Axle noise and rebuild advice

[jeremy56]

I rebuilt the axle in 2017 but only drove 10k miles since. I have a clunking drive train sound coming from front. I can't pinpoint it and think its likely driveshaft. However I changed diff fluid and noticed grease in it.
The Side i thought might be making the noise appears to still have plenty of moly in it but can't tell if diff fluid got into it.
I guess I'll clean out the old grease while it's open. What should I inspect for cause of clunking? Brass bushing, spindle look good but not sure?
Can I just throw in another new inner axle seal and not mess with wheel and trunion bearings being they aren't that old.
I think I had a bad breather end on diff and upgraded that.
I want to examine this while I have it apart but whats reasonable to need to replace with such little use.

 

[greentruck]

You need to sort this out a little. Clunking is probably not the axle or diff, but the driveshaft as you surmise. Check the U-joints. Have they been greased lately? Give them a couple of shots at least and see if the noise changes at all.

If you have a busted inner axle seal, then you're likely to have a mess from that leaking out around the wipers on the swivel ball on that side, which you should be able to see pretty clearly.

Yep, no need for new bearings unless there's some reason you find an issue with them. Re-seal and reassemble and you should be good with that.

 

[jeremy56]

I tried greasing the u joints I got a junk grease gun and couldn't tell if it was working properly. I will probably just replace the front u joints. Repack the birf with some Moly and the wheel bearings and go from there

 

[greentruck]

Try the grease in the U-joint first. If that quiets it, then there's no need to tear down the rest at the moment. Depending ion how much play you find in the U-joint, you may want to go ahead and R&R it, of course. Otherwise, have some confidence that you most likely did NOT mess up this work in three different places. Even I usually avoid that...

 

[jeremy56]

Welp one of the u joints was bad for sure. Also have soup ish in the knuckle. Not bad but definitely had some oil in it. Never weaped out the back. Ordered the marlin inner axle seal from cruiser outfitters hope to slap that in with some new moly and be ready to rock.

 

[BILT4ME]

Welp one of the u joints was bad for sure. Also have soup ish in the knuckle. Not bad but definitely had some oil in it. Never weaped out the back. Ordered the marlin inner axle seal from cruiser outfitters hope to slap that in with some new moly and be ready to rock.

Only use the Marlin seal if you're doing a lot of rock crawling. If this is a DD and mall crawler, you are better off with a Toyota seal.

 

[Broski]

I would not use the Marlin seal at all, Marlin no linger list them on there web site for the 80. The first time I rebuilt my front axle I used them with brand new axle shafts, I do not DD drive mine it's a trail Reg rock crawler and the Marlin seals failed in short order. Replaced them with OEM Toyota seal and it's been over two years no issue.

 

[jeremy56]

Well its already ordered. The Toyota seal failed in short order as well. Less than 10k miles. Worth a try

 

[Broski]

If you are still running the original axles, my guess is there is a wear spot on the axle that is causing the leak and that the Toyota seal is fine. It's well documented that the Marlin seals do not hold up well in a full time 4 wheel drive. Just sayin
My Marlin seals failed in less then a thousand miles.

 

[BILT4ME]

Well its already ordered. The Toyota seal failed in short order as well. Less than 10k miles. Worth a try

Also what @Broski said.

I'll add to that.

Did the seal actually fail or is the breather hose clogged?
I rebuilt my front axle, only to have birf soup in one side under 5000 miles. I was upset.

I pulled the vent hose and made a new one with a fuel filter up over the brake booster. I also pulled the fitting and I had to use a pick to dig out the hardened gear oil and crud from the PO that was in the fitting as well as the opening in the axle.

Once the new vent was installed, and I drained out the birf soup best I could, refilled with moly and diff oil accordingly, and haven't had another issue with it for 85K miles.

Could be a combination of both.

Also check your wheel bearings. Loose WB will cause the axle to push up in the opening and eat your inner seal.

 

[jeremy56]

It very well could have been the breather dont know that it was breathing but I did the same breather with fuel filter up in engine just recently when I discovered grease in diff.
Still haven't cleaned out the knuckle yet, to see if old seal or Birf can be cause.