Rear axle job and pics.
- Thread starter OGBeno
- Start date
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Another example of a home-made SST
Hey the pin bolts what size are those? I used 5/16 and they berely fit those look bigger.
Sadly my tool suffered catastrophic failure (I had center bolt snapped.) I would weld crap out of the tool but me being so quick to start on work, I parked my cruiser blocking my welder
So I had to improvise and just used another 5/16 as the center bolt.
Sadly my tool suffered catastrophic failure (I had center bolt snapped.) I would weld crap out of the tool but me being so quick to start on work, I parked my cruiser blocking my welder
So I had to improvise and just used another 5/16 as the center bolt.
Bad luck with your STT.
I used Gr8.8 M8 bolts which actually measure Ø 7.85mm. The three holes in the hub nut measure Ø 8.25mm, so 5/16" bolts should fit no problems.
Measuring with a vernier makes it easy.
Any idea if trust washers are double sided? Can you flip them on the other side?
I had been checking my rear end (no jokes please
) and looking for info on the internet and came to conclusion that some of the setups o n this forum calling for little loose side on bearings are wrong. That trust washer appears to be there to stop lower portion of outter bearing from spinning on spindle, and it will not stop it if washer is polished or does not apply enough force to the side of the bearing. I am going to flip mine on the side that has most friction if it is double sided. It looks like it is. Any idea?
Or maybe I get new one?
Anybody know where to get new thrust washers ?
I had been checking my rear end (no jokes please
) and looking for info on the internet and came to conclusion that some of the setups o n this forum calling for little loose side on bearings are wrong. That trust washer appears to be there to stop lower portion of outter bearing from spinning on spindle, and it will not stop it if washer is polished or does not apply enough force to the side of the bearing. I am going to flip mine on the side that has most friction if it is double sided. It looks like it is. Any idea? Or maybe I get new one?
Anybody know where to get new thrust washers ?
CruiserDan or your favorite Toyota dealers. AFAIK, those washers can be oriented either way. You are over-thinking this.
-B-
Well lock nut plate appears to be only one sided. They can be installed wrong way which is a bad thing but they are not double sided.
FSM does not mention it just shows the picture. When one is looking at the edge of the lock nut plate, he can discover that one side is cut deeper then the other. The "shallow cut" side goes towards the lock nut the longer cut side goes to bearing. Somebody who worked on my axle before put lock nut plate wrong way allowing it to move.
Here is the pic from the FSM
Now I need to unbolt passenger side and check it.
According to cruiserdan, flush is the nominal correct depth:
And according to DougM, a little deeper than flush, if needed.
I did this over the weekend after getting the parts from CDan. I have been reading on this very briefly for past few weeks and completely missed the part of this small seal until I came across actually installing it. I had grease all over me so did not want to piss off the wife by walking in the house (from the garage) to login here and check the details. So I installed the small seal; one side with flush and the other side deeper (on the tapered)
. I guess I will find out over time which side goes first. 
And it also keeps my consistent with CDan and DougM said .
- Thread starter
- #69
Check the hub studs!!
Well, with the rig down in preparation for the Spring/Summer wheeling season, I tore apart the rear axle and found some disturbing sights and pieces of metal (much of it conforms to Rick's conjectures about the Poly Performance rear axle shafts):
Background: Last winter I installed the PP rear axle shafts for the wheeling season. Did the job and everything seemed kosher.
Fast forward to my first wheeling trip with some folks on here and I'm heading up Hurrah Pass after having done Lockhart Basin, and I hear some serious metal sounds....odd....I don't feel anything....I look out my USPS rear view mirror and I watch as my rear axle goes flying out the side!
Pull up and over Hurrah Pass and then go back and find my axle shaft (USPS RR) on the side of the trail. Get it and then go back to my rig and all of the studs and two dowel pins have been sheared off. The hub is in bad shape and gear oil spilling onto the trail. Well, luckily, it's a full floater. Stuff a rag into the spindle, put some tape over the opening, pull the rear drive shaft, lock the CDL and get into Moab and pull into CM09 and put the rig up on stands. Gave CDan a call and he was coming up the next day and --as always--saved my ass by bringing the spare hub he had from his donor vehicle. Stuff the axle shaft in--tough to do because the rear locker was not engaged, so the little gear fork fell in--put her back together and continued to do the Rubicon and a Death Valley trip throughout the rest of the year. The rig is not a DD, so it sees very little mileage. So, I still owe CDan a rear hub (and they are not cheap from Toyota--well north of $400.
