Birfield / Front Axle - Can it wait? What else while I am into it? (1 Viewer)

[KayyBaby]

Background: 1991 FJ80 with 191K miles

This is my first post. Up until now, I've just been lurking and learning.


This is my front passenger hub. I had noticed moly grease starting to leak. From what I am reading on here, it is at least an inner oil seal. Once I get it tore down enough to replace that, it seems to be a good idea to do some other maintenance while I am in there.

My questions are:
Should I totally stop driving until it is addressed or will it be okay? If I drive it like this, is there a chance of a catastrophic failure? I ask this because snow is forecasted where we live before I will have a chance to get all the parts. Wondering if this can wait any longer - maybe when it is a bit warmer in a month or so, but I don't want this to be my first and last post in one.

Second, what other maintenance tasks should I be sure to do once I get it this far? From what I can tell, I should at least get a kit with seals and gaskets like this Marlin Crawler. I've also seen it is a good idea to do
- Seals and gaskets on other side of axle
- Wheel Bearings
- Brakes
- Anything else?

Finally, what do I need to look for to know if the entire axle needs replaced (like upgrading to a RCV Chromoly Axle Upgrade Set)? I've seen the axle can get bent with larger than stock tires. It came with 31x10.5. That's what I am running still and think it has had this size tire most of its life based on the paperwork that came with it. At some point I want to get 33s but that has fallen down the list until I get some of these bigger jobs taken care of.

I bought KayyBaby last fall after scouring forums, ebay, and Craigslist for over a year. I want to do as much work on it as I can, but even more than that, I don't want to shade tree mechanic myself into a very expensive job because I didn't do something I should or did it wrong.

I appreciate you reading this. Thanks in advance for any feedback.

 

[Blade 80LC]

I'm no expert, but my reading on Mud is in line with your post. Yes, it looks like you have a bad axle seal. I don't think catastrophic failure is likely, but the longer you drive on a truck with poor axle lubrication, the more likely something will wear out. My passenger birf was leaking when I bought my truck 2000 miles ago, and I haven't gotten around to rebuilding it, but certainly know I should.

I think people say they get 10-20,000 miles on their front brakes. I'll replace mine when I replace my axle seals and wheel bearings.

Bigger tires stress axles. Nearly every post I've seen, indicate the axles are still pretty bulletproof with 33" tires. Many say that 37" tires are where you should be concerned about stock axles and may need to swap to aftermarket chome-moly axle shafts. I plan to run 35's on my rig.

 

[DSRTRDR]

Kurt at cruiseroutfitters.com sells kits for what you need: Cruiser Outfitters

 

[madisonr34]

Dont buy marlin seals. They will leak. Go OEM. I learned the hard way.

 

[PermianCruiser]

Kurt at cruiseroutfitters.com sells kits for what you need: Cruiser Outfitters

Just ordered one of these kits, starting on it this week.

 

[LS1FJ40]

Highly recommend Kurt at Cruiser Outfitters as well. He will walk you through what you need to make sure you have everything (including the 54mm socket).

Yes you need to do the seals. But it isn't something you have to park it until you get it done. You can add moly grease to the knuckle via the square plug on top of the knuckle (towards the front behind the wheel). It is easiest to do this with the wheel off but you can do it by turning the wheel all the way to the right (or left for left wheel) and reaching back in there. A size 13mm open ended wrench will open the plug. Take a zip tie (or lawn mower line or whatever) and stick it down in the hole. There should be grease up to about 1-1.5" from the top (3/4 full).

I use the Valvoline moly grease in a tub from AutoZone. It is labeled as for Ford/Lincoln/Mercury. Take a ziploc freezer bag and turn it inside out. Put your hand in the bag (like you are going to pick up dog poop) and scoop out the grease from the tub in to the ziploc. Then unfold the ziploc to turn it back right side out. Squeeze the grease all down in to one corner. Cut a small 1/4-3/8 hole in the ziploc corner. Then squeeze the grease in to the port on top of the knuckle. Use the zip tie to occasionally push the grease down in the hole. Put the plug back in. Drive a few miles and then check the level again. Add more grease as necessary.

While you are doing your first knuckle job you should extend your diff breathers. This is really cheap ($10/diff). Search diff breather extend or something like that. You just use approx 6' of 3/8" hose (IIRC) and an inline fuel filter from AutoZone for each diff.

Good luck.

Oh yeah, and you'll need a box of nitrile gloves, 3-4 boxes of rags, heavy duty garbage bags, cardboard to lay out the parts and label with sharpie on the carboard as you take them out, two five gallon pails with two gallons of diesel fuel in each.

Oh, and more nitrile gloves and rags.

 

[KayyBaby]

Thanks, everyone!

This is great. I'll top it off and get in touch with Cruiser Outfitters.

 

[Chrash]

My hub was leaking bad when I bought it, had to keep adding gear oil until I rebuilt the axle. Drove about 2k miles that way. I used the marlin crawlers full kit. Didn't see the warnings about their seals until after, so what can I do. Its a good idea to do it all while you have it apart. Bearings, seals, gaskets. Parts aren't that expensive and you'll already have it apart, so why not. I needed brakes and rotors too. Put the 100 series front pads on the front, theres more pad surface and they're a direct replacement. Only been about 1k since I rebuilt, so far so good. Drives great. Took me two leasurly days, plenty of beer breaks and double checking the how-to's in this awesome forum. If I were to do it again I can get it done in less than one. Very dirty, greasy job.

Edit: I second the breather tube extension. Learned that tip the hard way.

 

[TexasJack]

When I replaced the birfs on my front axle I decided to rebuild the rear as well. I changed the gears from 4.11 to 4.88, and replaced the diffs with ARB lockers. If you are in there, you might as well as take care of everything in one big job.

 

[Columbia Cruiser]

Thanks, everyone!

This is great. I'll top it off and get in touch with Cruiser Outfitters.

Replace your rotors while you are in there, half way in already.