Rear end noises

[Matt Dumas]

I just bought my 96 GTS from Herb Chambers of Boston on wednesday .After 1 hour of driving the car developed a slight grinding sound in the rear when coming from 25 MPH down to a stop. Today was the first day I have had time to diagnose the problem. After approx. 45 min. of driving , the rear end makes this grinding noise.The rear end also makes a whining noise above 40MPH .I put the car on a lift,started the car, & duplicated the situations in which I heard these noises. Sure enough, by putting a metal rod from the rear end to my ear,I could clearly here these noises. I also did the same to the tail shaft of the transmission,just to rule that out. I called the dealer, & he said Vipers tend to make some rear end noise, but he would let one of his Viper techs check it out.He also said that the car only comes with a 90 day warranty & this item may not be covered.My question is ,does anyone have these noises in their Vipers? Has anyone replaced gears or bearings themseves?
I am in need of all the info I can get!
Thanks alot!!!!

 

[Geoff Green]

Matt, I wonder if the dealer changed the rear end fluid and did not add the limited slip additive. Do you notice the noise going around a corner? This has happened on numerous occassions when the fluid was changed and the additive was not added.

Also, check to see if the fluid is up to the bottom of the fill hole on the rear end.

 

[JimDavis MT 97GTS 650R]

Hi Matt. Geoff has some good suggestions. You definitely need the friction modifier added when changing the rear end fluid. Not all shops remember to put it in. As for the whining & clunking, for some reason, Chrysler chose to have a exceptionally large gear backlash. My friends GTS was about .13. He had the gears re-shimmed to about .06 and it really smoothed & quieted the rear end down. I plan to do the same to mine this winter. Hope this helps. (JD)

 

[Matt Dumas]

Rear end fluid is full.Car doesent make and chattering noises.Noise doesn't change by going around corners. Its definitely a bearing noise.

 

[Wing King]

When you had the car on the lift, did you rotate the driveline and wheels to do a quick check to see if the gear ratio has been changed? PROPERLY set up rear gears do NOT whine or make noise for the stock 3.07, OR 3.45, 3.54, 3.55, and 3.73 ratios.

The fact you're getting a "grind" after running a bit COULD indicate the absence or shortage of friction modifier additive, but that's generally more recognized when cornering. It's worth a check, particularly if the fluid HAS been serviced recently, but I'm more suspicious of the gear set up if it's ever been changed, or a bearing or side gear problem if not. A Viper tech or good mechanic with the right tools is a MUST for you. Sorry.... no easy answer here.

 

[Y2K5SRT]

It isn't a matter of the rear end fluid being full, but whether or not the limited slip additive was put in if they changed the rear fluid. I did not have the additive in mine after a dealership added a drain plug, but it was full. I got a grinding noise, especially on turns. It started when the car was warmed up - not cold. After changing the fluid again WITH the additive put in, the sound disappeared entirely. Good call Geoff!

 

[Matt Dumas]

Where would I get this additive?(a dodge dealer,I presume?)Have you guys had noises in your vipers coming from the rear end or are they quiet?I consider my self A pretty good mechanic.I have owned & operated a reputable garage for 12 years. It really sounds like a bearing ,though. The rearend assembly looks fairly easy to remove. Once it is out ,I have a good freind who can help me relace bearings & setup the gears.Where can I get a shop manual for this car? None of the local parts stores have them.

Thanks again for all the replies!

 

[Ron]

<FONT face="Comic Sans MS">Matt,

You can get your manual from:

www.techauthority.com

Since 1996 is a transition year (RT's had a GEN I engine and GTS's had a GEN II), you might want to go with the 1997 manual instead. Virtually no differance in the cars, but a more accurate manual. $90.00 and well worth it.

By the way my stock 3.07 rear is silent, straight and around corners.

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