DIY 4.3 Re-Gear

[LanceL]

Does anyone have the P/N’s for the OEM 4.3 R&P sets? I’d rather just get the parts new and have them installed rather than source unknown used ones (or have to buy whole brand new 3rds, as they’re quite expensive) but I can’t find the actual P/N’s for just the gears themselves. The Toyota parts website is hard to navigate and doesn’t do a great job of providing details or fitment info unless you put in the exact vehicle.

 

[TLC2013]

First post lists the part #: OEM R&P 4.3 parts kit 41201-80493

With the toyota parts sales that pop up every so often I as able to pick up the complete 3rd member for around $1250. Took a few weeks to arrive.

 

[bloc]

Does anyone have the P/N’s for the OEM 4.3 R&P sets? I’d rather just get the parts new and have them installed rather than source unknown used ones (or have to buy whole brand new 3rds, as they’re quite expensive) but I can’t find the actual P/N’s for just the gears themselves. The Toyota parts website is hard to navigate and doesn’t do a great job of providing details or fitment info unless you put in the exact vehicle.

Alternate viewpoint: Toyota would have set up those gears with better precision than the vast majority of shops doing the same work now. I’d personally prefer to use a 100-200k mile 100-series third member (assuming everything checks out) over a new gear set up installed by a random local shop.

Find a wizard like Zuk? Sure. But he’s only working with locals now.

 

[highfructose]

Alternate viewpoint: Toyota would have set up those gears with better precision than the vast majority of shops doing the same work now. I’d personally prefer to use a 100-200k mile 100-series third member (assuming everything checks out) over a new gear set up installed by a random local shop.

Find a wizard like Zuk? Sure. But he’s only working with locals now.

Was there a selectable rear locker equipped 200 series in the Middle East? Depending on the gears it uses, that differential might be a good swap.

 

[bloc]

Was there a selectable rear locker equipped 200 series in the Middle East? Depending on the gears it uses, that differential might be a good swap.

Yes but between the high cost with shipping, and the aftermarket presenting a good solution available here, it’s probably worth going to an Eaton/Harrop over that.

 

[cubaniche]

So I followed your recommendation @TLC2013 and picked up the ECGS bushing and both tools. I pulled both needle bearings. Had to disassemble the tube side to remove it because I had already assembled everything. This side could have used an ECGS bushing too. The LX diff doesn't have a bearing but the carrier is machined for an exact fit of the axle tube shaft to fit sugly. Pulling the needle bearing out of that side of the tundra diff leaves a wider diameter hole than on the LX diff so the axle tube shaft is only supported by the splined face of the shaft. I only ordered one bushing but I'll probably order another one and install it on that end as well. I checked and the bushing fits over the LX axle tube shaft.

Thanks for sharing the issue with the needle bearing and the nifty solution by ECGS. Upon searching around I found that these needle bearings fail and are inany toyota diffs.

 

[bloc]

IMO the bushing isn’t needed. The reason Toyota puts a bearing into the Tundra application is their ADD diff causing the passenger side spider and axle half to spin opposite of normal rotation when the ADD is disconnected, and then needing something to support that little half-shaft.

In the AWD LC/LX configuration the axle stub should be supported by the splined section into the diff and the outboard bearing. No support in the middle of that shaft is needed, which is why it didn’t come with support there in the first place.

 

[cubaniche]

IMO the bushing isn’t needed. The reason Toyota puts a bearing into the Tundra application is their ADD diff causing the passenger side spider and axle half to spin opposite of normal rotation when the ADD is disconnected, and then needing something to support that little half-shaft.

In the AWD LC/LX configuration the axle stub should be supported by the splined section into the diff and the outboard bearing. No support in the middle of that shaft is needed, which is why it didn’t come with support there in the first place.

I'm no engineer. So maybe I'm not describing things clearly enough. However, as I stated, that same area where the needle bearing is on the tundra diff (axle tube side) is a solid machined surface in the LX diff. So, the shaft is 100% supported there and by the splined area of the carrier on the diff side. When you remove the needle bearing you are left with a wider hole, where on the lex diff, that section is machined smaller, I guess like a race.

I grabbed the tundra axle stub and it slides in perfectly into the same side of the LX diff wich had no bearing, and it has zero play. I then took that same stub shaft and put it into the tu dra diff it came out of with the now removed needle bearing, and it wobbles when you spin it.

I guess the main point I'm trying to make here is that the LX diff doesn't have a bearing in that spot but it doesn't need one because it's a smaller diameter hole to begin with vs the tundra diff, and the shaft is guided or supported by it. Anyways, maybe there's zero need for anything there but the stock LX diff is machined in that area smaller diameter for a snug fit of the stub shaft.

