IdahoDoug said:
Not for me Doug, I'm thinking up and down as in a worn bushing, an over sized hole if you will and the axle not being held in it's center position.
Hope this helps clear it up from my end.
Leaky birf - but only on driver side??!!
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Not for me Doug, I'm thinking up and down as in a worn bushing, an over sized hole if you will and the axle not being held in it's center position.
Hope this helps clear it up from my end.
alia176
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Ok dudes,
here're some fresh pics. I made a mark using a pen on the 12 o'clock position for reference. Of interesting to note is the wear pattern on the shaft (to the left of the mark). I can't feel any low spots here. Are most of your marks in the same location or more toward the middle of the wear area?
Admittedly, I didn't see the bottom of the seal too worn at least not to my naked eyes. I'll check the spindle next to see if anything is amiss in there.
Ali
here're some fresh pics. I made a mark using a pen on the 12 o'clock position for reference. Of interesting to note is the wear pattern on the shaft (to the left of the mark). I can't feel any low spots here. Are most of your marks in the same location or more toward the middle of the wear area?
Admittedly, I didn't see the bottom of the seal too worn at least not to my naked eyes. I'll check the spindle next to see if anything is amiss in there.
Ali
alia176
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I did find two things after running my finger over the smooth area where the seal resides:
if you look at 3 o'clock, you'll notice some distrubance in the area. This happened the last time when I tried to remove the seal with the improper tool. I felt a sharp burr directly in this area. This shouldn't bother the seal, since it contacts the metal outer part of the seal.
Secondly, take a look at the seal itself. There's a tear on the outward facing lip (between the marks). Could this be the cause of my leakage of 90wt? Perhaps the tear is enlargening when the axle is spinning inside?
if you look at 3 o'clock, you'll notice some distrubance in the area. This happened the last time when I tried to remove the seal with the improper tool. I felt a sharp burr directly in this area. This shouldn't bother the seal, since it contacts the metal outer part of the seal.
Secondly, take a look at the seal itself. There's a tear on the outward facing lip (between the marks). Could this be the cause of my leakage of 90wt? Perhaps the tear is enlargening when the axle is spinning inside?
alia176
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More surprises!
Well, it seems that I now know where the metal shavings on the ABS sensor magnet are coming from
They're from the bell contating the housing when the axle moves inward (toward the diff). The upper trunion area is where the contact is being made. The lower one is fine. This explains why I'm feeling a bit "rough" kind of a feel from the front suspension while at hwy speeds. Two snap rings aren't enough but three is too much I gotta have a shop make me up a spacer with the exact thickness. Until then, the oem hubs are going back on.
Pics are below.
Ali
Well, it seems that I now know where the metal shavings on the ABS sensor magnet are coming from
They're from the bell contating the housing when the axle moves inward (toward the diff). The upper trunion area is where the contact is being made. The lower one is fine. This explains why I'm feeling a bit "rough" kind of a feel from the front suspension while at hwy speeds. Two snap rings aren't enough but three is too much I gotta have a shop make me up a spacer with the exact thickness. Until then, the oem hubs are going back on.Pics are below.
Ali
still would like to see a pic of that bushing.
There are grooves for grease that are on the inside that cross each other and should have been equal in depth. It's obvious if they are not even as their width changes with wear. If one has a narrow spot then there is wear in the bushing at that point.
Alia,
Seems to me you've go two issues here. Based on the birf contacting the upper trunion bearing area, I'd say your birf (and axle) are riding high vs the seal's center. This indicates your shim may be a bit thick, as a thinner shim would move the steering knuckle up vs the axle housing.
In addition, the birf is also a bit too deep into the steering knuckle, which leads me to wonder what's going on with these hubs you've retrofitted (no pics?). Are they perhaps not wide enough so that your axle tip C clips are not keeping the axle (and birf) properly pulled away from the axle housing - allowing the birf to penetrate deeper into the axle housing and striking it as noted by the damaged birf? The extra clip was a good idea, but as you said, not enough depth to compensate if this is the issue. Atop this issue, you've eliminated the dust cover, which reduces the stack height that would normally keep the axle tip farther away from the axle housing, which further allows the birf to be closer to the axle housing and may also be contributing to the birf hitting the axle housing.
