Rear end issue??

[TulsaSpider]

Hi guys. I was trying to track down a "tinny" popping noise (hard to describe) that has appeared lately. It only happens under initial acceleration and if I take off slowly it doesn't seem to happen. It seemed to happen this morning when I started the car, but I couldn't duplicate it and I was half asleep... Anyway.. after work I got under the car to try to duplicate the noise. I thought maybe it was my muffler or something because that is loose. I found one issue and fixed it. There was a bolt missing on one of the lower control arms. So I thought that was it. Well I took it for a test drive and it was still there. It might have been a bit better but I didn't drive it much. My next thought is U joints so I put it in neutral and checked for play. There didn't seem to be any play in the U joints, however I wanted to check with you guys about the amount of play there should be in the rear end. With the car in neutral taking the driveshaft in my hands (insert joke here) and turning it there seems to be about an inch of play in it, maybe less, it's hard to tell. So my question is is this normal?
Thanks
Clark

[racydave]

Its common for rear differentials to have some play in them. While you are down there, check very carefully, and very closely the rubber flex disc. Its a #1 safety check on the driveline.

[SpiderHead]

Tulsa,

That doesn't seem right to me, but a worn/failling differential makes a ton of noise. You would be able to hear it if that was all sloppy gear play.

to be clear, you are talking about one inch of play on the drive shaft right? beccause those things are only about 9-10 inches in circumference.. you are talking like 10%

perhaps it is not worn gears, but something else bedeviling you.

Someone who has had more than one of these apart (meaning me) should be on soon, and sort this for ya.

-Ryan

edit: as for the noise.. check your short and long trailing arms. You have 4. one may be cracked, or even broken. while back there, check your panhard rod as well. that is the one that runs side to side (that won't be your problem, but while you check the other 4, its easy to do...)

[TulsaSpider]

Checked the rubber doughnut while I was down there, it looks kosher. Yea I am a wee bit anxious right about now I hope it's nothing. If it's the diff isn't it likely to make noise all the time? I noticed that when I was turning the driveshaft with my hands the rear end would flex upward a bit just with the small amount of pressure I was applying with my hands/arms. I'll inspect more today after work.

[TulsaSpider]

I got a heads up about the drive shaft support bearing rubber that may be deteriorated, letting the shaft flex enough to contact the E-brake cable. I'll have to get under it again tomorrow, had to work late today, if this is the case how hard a job is it to replace?

[majicwrench]

If you are not familiar with rear ends, it will indeed seem like the driveline has a lot of "slack" in reality, this is usually normal.
U-joints, just cause they are tight does not mean they are good. Most noisy u-joints are rusting/seizing, and will not be loose till, as Mark noted, later on in the process of self-destruction. Do look around the rubber seals for signs of rust.
And certainly wheels and tires can make noises, try loosening and retorqing lug nuts.
Keith

[pope]

Make sure that its it first, cause removing the bearing is a medium pain in the ass job. Make sure that there is a big tear in the rubber support first and look for signs of rubbing on the brake cables. Hard part is removing the drive shaft from under the car. Everything else can be done on a bench. You'll need a puller and a new u-joint and rubber support with a new bearing already installed. You can buy the rubber support separate, but its not worth it when you can get it with the bearing installed already for about $50. Several hour job.

Make sure thats what it is first.

[TulsaSpider]

Medium pain in the ass eh? Well thanks for the info! I will certainly check it out and make certain that's it before I dive into that. What kind of puller are you referring to Pope?

[pope]

You will use it on two parts. Auto parts stores usually rent them for free with small deposit.

[SpiderHead]

and at the same time a 3 prong puller from an auto parts store is pretty cheap... 20-25 dollar range. Just buy you one.

-Ryan

[TulsaSpider]

Ah a gear puller! Gotcha! Thanks!
Buy one instead of free? That's just unnatural for a Scot!

[So Cal Mark]

you could borrow it, then forget to return it. Sort of like an old library book

[TulsaSpider]

Yea but they borrow your deposit as well! I got under her again and the rubber as far as I could tell looked ok on the center bearing, but when I used a light I could tell that there was fresh red powder all around the rear U joint so I'll bet that's the culprit, well I'll change it out and see. Looks like I get to do double duty tomorrow, rear caliper and new U joints! It will be nasty this weekend.

[pope]

What is the FRESH red powder?

[TulsaSpider]

The powder is a sign of the U joint grinding itself away.