: Rear End Shutter in an AWD CTS



crossbow11
06-12-13, 05:23 PM
I have a 2008 CTS4 3.6L . It is AWD and when you accelerate, it has a shutter that seems to come from the rear end about the time that the cars shifts from 1st to second. It doesn't seem to have that problem in manual mode. Any ideas?

exm22psu
06-12-13, 06:07 PM
Is it under WOT? If so, mine does to, because it's loosing grip in the shift.

Cadillac Cust Svc
06-12-13, 08:00 PM
I have a 2008 CTS4 3.6L . It is AWD and when you accelerate, it has a shutter that seems to come from the rear end about the time that the cars shifts from 1st to second. It doesn't seem to have that problem in manual mode. Any ideas?

Hello crossbow11,

I apologize that you are experiencing a concern in the rear end of your CTS when you accelerate from first to second. I do see that you are asking the community for any ideas, but if you are interested in taking your CTS to a dealership for a diagnosis, I would be happy to assist you in working with them. If that is the route you would like to pursue, please private message me your name, contact info, VIN, mileage and dealership you would like to work with. Thank you for taking the time to read my post.

Gregory W.
Cadillac Customer Care

C "T" ess
06-13-13, 11:28 AM
I wonder if it's a rear u-joint?

JackB
06-13-13, 08:26 PM
This is a little differn't than you describe but my 09 AWD DI had an issue with the driveshaft hitting the tunnel on hard acceleration. In my case it was a real racket not a small shudder. It was fixed under a warranty TSB. Just wanted you to be aware just in case it might be a minor case of that problem.

Michael_atDell
06-14-13, 11:48 PM
You have the TSB #? Mine started doing this last week...

RAB
06-15-13, 07:29 AM
I have a 2008 CTS4 3.6L . It is AWD and when you accelerate, it has a shutter that seems to come from the rear end about the time that the cars shifts from 1st to second. It doesn't seem to have that problem in manual mode. Any ideas?

Crossbow11, the issue you describe may mean you need to have shims installed at the CV Joint of your drive shaft (aka prop shaft) assembly. Note the prop shaft will rotate in an elliptical (non-concentric) manner at times of high torque, and a section of your prop shaft assembly may sometimes be contacting the tunnel /underside of your vehicle. Below is a simplified drawing of the prop shaft assembly. Your dealer should be able to confirm whether the prop shaft has been making contact with the vehicle's underside, and then apply the appropriate fix - which is typically a shimming job at the CV Joint. From historical comment on the forum this particular problem seems to occur only on '08 and '09 CTS's equipped with AWD.

http://i248.photobucket.com/albums/gg195/RAB_2008/CTS4drivelineimage.gif (http://s248.photobucket.com/user/RAB_2008/media/CTS4drivelineimage.gif.html)

Service Information
2008 Cadillac CTS | CTS VIN D Service Manual
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#PIP4597: Rumble Thumping Grinding Ground Out Noise On Acceleration - keywords 4477 AWD bearing body case center clunk drive driveline grind prop propeller rear rumble scrape shaft shim suspension thump - (Mar 12, 2009)
Subject: Rumble, Thumping, Grinding, Ground Out Noise on Acceleration

Models: 2008-2009 Cadillac CTS with AWD
Built Prior to Vin 90144280

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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
A thumping noise may be heard from under the vehicle on acceleration. Inspection of the vehicle may reveal witness marks on the rear drive shaft and the under body of the vehicle.

Recommendation/Instructions:
1. Wrap 1 layer of masking tape around the CV joint just forward of the center bearing and drive the vehicle under the same conditions to determine if the noise is from this area. If the tape shows evidence of contacting the floor pan, proceed to step 2.
2. Lower the rear propeller shaft center bearing and inspect for the presence of shims. If no shims are present, proceed to step 3.
3. Install (1) 6MM shim under each side of the rear propeller shaft center bearing. The rear of the prop-shaft must be match mounted with the rear differential to avoid driveline vibration. To do this the yellow mark on the rear flange of the prop-shaft must be lined up (or as close as possible) to the orange mark on the rear differential pinion flange.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Michael_atDell
06-15-13, 10:28 AM
Is that covered under power train warranty?

Cadillac Cust Svc
06-15-13, 05:19 PM
You have the TSB #? Mine started doing this last week...

Hello Michael_atDell,

I am sorry to hear that your CTS just starting to experience this issue with the shutter in the back end. If you would like me to speak to the dealership on your behalf about this, please private message me and I would be happy to assist you. Thank you very much for your time.

Gregory W.
Cadillac Customer Care

csudhoff
07-01-13, 10:05 AM
Did you have any luck with getting this resolved?