Knowing what I know, I went ahead and would torque down the hub nuts every time just to be sure nothing was loosening up on me. I thought everything was fine.
So I tear into the rear end a week or so ago and lo and behold, the hub studs on the USPS RR came off by hand and each of them were bent. Bummer. Worse still, the two dowels had sheared off underneath the face of the hub, so no way I could go in and get them out.
The USDS RR hub was mostly fine: the dowel pins were intact, but the hub studs again were bent to all hell and one of the set-screws had sheared its head off meaning I had to bust the rear axle hub nut geting it off (those aren't cheap either--almost $90 a pop--I have two extras luckily).
Long story short, I am convinced now that I have for all intents and purposes destroyed two USPS RR hubs that the short side PP rear axle shaft had something to do with it. Not sure what, or how, or in what type of situation, but indeed these have been a costly error and a costly experiment in terms of upgrading to something solid.
What I am doing currently: I took both hubs, cleaned them up and took all four axle shafts (2 PP and 2 OEM) and brought them to a machinist. First off, he is going to put 4 3/8" dowels into the hubs and drill out corresponding holes in all 4 of the rear axle shaft flanges, so that I will put the OEM shafts back in, strengthened with 4 total dowel pins, and I am throwing the PP rear axle shafts into the extra/emergency parts bin. They just aren't worth it and I do not recommend them for anyone who will be doing some tougher stuff.
Now there is a caveat: maybe I got a one-off bad production model from PP (I did talk with them and they said "sorry...good luck"
), or maybe there was user installation issues (I doubt it). CDan is convinced it's those shafts. Also talked with Robbie about this issue and he also said it would be logical to assume that something is obviously going wrong with the combination of the PP shafts and the OEM hub. He did say Christo has run them and that he didn't know if there were any issues when he wheeled with them hard (and Christo wheels hard, as we all know).
At this point, I am going back to OEM and seeing if some extra/hardened/larger dowel pins will keep things in order.
Anyway, sorry for the long winded explanation, but figured a whole picture would be better than just a couple of snapshots....
Speaking of....here are some pics of the bent hub studs and the sheared off dowel pin, along with a portion of the hub face.
Best.
-onur
Well, with the rig down in preparation for the Spring/Summer wheeling season, I tore apart the rear axle and found some disturbing sights and pieces of metal (much of it conforms to Rick's conjectures about the Poly Performance rear axle shafts):
Background: Last winter I installed the PP rear axle shafts for the wheeling season. Did the job and everything seemed kosher.
Fast forward to my first wheeling trip with some folks on here and I'm heading up Hurrah Pass after having done Lockhart Basin, and I hear some serious metal sounds....odd....I don't feel anything....I look out my USPS rear view mirror and I watch as my rear axle goes flying out the side!
Pull up and over Hurrah Pass and then go back and find my axle shaft (USPS RR) on the side of the trail. Get it and then go back to my rig and all of the studs and two dowel pins have been sheared off. The hub is in bad shape and gear oil spilling onto the trail. Well, luckily, it's a full floater. Stuff a rag into the spindle, put some tape over the opening, pull the rear drive shaft, lock the CDL and get into Moab and pull into CM09 and put the rig up on stands. Gave CDan a call and he was coming up the next day and --as always--saved my ass by bringing the spare hub he had from his donor vehicle. Stuff the axle shaft in--tough to do because the rear locker was not engaged, so the little gear fork fell in--put her back together and continued to do the Rubicon and a Death Valley trip throughout the rest of the year. The rig is not a DD, so it sees very little mileage. So, I still owe CDan a rear hub (and they are not cheap from Toyota--well north of $400.
Knowing what I know, I went ahead and would torque down the hub nuts every time just to be sure nothing was loosening up on me. I thought everything was fine.
