
Ha, I read all those posts. That coupled with all the trouble to get the old one out is what makes me analyze this. Plus, Im putting in the CS instead of the UUC which seems to slip in much easier.

Im at work and have nothing to do other than overthink this...leave me alone :) Ill just squirt some KY Jelly on it - you can get a cadillac in a doghouse with that stuff.

rjoffe
08-07-2012, 04:33 PM
hmmmm

SSmokd U
08-08-2012, 12:49 AM
BTW I did the CS bushing too. I have all of their bushings/mounts. FREEZE IT & BEAT IT! LOL

Bacon
08-08-2012, 08:11 AM
I must have been tired the other night and gave up too soon. Came home after work yesterday and with one tap of the hammer i heard a loud TING, and then the old steel ring popped right out.

Before I left work I took .005 off the diameter of the new CS unit for the first .200 to give it a lead in. With a rubber mallet that first 200 seated like butter. Lubed the rest of it up and put the press on and it went in nicely on the first try. Getting a press fit started right is all it takes.

The whole reassembly took about an hour and was much easier. Left the exhaust on (lowered it from the hangers though), left the driveshaft in place. You dont need to take those out.

Heres what I pulled out - completely shot. The new bushing completely eliminated the clunk that I had and left me with a slight click. The holes in the mounting bracket are just a little bigger than the bolt so I think its the bolt moving around under load. There is a little more whine present now, but its much better than the clunk.

http://i992.photobucket.com/albums/af49/mbakken/CTS-V/2012-08-08_07-21-58_41.jpg

http://i992.photobucket.com/albums/af49/mbakken/CTS-V/2012-08-08_07-22-36_431.jpg

BudRacing
08-08-2012, 11:33 AM
Yeah, whoever designed those original bushings failed miserably.

Cadzilla
08-08-2012, 12:41 PM
Did that thing look like this in the housing?

http://i1027.photobucket.com/albums/y332/memphisctsv/IMAG5307.jpg

http://i1027.photobucket.com/albums/y332/memphisctsv/IMAG5309.jpg

I'm wondering if mine could be shot but look fine on the outside edge..

Bacon
08-08-2012, 12:56 PM
Even in the dark mine was noticeably worn looking and you could see some of the rubber strings sticking out. I was also able to move the front of the diff up and down about 3/8" by hand while laying on my back.

Cadzilla
08-08-2012, 01:39 PM
Ah, ok. Mine had no movement so I just left it in there.

furbe
08-09-2012, 06:15 AM
If it is shot you will have a serious clunking in the driveline and be able to grab the diff and move it up and down.. no clunk, your good.
On the other hand, you may as well replace it cuz it will go bad.

Quik Z06
08-09-2012, 06:22 AM
This is something I may have to do soon. Our 1-2 shifts make a clunking noise and it's very jerky, first manual car I've ever owned that is that jerky when shifting. I have access to a lift and a friend with a million tools (dad used to be a mechanic for 30 years) and he's a decent mechanic himself.

Bacon
08-09-2012, 09:47 AM
Just a thought, but has anyone ever bought a stock replacement and just swapped the guts so you dont have to press that old bushing out? It wont last as long as an upgraded unit, but if you can swap the internals this could be a MUCH shorter job. Probably on the order of an hour or 2 once youve done it a time or two.

furbe
08-10-2012, 04:37 AM
I am willing to bet the factory bushing in not a 2 piece when new. The outer shell is bonded to the inner rubber making a one piece OS.

I also replaced mine with the hack-saw + freezer + heat diff with torch method. Works excellent

catch2otwo
09-16-2012, 05:16 PM
So you guys who are arent renting the tool. Your hack sawing a slot into the steel sleeve and then getting at it with a screw driver?

Was this slot cut with a hack saw?
http://i992.photobucket.com/albums/af49/mbakken/CTS-V/2012-08-08_07-22-36_431.jpg


And also does anyone have a write up with pictures? Lollys original write up is now pictureless.

Dmax/04V
09-16-2012, 08:31 PM
This makes me so happy I have an 8.8 sitting on my floor, can't wait to put it in and never have to deal with this again. The Block from CS combined with their bushing seems to be holding up relatively well for much I beat on mine. Would absolutely recomend the block to anyone doing this.

lollygagger8
09-18-2012, 01:22 PM
So you guys who are arent renting the tool. Your hack sawing a slot into the steel sleeve and then getting at it with a screw driver?

