Cadillac Owners Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
68 Posts
Discussion Starter #1
I tried a search and didn't find much.

Car has been great, I have 145K on it so far.... I have dropped it with FE4's from a V (with springs), and I swapped rear diff fluid with 75W140 RP.

It began making a groaning noise starting about 45MPH. It hasn't really gotten much worse, but I thought it might be tires, so I put new tires on. No change. It isn't a whine, and it doesn't sound like gears. It is constant and goes up and down with speed. Does it regardless of acceleration, and it is there with the car off the ground.

I didn't add any friction modifiers to the new oil, and I have read that the clutches may be chattering? I didn't think this thing had a limited slip rear end, so I may have just been reading about a V. With it in the air, you can hold one tire still with your pinkie and the other spins.

The sounds really seems to be coming from the hub bearings off the ground, but it is louder in the car than outside. I couldn't get close to the driveshaft, but it really sounds like a hub bearing, and they are cheap enough.

Any thoughts? Sorry for the long post, but I wanted to be thorough.

Thanks
 

·
Registered
Joined
·
324 Posts
With the rear tires off of the ground, grab one and try to shake it around.... if it is moving around, look at the rotor and see if it is moving with the tire... If so, the hub bearing is worn. You can also watch the rim and tire as you jack it up..... if the wheel kinda "falls in" as soon as it gets off the ground, that is another sign. Best thing to do to check for a LSD is to pull the spare tire cover up and look at the RPO label on the underside of it. Look for G80... if that is printed there, then you have a factory LSD, in which case, you'd want to add the friction modifier to diff. Failure to do so when changing diff fluid on an LSD wil cause chatter while turning and eventually failure.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #3 (Edited)
I tried shaking it off the dround, and there is no play in any direction. I will check the RPO label to see if I have an LSD. pretty sure it isn't because it has never locked up before. I have been stuck several times in the snow because of the TCS. even with it off, it only spun one tire.

Yup, just checked, GU6. regular 3.42 ratio.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #5
Well, it isn't getting any worse, but I really can't pinpoint it. I guess I will just run it until something roars. Thought someone may have had a problem with the rear, but I guess I am unique.

It sounds like I have really bad tread on the rear tires and I will post if anything ever fails... just not sure where to go from here..
 
1 - 5 of 5 Posts
Top