Question about u-joints and a strange noise

[d0n_3d]

Whenever I put my car into gear from a stop, I always hear a loud CLANK sound. This has done it since day 1 of me owning the car. I always ignored it until now. I am about ready to install a driveshaft loop and figured maybe my u-joints need to be replaced? I want to do it anyways because the car has 85k miles on it and I am starting to race it now. What are the best u-joints to buy and where from? Does it really matter where I get them? What else could be causing that sound???

 

[timothydog]

I have the same problem.
I hear a pretty good "clank" when I throw it into gear.

Any input is appreciated.

 

[Renthorin]

Same here

My GN only has 26k on it but when I go from rev to D or N to D I hear the familiar clunk.

I have been told not to worry but if there is something wrong...well...I must know.

TIA

 

[6pack]

Most likely u-joints

Worst case scenerio is ring and pinion. Spicer are a well known u joint. Not sure of anymore. Call your local parts house and see what they carry.

 

[Carolinaturbot6]

http://www.turbobuicks.com/ubb/Forum1/HTML/002349.html

Ahh yes, the infamous clunking sound...see the link above.

Yes, it is annoying, but very common. Steve gives a good explanation of it above. I replaced my u-joints last summer thinking that would surely fix it...didn't work. I've since learned from others that u-joints rarely need replacing. Hell, the ones I pulled off of mine looked just fine...with 152k on them. HTH

 

[timothydog]

Here's a thought if it IS the pinion and ring gears...
Could changing the differential fluid possibly deaden the clank a little?

Just brainstorming.

 

[Ormand]

Clank....

Here's another possible cause. In the posi rear-end, the backlash between the side gears and the spider gears is set by the posi clutches. When the rear gets "worn" the clutches get thinner, and there is more backlash in the differential, not necessarily between ring and pinion. Here's how to check. Get both rear wheels up off the ground. Stick a screwdriver down through the vent on the rear, and it will "lock" the ring gear. Now try to turn the drive shaft. If there's slack, the slop is between the pinion and the ring gear, and you found the problem. If there's no slack try to turn one wheel. If the wheel will turn a little, that slack is due to excessive backlash between the side gears and spider gears. Replace clutches, much easier than replacing a ring/pinion, and it will make the posi work better. (I've only done this once, on another car with an 8-1/2" GM axle. The "preload" springs actually push th side gears away from the spider gears.) Clutch pack is relatively cheap, less than $100, I think. But it sure is a messy, smelly job!!

 

[Jimn8or]

Like you, my car did this since I purchased it. Did the u-joint thing and learned to live with it...started to hear a little howling now and again around corners last week. Brought it to a Turbo Buick fluent shop. The carrier bearings were so shot that it allowed too much load, for too long [remember me living with the noise?] and wrote off the ring and pinion gears as well. [.006 - .010 clearance parameters...mine was more than 10 times amount re backlash] Throw in a carrier stud kit and T/A Perf rear girdle and I have no clunk, no howling and no $$$ either...$1100 this week and she's good to go.
Jim

 

[85_SS]

My SS also does this - I have checked the U-joints and they look fine. The sound was also there with the TH350 trans and the current 200-4R trans, so I doubt its that and must be the rear as you guys have said. I guess I have learned to live with it (although it is annoying) until I rebuilt the rear and maybe install a POSI FWIW, my parent's '87 Cutlass (almost 200,000km) has just recently started doing this too...