Lexus RX Towing

vic47vic47 Member Posts: 4
For information. I just purchased a 2010 RX 350 AWD Lexus. The sticker on the door, the manual, and as validated by Lexus,say that the payload is 825 lbs. Four guys slightly over 200lbs without luggage would break the weight budget. More applicable, me, my wife, daughter and son-in-law (both thin), 5 year old grandson as well as the dog also blow the weight budget. Can't even think about luggage when transporting the family. I checked the Lexus web site as well as the vehicle brochure and nowhere could I find a payload figure. Also, It seems that most other web sites have a much higher number for the payload. This is somewhat disappointing and may be a factor in considering the purchase of this vehicle.

I am reposting this message under its own discussion title. Orginally I had inadvertently posted it under another discussion. My apologies.


  • jbl85jbl85 Member Posts: 49
    I am considering towing a load of 3400 pounds behind my '05 RX330. I do have the towing package installed but I wanted to get other's input on their towing experiences with the 330 and if it is advised or not?

    Also, is the towing hitch that Lexus installs sufficient for the job or are there better alternatives.

  • tidestertidester Member Posts: 10,059
    Be sure to check out Towing tips for SUVs as well.

    tidester, host
  • jbl85jbl85 Member Posts: 49
    Thanks much. I searched that forum for an RX330 and no go...I guess people just don't do a lot of towing with the RX's...
  • tidestertidester Member Posts: 10,059
    While waiting for a reply here you may want to toss out your question in the main Lexus RX 330 discussion.

    tidester, host
  • la4meadla4mead Member Posts: 347
    I have an early '99 RX300 with the towing package, which includes one additional auxilery factory transmission cooler and heavy-duty radiator, etc. A main weak point of towing a fairly light load (under the 3500 lbs mine is rated at, and I assume yours is, too) according to the transmission mechanic and a trusted Lexus dealer I sought out is the transmission heat, and I'm guessing that hasn't changed on your 330 with your 5 speed trans. These units were not built with heavy duty bearings or towing or extended idling in mind, and the exhaust passes right under the tranny, so in extended low-speed pulling, idling, maneuvering, etc. they can't get rid of the heat build up, even with the radiator fan on. :sick:

    The factory trans cooler is not fan-forced; it is in the fender well so the heat does not flow back to the radiator and engine (cooled only by the airflow from the brake cooling duct-fine when the airflow is moving).

    I have one of the first RX's out. Although I originally did not tow anything with it, it developed well-known valve body issues that were resolved by Lexus by replacing the whole transmission under warrantee with a brand-new upgraded unit. Now it works as it should, but I also take extra care since I want to keep this car in good shape for a long time. Even though I have another vehicle for heavy towing, I also want to be able to tow with the RX, on occasion.

    I service it very often. New fluid at 6 months, full service with filter at 18 months, just to be safe. You might not go so often, but I would service it before towing.

    I asked the Lexus dealer's Service Manager who was in charge of the transmission replacement if it would void the warrantee if I added an additional transmission cooler, or it would hurt anything. He said no, it would be a good idea, but not in front of the radiator. I didn't say it was specifically for towing, but I said someday I would like to... So I added an additional redundant trans cooler in back of the factory cooler in the fender, and cut the vent holes larger in the black plastic inside fender skirt (you can't see it from outside the car) to let the heat vent out easier. It wasn't really hard to install if you are a do-it-yourselfer, but if not, a transmission shop could do it, too. Just be sure to specify you want them to use only Toyota fluid! ;)

    Since then, I've seen coolers that are thermostatically fan-forced (I don't recall where, you would need to search for them) but finding one that would fit between your windshield washer bottle and the stock trans cooler in the fender well might prove to be a trick, unless there is room in the driver's side fender brake cooling duct on the 330! That may be overly complicated.

    Tips... Make sure when you are towing you take the transmission out of overdrive, so the transmission does not have to make that shift automatically. It will also be easier on your brakes, too.

    Does your 3400 lb trailer have brakes? Usually they do.

