Drivetrain Play

Howdy,
07 OR access 159K 4.0, single piece drive shaft. I have what feels to me to be too much play in the drivetrain. It has not always been this way and has gotten worse over time. As an example when I put the truck in park it can be rolled back and forth quite a bit. If parked on a hill and I put the truck in R or D there is a loud metallic clank. It's so concerning that I now throw on the E brake and let the truck roll in whatever direction, forward or backward, based on conditions before putting it in park. This is not a bad idea anyway but it's not normal IMO. I got under there and all the u joints are good but the play seems to be in the transfer case or transmission as if a backlash adjustment is off. I know very little about drivetrains when it comes TCs or transmissions so I'm curious if a backlash adjustment in there is even possible. let me know what you think I'm dealing with here

 

Bump

 

Interested to hear legitimate replies as well.

 

monday bump day

 

It's possible you have excess parking pawl wear.

When you are using the ebrake to hold the load, do you still have the clank when shifting from park to D or R? If not, that's another indicator of pawl wear.

Pawl wear is avoidable if the ebrake is used to hold the vehicle weight, as opposed to having the pawl do it.

If using the ebrake solves your issue, I'd keep doing that before digging into the trans.

Our friend @gearcruncher might have some other thoughts for you too.

(generic image)

 

When I do use the e-brake to hold the weight of the vehicle I do not hear the clunk so I think that may be part of it. To further expand on what I am experiencing at times it almost feel like excessive axle wrap. Here's an example: driving at 30mph and I slow the vehicle for some reason. when I go to accelerate back up to 30mph there is a brief second of hesitation before it feels like the transmission catches or grabs. I'm positive all Ujoints are in good condition but I'm gonna get under there this afternoon and makes sure they are all lubed well.
Additionally, sometimes when stopped at a light there is a bit of vibration. this goes away when shifting in neutral.

 

When those parking pawl lobes break off , they usually fall into the transmission pan but they will cause the truck to roll ahead a bunch before it holds in park . Have you serviced your transmission lately ?
No backlash adjustments inside the transmission or the transfer case . Its all done with end play shims . All gearing is constant mesh in both the trans as well as the transfer case .

It doesnt take much free movement to create a metal to metal clanking sound .
Driveshaft Yokes inner female splines are soft . They are designed to wear rather than the solid male shaft that drivers them .
I would be jacking up the back end of the truck and checking the driveshaft splines on the yokes .
If the splines are good , add some slip yoke lube before you put the driveshaft back on . Dont use grease as it just wipes away .
Spicer pretty much has the contract for all driveshafts made in North America including our Toyota trucks
http://www.lowrangeoffroad.com/ptfe...-ford-motorcraft-xg-8-ml1167-31508-42027.html

While you have the truck jacked up in the rear , grab the rear diff yoke and see how much play your rear differential has .
Backlash play when cold should be .0008 thousandths of an inch

 

I have changed the fluid on the transmission within the last 5K miles. The was no shards or large flakes of metal. I have a one piece drive shaft made locally about a year ago due to vibrations caused by a mild lift . When I move the driveshaft while in park there is little to no play in the slip joint so I think that's OK. I have been using regular Mobil1 grease in there so i will grab some slip joint specific grease.
New observation: there is significant play in the rear diff yoke. I don't currently have a dial indicator but it has to be more then .0008 of an inch
https://youtu.be/llcIC2oUXzU

first time posting a video so let me know if you can see that

 

Great video .
I think that play in your rear diff is a serious contributor to your clanking sound .Also very very common for your complaint
Looks as if you have no preload on the pinion bearing . You can check that with an inch pound torque wrench by removing the rear of the driveshaft and connecting the inch pound torque wrench to that big nut on the diff .
I cant remember what the preoad is but yours is way too loose .
Might be time to grab some fresh bearings or if you are considering lower gearing , it may also be time .
You can get some good deals from Marlin Crawler . Thinking 400 bucks should fix you up

 

You can find your rear differential specifications here
http://www.customtacos.com/tech.old/files/05FSM/repair.html

 

I've got the exact same symptom with my truck, 06 6MT with 268k. Diff fluid was pretty clean when I drained it about 3k ago, but it was only about 15k old. (had the extra gear oil) If it is the pinion bearings, is it worth it to undertake replacing those as opposed to getting a much younger replacement or an upgrade axle as a whole? If I'm pulling the third, I'll also want to do the rear wheel bearings.

EDIT: I'm not opposed to doing the job, but say I do, aside from the appropriate torque wrenches, are there any other special tools necessary?

 

Yes , bearing pullers are required for the 3rd member as well as your axle bearings .
https://www.tacomaworld.com/threads/gears-and-lockers-bs-thread.326238/page-2

 

Setting axle gears should be left to professionals is my understanding. I always take mine to reputable shops that offer a warranty. Anything else on a vehicle I will tackle myself.

 

dunno, that doesn't look that bad to me and its certainly not going to cause an issue anytime soon. I've seen waaaay worse and they've run for years with no issues. It doesn't appear to be a pinion bearing preload issue but just excessive backlash in the ring and pinion due to wear from use. If the pinion gear moves axially then yes there's an issue with preload. So check for axial movement.
You can live with it or spend a lot of $ to fix it. I've set up ring and pinions...

Edit- when you do the check in your video you need to have the parking brake set to help focus on the R&P

 

When I looked into buying the tools to setup a diff it was cheaper just to get the third member from east coast gear supply. Plus they have a 5 year warranty

 

Keep in mind that with that simple test you're checking the R&P backlash and also the play in the axle splines- they're adding together, so it's not just the R&P backlash. Some manufacturers have a maximum specification for that check and will say something like 12 mm yoke movement is the maximum limit.

Yes, the proper installation tools are expensive so I definitely don't recommend setting one up yourself.

 

In years past , I have probably installed well over 500 rear diffs on Toyota trucks . This issue was much more noticeable in the Forunners and actually lined my pockets for many years . The most common problem in 99% of these trucks was a loss of pinion bearing preload which in turn over time takes out the pinion bearing creating serious backlash issues . I suppose I might say I am pointing at the root cause rather than the end result
I am not basing my opinion on the one vehicle presented in the video , but using past experience of hundreds of common pattern failures to form a suitable answer .
The procedure for measuring preload is ofcourse with the axles removed .
http://www.customtacos.com/tech.old.../06toyrm/06toypdf/06rmsrc/rm2006ta/037004.pdf
Yes , the truck may still function for years like this .

 

Hey man sorry for the thread jack, but I can just buy re geared third members, install them, and send my old ones back for a cor charge right?

 

Yes.

Or you can send yours in and wait for them to regear it and send it back if you don’t want the core charge