Front Diff Output Shaft Bearings

[P_nlsn]

Hey guys! I've been trying to read up on and research the bearings for the for the front diff output shafts (where the CV's enter the front diff). I can't find much info out there on this for 4th gens, so I'm reaching out in hopes some of you out there have some input

Upfront/Bare question: "Are these bearings bad based on their wiggle room, and do I have the right parts to replace with?"

I was under my 4runner working on my skid plates and did the usual check where I just wiggle stuff while I'm down there. I noticed my CV's had a lot of play where they enter the front diff - see embedded videos

Driver Side
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Passenger Side
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From the few threads I've found, it seems some play in these bearings is usual. On TacomaWorld, user Taco'09 said

With the CV shafts installed and the truck sitting on the ground and the drive line unloaded the RH bearing should have a little play and that would be normal. I believe there is a spec. Contrast that with the LH that may have an alarming amount of play present, even when brand new.

Even though I cant find or measure what play would be in spec, I believe that mine have an excessive amount of play and the bearings need to be replaced

From the diagrams I've looked over, the only parts I should need to replace are:

9036435008 (41331G) - FRONT DIFFERENTIAL DRIVER SIDE INNER BEARING
9036343001 (41304L) - FRONT DIFFERNTIAL PASSENGER SIDE BEARING

And replacing them should consist of the following, I think - please correct me if I'm wrong:

1) Do everything needed to remove CV's
2) Remove CV c-clip
3) Remove CV shaft
4) Remove output bearing c-clip
4.5?) Maybe drain diff here? I assume pulling the bearing will allow the diff oil to leak out and make a mess?
5) Use slide hammer to pull old bearing
6) Press new bearing in
7) Reinstall bearing clip
8) Reinstall CV shaft
9) Reinstall CV c-clip
10) Put everything else back together

Any info regarding anything I mentioned above - the bearings, their play, procedures and parts to replace, etc - would be greatly appreciated

Thanks guys!

 

[montijo505]

Are you having any grinding or other symptoms? Tacoma’s are notorious for having the needle bearing on the driver side get loud and replaced with a solid bushing from ECGS. That being said, I’ve never heard of anyone replacing the passenger side for any reason.

Edit: also watching the videos, the slop you’re seeing is mostly from the cup/cv shaft side. I don’t see much movement on the diff side actually at all. Have you always wiggled them like that to check or was this the first time?

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[P_nlsn]

Are you having any grinding or other symptoms?

It's honestly hard for me to tell what symptoms I'm having - I have a hard time differentiating road noise, old truck noise, and broke noise - and then I have a hard time pin pointing what broke noise is from what too

I get a hum/drone at certain speeds (mainly noticeable around like 50-60mph) - no idea if that could be from these bearings though. Not really any constant grinding though, unless I'm mistaking it for tire/road noise (or I can't hear it over the other noise, but I doubt that)

Tacoma’s are notorious for having the needle bearing on the driver side get loud and replaced with a solid bushing from ECGS. That being said, I’ve never heard of anyone replacing the passenger side for any reason.

Yeah, most of the reading I do is for tacomas, and I get the same thing - no one ever talks about the passenger side for some reason. I don't know if that bushing is compatible with the 4th gen 4runner diff though - it's not listed on ECGS's website as such, but I'd have to call them and ask to be sure

Edit: also watching the videos, the slop you’re seeing is mostly from the cup/cv shaft side. I don’t see much movement on the diff side actually at all. Have you always wiggled them like that to check or was this the first time?

To me it looked like it was almost all diff side wiggle. Cause you can see the shaft that enters the diff wiggles too - meaning there is play in the bearing it sits in. Or maybe it's hard to see it in the video, but I can definitely see it in person

Have you always wiggled them like that to check or was this the first time?

Yes and no. I typically wiggle them like that from time to time, but more on the wheel side by grabbing the shaft. I've just never wiggled the end where it goes in the diff like that

 

[Boxermachine]

My left shaft is leaking even after a new oem seal. Could this be the bearing causing this? thanks in advance

 

[P_nlsn]

My left shaft is leaking even after a new oem seal. Could this be the bearing causing this? thanks in advance

From my understanding, yes, sometimes the play caused from bad bearings can allow the piece to move enough and break the seal, allowing oil to leak. I would try and do as much diagnosing as possible to confirm this, and confirm the seal is seated properly before anything else - I've read there is a very specific seat depth required or they will leak

As Taco85 said on TacomaWorld,

Careful not to drive it [the seal] too far, FSM specifies a depth of 0.189 to 0.229 in. from the lip of the differential tube, mine ended up at .228". These seals are notorious for leaking if you don't set the depth properly

 

[Boxermachine]

From my understanding, yes, sometimes the play caused from bad bearings can allow the piece to move enough and break the seal, allowing oil to leak. I would try and do as much diagnosing as possible to confirm this, and confirm the seal is seated properly - I've read there is a very specific seat depth required or they will leak - but it's definitely possible that the bearing is the case for you since you already replaced seals

As Taco85 said on TacomaWorld,

Thank you, I'm going to try the ECGS bushing, I'll post if it stops the leak.