Finally, the resultant metal bits contaminating the birf grease are not coincidentally contaminating the grease closest to your inner axle seal and it's a safe bet the seal's rubber lip is taking a beating. The wear mark on the axle from the seal is unusually wide, which indeed indicates more axial play than normal exists. Ironically, this may have worked in your favor as without the seal running back and forth spreading its wear, you might have a deeper groove in one spot from the metal bit laden grease. Lucky you, eh? Heh.
So, lose the aftermarket hubs, put a slightly thinner shim on the knuckle housing top (gotta put new trunion bearings/races in, though for proper stack height) and put either the dust shield back on, or cut the shield down to the flange if you worry about caught gravel, so its flange contributes to the proper spacing of your spindle/hub assembly. Then put in a new C clip on the axle tip.
The only other variable I could think of was that 95-97 drive plates are thicker. So if the hub maker you're using spec'd their hub for the 93/94 superior Heavy Duty 80 series trucks and your later model needs the hubs to be thicker to account for the slightly longer 95-97 outer axle then they did you a disservice and that's another reason the birfs are hitting the axle housing. A call to see if they have a different hub model for the later models like yours should confirm if they overlooked this running change and may not even be aware of it.
HTH,
DougM
Seems to me you've go two issues here. Based on the birf contacting the upper trunion bearing area, I'd say your birf (and axle) are riding high vs the seal's center. This indicates your shim may be a bit thick, as a thinner shim would move the steering knuckle up vs the axle housing.
In addition, the birf is also a bit too deep into the steering knuckle, which leads me to wonder what's going on with these hubs you've retrofitted (no pics?). Are they perhaps not wide enough so that your axle tip C clips are not keeping the axle (and birf) properly pulled away from the axle housing - allowing the birf to penetrate deeper into the axle housing and striking it as noted by the damaged birf? The extra clip was a good idea, but as you said, not enough depth to compensate if this is the issue. Atop this issue, you've eliminated the dust cover, which reduces the stack height that would normally keep the axle tip farther away from the axle housing, which further allows the birf to be closer to the axle housing and may also be contributing to the birf hitting the axle housing.
Finally, the resultant metal bits contaminating the birf grease are not coincidentally contaminating the grease closest to your inner axle seal and it's a safe bet the seal's rubber lip is taking a beating. The wear mark on the axle from the seal is unusually wide, which indeed indicates more axial play than normal exists. Ironically, this may have worked in your favor as without the seal running back and forth spreading its wear, you might have a deeper groove in one spot from the metal bit laden grease. Lucky you, eh? Heh.
So, lose the aftermarket hubs, put a slightly thinner shim on the knuckle housing top (gotta put new trunion bearings/races in, though for proper stack height) and put either the dust shield back on, or cut the shield down to the flange if you worry about caught gravel, so its flange contributes to the proper spacing of your spindle/hub assembly. Then put in a new C clip on the axle tip.
The only other variable I could think of was that 95-97 drive plates are thicker. So if the hub maker you're using spec'd their hub for the 93/94 superior Heavy Duty 80 series trucks and your later model needs the hubs to be thicker to account for the slightly longer 95-97 outer axle then they did you a disservice and that's another reason the birfs are hitting the axle housing. A call to see if they have a different hub model for the later models like yours should confirm if they overlooked this running change and may not even be aware of it.
HTH,
DougM
alia176
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Doug,
Here's my take on it:
Everything was great until I installed the Mini truck Aisin lockout flange like some other folks here. My reasons for using the Aisin were two folds: I was getting a drveishaft vibe from the front and to save some mpg on a 4,000+ plus roadtrip last Xmas.
These flanges don't pull the axle all the way out like the stock flanges do. Yesterday, I mimicked the stock axle location by using four C clips; three on top of the splines (behind the groove), one in the groove. This puts the axle in same location as oem flange, however, the Aisin outer dial (lock/free) wouldn't fit as needed. Meaning, that there's a dust cover inside the dial that's hitting the tip of the axle. I think the Aisin lockout hubs was discussed in a prior thread some time ago. The conclusion at that time was to mill the end of the axle down in order to accomodate the Aisin hubs properly. Or mill another C clip groove, further outward than the oem groove, or perhaps extend the oem groove.