Michael_atDell
07-01-13, 12:06 PM
Mine just stopped; did it about a week and stopped as suddenly as it started...

csudhoff
07-09-13, 08:13 AM
Starting to see this with mine as well.... so odd! Noticed that if i use the cruise control it happens less as well.

Cadillac Cust Svc
07-09-13, 04:05 PM
Starting to see this with mine as well.... so odd! Noticed that if i use the cruise control it happens less as well.

Hello csudhoff,

I am sorry to hear your vehicle is experiencing a rear end shutter also. If you private message me, I am more than happy to discuss your concerns and work towards a resolution for this issue.

Regards,

Laura M.
Cadillac Customer Care

syeager
07-11-13, 12:16 AM
Got a 09 cts-4 that the same thing is happening to. It's going under the knife tomorrow..... Will let ya know what the experts say about it. Kinda interested to hear their take on it now that I have read this forum!

Michael_atDell
07-28-13, 04:21 PM
Mine started up again end of last week and continued until it became quite violent on Friday. Called the dealer and they recommended making sure all bolts are torqued to spec, other than that I'd need to replace the shaft.

Crawled under yesterday and checked all bolts; two in center support bracket were slightly loose, torqued to no avail.

Couldn't have come at a worse time (financially), maybe it's a warranty repair...

Tbbt
07-28-13, 07:48 PM
Anyone having ANY problem with their car (when under warranty) need to take it in to the dealer and make sure it is logged in as a problem! That way should it fail after the warranty expires, you have a chance of getting it replaced under warranty. If the dealer can't replicate the problem, keep taking it back until they do see it as a problem. Keep your copy of all paperwork from the dealer too!

Marv

Michael_atDell
07-28-13, 09:45 PM
Anyone having ANY problem with their car (when under warranty) need to take it in to the dealer and make sure it is logged in as a problem! That way should it fail after the warranty expires, you have a chance of getting it replaced under warranty. If the dealer can't replicate the problem, keep taking it back until they do see it as a problem. Keep your copy of all paperwork from the dealer too!

Marv

Well, by warranty I mean drivetrain, should have said that. I just turned over 100k...

Cadillac Cust Svc
07-29-13, 09:06 AM
Mine started up again end of last week and continued until it became quite violent on Friday. Called the dealer and they recommended making sure all bolts are torqued to spec, other than that I'd need to replace the shaft.

Crawled under yesterday and checked all bolts; two in center support bracket were slightly loose, torqued to no avail.

Couldn't have come at a worse time (financially), maybe it's a warranty repair...

Hello Michael_atDell,

I am sorry your vehicle issue started up again. I see you were in contact with the dealer discussing this concern, and after checking your vehicle you did find loose bolts. If you private message me with your VIN and current mileage, I can check on your warranty status for you.

Regards,

Laura M.
Cadillac Customer Care

Michael_atDell
07-29-13, 02:42 PM
Laura, I sent you a PM earlier this morning, but haven't heard back. I did speak with a service advisor and was told the dealer does not make a decision on warranty, it's at the discretion of Cadillac. I hope you can respond soon, as I'm sitting in the customer waiting area at the dealer...

Cadillac Cust Svc
07-29-13, 04:24 PM
Laura, I sent you a PM earlier this morning, but haven't heard back. I did speak with a service advisor and was told the dealer does not make a decision on warranty, it's at the discretion of Cadillac. I hope you can respond soon, as I'm sitting in the customer waiting area at the dealer...

Hello Michael_atDell,

I did see your PM earlier this morning. Sorry for the delayed response, but I did send you a message back.

Sincerely,

Laura M.
Cadillac Customer Care

Michael_atDell
07-29-13, 07:36 PM
Dealer quote for $1100!!! Not under warranty...

:banghead:

Pdabs
07-29-13, 08:50 PM
What did they diagnose it as

Michael_atDell
07-29-13, 09:49 PM
What did they diagnose it as

Said the rear joint has broken apart... Not sure what's holding it together... It's actually doing better than when I took it in, but I'm still scared to drive it, especially with my kids...

Michael_atDell
07-30-13, 12:10 PM
Laura, I sent you another PM...

Cadillac Cust Svc
07-30-13, 01:03 PM
Laura, I sent you another PM...

Hey Michael_atDell,

Yes, I received your message and responded back to you!

Laura M.
Cadillac Customer Care

csudhoff
08-08-13, 11:42 AM
Hello csudhoff,

I am sorry to hear your vehicle is experiencing a rear end shutter also. If you private message me, I am more than happy to discuss your concerns and work towards a resolution for this issue.

Regards,

Laura M.
Cadillac Customer Care

Hello Laura M. - PM Sent.