Front Axle Rebuild Lessons Learned/Questions (1 Viewer)

[elmariachi]

So if that's what dealers are doing, I think we'll be fine with our ANALytical selves

I wouldn't trust the knowledge of today's dealership personnel on my 80 Series any farther than I could throw one of them. Seriously, there is nothing implied by the fact that they wear that uniform.

However, at this point (via what Disney calls movie magic ), the order has been changed to correctly show the felt nearest the diff, then the rubber seal, then the metal ring. Unfortunately, the rubber seal still has the groove facing the knuckle instead of the diff. but I figured, like the grease issue, it really didn't matter that much.

All we did was pull the rubber ring through the inside perimeter of the felt seal and that put it first in line against the steel ring, no disassembly required. And on both new 80s I have owned, the groove faced the steel ring upon first service disassembly.

 

[Miescha]

As long as you used moly grease for the birfs, I think we are over analyzing this. When I went to my dealer a few years ago when I first got my 80 and asked them what kind of grease they used in birfs, they told me, "umm, general purpose wheel bearing grease, what else?"

So if that's what dealers are doing, I think we'll be fine with our ANALytical selves

Dang, Arya is fast! That is what I ultimately decided and still firmly believe. It doesn't really pay to over-analyze the grease issue.

In fact, as shown in the pics I posted, my dealer repacked the wheel bearings previously with a mix of black (moly?) and red (non-moly?) grease. This is precisely why I now do my own service.

 

[MoCoNative]

Not an 80, but I actually looked in the FSM for a 60 series last weekend when I did the birfs on it. It was plainly stated in the manual to use Moly type grease on the birfs and knuckle bearings, multipurpose on the wheel bearings.

This is a different scenario of course, because a 60 is part time, so really any grease would proabbly work as my front end really only sees about a 1/3 of the miles that is actually put on the vehicle.

On my 40, following the FSM from 1972, they say multipurpose on everything, and that is the way I did it several weeks ago. It has hubs on it, so it is fully part time now too. My birfs are in good shape on it, as it has had hubs a long time. My 60 however has worn birfs due to PO neglect, and alot of hiway miles in 4wd.

I decided to use moly in the 60 this time, as I used multipurpose in it last time. What alarmed me is the knuckle/trunnion bearings I replaced 45,000 miles ago were already worn. I am hoping the the Moly will help to extend the life of the bearings a bit further than that. I also hope it will quite the birfs a bit.

So I wonder what the Toyota FSM says for the 80, I assuming it says the same as a 60 manual. I also assumed that older 40 manual says what it does, due to the possible lack of that formulation of grease at that time.

On a side note, I use a lithium based wheel bearing grease from Lubriplate, it is white in color for wheel bearings. Works very, very well, sticks very well, and as it is used up in the cavbity it changes color from creamy white, to gray to black and tells you exactly how much use you are getting out of the grease. Also will turn brown if water has intruded someplace, good at showing a leak point in a cavity, and how far the water actually got. Hard to locate though, order it locally from a bearing supply, but I have to give them the number, as they are clueless. I think I will get Moly grease the next time from Lubriplate also. The cheap Moly stuff I got at NAPA was not very impressive.

 

[elmariachi]

So I wonder what the Toyota FSM says for the 80, I assuming it says the same as a 60 manual. I also assumed that older 40 manual says what it does, due to the possible lack of that formulation of grease at that time.

It says moly in the birfield and knuckle cavity and wheel bearing grease in all bearings, including trunnion.

If you had excessive wear at 45k miles, you may not have had the preload set correctly on the knuckle housing. There is a LOT of weight and pressure on those bearings, especially if they are too tight.

 

[MoCoNative]

That could be. I didn't have a way to check preload last time, just put the shims back in the same again. I put in new ones again this time. Did the preload deal with the scale I got from Marlin. They are on the tight side again, going off the recomendation of some board advice that they will loosen up a tad. I think the book called for 6-8 or so pounds, they both pulled at 9ish. Felt good though. They were not leaking though, with sotck style seals, put in marlin seals this time, good looking product. Strange thing is, both times I have gotten the shims, they come with four thick and four thin as usual. My 60 is normal with one thick on each bottom and a thick/thin on the tops. But the thick shim is thicker than any thick shim you get in the kits, so I keep reusing them. Not sure why it is that way, or if the shim kits are just that generic. I'll see if the moly makes a difference. Hopefully I won't find out, want to sell it maybe and get an 80 here soon. Then I can enjoy all the little problems they can have in the front end, ohh what an addiction.