Since i wasn't able to use four C clips, I been using only two. Even using three clips prevented the Aisin outer to go on properly. With only two clips, the axial movement was a hair over 0.19" (see math below), perhaps a bit more. While drivng with the hubs "locked", the axle moved toward the diff and the bell rubbed the ceiling of the housing. Obviously some of the metal shavings were picked up by the ABS magnet. Perhaps the seal got damaged from the shavings, I don't know. The covered magnet explains my occasion ABS freakout during stops. Incidentally, the passenger side magnet had some shavings but not nearly as much. That side doesn't have birf soup that I can tell.
Math for determining axial play:
One C clip is .095". So using three C clips behind the groove is: .095" *3 = 0.285". Since I was using only one behind the groove, the axle movement was at least: 0.285" - 0.095" =0.19" (+/-) .
0.19" was enough for the bell to contact the housing. There isn't a whole lot of play in there. If this was a Land Rover
, this wouldn't matter but uncle Toyota likes his tolerances to be precise !
For right now, I'm using the oem flange until things are sorted out. If there's a way to either mill down the internal dust cap then I'll go back to the Aisins. I could machine out a spacer to go behind the oem C clip groove but that wouldn't solve all of my problems.
So, I guess for those of you Aisins, take a look at the ABS sensor for metal shavings. If you got shavings, then you probably have the same issue as me.
I'm attaching the Birfield diagram that I got from this board in the past for everyone's reference. Also attached is a pic of the internal dust cap/dome that's preventing me from using four clips (three behind the groove + 1 in the groove).
Ali
Here's my take on it:
Everything was great until I installed the Mini truck Aisin lockout flange like some other folks here. My reasons for using the Aisin were two folds: I was getting a drveishaft vibe from the front and to save some mpg on a 4,000+ plus roadtrip last Xmas.
These flanges don't pull the axle all the way out like the stock flanges do. Yesterday, I mimicked the stock axle location by using four C clips; three on top of the splines (behind the groove), one in the groove. This puts the axle in same location as oem flange, however, the Aisin outer dial (lock/free) wouldn't fit as needed. Meaning, that there's a dust cover inside the dial that's hitting the tip of the axle. I think the Aisin lockout hubs was discussed in a prior thread some time ago. The conclusion at that time was to mill the end of the axle down in order to accomodate the Aisin hubs properly. Or mill another C clip groove, further outward than the oem groove, or perhaps extend the oem groove.
Since i wasn't able to use four C clips, I been using only two. Even using three clips prevented the Aisin outer to go on properly. With only two clips, the axial movement was a hair over 0.19" (see math below), perhaps a bit more. While drivng with the hubs "locked", the axle moved toward the diff and the bell rubbed the ceiling of the housing. Obviously some of the metal shavings were picked up by the ABS magnet. Perhaps the seal got damaged from the shavings, I don't know. The covered magnet explains my occasion ABS freakout during stops. Incidentally, the passenger side magnet had some shavings but not nearly as much. That side doesn't have birf soup that I can tell.
Math for determining axial play:
One C clip is .095". So using three C clips behind the groove is: .095" *3 = 0.285". Since I was using only one behind the groove, the axle movement was at least: 0.285" - 0.095" =0.19" (+/-) .
0.19" was enough for the bell to contact the housing. There isn't a whole lot of play in there. If this was a Land Rover
, this wouldn't matter but uncle Toyota likes his tolerances to be precise ! For right now, I'm using the oem flange until things are sorted out. If there's a way to either mill down the internal dust cap then I'll go back to the Aisins. I could machine out a spacer to go behind the oem C clip groove but that wouldn't solve all of my problems.
So, I guess for those of you Aisins, take a look at the ABS sensor for metal shavings. If you got shavings, then you probably have the same issue as me.
I'm attaching the Birfield diagram that I got from this board in the past for everyone's reference. Also attached is a pic of the internal dust cap/dome that's preventing me from using four clips (three behind the groove + 1 in the groove).