    I think it will be fine. Don't overload the car or trailer with weight. Distribute the weight evenly, and not too much near the tounge or back of the car, and certainly not on the roof.

    The factory hitch is rated at 3500, I believe. If you don't have the factory hitch already, you can find heavier-duty hitches which will be stronger, rated for more weight even though you won't tow with more, and distribute the weight to the frame better (try the internet, like or others), but don't go over the weight rating for the car anyway, but they are stronger. Uhaul's are barely adequate, only very light duty, but usually in stock.

    Let me know what you find out, and keep it cool! :shades:
  • jbl85jbl85 Member Posts: 49
    Wow thanks for all of your input. Actually the 3400 weight rating is the GVWR. The trailer unloaded is actually 2500 pounds and we don't plan on putting too much additional weight inside the trailer if we are towing it.

    I have the towing package installed from the factory and I hate the fact that I may have to second guess that system and have to install an additional cooler for the tranny?? I will talk to the service manager as you did to get the skinny on that. I guess what bothers me is the fact that these cars' transmissions are not meant for heavy duty applications and even though they are rated at a certain load (3500 w/the TP) I am just a little paranoid as you might imagine.

    Thanks again for your input and I will be inquiring with the Lexus dealership with an authority on the subject not the sales guy I spoke to before.

  • la4meadla4mead Member Posts: 347
    It sounds like your fairly light trailer will be fine, I wouldn't be worried at all. I added the extra cooler just to add an extra measure of longevity; my early model is known for having a problematic 4-speed trans, before they replaced it under warrantee.

    However, I'd still keep in mind to be aware of extended low-speed maneuvers and idling (towing or not), that's where the trans picks up extra heat from the engine exhaust that doesn't necessarily show up on the engine's "temp" gauge.

    My gauge never moves from it's normal spot, even before the cooler, but I can put my finger on the trans cooler, and it's damn hot, much hotter than the metal part of the radiator, so I know that trans fluid is hot (hotter than my motorhome runs at) and having the cooler is better than not having one (normal driving, no trailer)!

    I think most trans shops and some other folks who tow a lot will always err on the side of adding an additional cooler and frequent fluid changes, since it doesn't hurt anything and could only help the trans last longer. Lexus always says they don't recommend any modifications, but when pressed, they just won't warrantee the cooler mods... See what the Service Mgr. says. They probably will tell you just to change the fluid, but wouldn't hurt to have a cooler, even if you never, ever tow.
  • rav4mnrav4mn Member Posts: 10
    Looking at several used 2004 RX330's. I often get poor anwsers when I ask if it has tow prep pkg or not...even from Lexus dealers!

    Is there a way I can tell...e.g. can I spot the tranny cooler somewhere or some wire harness mod in the back? Or is there someway to decode the VIN to tell me?
  • la4meadla4mead Member Posts: 347
    I'd love if someone else who has this model without the tow prep package would verify this... Mine is RX300, however on the model you are looking for, I believe you will want bring something to be prepared to lay on the ground under the back bumper so you are not uncomfortably crouched. Laying on the ground looking up at the inner metal bumper frame you should be able to see a capped-off wiring harness (the part that comes with tow prep package) near the middle of the bumper frame somewhere, unless they already added the trailer wiring plug (usually associated with the hitch).

    The transmission fluid cooler will be in front and inside the front passenger-side fender well. You will look inside the front lower (brake) intake air duct (the one under the pass. side headlights) with a flashlight, I'm not positive on the '04 but on mine it's behind and under/behind the bottom of the windshield washer reservoir bottle, I think it will be the same description for the '04-07. It looks like a small "radiator" with hoses going back to the radiator.

    I don't know how to tell you the difference between the heavy-duty alternator and radiators, unless two vehicles with different equipment were sitting side-by-side.