 

[gotmud]

FWIW...I am in the process of rebuilding mine as well, and using Mobil-1 Red grease for everything. I am sure this is a true sign of the Apocalypse since I didn't follow the FSM to the letter

 

[Miescha]

I'm no expert and I'm sure others more knowledgeable than me will chime in, but you really need to use moly in the knuckle.

 

[subdave]

Wow, thanks for all the replies.

What I have summarized from your replies:

1. It's ok for the lithium and moly grease to mix. It's ok to use moly grease in the trunnion bearings. It IS important to use the moly in the birf and to fill the knuckle. I have wasted a lot of everyone's time worrying about grease.

2. It doesn't matter if there is residual moly in the differential. Diff flushing is reserved for those with LC-OCD.

3. The black snap ring is for the birf. I'm ok there. No one knows what the heck the silver ring is. BTW, it may be steel. Hard to judge as it is small. My best guess from the parts list is that it is a 90521-34005 "RING, HOLE." Only a guess, though. Pic posted below. Maybe a crush washer as jmvar stated. Never even thought of that...

 

[elmariachi]

No one knows what the heck the silver ring is.View attachment 184390

It won't fit either the diff fill or drain plug?

 

[gray]

Wow, thanks for all the replies.

What I have summarized from your replies:

1. It's ok for the lithium and moly grease to mix. It's ok to use moly grease in the trunnion bearings. It IS important to use the moly in the birf and to fill the knuckle. I have wasted a lot of everyone's time worrying about grease.

2. It doesn't matter if there is residual moly in the differential. Diff flushing is reserved for those with LC-OCD.

3. The black snap ring is for the birf. I'm ok there. No one knows what the heck the silver ring is. BTW, it may be steel. Hard to judge as it is small. My best guess from the parts list is that it is a 90521-34005 "RING, HOLE." Only a guess, though. Pic posted below. Maybe a crush washer as jmvar stated. Never even thought of that...

View attachment 184390

The alumininum ring is a crush washer.

It IS important to flush the diff; Why?

Depends what you got in there;
Pure Moly; not a problem.

But the grease we use is 99% lithium/soap complex, lubricating oil, and some other additives; only 1 % Moly;

The grease causes the Gear Oil to foam which means air gets entrapped in (or whipped into) the Gear oil.

Air is compressible, and the bubbles collapse under pressure ie: when two teeth
are meshing, and the oil layer is not there; that means gear oil full of air is not lubricating as well as 100% gear oil.

On the other hand if your diff is full of water and mud, then you want to flush that out to get rid of the water, which will also cause the gear oil to foam, and will cause rust, and the mud will grind down
your bearings and damage the seals.

Not OCD, just good maintenance.

G

 

[roncruiser]

Wow, thanks for all the replies.

What I have summarized from your replies:

1. It's ok for the lithium and moly grease to mix. It's ok to use moly grease in the trunnion bearings. It IS important to use the moly in the birf and to fill the knuckle. I have wasted a lot of everyone's time worrying about grease.

2. It doesn't matter if there is residual moly in the differential. Diff flushing is reserved for those with LC-OCD.

3. The black snap ring is for the birf. I'm ok there. No one knows what the heck the silver ring is. BTW, it may be steel. Hard to judge as it is small. My best guess from the parts list is that it is a 90521-34005 "RING, HOLE." Only a guess, though. Pic posted below. Maybe a crush washer as jmvar stated. Never even thought of that...

View attachment 184390

Where does the black snap ring (pictured) go in the birf??? It's an extra snap ring, but can't figure out where it goes. The other snap ring that came in the same baggie is used for the end of the axle shaft. Are they interchangeable?
The one used on the end of the axle shaft is flat, the one pictured is round-wire type. So, where does it go.

The silver rings went unused for me on my rebuild too.