 

[montijo505]

Thank you, I'm going to try the ECGS bushing, I'll post if it stops the leak.

You probably didn’t seat the seal properly, the best way is to remove CV, remove seal, place seal on CV, insert and seat CV, that should seat the seal at the correct depth. If you inserted the seal on its own it’s likely too far in or at an angle thus causing the leak.


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[montijo505]

The ECGS bearing will work as diffs are interchangeable, just select the correct diff, I believe ours is the 8”.

If the noise goes away when you put it in 4hi then your culprit is the bearing. That’s the main troubleshoot on that one. I suppose if it’s not very expensive and you’re doing it yourself, you can replace those bearings. I’ve personally never heard of anyone doing it and I believe there is some play there on any 4R. I’ll check mine today and report back.


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[emoto]

Is the play in the cv portion?

I have a similar amount of play on my front diff (maybe a wee bit less). Since yours isn't leaking does this mean there isn't too much?

I have a sharp clank noise when I hit something like a large crack in the pavement, which led me to start poking around. The only thing I've found with the kind of movement that could cause this noise it that area coming out of the front diff. If I grab the shaft itself and push/pull, it seems there is too much play inside the CV portion. If this is the case for yours, could that contribute to to the excessive play you are seeing?

2004 v8 with 220k mi.

 

[Boxermachine]

You probably didn’t seat the seal properly, the best way is to remove CV, remove seal, place seal on CV, insert and seat CV, that should seat the seal at the correct depth. If you inserted the seal on its own it’s likely too far in or at an angle thus causing the leak.


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That could be the case, should I get the ecgs bearing anyway? What is a good seal puller for this job? thanks

 

[P_nlsn]

The ECGS bearing will work as diffs are interchangeable, just select the correct diff, I believe ours is the 8”.

If the noise goes away when you put it in 4hi then your culprit is the bearing. That’s the main troubleshoot on that one. I suppose if it’s not very expensive and you’re doing it yourself, you can replace those bearings. I’ve personally never heard of anyone doing it and I believe there is some play there on any 4R. I’ll check mine today and report back.

Ok. The bushing is only listed under the 7.5" IFS Clamshell, and we 4runners have the 8" IFS Clamshell, so I wasn't sure

Oh ok. I haven't heard about that troubleshooting step yet, so I'll definitely try that out. Thanks for the help!

 

[montijo505]

That could be the case, should I get the ecgs bearing anyway? What is a good seal puller for this job? thanks

If you want peace of mind by changing it out it’s up to you. You’ll be doing all the necessary steps anyway, just 1 extra process removing/pressing bearing.

This one:

TOYOTA 8" CLAMSHELL CV AXLE REMOVAL TOOL


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[montijo505]

Ok. The bushing is only listed under the 7.5" IFS Clamshell, and we 4runners have the 8" IFS Clamshell, so I wasn't sure

Oh ok. I haven't heard about that troubleshooting step yet, so I'll definitely try that out. Thanks for the help!

They do, in fact, have one for the 8”

TOYOTA 8" CLAMSHELL CV AXLE BUSHING


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[P_nlsn]

They do, in fact, have one for the 8”

TOYOTA 8" CLAMSHELL CV AXLE BUSHING

Ah, sweet! That's listed under the 8" Clamshell, not the 8" IFS clamshell, so I never saw it - says it fits our 4runners and replaces the correct part number though. Thanks man!

Did your 4runner have a similar amount of play when you checked it?

 

[montijo505]

Ah, sweet! That's listed under the 8" Clamshell, not the 8" IFS clamshell, so I never saw it - says it fits our 4runners and replaces the correct part number though. Thanks man!

Did your 4runner have a similar amount of play when you checked it?

Mine have a little less play but do have some play regardless.


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[P_nlsn]

Mine have a little less play but do have some play regardless.

Alright, thanks man. With the info you've given me, I'm starting to think they might not be as shot as I was thinking. My driver side CV started slingin a little grease not long ago though, so I might just go ahead and do the CV's and bearings too since they are aren't too expensive and I already gotta get in there. I don't know though, with 319k miles, I think it might be good to do them, but with plans to regear in the future, it may be best to wait until then - I'll think about it and let ya'll know what I end up doing. Thanks again for all the help