Ali
IdahoDoug said:
1st, the shims are for setting the preload on the bearings and not positioning the housing.
2nd, the housings position is determined by the knuckle arm and how it sits in the lower trunion bearing, as everything rests on that pin. So changing the shim thickness on the bearing cap in an effort to alter the position of the housing is a waste of time.
What holds the birf in the center of the housing is a product of the spindle bushing and the drive plate. The 2 of them align the tub shaft of the brf so it is centered.
Now either the bushing is shot or the hub assembly you have decided to install is not centering the birf. If that hub was slightly off centered it would cause a wobble in the birf as it rotated. Those marks on the outside of the birf, were they restricted to a section of it or uniformly around the entire outside.
alia176
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Rick,
I did take a look at the spindle grooves before reinstalling everything. They looked normal and uniform to my eyes. The marks on the outside of the birfs do go all the way around.
The Aisin hub assembly is the culprit here due to the fact that it's allowing the birf to move axially in and out. Remember, I didn't have any of this issue until I went to the Aisin hubs.
During my last major birf job, all bearings and races were replaced. I feel that everything is where they should be after I went back to the oem drive flange. Only time will tell I suppose.
Ali
I did take a look at the spindle grooves before reinstalling everything. They looked normal and uniform to my eyes. The marks on the outside of the birfs do go all the way around.
The Aisin hub assembly is the culprit here due to the fact that it's allowing the birf to move axially in and out. Remember, I didn't have any of this issue until I went to the Aisin hubs.
During my last major birf job, all bearings and races were replaced. I feel that everything is where they should be after I went back to the oem drive flange. Only time will tell I suppose.
Ali
The problem is the in-and-out movement of the birf/inner. This is causing the bell to hit the housing and it is acceerating seal wear because the seal lip is getting pushed back and forth. Spindle bushing wear is also a possibility but a result as opposed to a cause.
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I'd throw those hubs right in the trash or actually take the time to fab up a shim plate or what ever so they fit properly. I suppose that excessive back and forth movement might also "pump" oil into the housing.
I was only concentrating of the busshing as I've seen one that was completely trashed along with the splines on the drive plate and it was alowing tons of grease and oil to mix.
I was only concentrating of the busshing as I've seen one that was completely trashed along with the splines on the drive plate and it was alowing tons of grease and oil to mix.
Rick,
I agree with your 1st point that the shims affect the preload on the knuckle (trunion) bearings.
However, I disagree with your 2nd point and here's why. The top knuckle bearing cap and the lower knuckle arm cap have shouldered bushing surfaces. The deeper the top knuckle bearing penetrates (thinner shim), the higher the steering knuckle will ride vs the axle housing because these shoulders are what places upward or downward pressure on the knuckle bearings - they bear the entire load of the truck. This also places a bit more upward pressure on the bottom knuckle bearing and corresponding downward pressure on the upper bearing, which is the gamble aspect of this mod I've been testing for about 50,000 miles.
To your supposition, the steering knuckle height vs the knuckle housing then determines the height of the spindle bushing and drive plate opening vs the differential housing, not the other way around as you suggest. It all starts with the knuckle-to-diff housing measurement and that's what I changed on mine years ago to see if I could indeed correct where the axle runs in the inner axle seal. Mine was running low (6 0'clock direction) so I've changed the shim. So far, so good.
I studied this very carefully before doing it. I even considered re-using the lower knuckle bearing/race while using new top knuckle/race on the theory that it would be more likely to allow the knuckle housing to be moved upward and still maintain proper knuckle bearing preloads top/bottom. In the end, I elected to use new top/bottom as if I were wrong I'd like to have new stuff in there to better handle any issues. In retrospect this will also allow me to see wear patterns starting from fresh parts to see how things lasted, vs the old lower bearing would not have yielded any usable wear data due to wear prior to making the change.
At any rate, I've got lots of miles on this change with no ill effects. When I tear it down (if the darned thing ever starts leaking
I'll be able to confirm if I changed the wear pattern on the inner axle seal but at this point I think I can say there have been no problems from knuckle bearing preload.
