Rx300 Engine Mount

[bowtie3]

The other day when I drove my wife's 2000 RX300 FWD [54,000 miles ] I noticed a clunk / jerk when put it into Drive or Reverse. Being the retired GM tech that I am, I had my wife put the car into gear, both drive and reverse while I observed with the hood open. The engine wanted to " roll over " in the engine bay. This is a trait of FWD vehicles when the top engine strut / mount [ dogbone ] is broken or worn-out. When told by the Lexus service rep that this is NOT covered by the Certified Warranty [ she referred to it as a " wear item " ] I contacted several of the websites mentioned on this forum. I ordered the part form Park Place Lexus in Plano, Texas. [ $52.00 including shipping ] Replacing this part took about 20 minutes. When observing the old part I noticed that the rubber wasn't ripped or torn but just worn-out. This part keeps the engine from moving forward and rearward when changing directions, thus PREVENTING transmission and axle damage due to misalignment. I'd like this post to enlighten other RX300 owners who have also noticed a " movement " of the engine while putting the car into gear. P. S. The Lexus dealer wanted about $215.00 to replace the part. [ 1 1/2 hours labor----$135.00 and $80.00 for the part ]

[TunedRX300]

The other day when I drove my wife's 2000 RX300 FWD [54,000 miles ] I noticed a clunk / jerk when put it into Drive or Reverse.  Being the retired GM tech that I am, I had my wife put the car into gear, both drive and reverse while I observed with the hood open.  The engine wanted to " roll over " in the engine bay.  This is a trait of FWD vehicles when the top engine strut / mount [ dogbone ] is broken or worn-out.  When told by the Lexus service rep that this is NOT covered by the Certified Warranty [ she referred to it as a " wear item " ] I contacted several of the websites mentioned on this forum.  I ordered the part form Park Place Lexus in Plano, Texas.  [ $52.00 including shipping ]  Replacing this part took about 20 minutes.  When observing the old part I noticed that the rubber wasn't ripped or torn but just worn-out.  This part keeps the engine from moving forward and rearward when changing directions, thus PREVENTING transmission and axle damage due to misalignment.  I'd like this post to enlighten other RX300 owners who have also noticed a " movement " of the engine while putting the car into gear.  P. S.  The Lexus dealer wanted about $215.00 to replace the part.  [ 1 1/2 hours labor----$135.00 and $80.00 for the part ]

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Can you post a DIY instruction and tools needed? Thanks

[RX in NC]

Thanks for the warning, Bowtie. It certainly pays to be aware of common problems to look out for on the RX series. Last autumn I was tipped off to the strut mount bushing failure design flaw (which as you know is a Technical Service Bulletin item). Sure enough, we had to address that issue in my wife's vehicle this past January. Looks like a worn-out dogbone issue may be next on the agenda. This vehicle is now pushing 95,000 miles so you can bet that I'll be paying attention to the dogbone. If any clunks or jerks surface, I'll look at the dogbone engine mount first. Thanks again.

[bowtie3]

Thanks for the warning, Bowtie.  It certainly pays to be aware of common problems to look out for on the RX series.  Last autumn I was tipped off to the strut mount bushing failure design flaw (which as you know is a Technical Service Bulletin item).  Sure enough, we had to address that issue in my wife's vehicle this past January.  Looks like a worn-out dogbone issue may be next on the agenda.  This vehicle is now pushing 95,000 miles so you can bet that I'll be paying attention to the dogbone.  If any clunks or jerks surface, I'll look at the dogbone engine mount first.    Thanks again.

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Replacement of the " dogbone " is relatively simple. Requires a 3/8" rachet, 14mm socket, a 1/4" rachet, and a 10mm socket. Unplug harness/wires from cruise-control. Remove 3 10mm nuts that secure the cruise-control and move it to the front of the engine. Lift the power-steering reservoir from its place on the inner fender. [ It's held in by a plastic tab, don't break it! ] Remove the upper and lower bolts. Put some " anti-seize " on the bolt threads. Reverse procedure. I swear it didn't take me more than 20 minutes and I was doing the laundry at the same time. Remember that the dealer wanted $135.00 [ 1 1/2 hours labor ] and $80.00 for the part. I really think that this top engine-mount " dogbone " is an often overlooked problem and anyone who changes their own oil/filter can do this job. I checked my neighbor's 2000 FWD RX300 and found the same condition. I ordered her the same part on Thursday; should be here Monday.