So I tear into the rear end a week or so ago and lo and behold, the hub studs on the USPS RR came off by hand and each of them were bent. Bummer. Worse still, the two dowels had sheared off underneath the face of the hub, so no way I could go in and get them out.
The USDS RR hub was mostly fine: the dowel pins were intact, but the hub studs again were bent to all hell and one of the set-screws had sheared its head off meaning I had to bust the rear axle hub nut geting it off (those aren't cheap either--almost $90 a pop--I have two extras luckily).
Long story short, I am convinced now that I have for all intents and purposes destroyed two USPS RR hubs that the short side PP rear axle shaft had something to do with it. Not sure what, or how, or in what type of situation, but indeed these have been a costly error and a costly experiment in terms of upgrading to something solid.
What I am doing currently: I took both hubs, cleaned them up and took all four axle shafts (2 PP and 2 OEM) and brought them to a machinist. First off, he is going to put 4 3/8" dowels into the hubs and drill out corresponding holes in all 4 of the rear axle shaft flanges, so that I will put the OEM shafts back in, strengthened with 4 total dowel pins, and I am throwing the PP rear axle shafts into the extra/emergency parts bin. They just aren't worth it and I do not recommend them for anyone who will be doing some tougher stuff.
Now there is a caveat: maybe I got a one-off bad production model from PP (I did talk with them and they said "sorry...good luck"
), or maybe there was user installation issues (I doubt it). CDan is convinced it's those shafts. Also talked with Robbie about this issue and he also said it would be logical to assume that something is obviously going wrong with the combination of the PP shafts and the OEM hub. He did say Christo has run them and that he didn't know if there were any issues when he wheeled with them hard (and Christo wheels hard, as we all know).At this point, I am going back to OEM and seeing if some extra/hardened/larger dowel pins will keep things in order.
Anyway, sorry for the long winded explanation, but figured a whole picture would be better than just a couple of snapshots....
Speaking of....here are some pics of the bent hub studs and the sheared off dowel pin, along with a portion of the hub face.
Best.
-onur
Very interesting Onur and thanks for taking the time to document it all. I'd be very interested to know exactly what was causing the stud issues.
Conjectures made in this forum somewhere? Link? I'd like to know what the issue is exactly, as I've been toying with the idea of going with stronger shafts to try to avoid the twisted spline nightmare.
- Thread starter
- #72
Got the Hubs back....
Got the rear FF hubs back and I am really happy with the work my local machinist did.
Added 2 extra 3/8" dowels to each hub, and drilled out the other two sheared dowel pins from the USPS hub. He also drilled each of the rear axle flanges to accommodate the new dowels and the old ones combined, thus having 4 dowel pins on each axle shaft as opposed to the two that came stock.
Looking forward to seeing if this "retards" my ability to bust rear hubs.
I also bought brand new OEM studs for each, as well as OEM wheel studs for each and tapped out the hub holes for the studs, and added Locktite Blue on each to add strength to the hub studs.
Best.
-onur
Got the rear FF hubs back and I am really happy with the work my local machinist did.
Added 2 extra 3/8" dowels to each hub, and drilled out the other two sheared dowel pins from the USPS hub. He also drilled each of the rear axle flanges to accommodate the new dowels and the old ones combined, thus having 4 dowel pins on each axle shaft as opposed to the two that came stock.
Looking forward to seeing if this "retards" my ability to bust rear hubs.
I also bought brand new OEM studs for each, as well as OEM wheel studs for each and tapped out the hub holes for the studs, and added Locktite Blue on each to add strength to the hub studs.
Best.
-onur
- Thread starter
- #73
And a few more for fun.....
I wonder if the issue has to do with stronger shafts that do not absorb shock like the factory shafts. It would surprise most to know that under load an axle shaft twists and untwists constantly. It's been awhile but if memory serves an axle shaft can actually do a full twist under shock load and untwist without harm. In this way, they act as a shock absorber. In the old days with older mettalurgy I think they twisted even further.
