: rear diff

06-22-11, 02:06 AM
so i finally managed to crack my diff, nice hairline crack, have a line on a regular cts diff, all i can find is that they are the same, so buy that for cheap, and swap the guts? any problems you guys can tell me from experience? will the guts swap? and should my internals be fine? i jb welded my case, filled it back up, but it started leaking slowly again after a few km's drove and felt fine tho

06-22-11, 07:28 AM
That sux. Was it original diff? What part number? Did it crack during wheel hop or what?

06-22-11, 10:18 AM
I didn't think JB Weld would work that well on aluminum.

I don't think it'd be hard to switch out the base CTS gears (3.42 maybe? not sure about SRX gears) to 3.73 V gears. Setting backlash is the hardest part. Only certain CTS diffs are LSD, so be sure to get one with them in it. That said, the diffs do bolt right up on the outside though.

Now that I think about it, I don't think I'd even bother with that, and just get a V diff. Spend the extra coin and save yourself the hassle.

06-22-11, 10:42 AM
SRX gears (at least my friends) are 3.90.
I know someone had a problem with the guts not fitting. It might have been an SRX diff, but I'm not sure. This was 2-3 years ago.

06-22-11, 11:14 AM
Yes it cracked on some wheelhop, had barely any, have a good picture i'll have to load with 2 patches and a trail of oil in between :thepan:
Diff is original, and i have been bagging on it foot to the carpet all the time for months now:rolleyes:

i only wanted to jb so i could limp it around until i get another one, but looks like the oil is seeping out of the fins, where i wasn't able to groove them out, but still covered with jb, oh well
The diff i have a line on has 3.42 gears, ive set gears up before, for 4x4's but with my V i dont want t bother, i have a friend in a shop that could do it. im about to drop the money on this cts diff, and thought i would chirp up here, before i get it, try and swap the internals and they dont fit...

06-22-11, 11:17 AM
lame because i never notcied the oil dripping til after i threw new 275s on the back and tuned it all up, and wasn't going to bag on it anymore, did 2 burnouts with the old tires, and she cracked on the last lame one, haha, oh well, this diff had a hard life, i'll grab a part number off of it later

06-22-11, 11:50 AM
1st good show




06-22-11, 03:56 PM
Woopsie. Got axle?

06-22-11, 07:40 PM
Damn dude :lol:

06-22-11, 08:45 PM
Nice pics! hahaha.....

06-22-11, 09:58 PM
... 2nd.....


Now, THAT is a classic V1 pic. :histeric:

06-22-11, 10:16 PM
shat itself right there in the 2nd pic

06-22-11, 11:14 PM
LOL at the pics... sucks that it cracked though

06-23-11, 02:24 AM
when i drove by the rd of the 2nd burnout the day after i had left sideways, and had noticed a trail of oil swerving back and forth, so had to go for a drive, i laughed pretty good when i saw the 2nd burnout, thought it would be a good picture for you guys, haha

06-23-11, 07:03 AM

What axles?

06-23-11, 11:14 AM
stock axles
so question is, will my 3.73 internals with limited slip fit into a cts 3.42 carrier

06-24-11, 07:29 PM
this should be a sticky :D

06-24-11, 11:17 PM
Videos show some of the past few months enjoyment here and there :D
Fun getting rid of the shitty tires that came with the car, all have been replaced now, too bad the diff had to go with them :D



06-25-11, 04:57 PM
Just called gm, and i can get just the case, they told me $500, which i know they're skinning me, but at least thats cheaper than a whole diff which they want 4000 for

06-25-11, 05:27 PM
Just called gm, and i can get just the case, they told me $500, which i know they're skinning me, but at least thats cheaper than a whole diff which they want 4000 for

Interesting since the MRSP on the new differential is only $1922.96, and Luke at Lindsay Cadillac will beat that significantly.

