Front Diff question

[BILT4ME]

OK help me out here. How is knuckle grease pushed into the differential from the drive flanges?

I agree on the breather fitting getting plugged when there is mixing of diff oil and birfield grease, but that's due to a failed inner seal. Or what am I missing?

It's not pushing GREASE from the drive flanges, it's pushing as in rotating the axles and pinion because the drive flanges are still on. He was going to remove the DS so it wouldn't turn and I wanted to point out that doesn't work unless you have locking hubs or stripped DF.

 

[Imagery]

So today I decided to pull the left side apart just to see the condition of the grease inside the birf. It wasn’t as bad as I thought it might be but it was still a little soupy. The birf itself was still covered with grease so I think for now it will be Alright till I get parts ordered and get the front diff checked out. I added about three 3 finger scoops of fresh grease just to be sure.

 

[Imagery]

So today I decided to pull the left side apart just to see the condition of the grease inside the birf. It wasn’t as bad as I thought it might be but it was still a little soupy. The birf itself was still covered with grease so I think for now it will be Alright till I get parts ordered and get the front diff checked out. I added about three 3 finger scoops of fresh grease just to be sure.

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[Imagery]

I’ve decide to just go ahead and order the r&p and install kit and just have the shop do the differential. I will also get the complete axle rebuild kit with bearings and do that myself. I can take my time and do it the way I like. The diff shop is not in the business of rebuilding complete front axles plus what I would have to pay for just labor would be twice or more what I pay for parts.

 

[Imagery]

Since the Cruiser has 240K on drivetrain and just 30K on newly built motor, I was thinking about just getting new birfieldseither standard or the Heavy Duty or even the Nitro Heavy duty chromoly birds. Now my truck does have ABS but the ABS manifold and module does not work so I don't have ABS anyway. Can I still just get the non ABS version since its not functional. I just figure that since Im in there doing the work myself instead of paying someone else, I would still be spending less overall doing the work here.

 

[FMC80]

Aren’t there several accounts of nitros twisting?

 

[Oneops]

I've been wondering about this and their quality on ring and pinions.

Aren’t there several accounts of nitros twisting?

 

[thatcabledude]

Should’ve just changed the diff oil and checked it again after a couple weeks or a month. I think your wasting money.

 

[Imagery]

Well I don't know about which R&P brand is best about like I don't know what motor oil is best. But I run 35's and I don't wheel hard in my rig like a lot of guys, and I don't have lockers, so Im not really pushing them to the limit so I probably won't be twisting or breaking them. I just think mine was set up incorrectly and as a result has just worn prematurely. Right now when I drive, it feels and sounds like I have loose wheel bearings, mostly on the drivers side because I haven't ridden co driver but its probably the same on that side. When i get to 40 mph, it starts sounding like my tires are cupped and unevenly worn but that is not the case. It also has the sound and feel of loose shock mount but that's not the case either. Its not something I can hear with my head out the window but can just hear it inside with the windows up, like a bumping or knocking sound. It feels like a rattling in front when just driving in town and going over normal road bumps and its mostly felt in the floorboard too.Thats the only sound I can equate for a description. My front wheels are not loose and I pulled the DS just to inspect the condition and set the front wheel preload and torqued the lock nut. Then when at highway speed, 65-70, it still doesn't feel quite right but when I slightly let off the gas and its between acceleration and deceleration, it makes a moaning sound.

I still have to drive it every day but just afraid to really go out of town, but I do anyway, but I don't think its in danger of the wheel coming off but it needs to be addressed sooner than later. The DIFFF shop scheduled me for June 6 so a little over a month. I could just have him do the diff and put everything back together with the old gaskets, if they don't break or tear during dissemble, and then drive it and see if there are still those clunking sounds and loose wheel or shock feelings and go from there. Then if all is Alright, It might still be a good idea to go in and at least replace all the seals and gaskets and use fresh grease.

 

[jpoole]

"It also has the sound and feel of loose shock mount but that's not the case either. Its not something I can hear with my head out the window but can just hear it inside with the windows up, like a bumping or knocking sound. It feels like a rattling in front when just driving in town and going over normal road bumps and its mostly felt in the floorboard too."

I didn't read the whole thread, sry, but the knocking noise/feel you are describing could be a sway bar bushing. Have you check those and the other suspension/shock bushings to see if any are blown out or loose?

 

[Imagery]

"It also has the sound and feel of loose shock mount but that's not the case either. Its not something I can hear with my head out the window but can just hear it inside with the windows up, like a bumping or knocking sound. It feels like a rattling in front when just driving in town and going over normal road bumps and its mostly felt in the floorboard too."

I didn't read the whole thread, sry, but the knocking noise/feel you are describing could be a sway bar bushing. Have you check those and the other suspension/shock bushings to see if any are blown out or loose?

yes I checked everything there and all is ok. One thing that was suggested that I check is the bushing inside the spindle. I don't know if mine has the needle bearing or the brass bushing but I will be checking that as well. That actually is making the most sense at this point. If the bushing or needle bearing is bad, is one preferred over the other? I think Toyota started using needle bearing in the spindle in the 100 series and Late 80 series. If that is what is wrong, I might need to check the birf where that bushing rides and make sure its not damaged, if so I will get a new Birf and probably one for the other side just to have them both in new condition.

