Front leak - Toyota 4Runner Forum

carlodonz · 09-10-2021, 11:29 PM

Hi all,

I was just doing some maintenance while looking under the truck when I noticed a dark are on the front skid and after closed inspection I believe I found the source of the leak, see attachment.

This is happening on the front passenger, the driver side looks fine. Can anyone help me identify what could cause this and which is the part leaking?

Thanks!

02SE · 09-11-2021, 01:19 AM

Make sure the front differential vent is venting. Otherwise as the gear oil heats up, pressure builds, and seals leak. It could also be the seal is leaking, even with the vent not plugged. It's a relatively easy seal to replace for a mechanic or skilled DIYer.

MyanRagahis · 09-11-2021, 03:57 AM

Should be this one. It'll be your front diff fluid leaking past the seal.

Had the same dripping experience a month or so later after I swapped my driver axle a year ago. Guess I damaged the seal putting the new one in. Had a shop change both seals for me since I needed other work at the time. No more leaking since.
Yours may just be wear and tear. All part of the maintenance.

carlodonz · 09-11-2021, 09:08 AM

Quote:

Originally Posted by 02SE

Make sure the front differential vent is venting. Otherwise as the gear oil heats up, pressure builds, and seals leak. It could also be the seal is leaking, even with the vent not plugged. It's a relatively easy seal to replace for a mechanic or skilled DIYer.

Thank you! Can you point out where I can find the front diff vent?

carlodonz · 09-11-2021, 09:11 AM

Quote:

Originally Posted by MyanRagahis

Should be this one. It'll be your front diff fluid leaking past the seal.

Had the same dripping experience a month or so later after I swapped my driver axle a year ago. Guess I damaged the seal putting the new one in. Had a shop change both seals for me since I needed other work at the time. No more leaking since.
Yours may just be wear and tear. All part of the maintenance.

Thanks this helps. Do you remember approximately how much they charged for replacing both seals?

DougR · 09-11-2021, 12:13 PM

Quote:

Originally Posted by carlodonz

Thank you! Can you point out where I can find the front diff vent?

Vent tube bolts to the top of the front differential carrier assembly. The tube terminates with a vent as shown in this image. Go to YouTube and search "clean check differential breather Toyota". Front differential breather check or clean is similar to servicing a rear differential breather.

MyanRagahis · 09-12-2021, 04:35 PM

Quote:

Originally Posted by carlodonz

Thanks this helps. Do you remember approximately how much they charged for replacing both seals?

I don't, sorry. Majority of the work was to weld on the total chaos alignment tab gussets. The shop had to remove the LCAs and axles anyway so while I bought the seals on my own, I just had them swap it out.

DougR · 09-14-2021, 11:40 AM

I suspect the seal should be replaced because only one side is leaking. If that doesn't fix it, then replace the breather plug per this TSB for 2010-2015 4Runners. (However, I would try cleaning it first.)

https://static.nhtsa.gov/odi/tsbs/20...42475-9999.pdf

Hammer0313 · 09-14-2021, 01:07 PM

Can someone provide the part numbers for the front diff breather vent/tube and the axle seals? Please!

DougR · 09-14-2021, 01:51 PM

Quote:

Originally Posted by Hammer0313

Can someone provide the part numbers for the front diff breather vent/tube and the axle seals? Please!

Seal part numbers are "LH Front Axle Seal P# 90311-47027 or P# 90311-47013 for RH Seal" as published here in this DIY 5th Gen 2010-2018 Front Axle Seal DIY

A search for "front differential breather tube", "breather" or "differential breather vent" doesn't yield anything for my 2011 Trail on the Camelback Toyota website.

Toyota 4Runner Plug, breather (for front differential) - 9093003136 - Genuine Toyota Part shows a breather and tube assemblies. I found it using this Google search "2011 4Runner front differential breather vent".

Hammer0313 · 09-15-2021, 08:54 AM

Quote:

Originally Posted by DougR

Seal part numbers are "LH Front Axle Seal P# 90311-47027 or P# 90311-47013 for RH Seal" as published here in this DIY 5th Gen 2010-2018 Front Axle Seal DIY

A search for "front differential breather tube", "breather" or "differential breather vent" doesn't yield anything for my 2011 Trail on the Camelback Toyota website.

Toyota 4Runner Plug, breather (for front differential) - 9093003136 - Genuine Toyota Part shows a breather and tube assemblies. I found it using this Google search "2011 4Runner front differential breather vent".

Thank you Sir

repo · 09-15-2021, 11:16 AM

Do your rear diff breather too while you're at it, it's a good idea to use a coupler, fuel hose and zip ties to extend it up behind the fuel filler so it's protected. Since it's the driver side you could replace the needle bearings with the ECGS teflon bushing sleeve as some preventative maintenance while doing that oil seal.

EDIT: nevermind about needle bearing I see it's the passenger side leaking.

repo · 09-15-2021, 11:22 AM

And if you don't already, after you get it fixed remember to run 4H for a few miles on straight or dirt road every month to keep the diff nice and lubed.

carlodonz · 09-16-2021, 03:06 PM

Quote:

Originally Posted by repo

Do your rear diff breather too while you're at it, it's a good idea to use a coupler, fuel hose and zip ties to extend it up behind the fuel filler so it's protected. Since it's the driver side you could replace the needle bearings with the ECGS teflon bushing sleeve as some preventative maintenance while doing that oil seal.

EDIT: nevermind about needle bearing I see it's the passenger side leaking.

If you mean to add a breather line to read diff, I have done that already!

1000MPH · 09-17-2021, 12:16 AM

Good timing? Timmy the Tooolman just posted a vid on front diff axle seal replacement on a Lexus GX470. Should be similar, the part numbers look the same at quick glance.
Front Differential Axle Seal Replacement (Lexus GX470) - YouTube

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