 

[greenfox]

I will be doing a axle rebuild on the wife's 80 in a week. Because I went to replace the front brakes with new rotors and 100,s pads and got the spindle off and there was rust on the inner wheel bearing......fawk.

But it should only take me about 30 min to do the hole axle rebuild

 

[subdave]

roncruiser- I believe th little black snap ring is used if you pound the bearing portion of the birfield off of the shaft. My understanding is that it actually holds the shaft in there. There is no apparent need to disassemble that far unless you want to just clean better.

greenfox - good luck with that 30 min. It took me about 23 solid hours to do the rebuild and egr vsv swap.

 

[threatminor]

spindle bushings

Did any of you guys replace the spindle bushing while you did your front end? It seems most people I've talked to don't, but I have some pretty good clicking nowadays, so I'm debating if it might be worth the trouble of replacing those too while I'm at it.

 

[greenfox]

greenfox - good luck with that 30 min. It took me about 23 solid hours to do the rebuild and egr vsv swap.[/quote]


That's only because I only do about 4 a month

 

[Miescha]

There is no apparent need to disassemble that far unless you want to just clean better.

Or you have clicking indicating the birfs are worn so you want to swap sides with the birfs. Or if you don't have clicking but you want to swap sides just to get a different wear pattern and, presumably, extend the birf life.

I planned to swap sides for extended life (b/c all the LC-OCD people said it was the thing to do), but when I got in there it looked a lot tougher to get the birf back together than I thought. I had no clicking or other problems, so I chickend out and just cleaned them well without disassembly.

The silver washer is definately the crush washer for the diff. You should have two - one for the drain and one for the fill plug. I need to order four more - for the center transfer and the rear diff.

 

[96r50]

I planned to swap sides for extended life (b/c all the LC-OCD people said it was the thing to do), but when I got in there it looked a lot tougher to get the birf back together than I thought. I had no clicking or other problems, so I chickend out and just cleaned them well without disassembly.

Same here!

 

[badmuthatrucka]

Well, for once something I feel I know a little something about! I just got done, as in a week ago, doing my front axle rebuild. Yes, use molybdenum fortified grease in your knuckle, and all incorporated parts, i.e. trunnion bearings. Use wheel bearing grease, I prefer the Mobil 1 red stuff, on the wheel bearings and inside the hub.

There seems to be some confusion concerning mixing greases. Unless otherwise noted, essentially all grease is lithium based. Moly grease, is fortified with molybdenum disulfide, aka molybdenite, with a base of lithium soap. You can find, at about $45 per tube, some silicone based moly grease, if you look hard enough, and want to spend that much money. Molybdenum acts as a friction reducer. It is chemically "sticky" to steel, iron, most metals, and has a much lower coeffecient of friction than steel on steel, or even steel on regular grease on steel. Because of the chemical bonding with metal parts (adhesion), you end up with a bit more of a sandwich: metal moly moly metal. And, since the moly is more adhesive than cohesive, it likes to stick to other things more than it likes to stick to itself, you end up with a very slick surface interaction. The added bonus of moly-grease is that even if the substrate is used up, or pressed away from the part it was applied to, the molybdenite stays put up to certain temperatures. Of course, by this point the heat-sink effect of the substrate has also been taken out of the equation, and the moly will soon be released from its chemical bond with the metal as well. But going into that will make me sound like even more of a nerd than I already do.

All of the above is essentially just my $0.02 Thanks for reading!

 

[badmuthatrucka]

Oh, yeah... Don't mix greases with different substrates, that would be a bad thing. But that goes into chemical reactions, and more of the giant nerd in me trying to get out.

I also did the birf swap side to side. I agree, it seemed like a lot of trouble, but I'm grateful for the advice from ToothFairy, we'll see what it does. Never did have any clicking, so I'll just have to look at everything again in a few thousand miles, see what the wear pattern is like then.

 

[gray]

badmuthatruka explained the role/actions/abilities of Moly grease very well. Which underscores the reasons why they recommend it to be used in birfs; one is so that if you drive across a few rivers, something will be left behind to lubricate the birf (being a "leaky" CV joint design) until you can repack it.
I am not a Tribologist; just read too much and ask a lot of questions; like you guys are doing; I just started earlier as I got my first LC about 25 years ago.

g