The splines on each end and the parts they transmit torque through are designed as a unit to handle the maximum designed load. By putting in a different axle shaft that either is stiffer or has different rebound characteristics it is easy to end up with force spikes at the beginning or ending of this twisting action that are far higher than the factory intended. So it may well be that a "stronger" shaft is not the best solution, but a new shaft and new parts at each end that the splines engage in.
Speaking more generally about the rear shafts and splines that have been broken on the FF rear axle, it is worth noting the decrease in spline strength that occurs with wear. Anybody who's pulled their axle shafts will note that the splines show wear. What's important to know is that the splines wear unevenly along their length - especially if the axle has been twisted and untwisted frequently as might occur in a rig with lockers, big tires and wheeled hard. What happens is the splines wear more as they enter the diff gear and less at the tip of the axle deep in the diff. So gradually the splines aren't carrying the full load simultaneously along their length anymore. The same wear characteristic is taking place on the gears these splines slide into - with their "female" splines exhibiting the same wear. Eventually, a shock load puts more and more twist into the splined section until it finally cracks as only part of the spline length is taking the load.
So, a way to avoid rear axle shaft failure might be to consider replacing the splined parts when a new OEM shaft is installed in order to have the load spread evenly along the splines. I'd be curious to know if anyone's been able to break a Toyota shaft with new shafts and new splined gears in the diff and at the hub. That combo would restore the even load along the splines.
Anyhow, I'm rambling but I would be interested if a "stronger" axle shaft is not such a good thing in terms of placing WAY more stress on other parts by no longer absorbing shock loads itself.
DougM
The splines on each end and the parts they transmit torque through are designed as a unit to handle the maximum designed load. By putting in a different axle shaft that either is stiffer or has different rebound characteristics it is easy to end up with force spikes at the beginning or ending of this twisting action that are far higher than the factory intended. So it may well be that a "stronger" shaft is not the best solution, but a new shaft and new parts at each end that the splines engage in.
Speaking more generally about the rear shafts and splines that have been broken on the FF rear axle, it is worth noting the decrease in spline strength that occurs with wear. Anybody who's pulled their axle shafts will note that the splines show wear. What's important to know is that the splines wear unevenly along their length - especially if the axle has been twisted and untwisted frequently as might occur in a rig with lockers, big tires and wheeled hard. What happens is the splines wear more as they enter the diff gear and less at the tip of the axle deep in the diff. So gradually the splines aren't carrying the full load simultaneously along their length anymore. The same wear characteristic is taking place on the gears these splines slide into - with their "female" splines exhibiting the same wear. Eventually, a shock load puts more and more twist into the splined section until it finally cracks as only part of the spline length is taking the load.
So, a way to avoid rear axle shaft failure might be to consider replacing the splined parts when a new OEM shaft is installed in order to have the load spread evenly along the splines. I'd be curious to know if anyone's been able to break a Toyota shaft with new shafts and new splined gears in the diff and at the hub. That combo would restore the even load along the splines.
Anyhow, I'm rambling but I would be interested if a "stronger" axle shaft is not such a good thing in terms of placing WAY more stress on other parts by no longer absorbing shock loads itself.
DougM
- Thread starter
- #75
Nice read Doug and reasonably logical analysis.
CDan and I have been thinking about my rear hub issues for almost a year now since I upgraded to the PP axle shafts.
I am hoping going back to stock shafts and with the strengthened hubs I will avoid future failure. The PP's will be used as spares now.
Expensive experiment indeed.
You can buy upgraded hub studs as well as adding dowels to strengthen the hubs. They can be bought from Front Range Offroad.
Upon assembly, the outer face of the hub as well as the axleshaft flange were completely dry and used a paper gasket right? I've heard of lots of issues when using RTV or assembling without cleaning the mating surface between the axleshaft and hub.
I've got a 60 FF rear so this is a very interesting discussion.
Upon assembly, the outer face of the hub as well as the axleshaft flange were completely dry and used a paper gasket right? I've heard of lots of issues when using RTV or assembling without cleaning the mating surface between the axleshaft and hub.
I've got a 60 FF rear so this is a very interesting discussion.
- Thread starter
- #78
- Thread starter
- #79
I for one enjoy your experiments.
Makes mine less expensive.
That 's called negative learning.
