Water retention point

[GrantK]

While installing my front diff drop over the weekend I encountered something that concerns me a little. When I loosened the driver side diff mounting bolt a yellowish liquid started dripping from the bottom of the bolt. It turned out to be slightly rusty water that was trapped behind the bolt in the hole. The passenger side didn't have any. Since there are skid plates blocking splashes, etc. and I haven't driven through deep water and it's been two weeks since the last car wash I am surprised that any water could get in there let alone be there after two weeks.

The rust in the water concerns me since this is one of only two mounting points for the diff. When I put it back together I coated the bolt shaft and head with anti-seize for added rust protection but who knows...

I'm not sure what to make of this and am just posting it here as info to others to watch out for.

 

[NorthWest 4R]

Yes I have seen this as well on a few FJ's and Tundras as well. I have also seen the body mount bolts on a few of them as well full of water and bolts rusted to chit :wow2:

 

[Okki]

hi Grant..

I have a hard time visualizing where you are talking about, but could you drill a small pilot hole to facilitate draining without compromising the strength of the area holding the bolt?

Just a thought...

Okki

 

[GrantK]

I have a hard time visualizing where you are talking about, but could you drill a small pilot hole to facilitate draining without compromising the strength of the area holding the bolt?

I don't think a drain hole can be drilled without compromising the diff mount. The red circled bolt head in the diagram below shows where the water came from as soon as I loosened it. I think it got in between the upper and lower "mount stopper" (aka bushings) and was trapped there. It was only about a tablespoon but any water retention is a concern for rusting.

 

[Rubberdown]

Cover it in grease and call it a day

 

[eddiebx]

For argument's sake, would it really matter if those bolts rusted out? Based on the diagram you posted, it seems like the upper nut is removable along with all the misc bushings and washers, so in the event it was heavily rusted couldn't we just replace all the pieces and call it a day?

Not that I'm suggesting that you should've just left it alone (since preventative maintenance is the best maintenance IMO), but I am curious if there's other detrimental effects that I am not realizing?

 

[nashman69g]

Where are all of these wonderful diagrams coming from?? :hiding:

:biggrin2:

 

[GrantK]

Where are all of these wonderful diagrams coming from?? :hiding:

:biggrin2:

The repair manual. Link in the mods sticky

 

[gray street]

The repair manual. Link in the mods sticky

He's the one who hosts them imp:

 

[Okki]

Where are all of these wonderful diagrams coming from?? :hiding:

:biggrin2:

Scratching Nashman behind his ear.. who's a good boy.. who's a good boy.. yes he is! :jump:

Okki :withstupid:

 

[Jivewalker]

Good catch! Going to remove mine, pack the hole with grease and re-assebmble. One less thing to worry about down the road...