CB700S

Hi - I've recently purchased a new-to-me 1999 RX300 AWD in surprisingly good overall condition for its age and mileage. It only has two major problems - it is in limp mode because of bad knock sensors, which I am going to see about relocating as a temporary diagnostic measure. The other problem is that the SUV has a howling transfer case, which I believe means it needs replacement - I have to check fluid levels to make sure it's not somehow low or empty, but I expect it will need to be replaced. I had thought it was tire howl when I test drove it prior to purchase as it had bad tires, but replacing the tires showed it was not that. A local well regarded mechanic examined the car and diagnosed it as the transfer case, just to confirm, This sounded likely to me, particularly after I realized that the old tires had significantly different levels of wear and could have screwed up the case.

I have read the factory service manual which says that you must remove the engine, transmission and subframe to get the transfer case out. I was hoping to find a shortcut or a simpler way to do it - and I came across this thread: https://www.clublexus.com/forums/rx-...999-rx300.html

In that thread,@Lexmex seems to imply that the transfer case can be removed from the transmission with everything else in situ. However, it isn't confirmed there or anywhere else that I can find. Does anyone have any details of this potential shortcut? Any assistance would be appreciated.

CB700S

Further research has turned this up - anyone know if this works with our RX300s?

JacobsDad

No short cut.....you have to remove the subframe with drivetrain (motor/transmission) as a single unit. It sounds like a daunting task but actually it's not very difficult. These vehicles are designed to be assembled and disassemble in big chunks.

I mean, you could possibly drop the subframe, steering rack and brake rotor assembly junk..... You could possibly drop it separately from the vehicle if you have some type of cradle to suspend the engine and transmission from above because three of the engine and transmission mounts bolt onto the subframe and once those mounts are gone there's nothing holding the engine up.

PorchDawg

By suspending the engine, as stated above, dropping the cradle, exhaust beneath the engine, both halfshafts/rear driveshaft, engine motor mounts, all steering components, and detach all drivers side electrical, disconnect steering and trans cooler lines then, the transmission and transfer case could be removed and then separated, you're going to end up with tight work trying that method. The engine lift cannot leak down or move in any way while suspended.
Add to that the weight of the trans/TC assembly and IMHO dropping the cradle as as assembly is the best way. Trans/TC weight about 275-300 lbs? TC about 60 lbs.
The TC must move about 5" to the passenger side in order to remove from an internal shaft.
I'm swapping the transmission out on a 2002. Dropping the assembly seems to gave been the correct choice.
you'll likely find engine needs that are easily accomplished while it's out.
Pics and ideas in "Trans No Move" thread that's active.
Good luck!

PorchDawg

Few pics that show thd drain and fill plugs. I believe 15/16 fits. You need to grind a flat edge and radius a 15/16 wrench for the drain plug. The fill plug is accessed with a socket. Use a squirt bottle and hose to fill.
The T case holds 1 qt of 85-90 gear oil (not ATF).
*Don't drain the differential...
Before going into the case, drain whatever is in the case and verify for metal, no oil, wrong oil, grey coloration, and if no overt metal parts in the oil (or stick a magnet into the drain plug hole for residue), refill the case and see if the sound improves. If it does, monitor for seal leak. Rattle the tailshaft yoke and see it it has play or a wet seal.
Check trans fluid too. A failing differential would sound the same.
The TC case and transmission/differential are separately lubricated.



items. Whereas, the trans and differential circulate the trans ATF.

CB700S

Update - I've had a couple local mechanics look at the RX to check my diagnosis, one of which being the shop foreman of a local Toyota dealership. Both informed me that it was absolutely a failing transfer case; the Toyota tech even put the RX up on a lift and pointed out that he'd gone over it with a stethoscope and found the noise seemed to be coming from the back of the transfer case extension.