 

[High Lander]

I don't think it's unreasonable to rebuild your axle at 240k personally, and that mix does look a little soupy

 

[Malleus]

IMHO, a lot soupy...

 

[Malleus]

yes I checked everything there and all is ok. One thing that was suggested that I check is the bushing inside the spindle. I don't know if mine has the needle bearing or the brass bushing but I will be checking that as well. That actually is making the most sense at this point. If the bushing or needle bearing is bad, is one preferred over the other? I think Toyota started using needle bearing in the spindle in the 100 series and Late 80 series. If that is what is wrong, I might need to check the birf where that bushing rides and make sure its not damaged, if so I will get a new Birf and probably one for the other side just to have them both in new condition.

A bushing is prefectly acceptable here; the needle bearing is gilding the lily, IMPO

 

[jpoole]

I prefer to run the bushings over the bearings in my spindles. My thinking is that the bushing won't fail catastrophically while the bearings certainly can. When I pulled my axle down the first time there were little rollers scattered around/etc. from abuse. I'm sure if you set them up right and maintain them that either is a good option and that there must have been some benefit to the rollers to justify the switch.

Regarding birfs, keep in mind that some of the "stronger" birfs for off-roading are actually softer metal so that they don't shatter and as a result they don't wear as long in fulltime rigs like ours. As I understand it some of the "off road" birfs are simply not heat treated while others use different alloys/etc. that help them handle high impact situations like sudden grip found under throttle, etc. Stock birfs are heat treated to harden the wear surfaces that the balls ride on which helps them last much longer in normal driving though that heat treating does make the bell/metals more brittle which can lead to exploding birfs if you really hammer them on the trail. Anyway, both types have their place and I assume there is more to it than this summary like number of splines, etc. etc. but I wanted to point out that you need to identify your use case and shop appropriately. Ie do you drive a part-time 4wd rig that sees heavy trail use, a trail only rig, a mostly hwy rig, etc.

 

[Imagery]

I prefer to run the bushings over the bearings in my spindles. My thinking is that the bushing won't fail catastrophically while the bearings certainly can. When I pulled my axle down the first time there were little rollers scattered around/etc. from abuse. I'm sure if you set them up right and maintain them that either is a good option and that there must have been some benefit to the rollers to justify the switch.

Regarding birfs, keep in mind that some of the "stronger" birfs for off-roading are actually softer metal so that they don't shatter and as a result they don't wear as long in fulltime rigs like ours. As I understand it some of the "off road" birfs are simply not heat treated while others use different alloys/etc. that help them handle high impact situations like sudden grip found under throttle, etc. Stock birfs are heat treated to harden the wear surfaces that the balls ride on which helps them last much longer in normal driving though that heat treating does make the bell/metals more brittle which can lead to exploding birfs if you really hammer them on the trail. Anyway, both types have their place and I assume there is more to it than this summary like number of splines, etc. etc. but I wanted to point out that you need to identify your use case and shop appropriately. Ie do you drive a part-time 4wd rig that sees heavy trail use, a trail only rig, a mostly hwy rig, etc.

 

[Pin_Head]

If you are going to get a new front ring and pinion, you might want to consider rehearing to 4.88s so that you can run 35 inch tires. Othersise, changing the R&P is likely a waste of money.

 

[Imagery]

Well thanks for pointing that out, and I currently am mostly driving on the pavement and some country dirt roads. This is my daily driver and I can't be wheeling it hard and risking breaking things. I wouldn't to that with this truck even if I had a new truck as a daily driver. I've driven this truck for 24 years and plan to have it still running and in good condition in another 24 years. I know what it is capable of as well as my own driving skills so I don't feel I have to prove it by beating it up on the weekends. If that's what I wanted to do, I would buy another 80 and prep it for that type of use primarily. Turns out, aside from the metal shavings in the front diff and the axle seals failing after only 30K (front and rear axles rebuilt along with new brake calipers rotors and 100 series pads and more was done with the motor rebuild), but I don't know if i mentioned earlier in my post because I have been hyper focused on the Diff oil contamination and metal partitals, but I did discover that my DS front wheel bearings had a little slack and needed to be readjusted. Not sure how long it was loose but the spindle shows that the rear wheel bearing race was spinning on the spindle and caused a lot of heat on the front and back sides. That may have contributed and started a chain reaction of failures in the spindle bushing, birfield heating up more and allowing grease to enter the axle housing as it cools and diff oil getting back into the birf. I was told that because I am running 35's, I should be servicing the wheel bearings at least every 30K, re-pack and set preload. I notice also the dust cover and seal is wet too. I guess I should replace this spindle with a new one with the bushing already installed. The other side is fine and that wheel never loosened up.

 

[jpoole]

In case they aren't on your radar a good source for axle rebuild kits, spindles (with bearings or bushings), gears, etc. etc. is Cruiser Outfitters.

Cruiser Outfitters

OE is usually the best parts source for these trucks but Cruiser Outfitters has sourced OE quality parts, with lower prices, for some of the regular service items (and many other parts also). They are my go-to when it's axle service time.

 

[mudgudgeon]

I’m not sure if this shop is familiar with the 80 front end. And I’m sure they won’t clean all the old grease off and do a good visual inspection

Honestly, sounds like you would be better to find a different shop.

That paragraph does not ooze confidence!