 

[TeCKis300]

I'm no engineer. So maybe I'm not describing things clearly enough. However, as I stated, that same area where the needle bearing is on the tundra diff (axle tube side) is a solid machined surface in the LX diff. So, the shaft is 100% supported there and by the splined area of the carrier on the diff side. When you remove the needle bearing you are left with a wider hole, where on the lex diff, that section is machined smaller, I guess like a race.

I grabbed the tundra axle stub and it slides in perfectly into the same side of the LX diff wich had no bearing, and it has zero play. I then took that same stub shaft and put it into the tu dra diff it came out of with the now removed needle bearing, and it wobbles when you spin it.

I guess the main point I'm trying to make here is that the LX diff doesn't have a bearing in that spot but it doesn't need one because it's a smaller diameter hole to begin with vs the tundra diff, and the shaft is guided or supported by it. Anyways, maybe there's zero need for anything there but the stock LX diff is machined in that area smaller diameter for a snug fit of the stub shaft.

Let us know what you figure out. Keeping an open mind as to new ways to tackle this. I did notice what you're describing. Normally a support interface like that wouldn't be metal on metal unless there was sufficient oil pressure to create a fluid film bearing and I wasn't sure that's what's there.

My setup has been in place since 2020 and 50k miles without that intermediate support. Lots of off-road miles and heavy towing with no issues. Time will tell.

I also didn't both bother to change the needle bearing on the CV / driver side. Figuring most that have issues with the needle bearing are due to higher lifts creating more CV angle and load on that bearing. The LX has the benefit of AHC and lower on freeway. So far so good but I'll share back if anything comes up.

 

[cubaniche]

Let us know what you figure out. Keeping an open mind as to new ways to tackle this. I did notice what you're describing. Normally a support interface like that wouldn't be metal on metal unless there was sufficient oil pressure to create a fluid film bearing and I wasn't sure that's what's there.

My setup has been in place since 2020 and 50k miles without that intermediate support. Lots of off-road miles and heavy towing with no issues. Time will tell.

I also didn't both bother to change the needle bearing on the CV / driver side. Figuring most that have issues with the needle bearing are due to lift creating more CV angle and load on that bearing. So far so good but I'll share back if anything comes up.

Cool man. Yeah, I figured it would be ok since many have done it just like this without issue. Just bringin it up since I'm doing the work and noticing little stuff like that, and I like to discuss. I'm huge on trying to stay as close to the way the engineers designed things.

One thing I messed up, now that I'm looking at it, is I didn't mark the front drive shaft when I took it off because it was supposed to stay in place. Well, what happened was the slip yoke section slid off while I was removing the diff so now I'm unsure of how it was oriented before. I was looking online and it seems like the joints should line up on both ends the same so it's "in phase" and not rotated opposite of one a other like in out of phase setups.

 

[TLC2013]

Digging into these needle bearing failures on other Toyota platforms it looks like that they are much more common in high lift trucks and only on the driver side of the front diff. The passenger side doesn’t suffer from the same failures as there is the axle extension tube between the CV and the Diff. The driver side has the CV passing directing through the needle bearings and at high angles and load ultimately leads to early failure.

@cubaniche I havent seen the bushing installed on the passenger side, does it look like the same bushing will fit in? EGS only markets it for the driver side. At this stage With the diff out and apart it sure would make for the perfect time to install, never be easier.

Between the cost of 2 EGS bushings and their tools, the cost is more then I spent on my low mileage used Tundra diff

 

[cubaniche]

Digging into these needle bearing failures on other Toyota platforms it looks like that they are much more common in high lift trucks and only on the driver side of the front diff. The passenger side doesn’t suffer from the same failures as there is the axle extension tube between the CV and the Diff. The driver side has the CV passing directing through the needle bearings and at high angles and load ultimately leads to early failure.

@cubaniche I havent seen the bushing installed on the passenger side, does it look like the same bushing will fit in? EGS only markets it for the driver side. At this stage With the diff out and apart it sure would make for the perfect time to install, never be easier.

Between the cost of 2 EGS bushings and their tools, the cost is more then I spent on my low mileage used Tundra diff

Nice! Mine was 200 but it came out of a 19 with only 49k. Yup, both bearings are identical. Yeah, I read a ton of reports on the beedke bearing failing on the driver side on tundras, 4r, sequoias. It's well documented. I just never came across the issue until TLC2013 brought it up.

