Broc Luno

OK, year later and I should update the group. Everything has been fine. The only hit is about 0.3 MPG. I used to average 22.2 on mixed, but mostly highway miles. The same drive now is 21.8 MPG or so. Other than that, you'd never know it was in there, until you go to launch the boat on an unimproved ramp ... Never even turn a tire. Just up the beach and away you go 🙂

Ride should be similar, maybe a bit stiffer ... Compression will not be compromised much. But droop (drop) will be limited. Suspension modification are always a compromise. You have to trade something for what you want ...

In Kazakhstan with all the unimproved roads, I would do the Highlander rear spring/strut upgrade. Probably easier to get the parts off a wrecked car. Wheel spacers are OK, but they do put extra load on the wheel bearings. I would try for a build that would minimize any unnecessary strain on suspension parts. Have fun and be safe :)

RX's will usually go over 300K with normal maintenance and some attention paid to the suspension. I plan to keep rolling mine until they pry it out of my hands. I don't think you get into the sweet spot on pricing until they hit about 125K. There is a psychological threshold there somewhere. For both buyers and sellers. And I agree on the Hybrids :)

Probably no problems ... The biggest issue is off road in rocks. The rim width will expose more sidewall to rock cuts. Usually for off road in tough country we use a tire about an inch wider across the tread than the rim width. That pinches the sidewall in a bit and protects it. The tread is the widest part, so takes almost all the abuse. Yours will be somewhat different ...

Yup, most are interchangeable. There are some differences in special order axles and stuff. But run of the mill stuff all goes over.

OK, but the only way to really know is pull the rear diff cover and look. Might do that when you get ready to change the rear diff fluid ... Easy to reseal as Toyota/Lexus only uses a bead of RTV around the edge to seal the rear cover, even from the factory.

OK, I just posted an update on the Torsen Posi swap for my RX in that thread: Posi (Limited Slip Diff) for your RX Some decent info if you need one.

OK, here is the long over due update. I have an 03 and I contacted Jimmy Vasser Toyota (JVT) in Napa Calif to see whether they would do the swap for me? Yes, they would. So I found a Torsen rear diff at B&R Auto Wrecking in Oregon (excellent source of good parts: https://www.autowrecking.com/ ). Bought it and had it shipped. Around $240 by the time it got here. I had already been shipped a couple of non-posi's by other vendors (advertised as posi's), and refunded my money when I pulled the rear covers and found them to be std open diffs. eBay adverts can be misleading ... But they all made it right, just annoying. In case anyone is looking at door stickers and build codes, and trying to decode stuff, that is a gamble. The only way to make sure is to put the VIN # into the Toyota "as delivered" database and see if it comes up with a posi as an installed option. The donor vehicle for these parts was: JT6HF10UXX0090348 I do not know which number in this sequence denotes posi ... I took the car in to JVT to have some other service work done last month. I needed the dash dissembled to fix a non-functioning blend door, an engine service, etc. The car has less than 100K on the ODO, so I'm letting dealer do the work for now. That way it's all in the Toyota/Lexus system. This is planned to be our travel car, so I want any Toyota dealer to see what has happened so far, if I need a fix on the road ... I had them pull the rear cover and inspect (all good), install all new seals, etc. In about a week, they called and said they had finish everything but ... They could not get the axles to fasten up. The Torsen Posi has larger axle shafts and bigger differential flanges than a stock open diff. So they "one bolted it" so it could be moved outside while I went on the hunt for used proper axles and hubs. They quoted $4K if they had to order all new parts from Lexus. That's a big ouch if I could not find what I needed ... While this was going on, the Hennessy Lightning Fire blew up and became the LNU Complex Fire, and then parts of southern Oregon started burning too. So B&R found the correct parts in one of their yards, but the yard was in a fire zone. By the time we all slowed down from burning enough to resume business, weeks had gone by. But JVT was kind enough to store the car and wait. Another $180 for both rear axles, CV joints and hubs finally got drop shipped to JVT. While that was going on, the Glass Fire started. We were in the fire zone and had to fight the fire to keep our house, so glad the car was safely away. You can read about it here: https://www.mercurynews.com/2020/09/29/as-famous-wineries-burn-around-them-not-so-typical-napa-valley-couple-fights-all-night-to-save-home/ After the fire was under control and travel could resume, we fetched the car. JVT's charges were around $800 split over two bills due to the delay in parts sourcing. I have since driven the vehicle a little less than 1,000 miles and it acts just like a regular RX 300 on the road. No chirping, shudder, whine, or any other sign it has a posi. But on the dirt or gravel it is different. 99% of the time you can not get it to turn a wheel from a standing start. Granted I have not hit hard from dead stop, but I have a pretty steep part of my gravel drive (35* slope) and it'll go up that from a standing start on slope w/o so much as hearing one little rock roll over. It is uncanny how grippy it is. This car will be used to pull my 16' fiberglass runabout, hopefully to Lake Chelan next year, and launch it on some "primitive" ramps (gravel). I expect it to perform perfectly, but I'll test that here on slippery tidal ramps in the next week or two. Anyway, anyone contemplating this should not be put off. The parts are out there. My stuff came off a nice clean wrecked 1999 RX 300. But there were no fitment issues other than needing the correct axles and hubs. There are no error codes. The ABS seems to act normally. I can't see why or how it is not a 100% improvement over stock open diff vehicle 🙂

