Aloha all,
This is my first post after lurking on Mud for tech help for a couple years.
In short, my friend and I did a front axle rebuild on my 93 80 this weekend and ran into a couple snags after following the FSM and the FAQ thread for this job.
The job went smoothly, despite using about 500 pairs of nitrile gloves and ruining some work clothes. Having two people to work on everything definitely made it easier, and there were two sets of eyes to double-check everything we did.
We used the Nitro Birfield internals to replace the worn, but undamaged, OEM Birfield internals. We lightly tapped the Nitro components into the OEM Birfield housings. They were tight, but we figured that was normal given that they're new parts. They didn't require as much force as depicted in the video we used for this technique, and we used a soft punch the whole time, with no visible wear on the new parts from the install. We also continued using the OEM axle shafts; they had no visible wear. We used the Nitro set of seals and bearings.
The seals on the passenger side had failed, resulting in contaminated grease and gear oil, but the new seals should fix that. The component that was most worn was the passenger side Birf housing, which had some marks where the housing had clearly experienced more heat than it was supposed to due to improper lubrication. Other than that, we observed no obvious or serious wear and tear on the OEM parts.
After reassembly, we noticed a couple issues, and we can't figure out how to explain them or where to go from here:
1. Passenger side axle shaft sticks out of the hub slightly more than we think it should. The length it sticks out is just enough to prevent the grease cap from seating properly. It looks pretty normal, but definitely sticks out a little too far. We tried hitting it a few times with a plastic deadblow hammer, thinking maybe we didn't seat it all the way in, but it didn't budge. Not sure if this is within normal range of behavior or not.
2. More concerning, we did a test to make sure the passenger side was getting power (and thus seated in the differential) by jacking up all four wheels and letting the truck idle in low range. The passenger side axle does in fact have power, so it should be seated--raising more questions about why the shaft sticks out. The issue we noticed in this test is that the Birfs didn't allow for full steering articulation; we get about one turn of the steering wheel in each direction. After one turn, the Birfs feel like they're seizing, and we get a concerning steel-on-steel squeal from the drivetrain at maybe 2000 RPM. Note that at this point we hadn't refilled the diff with 75W-90, but we're not thinking that was the source of the squealing.
My hypotheses are as follows:
a. The Nitro parts are not intended to be installed in OEM Birf housings, despite their website saying so.
b. The Birf internals need to be seated and worn in by a road test. I suspect our shade-tree jackstand dyno test is not a common practice, and that people just reassemble things and take the newly rebuilt axle for a spin.
c. Despite following the FSM and FAQ to the letter, we inexplicably did something wrong. In this case, I blame beer, and await someone explaining where I screwed up so I can fix it in shame.
Hopefully someone can tell me what maybe went wrong here, and what to do next. Thanks everyone for your help!
This is my first post after lurking on Mud for tech help for a couple years.
In short, my friend and I did a front axle rebuild on my 93 80 this weekend and ran into a couple snags after following the FSM and the FAQ thread for this job.
The job went smoothly, despite using about 500 pairs of nitrile gloves and ruining some work clothes. Having two people to work on everything definitely made it easier, and there were two sets of eyes to double-check everything we did.
We used the Nitro Birfield internals to replace the worn, but undamaged, OEM Birfield internals. We lightly tapped the Nitro components into the OEM Birfield housings. They were tight, but we figured that was normal given that they're new parts. They didn't require as much force as depicted in the video we used for this technique, and we used a soft punch the whole time, with no visible wear on the new parts from the install. We also continued using the OEM axle shafts; they had no visible wear. We used the Nitro set of seals and bearings.
The seals on the passenger side had failed, resulting in contaminated grease and gear oil, but the new seals should fix that. The component that was most worn was the passenger side Birf housing, which had some marks where the housing had clearly experienced more heat than it was supposed to due to improper lubrication. Other than that, we observed no obvious or serious wear and tear on the OEM parts.
After reassembly, we noticed a couple issues, and we can't figure out how to explain them or where to go from here:
1. Passenger side axle shaft sticks out of the hub slightly more than we think it should. The length it sticks out is just enough to prevent the grease cap from seating properly. It looks pretty normal, but definitely sticks out a little too far. We tried hitting it a few times with a plastic deadblow hammer, thinking maybe we didn't seat it all the way in, but it didn't budge. Not sure if this is within normal range of behavior or not.
2. More concerning, we did a test to make sure the passenger side was getting power (and thus seated in the differential) by jacking up all four wheels and letting the truck idle in low range. The passenger side axle does in fact have power, so it should be seated--raising more questions about why the shaft sticks out. The issue we noticed in this test is that the Birfs didn't allow for full steering articulation; we get about one turn of the steering wheel in each direction. After one turn, the Birfs feel like they're seizing, and we get a concerning steel-on-steel squeal from the drivetrain at maybe 2000 RPM. Note that at this point we hadn't refilled the diff with 75W-90, but we're not thinking that was the source of the squealing.
My hypotheses are as follows:
a. The Nitro parts are not intended to be installed in OEM Birf housings, despite their website saying so.
b. The Birf internals need to be seated and worn in by a road test. I suspect our shade-tree jackstand dyno test is not a common practice, and that people just reassemble things and take the newly rebuilt axle for a spin.
c. Despite following the FSM and FAQ to the letter, we inexplicably did something wrong. In this case, I blame beer, and await someone explaining where I screwed up so I can fix it in shame.
Hopefully someone can tell me what maybe went wrong here, and what to do next. Thanks everyone for your help!