I don't want to wait for another bushing to show up, plus all you guys are running the diff and lx axle tube without the bearing so I'm just going to finalize the install. I already have the diff installed. Gotta break in the rear gears since I went with new nitro R/P. Can't wait to start driving it again and see how these 4.30s do with the supercharger.

 

[TLC2013]

Nice! Mine was 200 but it came out of a 19 with only 49k. Yup, both bearings are identical. Yeah, I read a ton of reports on the beedke bearing failing on the driver side on tundras, 4r, sequoias. It's well documented. I just never came across the issue until TLC2013 brought it up.

I don't want to wait for another bushing to show up, plus all you guys are running the diff and lx axle tube without the bearing so I'm just going to finalize the install. I already have the diff installed. Gotta break in the rear gears since I went with new nitro R/P. Can't wait to start driving it again and see how these 4.30s do with the supercharger.

Before your posts i never even considered adding the bushing to the passenger side, in hindsight i should have ordered two. I do know folks here are successfully running the tundra diff with that needle bearing left in place on the passenger side which was my plan from the beginning.
I am ready to install the diff and dont feel like buying another bushing and delaying my weekend re-gear project.

 

[cubaniche]

Before your posts i never even considered adding the bushing to the passenger side, in hindsight i should have ordered two. I do know folks here are successfully running the tundra diff with that needle bearing left in place on the passenger side which was my plan from the beginning.
I am ready to install the diff and dont feel like buying another bushing and delaying my weekend re-gear project.

Same! I wanted to be done with this so bad that I ordered from ECGS very early yesterday with overnight delivery just so I could have it today and finish tomorrow
It didn't occur to me to order a second bushing until I was in there today removing the needle bearing from both ends.

 

[TLC2013]

Same! I wanted to be done with this so bad that I ordered from ECGS very early yesterday with overnight delivery just so I could have it today and finish tomorrow
It didn't occur to me to order a second bushing until I was in there today removing the needle bearing from both ends.

Ahh man, i feel your pain. Looking forward to hearing how the gears and SC perform!
You'll be the fastest cruiser to the gas station

 

[bloc]

Normally a support interface like that wouldn't be metal on metal unless there was sufficient oil pressure to create a fluid film bearing and I wasn't sure that's what's there.

This is the key detail. I know it may seem like that area supports the axle but aluminum on steel without a pressurized oil film is a very quick path to a grenade.

And the support isn't needed anyway. Our rear axle shafts have one bearing at the hub but a -lot- of load (orders of magnitude more than the front) is still transmitted to the diff carrier via the axle shaft end, and there are no additional supports there.

If I were to guess the reason for the tighter tolerance is just to help alignment during assembly. Our rear axle does have a steel neck welded in to help guide the axle into the diff during assembly..

One thing I messed up, now that I'm looking at it, is I didn't mark the front drive shaft when I took it off because it was supposed to stay in place. Well, what happened was the slip yoke section slid off while I was removing the diff so now I'm unsure of how it was oriented before. I was looking online and it seems like the joints should line up on both ends the same so it's "in phase" and not rotated opposite of one a other like in out of phase setups.

Per the manual the best way is to line up the grease zerks. The ones in the u-joints and the one for the slip yoke should be arranged as below, and everything will be back to normal. It is possible to assemble it with the ends in-phase, but the slip yoke is rotated 180 degrees from when toyota assembled it. This will most likely throw off your balance.

 

[cubaniche]

This is the key detail. I know it may seem like that area supports the axle but aluminum on steel without a pressurized oil film is a very quick path to a grenade.

And the support isn't needed anyway. Our rear axle shafts have one bearing at the hub but a -lot- of load (orders of magnitude more than the front) is still transmitted to the diff carrier via the axle shaft end, and there are no additional supports there.

If I were to guess the reason for the tighter tolerance is just to help alignment during assembly. Our rear axle does have a steel neck welded in to help guide the axle into the diff during assembly..



Per the manual the best way is to line up the grease zerks. The ones in the u-joints and the one for the slip yoke should be arranged as below, and everything will be back to normal. It is possible to assemble it with the ends in-phase, but the slip yoke is rotated 180 degrees from when toyota assembled it. This will most likely throw off your balance.

View attachment 3649638

Awesome thanks! I'll line it all up like that tomorrow when I put it back on.

 

[TLC2013]

This weekend installed the 4.30 tundra front diff and 4.30 OEM rear diff.
@100kiwi and @psnyman for their assistance and time in getting these installed. Team effort led by @100kiwi for a sub 4.5 hour install for the whole project. The Eaton locker and wiring harness were installed prior so this was as straightforward as possible and a plug and play install.


