Need help guys...ckunk sound when coming to a stop

[Archtoker420]

If I'm reading those codes correctly, it's a 3.73 ratio, posi locker

View attachment 211689

Then i guess i already have 3.73, whats wierd is when I look up rear ends all the rwd say 3.42 and the 3.73 all say 4wd only, mines not 4wd. Can i put a 4wd rear end on mine and be ok? Cause it should only matter if i had a front differential, right? Is there anything different on a 4wd rear end than a reg. rwd rear end?

 

[swathdiver]

And he told me 7 1/2 hours labor to do it. That doesnt sound right to me. A rear end replacement shoukdnt take that ling right?

My shop manual says 4.2 hours labor to swap the differentials out, not rebuild them. Plenty of these older 2WD trucks came with 3.73s and even 4.10 gears in certain circumstances.

You could buy a new or used center chunk with new or used gears and pay a local guy anywhere from $150-400 to install and set the teeth. Bunch of guys did that this year on this forum.

 

[Archtoker420]

My shop manual says 4.2 hours labor to swap the differentials out, not rebuild them. Plenty of these older 2WD trucks came with 3.73s and even 4.10 gears in certain circumstances.

You could buy a new or used center chunk with new or used gears and pay a local guy anywhere from $150-400 to install and set the teeth. Bunch of guys did that this year on this forum.

See that makes more sense to me. 7.5 hours seemed like too much for unbolting some things and dropping it then rebolting everything back with new. I think i could do the job with my limited exp. Now rebuilding one myself is still a little out of my league. Itd be diff if this wasnt my only vehicle lol.

 

[steve45]

Sounds like dry splines on the driveshaft where it goes into the transmission. When the brakes are applied, the axle torques up and pulls the driveshaft out a little bit. You can verify that this is your problem by shifting into neutral before coming to a stop. If the problem goes away, you have dry splines. My '97 Tahoe got to the point where it had to be greased 2 or 3 times a year. GM makes a special grease for this (about $50 per can!).

I quickly tired of pulling the driveshaft out to do this, so I drilled a small hole in the driveshaft yoke so I could just squirt grease in with a needle-style grease gun. I drilled the hole where it would normally be away from the seal.

 

[Archtoker420]

Ok guys new problem. Keeps getting worse. When ever i come to a complete stop and then go to take off s9metimes i get a horrible vibration like the back end is bouncing and my truck acts like it doesnt want to go. So i parked it for a couple days, then drove it. When i stop and go it doesnt shake but it acts like the rear tires dont wanna go, like the brakes are half appplyed. The motor revs up like normal but it doesnt take off like normal. Could this be rear end issue or drums sticking. Had brakes all redone like a year ago

 

[steve45]

Did you even bother to do the dry spline test?

 

[Archtoker420]

Did you even bother to do the dry spline test?

Not yet. I just got home and its already dark out. And coming to a stop its fine besides the occasional clunk. Its when i take off from a stop that it acts up. But i took tomorrow off work to go to a rear end shop, so ill check the dry spline while im driving tomorrow

 

[Tonyrodz]

Ok guys new problem. Keeps getting worse. When ever i come to a complete stop and then go to take off s9metimes i get a horrible vibration like the back end is bouncing and my truck acts like it doesnt want to go. So i parked it for a couple days, then drove it. When i stop and go it doesnt shake but it acts like the rear tires dont wanna go, like the brakes are half appplyed. The motor revs up like normal but it doesnt take off like normal. Could this be rear end issue or drums sticking. Had brakes all redone like a year ago

Had a similar issue with my Formula years ago. Got rearended and the rear got tweaked a little. Diff fluid was slowly leaking out. It ran dry, hummed like crazy. Ring and pinion were toast. It was doing exactly what you described, felt like the brakes were appkied, and the rear wheels were kind of "skipping" when taking off from a dead stop. Do you have any humming?

 

[Archtoker420]

Had a similar issue with my Formula years ago. Got rearended and the rear got tweaked a little. Diff fluid was slowly leaking out. It ran dry, hummed like crazy. Ring and pinion were toast. It was doing exactly what you described, felt like the brakes were appkied, and the rear wheels were kind of "skipping" when taking off from a dead stop. Do you have any humming?

No thats what i thought was wierd. No humming or any noises that ive noticed. Just the feeling of like you said the tires skipping which quit afyer not driving a few days, but it still takes off like the back tires are bogged down. And no fluid seems to be leaking out. Im kinda stuck thinking maybe the rear brakes are getting stuck or the rear end is going out. I dont trust the first shop i stopped at cause all he did was slide under the truck and wigfle the drive shaft, he didnt even get in the truck and exp the problem himself.

 

[bigfootchiro]

Cant catch a break

Can’t catch a break cuz it may not be the brakes sorry, I had to...

Anyways, if you’re sticking with stock height tires, and do mostly highway driving, you can get away with 3.42 gears; however, 3.73s are a good middle ground. You may not know your rear diff is gone. Sometimes they don’t throw you a sign. I was driving home to WA state from Utah in my 1999 Cummins with 648HP. Had two people pull up alongside me to say something was wrong. Pulled over, and sure enough, I shot a gear bolt out the pan and fluid leaked everywhere. Still was running smooth! Took it apart, and literally only 2 bolts were holding the gear together, and I took them out with my fingers. All the others had exploded and gone everywhere inside the pan.

So, do the dry spline test like the other guy said. Then, drain your diff fluid (save it if it’s new), then inspect the spider gear and ring bolts. You can use brake cleaners to clean the inside so you can see everything better. Make sure you give it ample time to dry before you put it back together. Oh, and don’t use RVT sealant, only use the paper gasket.