DougM
I agree with your 1st point that the shims affect the preload on the knuckle (trunion) bearings.
However, I disagree with your 2nd point and here's why. The top knuckle bearing cap and the lower knuckle arm cap have shouldered bushing surfaces. The deeper the top knuckle bearing penetrates (thinner shim), the higher the steering knuckle will ride vs the axle housing because these shoulders are what places upward or downward pressure on the knuckle bearings - they bear the entire load of the truck. This also places a bit more upward pressure on the bottom knuckle bearing and corresponding downward pressure on the upper bearing, which is the gamble aspect of this mod I've been testing for about 50,000 miles.
To your supposition, the steering knuckle height vs the knuckle housing then determines the height of the spindle bushing and drive plate opening vs the differential housing, not the other way around as you suggest. It all starts with the knuckle-to-diff housing measurement and that's what I changed on mine years ago to see if I could indeed correct where the axle runs in the inner axle seal. Mine was running low (6 0'clock direction) so I've changed the shim. So far, so good.
I studied this very carefully before doing it. I even considered re-using the lower knuckle bearing/race while using new top knuckle/race on the theory that it would be more likely to allow the knuckle housing to be moved upward and still maintain proper knuckle bearing preloads top/bottom. In the end, I elected to use new top/bottom as if I were wrong I'd like to have new stuff in there to better handle any issues. In retrospect this will also allow me to see wear patterns starting from fresh parts to see how things lasted, vs the old lower bearing would not have yielded any usable wear data due to wear prior to making the change.
At any rate, I've got lots of miles on this change with no ill effects. When I tear it down (if the darned thing ever starts leaking
I'll be able to confirm if I changed the wear pattern on the inner axle seal but at this point I think I can say there have been no problems from knuckle bearing preload.DougM
Wow
Man, believe me this was a real brain squeezer to figure out when I did it years ago. Cross your fingers, cause if this works out I think a lot of 80s are going to be able to go a lot longer before their axle seals leak. I even called in a favor at Toyota HQ and had a long conversation with one of their best national service trainers who was intimately familiar with the 80's front axle design. Turns out there's actually a factory tool to align the axle on FJ40s, but none for the 80. Grrr....
DougM
DougM
Doug, I've re-read your post another 3 times and all I can say is that one of us has no idea what's going on. 
alia176
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- #39
Doug,
Is the wear pattern THAT obvious on the seal?
Rick,
I wouldn't blame the hubs just yet. If so, then lots of folks on this board will need to chuck their Aisin hubs. Like any mods, this one needs to be studied further. If folks are going to go to the 2wd Tcase mod like in Australia, then these hubs need to work. Aisin hubs are by far the best hubs for our vehicle from what I've read on this board. I just don't feel like machining my axle shaft right now nor do I have the facility to do this!
Keep the ideas coming!
Ali
Is the wear pattern THAT obvious on the seal?
Rick,
I wouldn't blame the hubs just yet. If so, then lots of folks on this board will need to chuck their Aisin hubs. Like any mods, this one needs to be studied further. If folks are going to go to the 2wd Tcase mod like in Australia, then these hubs need to work. Aisin hubs are by far the best hubs for our vehicle from what I've read on this board. I just don't feel like machining my axle shaft right now nor do I have the facility to do this!
Keep the ideas coming!
Ali
Alia, ok I won't blame the hubs just the guys using them. Take a little time to think through these types of changes. Any time you're being told to space things with washers or such an alarm should go off in that knoggin of yours that this might not be something all that wonderful. Your truck is a 96 which would mean you have the longer stub axle to start with. Now if all the other successful installs are on older trucks than that might be where you are having some issues and they are not.
This mod has been kicking around here for a while and I haven't really put any time into it as I think it's pretty rediculous to cripple a vehicle in this way just to save some gas. But that's me, if I wanted a part time 4x4 then that's what I would have bought.
This mod has been kicking around here for a while and I haven't really put any time into it as I think it's pretty rediculous to cripple a vehicle in this way just to save some gas. But that's me, if I wanted a part time 4x4 then that's what I would have bought.
