Differential lash, help needed!

I've been trying to figure out why my truck jerks and clunks on takeoff, while shifting gears, and when getting on and off the gas. It's quite annoying and makes it a total bitch to drive, especially trying to drive slow, like in a parking lot at the store. I've done some poking around and have figured out that it's excessive lash (or play) in my rear diff. It's not axle wrap, the rear leafs are fine. With the truck parked and the tranny in neutral, you can rotate the drive shaft about a 1/4 turn. The clunk and jerk is the gearing moving through the slop and then all of the sudden it finally all makes contact and gets the wheels turning. Of course when you let off the gas everything gets rotated by force of the wheels, instead of from the drive shaft, thus taking up the play in the opposite direction, and setting up for another clunk and jerk when I hit the gas again.
From when I have read, there is a way to adjust the amount of play in the gearing, I'm just not sure what all is involved, other than taking apart the axle and removing the 3rd member. This is also assuming that my gears aren't trashed. Anybody have any suggestions or info on adjusting a rear end?

 

Well some say its a piece of cake, others sound like a bitch, I think its somewhere in between.... I've never done it but I know you'll need a gauge for setting the lash & preload of the pinion too IIRC

I guess if you have the right tools to do it, & some skills its doable I'm going to have to do my pinion bearing sometime ...

 

The pinion nut isn't loose is it, the GM's that I have worked with have a crush sleeve to set the pre load on the pinion brg, is there a chance that Toyota has a crush sleeve and thats part of the problem?

The only time that I had to mess with the pre load on the pinion was when the pinion seal was replaced.

 

Adjusting the gearing is not to be taken lightly....... it's a critical adjustment and should be done by a professional to get it done right.

If your gears are worn - they are worn. Nothing you can do (or should do) to make them any better. If you make an adjustment to 'tighten' things up - you will only put pressure on the gear teeth that are already THIN from wear. The last thing you want...is to break a tooth (or teeth) and grenade the entire differential.

If you are that worried about it....pull the 3rd member and have someone look at it. Or, you could pay $$$ to have new gears put in. OR simply adjust your driving habits.....

My 96 tacoma had the same 1/4" rotation at the driveshaft when you spin it by hand. I simply changed the way I clutched & gassed.

 

Janster is giving you accurate advice. A properly set up diff will only get slop from wear or damage. Have it inspected/measured to verify.

 

So I went through and greased everything on the drive shaft, the rear slip joint took quite a bit. The clunk is now almost gone, and the jerking on takeoff is much better. I think that may have been the majority of the issue. I'm thinking maybe the rear end is a little worn, but it's not as bad as I originally thought. I'm gonna just roll with it until it goes out, or until I get bigger tires, and then just get both diffs re geared. Good news is, I now know that my U joints are ok. I also found a video on how to re gear and set up a diff, it's not that complicated if you have the time and the tools. I think I will take it in to a shop though, as I have little free time, and none of the required tools. Here's a link to the video if any of you are interested, even if you don't have the tools, it's good to know what the process involves.

http://www.youtube.com/watch?v=dAqAqODmcj4

 

Yes, our diffs come with crush sleeves on the pinions.

 

Its not something you normally adjust, if it is out of spec its going to need more than a lash adj..

What your describing is a common issue, in some cases it has a lot to do with the wimpy leaf springs allowing the axle to twist, lots of things under there that can cause that noise and feeling.

Leaf spring U-bolts loose, bad carrier bearing, bad or worn U-joints, these are a few places to start checking..

 

Problem solved, and actually it's no problem at all, just driver ignorance Apparently, the previous owner installed a powertrax lockright in the rear diff. Reading a few online reviews it seems the issues I'm having are all related to the way I drive, and the way the locker works. So I just have to learn how to drive with it. Here's a link to a review that describes exactly what I've been experiencing, and also explains why I have excessive lash in the drive shaft, apparently the lockright has a bit of extra lash.

http://www.4x4wire.com/reviews/no-slip/review/?