    Many (but not all) of the vehicles off the line were equipped with the "towing prep package" (a low-cost option, they just came that way) except when they had the "performance package". PP equipped vehicles were not eligible for towing, for some reason Lexus decided not to make the air suspension heavy-duty in this model while their other models (LX, GX, etc.) it was. I think the tow prep package raised the tow rating from 1500 to 3500 lbs, but even if you never tow, I think it's worth every penny for the heavier-duty components, and you are wise to look for a used car that was so equipped, especially if it does not have a hitch and never towed a thing.

    I don't know if any RX's without the tow package were equipped with factory tranny coolers or not, which may throw you off. It's possible some of the AWD models were, even if they didn't have tow package. It would be interesting to hear from other owners.

    P.S. See more info on the RX330 Forum on this subject. They are really good cars and when well cared for give years of great service. From what I've read, 2005 seems to be an even better year than '04, if you come across one that fits your budget. I hope you are happy with what you find!
  • la4meadla4mead Member Posts: 347
    Hey RAV and/or JBL,

    Just curious if you found what you were looking for.
  • rav4mnrav4mn Member Posts: 10

    Yes and No. I found and purchased a beautiful 2004 RX330...but it did not have the tow pkg. I figured this out by NOT finding a second tranny cooler anywhere (the dealer did not know and could not confirm or deny!).I do tow a 2000 lb. pop-up camper about 3 times per year, so not "heavy duty" use. I doubt I am even going to pay for an add-on cooler. In an ideal world, it would be nice to have add all that extra margin that the tow pkg provides, but the RX we do have is the car or our dreams and we're happy and no lookin' back. (Crystal white, Navigation, Mark Levinson, premium plus, 18" wheels, 30k miles, flawless)
  • mike208mike208 Member Posts: 3
    I just bought a 2005 RX does not appear to have the towing prep package...I can't find any wiring behind the bumper...I can find lots of trailer hitches but no light conversion the dealer my only choice?
  • krisvkrisv Member Posts: 25
    Anybody out there have the factory installed trailer hitch? We're trying to find a picture of the factory hitch and the Lexus website only has a close up of it so you can't see how it fits around the tail pipe. If you have the factory hitch and can send a picture I'd greatly appreciate it. You can send it to [email protected] THANKS!
  • wwestwwest Member Posts: 10,706
    Even if your RX has the towing package, extra ATF cooling, it probably REQUIRES the extra ATF cooling for normal operations and so there is no EXTRA cooling provided for "abnormal", towing use.

    This appears to be especially true for the RX330 series as the factory recommended maintenance schedule for ATF flush/refill has been revised downward, from infinity to every 15,000 miles.

    At only 40,000 miles the ATF in my '01 RX300 was quite clearly BURNED, I assume due to being overheated. My '01 has the towing package but I removed the hitch the week I bought the RX and it has not endured any level of heavy or seevre duty, at least not by normal standards.
  • wwestwwest Member Posts: 10,706
    Mine is leaned up against a tree out in back so I'll try to get you a quick snap.
  • tidestertidester Member Posts: 10,059
    That's kind of surprising. I'd think the payload would be closer to 1300 pounds or so. The lowly Geo Metro is supposed to be capable of carrying a 600 pound payload. Anyone know what the deal is here?

    tidester, host
    SUVs and Smart Shopper
  • marqevansmarqevans Member Posts: 29
    Then how is it capable of towing?
  • vic47vic47 Member Posts: 4
    My understanding is that vehicle payload is only one factor in determining towing capability and is part of the maximum allowable gross vehicle weight capability of the vehicle . Per the manual, "when towing a trailer it is the sum of the vehicle weight (including the occupants, cargo, and any optional equipment installed on the vehicle) and the tongue load".
  • jbl85jbl85 Member Posts: 49
  • wwestwwest Member Posts: 10,706
    Your RX330, and all later RXes, makes use of DBW for a myriad of reasons but the primary one being to "protect the drive train". The "abolition" of the old style ATF line pressure pump with the introduction of the RX in '99 resulted in the transaxle not having the capability of completing a second gear change in quick sucession to the previous.

    With your RX330 you are likely to encounter 1-2 second re-acceleration engine torque delivery delays as a result of this drive train protection measure.
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