Just to be clear on my terminology: Center section means the guts of a differential (carrier & internals), and in my posts, does not refer to the transfer case. I do mean to be introducing the transfer case into this discussion in any way. The used diff example I'm dealing with is not simply a Posi, this is a Torsen center section with spiral gears and no clutches. I am new to Toyota and Lexus and their terminology. I use phrases and terms I have used all my life, all the way back to NASCAR in the late 1960's (Super Modifieds). I am an experienced off roader who got paid for years to do off-road trail condition surveys, erosion assessments, etc. I am not an expert in Lexus or Toyota parts naming conventions. But among the off road community outside of Toyota the terms I use are fairly commonly used ...

That works fine if you have a Lexus VIN. In general, Toyota VIN's are a bit harder to decode. And not all Wreckers will supply the VIN until after you buy the part ... Since Lexus stopped offering Torsen Posi's after 2001 or so in the USA, you'd be searching on old vehicles, usually with a lot of miles. But, Toyota offere3d the same rear diff in Highlanders and Rav 4's. So getting a later model rear diff with less miles out of one of these is more likely. But, in doing so you end up where I was with bogus and misleading parts sales and the hassel of sorting it all out. Of course, if you are really fixated on this and have the cash, you can still buy a Torsen center section from Toyota for your existing re4ar diff at about $2,400 and then the cost of installation. That's why I went the used route ...

Well, just a short update: After ordering and cancelling or returning, or just dumping in the recycle bin (after getting refund) on three eBay "Torsen Posi's" sold as used, I finally got a real one. Came out of a Highlander with 119K miles in Oregon. So they are out there 🙂 Had back and forth's with the vendors. Most won't even take the time to pop the rear cover and actually check ... They insist they are factory Torsens. But when they get here, they are not. Sent letter to Toyota asking about using VIN or Build Plate to ID candidate cars, no dice - they would not supply any info (not good customer support). I really don't get the secrecy around this stuff ?? Car's at Vasser Toyota in Napa getting other service work (door locks, blend door failure, etc) and they are putting new seals into my Torsen and installing. Will report on drive-ability issues if any come up ...

I dunno if the Gen II RX's will work well with the Toyota Limited Slip Differential (LSD) due to the change in transfer case? I just don't know enough about that build. But, if you want to add capability, you could try a posi rear end. You'd be looking for a donor vehicle (RX, Highlander, Rav4) with an axle code -04A denoting the factory Torsen LSD option. If you find one in the same year as yours, you'd know it'll work with the transfer case and it would be a good upgrade 🙂

Well I found one in Oregon with 158K on the ODO. Seller (B&D Auto Wrecking) confirmed that it was/is a locker. So after the previous three vendors failed to check well enough and either sent the wrong part, or just refunded my money after double checking, I pulled the trigger and got it. Yup, it's a Toyota OEM Limited Slip Differential carrier complete. Raining right now, so don't want to open it up, but will in a few days. Looks like the right rear stub axle seal was weeping, so before it goes into my RX, I'll have the shop install all new seals and double check the lash. I don't want a noisy one replacing a dead silent existing one... So I got a photo of the "Build Plate" off the drivers door jam (sticker) from the donor vehicle (Highlander) : So you see the axle data in the lower right hand corner? It says -04A for this axle. My existing one is a std open diff (-02A). It's the thing you are looking for when out shopping. -04A is the axle code to look for in the field when hunting for one of these. I have seen one door sticker with an -03A on it, but was not able to get any more info about what axle that might be ...

Well I found one in Oregon with 158K on the ODO. Seller (B&D Auto Wrecking) confirmed that it was/is a locker. So after the previous three vendors failed to check well enough and either sent the wrong part, or just refunded my money after double checking, I pulled the trigger and got it. Yup, it's a Toyota OEM Limited Slip Differential carrier complete. Raining right now, so don't want to open it up, but will in a few days. Looks like the right rear stub axle seal was weeping, so before it goes into my RX, I'll have the shop install all new seals and double check the lash. I don't want a noisy one replacing a dead silent existing one... So I got a photo of the "Build Plate" off the drivers door jam (sticker) from the donor vehicle (Highlander) : So you see the axle data in the lower right hand corner? It says -04A for this axle. My existing one is a std open diff (-02A). It's the thing you are looking for when out shopping. -04A is the axle code to look for in the field when hunting for one of these. I have seen one door sticker with an -03A on it, but was not able to get any more info about what axle that might be ...