2wd extended cab propeller shaft question

Propeller shaft question that I have been reading for days without finding anything quite applicable.

I have an 07 Tacoma prerunner SR5 that I just bought after being involved in a wreck that totaled my 04 ford ranger (yes, I know, the tacoma is ten times the truck, but I knew that before I started). In any case, the truck was apparently owned by a little old lady, there is not a single scratch or dent on the radiant red paint. So I have been extremely happy, rides better than ranger (4.0 v6 ranger BTW) gets better gas mileage, you name it. But it has the infamous braking "clunk". I have been studying the service manual to try to understand the two piece driveshaft before I see if I can quieten this down a bit (it has the original 3 leaf springs, but is well out of warranty, and I am among about 700,000 others waiting on the rear spring recall to actually start being done.)

In any case, I noticed several talking about greasing the yoke joint(s) which I assume would probably be just the center joint, which on a 4wd has a zerk. But the 2wd has nothing. So here are my questions, before I start taking things apart (step one is to drop driveshaft probably).

(1) there is apparently a yoke in the center of the shaft with splines that connect the two shaft halves together. Looks like the front half of the drive shaft is male, the rear half is female. Is there any slippage possible in this joint? I ask because taking it apart to grease the splines is a bit of a royal pain, since the u-joint has to be removed to expose the nut that allows the rear yoke to disengage. If there is some slippage possible at this joint, I had planned on unbolting the driveshaft from the differential flange, and then perhaps pulling it rearward, greasing the splines if I can see them, then sliding it back up, and repeating to work some good synthetic/moly grease into the splined interface. But I can not tell by looking at the service manual pics whether there is any slippage/play there or whether the nut (which is torqued pretty stoutly) actually locks the male/female splined shafts together. Logically I believe there must be some slippage possible here as I can't imagine the entire drive-shaft slipping forward due to the usual axle-wrap that seems common.

(2) removing the whole thing seems easy enough (I have done everything from rebuild motors, transmissions and rear-ends so this is not exactly frightening to me) but I can't imagine the front yoke being the source of the "thump" since it would seem to me that the front splines are going to be flooded with trans fluid anyway since they are north of the rear transmission yoke seal. So question 2 is, which of the two splined yokes is suspected as being the source of the infamous "thunk"? (my symptom is that I stop at a light or whatever, and whether it be gently or fairly abruptly doesn't seem to matter. When I release the brake, about 1/2 of the time I hear the thump. Does seem to be worse on an abrupt stop, but that seems to be relatively normal based on all the threads on this problem here.

(3) if it is the rear yoke, is it possible to get grease onto the splines with out removing the u-joints or is that where I have to start?

Any suggestions, or even a link to an appropriate 2wd thump thread would be appreciated. It seems like I have read literally hundreds of posts, but most say "grease it" but us poor 2wd folks are zerkless. If we were only thumpless as well.

Any help would be greatly appreciated.

 

I believe what you are describing is the axle wrap these trucks have. The crap rear springs flex while breaking and when you hit the gas they unload. I have real a traction bar would fix the problem. I just ignore it on my 07 AC

 

I'm certain that is the issue. I'm trying to figure out just what is needed to lube the slip joint and if the center section actually slips (which I assume it does but can not tell as of yet).

 

You didn't say how many miles are on your truck?
I wouldn't worry about the slip-joint (the center section slips inside the tailshaft of the tranny)
I believe what you read about was referencing u-joints as yours are nongreasable.


As far as axle wrap, first thing to check is how tight are the u-bolts are,, it's been well documented on TW that toyota doesn't torque them to the right number, (usually only half tight).

Any other questions feel free, TW is here to help.

 

Miles = 104,000 yet it runs and looks like new. I hit the 8 nuts with my torque wrench yesterday. They were probably around 30 ft/lb or so. I took 'em to 73 as I had seen in other threads. Been so damned messy I have not been out since the torque wrench but will later today.

Back to my question, Does that center joint slip? The service manual shows a male splined shaft on the rear of the front propeller shaft half (why can't they call the damned thing a drive shaft? I have been removing drive shafts for 50 years now) that mates with a female splined yoke on the back half of the prop shaft. And they show a large nut that screws on the end of the male splined shaft, I assume to keep it from slipping too far and separating since there is another slip joint at the tranny tail shaft. If that center joint really does shift, and if the re-torque of the spring u-bolts didn't stop the thump, I'm going to grease the thing regardless of whether I have to remove the u-joint to get to that large nut or not. (I suppose my wife would say that a larger nut is trying to remove a smaller large nut here if she saw this.) I am certain this is the issue as I stopped in my driveway yesterday, not violently, just normally, and I sat there for a couple of minutes with my foot on the brake. When I let off, thump.

In any case, one last note. If you look at the extended cab service manual parts, there appear to be two slip joints. One at the front that engages the tranny output shaft, the other in the middle to join the two halves of the driveshaft. I just can't tell if the center section slips, but I can't imagine it being reasonable to transfer all of that motion forward and backward through the carrier bearing and all the way to the front.

And maybe one day I will actually get new rear springs when Toyota ever gets their crap in one sack and gets the recall moving. Just talked with them Thursday at the 1-800 number. No dates are available yet. Standard company party line.

 

If I'm thinking about the same nut that you are, it should be right next to the carrier bearing, if it's that one,, that holds the yoke on the front shaft (the one you would remove to change the CB) that is not a slip-joint. The slip-joint should be aft of that and right before the drvshft changes diameter.

At 104k, I would be focusing on u-joints not slip-joints, as they have never been greased.

Park your truck on level ground and chock the wheels, with the truck NOT running put it in neutral and crawl under it and grab the drvshft an twist it back and forth, this should help you identify where the noise is coming from.

I'm betting on u-joints as slip-joints rarely go bad or get sloppy.

 

U-joints are fine. Zero slop. This seems to be an axle-wrap unloading into the slip joint somewhere. I'm going to take a careful look later today, we finally have this bright orange ball up in the sky rather than liquid falling constantly.