I have located another transfer case at a local dismantler that is ready to go on a pallet - the donor car was a 2002 destroyed through a moderate front end impact at 144k miles. Other than replacing all the seals on the case, is there anything else I should do to the case prior to having it fitted? (Currently I'm not able to do any major car work as I am recovering from having my last Toyota destroyed by a kid running a red light - bought the RX as a replacement as the insurance company seems to be more interested in fighting than paying out.) Pictures of potential donor below:

PorchDawg

Reseal and have at it. TC cases are henerally good for several 100k plus.
Get your wallet ready! I would suggest letting your mechanic assess the replacement case. Installing it is a tidy bit of work.

CB700S

Yeah, I'm starting to get quotes/bids in on the job and it's not cheap at all. The Toyota book time on it is 14.4 hours and most of my usual shops don't want to touch it because they're already backlogged/booked up to the point where they can't spare the time for it. I suspect that this kind of failure would be why people just scrap the car if they have trans or t-case failures.

At least that donor case looks like it'll be cheap. Probably the only part of this whole affair that will be.

PorchDawg

Mechanics are more concerned with 'owning' the project when dealing with used assemblies and major labor on old, complex cars.
If the TC proves bad or any other issue pops up, customer walks away. And they do not warranty parts, or labor to install, that they don't supply.
I'm R&R'ing an AWD transmission and fully prepared to pull it back out if necessary. A commercial shop cannot get into such situations.
RX300s are plush little cars that age well...until they don't. Transmissions are a common weak point. Retail transmission (or TC) repairs equal the value of a Gen 1 RX. Before pulling that TC out, probably be a good idea to pressure check the transmission and trans filter and pan for metal. Consider any other issues the RX might have also. Also crawl under the car before working on it and verify absence of TC oil leaks. TC cases rarely fail. Might be dome history available?

CB700S

I'm pretty sure I know why the transfer case failed - the previous owner had put two different brands of tire on the front and rear - the fronts were down to the wear bars and the rears were new. Pretty sure that 7/32+ of tread depth difference plus a thousand highway miles would account for that quite nicely.

The trans itself has no leaks, there's no glitter in the ATF and no leaks aside from residuals from a burst power steering hose which has since been replaced. Had a decent maintenance history on it, but the engine was replaced two years ago with a low mileage used one after the original one threw a rod. The trans also seems to be working normally for what it is, though I'm half tempted to take the whole thing to a trans shop and get the trans rebuilt as a preventative measure 'and while you're in there, can you swap this transfer case?'

PorchDawg

That's a plan. Reputable trans shop knows the process.

CB700S

To be certain, you're saying having the trans shop rebuild it as a preventative measure and putting the t-case in as a 'side' action since the entire assembly's out is a good plan?

PorchDawg

Yes. That's exactly what I'm saying, so long as the cost fits your budget. And assuming no other issues with the vehicle?
Keep in mind that the transmission has probably been replaced considering the engine and TC failure. One would assume the car has been rode hard...so to say.
You're 'buying' a warranty on the work for the cost of a transmission service. Have them service the new TC too. That's a simple item...relatively speaking.
IMHO...

CB700S

I have quite a bit of it's service history as it was originally sold through a dealer famous for their high price but concierge service after the sale including maintenance. It doesn't seem to have had a lot of problems per what I can see of that (car has ~280K and I have records through 212K). However, i have now asked the previous owner if they reused the original transmission or used the one from the engine donor - will be interesting to see what they say.

I've been getting quotes on installing the transfer case. Local shops of good repute are quoting $1500-1700 to install the transfer case by itself. However, it’s ‘only’ $2800-3500 to overhaul the transmission *and* transfer case including remove/install. Warranties are running between 18 months/18K miles to 24/24K - so in terms of value, getting the trans rebuilt and 'incidentally' getting the replacement transfer case checked, resealed/repaired and installed is looking like the smarter way to go.

CB700S

Heard from the previous owner - they only swapped the engine from the donor, they kept this car's original transmission as it was known working and the donor had signs that it was scrapped because of transmission failure.