Here’s some data on the rear diff temps that I had been monitoring using an infrared laser temp gun. Is a real testament to the quality of Toyota gears.

LC weighs apprx. 7,000 lbs.

Factory 3.90 Rear diff with 130,000:
highest temp I logged was 114 F after 2 hours of highway and finishing on some winding country roads with elevation changes.

Brand new Toyota 4.30 rear diff with Eaton Locker:
Highest temp recorded on the two hour drive was 133F. Mix of highway, elevation changes and winding country roads.

 

[cubaniche]

This weekend installed the 4.30 tundra front diff and 4.30 OEM rear diff.
@100kiwi and @psnyman for their assistance and time in getting these installed. Team effort led by @100kiwi for a sub 4.5 hour install for the whole project. The Eaton locker and wiring harness were installed prior so this was as straightforward as possible and a plug and play install.


Here’s some data on the rear diff temps that I had been monitoring using an infrared laser temp gun. Is a real testament to the quality of Toyota gears.

My LC weighs apps 7,000 lbs.

Factory 3.90 Rear diff with 130,000:
highest temp I logged was 114 F after 2 hours of highway and finishing on some winding country roads with elevation changes.

Brand new Toyota 4.30 rear diff with Eaton Locker:
Highest temp recorded on the two hour drive was 133F. Mix of highway, elevation changes and winding country roads.

Awesome. Glad to hear it. I finished my install early yesterday morning. Then started the break in procedure for the new rear gears which is a 10 mile drive then 20 to 30 minute cool down, and do that 5 times. Then change the fluid at 500 miles or so. The break in fluid is non-synth 75w140. I'm going to put synthetic 75w90 once the break in is done.

It made a huge difference in drivability with the 35s. I don't have a bunch of added weight like full bumper and armor builds. I've just got the sliders and roof rack. I'll eventually be getting a dissent rear bumper. I'm babying the gears for the break in (rear). So I can't do any hard acceleration tests but these gears coupled with the superchargers low end tq is just so different vs the 3.90s. No longer downshift all the time. Doesn't hang on to a gear forever before shifting (under normal driving). It's essentially behaving just as it did when it was 100% stock. I can be doing 50 and goose the throttle a bit to accelerate up to 60 without it downshifting to 4th like it used to (it would downshift to 5th and then when it wasn't enough cause it was barely gaining speed, I'd have to give it a touch more throttle and bam, it'd shift to 4th). Now it just stays in gear and accelerates swiftly.

All in all, very happy with the preliminary results. I'm sure I'll see a slight bump up in fuel economy simply because of the elimination of all the bad shift behavior it had before.

 

[TLC2013]

Awesome. Glad to hear it. I finished my install early yesterday morning. Then started the break in procedure for the new rear gears which is a 10 mile drive then 20 to 30 minute cool down, and do that 5 times. Then change the fluid at 500 miles or so. The break in fluid is non-synth 75w140. I'm going to put synthetic 75w90 once the break in is done.

It made a huge difference in drivability with the 35s. I don't have a bunch of added weight like full bumper and armor builds. I've just got the sliders and roof rack. I'll eventually be getting a dissent rear bumper. I'm babying the gears for the break in (rear). So I can't do any hard acceleration tests but these gears coupled with the superchargers low end tq is just so different vs the 3.90s. No longer downshift all the time. Doesn't hang on to a gear forever before shifting (under normal driving). It's essentially behaving just as it did when it was 100% stock. I can be doing 50 and goose the throttle a bit to accelerate up to 60 without it downshifting to 4th like it used to (it would downshift to 5th and then when it wasn't enough cause it was barely gaining speed, I'd have to give it a touch more throttle and bam, it'd shift to 4th). Now it just stays in gear and accelerates swiftly.

All in all, very happy with the preliminary results. I'm sure I'll see a slight bump up in fuel economy simply because of the elimination of all the bad shift behavior it had before.

Right on, nicely done. Glad to hear all went well with the install and you are on your way with the break in procedure. Do you have the ability to check your rear diff temps? Sounds like the idea is to keep temps below the 200-250F range. I picked up a $15 temp gun on Amazon that is remarkably accurate for the price.

I was pleasantly surprised by how well the Toyota gears ran from mile one, no break in period necessary from what I have seen, I am still taking it easy for the first couple hundred miles.

I think if I wasn’t so heavy and aerodynamically challenged the gear upgrade would be even more noticeable. The peppiness off the line is much better now and 4-low is more responsible.