06-25-11, 06:00 PM
phoned another stealarship, they quoted me 4k aswell, and apparently the casing doesn't exsist anymore, stopped producing them, tried calling lue, but parts isn't open today, and he never got back to me on my online parts request, i'll have to give him a call monday, still wondering if i should buy that cts diff, and hope my stuff fits, been trying to search other options all day, if a new diff is a reasonable price i'll just buy it, moneys just tight!

06-25-11, 06:18 PM
Definately call Luke - he has no doubt been busy working on V-day. CTS differentials come with and without limited slip so there may be two cases with different internal cavities, but I do not know for sure. I do that those who have converted CTS-V differentials to different ratios (3.42 if I recall correctly) have used the ring and pinion gearsets from a CTS - so there a good chance that the cases have some interchangeability.

06-25-11, 06:30 PM
When my diff was changed by my dealer, the entire bill, parts and labor, was under $2000. Granted, GM was paying the bill, but $4k is rape.

06-25-11, 07:45 PM
deffinately rape, and thats not even install, thats just the diff, must be uranium coated to stop it from grenading. Would rather just buy a 9 inch if i could

Whats Gm shop rate down there? $2000 installed isn't bad at all, considering i know they charge $120 an hour up here
My car will never set foot in their shop

06-27-11, 10:53 PM
GM has them, just had a new one put in today under warranty.
Serial 0006450001210E
Took a look under there its all shiny and quiet so far. The fins look very deep on this model but I have no proof its any different than what came on my 07 V.

06-28-11, 09:09 AM
Have you tried www.car-part.com and search a common part to find parts cars and call to see if they have a diff?

06-29-11, 05:59 PM
I've seen a couple BRAND NEW on Ebay for under a grand, last maybe a month ago. Personally, If I was keeping the car, I'd invest in one of those new hyper diff set ups-several companies selling (g force maybe?) for about $4K. I think you get diff, axles, CVs, the works. Put that one in and forget about it for life...

This is interesting (in the performance section of this forum)

This is on Ebay NOW (6/22) $850 from an 07 http://cgi.ebay.com/ebaymotors/04-07-Cadillac-CTS-V-OEM-Rear-Carrier-Assembly-3-73-_W0QQcmdZViewItemQQhashZitem484109aa10QQitemZ31032 8797712QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries

Some tricks searching Ebay: Try CTSV AND CTS-V, you will get 2 entirely different sets of listings also try differential and carrier, different listings theres an 09 for under a grand!

06-30-11, 11:33 AM
Personally I'd be real careful about used diffs, eventually once I pony up for a gforce mine will find it's way to ebay as well... beware!!

06-30-11, 03:28 PM
True, but if you are able to swap a diff out yourself, having a backup for $100-200 or so is worth the stretch.

06-30-11, 04:56 PM
Yep very true, but $850 for a used one with no mileage info or mention of horrible whining is a BIG gamble I think. When I sell mine it will come with a nice disclaimer.

06-30-11, 05:48 PM
I've got a spare with the new part number... got it used for 550... its been sitting the shelf for about a year now... it's comforting to know it there.. if you really run stuck PM me. Since you are familiar with internals of the diff then I wouldn't feel bad about selling you mine as you could inspect the gears before you put it in.

Either way, just throwing it out there... I'm happy to keep it as well... so either way... good luck.

PS. liked the second picture... I think it's incredible that JB held up as long as it did..... unreal.

07-01-11, 10:21 AM
Interesting crack propagation. This would indicate that the stress riser already existed in the threaded boss.
All it needed was a good .. urr .. 'bad' vibration from wheel hop to set it in motion.

Good luck with the replacement.
Pictures when it happens . . right??

07-02-11, 09:30 PM
Yep very true, but $850 for a used one with no mileage info or mention of horrible whining is a BIG gamble I think. When I sell mine it will come with a nice disclaimer.

I am with you there, for $850, forget it. For $200, go for it. If it turns out to be garbage, $200 isn't a big hit to swallow. $850 is.