Was this slot cut with a hack saw?
http://i992.photobucket.com/albums/af49/mbakken/CTS-V/2012-08-08_07-22-36_431.jpg

Yes.


And also does anyone have a write up with pictures? Lollys original write up is now pictureless.

The pics are on the last page.
http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-general/161750-diff-bushing-install-removal-7.html

JazMiller
09-18-2012, 01:57 PM
...The Block from CS combined with their bushing seems to be holding up relatively well for much I beat on mine. Would absolutely recomend the block to anyone doing this.

Same here. Well, it's only been in for a week or so, the tool saved me a lot of grief and made the bushing pull the easy part of the job. i did the poly block at the same time as well, and I notice the most difference in 1-2 shifts and back. Hope that it holds up like dmax has experienced!

Cadzilla
04-24-2013, 03:34 PM
Ah, ok. Mine had no movement so I just left it in there.

update- defeated by diff bushing.

had some mad slop in the drivetrain so yesterday on a whim i decided to throw in my cs diff bushing. got up in there and got it all apart. i have one of brians old extractor tools and i still just could not get that damn bushing out. so i gave up and slept on it.. tried again today and it started pulling on the rubber section about 1/2 in, but still wouldnt budge...i was putting at least 175 ft lbs on it..

stock bushing still looked fine so i said f it and buttoned it all back up, torqued all 3 bolts to 129 ftlbs. drives much better than before!, i guess the rear diff bolts had just worked a bit loose again.

im never attempting this again until i get an actual clunk. ive never really had the clunk, just a ton of deflection in the drivetrain.

before i tightened those bolts the dfco alone would induce an overall rocking/shifting feel in the whole car..maddening..but its better now..

looks like my cs bushing will stay in the freezer for a while longer.

FuzzyLog1c
04-24-2013, 03:40 PM
Personally, I'd just throw out that bushing. Next time you order something from Revshift, get theirs.

Cadzilla
04-24-2013, 04:03 PM
i dont see myself ever needing it, at least not any time soon. bushing is going on 2 years old and ive rolled out on the throttle (hard) countless times, especially since installing my ls7 clutch... still looks brand new. i dont see how people are trashing them.

KamaSutra
04-25-2013, 10:10 AM
Personally, I'd just throw out that bushing. Next time you order something from Revshift, get theirs.

^-----This

i dont see myself ever needing it, at least not any time soon. bushing is going on 2 years old and ive rolled out on the throttle (hard) countless times, especially since installing my ls7 clutch... still looks brand new. i dont see how people are trashing them.

I'm guessing the stock bushing has a longer lifespan when it's not getting hammered away by the stock clutch/flywheel combo. It will eventually fall apart.

My CS bushing cured the clunk for a few months and then it eventually creeped back, this was when I still had the stock clutch/flywheel. I got a Revshift 95A bushing waiting to get thrown in now.

DarkCharisma
04-25-2013, 10:22 AM
I cut mine out with a reciprocating saw.

To get the new one in, I put a buffing/polishing wheel to de-burr the surface to a mirror finish (I marred it a tad trying other methods to get the old sleeve out), then heated the diff, froze the bushing, covered the whole thing in dish soap and it slipped into that bushing hole easier than an excited teen into a drunken blonde prom queen.

FuzzyLog1c
04-25-2013, 10:25 AM
I think everyone's definition of "hammering on" their car is different. My stock bushing didn't start clunking until after I did the LS7 clutch and a whole bunch of handling mods that enabled me to start throwing the car around.

Cadzilla
04-25-2013, 01:08 PM
well, i dont drive like i stole it but during the last few months that i had my stock clutch i drove with the intention of destroying it (the clutch). i would shift really hard at high rpm and ride the clutch until it stunk bad. you should have seen it when i removed it... looked like it had literally caught fire haha...

i did have the diff block in though, which i credit for saving the bushing.

etcts-v
04-26-2013, 08:19 PM
A freezer, hammer & block of wood is all you should need. You are over analyzing this big time. I rented the tool to do mine but if I had done a little more research I would have passed on the hassle of waiting then return shipping.

This did not work at all for me, freezing did absolutely jack shit for me and I let it sit in the freezer for 2 days!