[RX in NC]

Thanks for the details. This post is definitely a "keeper" for future reference. It sounds as if the rubber contact surfaces on the dogbone engine mount will break down and wear out over time, leading to slight engine/transmission alignment issues when shifting gears. As fragile as these damn RX transmissions seem to be, it certainly makes good sense to ensure that the dogbone engine mount gets replaced when its rubber surfaces start to decay.

[dcfish]

Thanks for the details.  This post is definitely a "keeper" for future reference.  It sounds as if the rubber contact surfaces on the dogbone engine mount will break down and wear out over time, leading to slight engine/transmission alignment issues when shifting gears.  As fragile as these damn RX transmissions seem to be,  it certainly makes good sense to ensure that the dogbone engine mount gets replaced when its rubber surfaces start to decay.

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There is a thread in the ES forums that covers this dogbone issue[ ES and RX just about the same ] Some guys rebuild the bushings with a 3M product and put a washer in the mount to reduce the wear. It saves some $$$ Hope this helps ;)

[RX in NC]

Thanks for the tip on doing your own dogbone re-build. If you can post the specific thread here, or include details of the products used for re-build, it would be much appreciated. If this works, I'm sure it saves quite a bit of money by allowing you to fix your existing dogbone for just a few dollars.

[RX in NC]

I inspected the dogbone engine mount on my wife's RX300 yesterday evening. The rubber appears to still be firm enough to allow this mount to do its job. I could see no cracks or chips in the hard rubber components of the dogbone that I could get to without removing the cruise control module or power steering fluid reservoir. So I'll add this component to my inspection routine for this vehicle and keep an eye on it. I also told my wife to let me know if she begins to experience any clunking or jerking as she engages her transmission into Drive or Reverse.

Thanks again for sharing the details.

[dcfish]

I inspected the dogbone engine mount on my wife's RX300 yesterday evening.  The rubber appears to still be firm enough to allow this mount to do its job.  I could see no cracks or chips in the hard rubber components of the dogbone that I could get to without removing the cruise control module or power steering fluid reservoir.  So I'll add this component to my inspection routine for this vehicle and keep an eye on it.  I also told my wife to let me know if she begins to experience any clunking or jerking as she engages her transmission into Drive or Reverse.

Thanks again for sharing the details.

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http://us.lexusownersclub.com/forums/index...1476&hl=dogbone

Search in the ES forums under "dogbone"

[bowtie3]

Thanks for the tip on doing your own dogbone re-build.  If you can post the specific thread here, or include details of the products used for re-build, it would be much appreciated.  If this works, I'm sure it saves quite a bit of money by allowing you to fix your existing dogbone for just a few dollars.

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The appearance of the " dogbone " won't always reflect the condition of the worn-out rubber inside. To really check it out have someone get in the car, put the brake on, and move the gear selector from reverse-to-neutral-to-drive, several times, to see if the engine " rolls over " from front to back. I just ordered a dogbone this morning for the man across the street. Also his '01 RX300 FWD [ 78,000 miles ] cabin air filter had never been replaced; it was ugly.

[TunedRX300]

Thanks for the tip on doing your own dogbone re-build.  If you can post the specific thread here, or include details of the products used for re-build, it would be much appreciated.  If this works, I'm sure it saves quite a bit of money by allowing you to fix your existing dogbone for just a few dollars.

←

The appearance of the " dogbone " won't always reflect the condition of the worn-out rubber inside. To really check it out have someone get in the car, put the brake on, and move the gear selector from reverse-to-neutral-to-drive, several times, to see if the engine " rolls over " from front to back. I just ordered a dogbone this morning for the man across the street. Also his '01 RX300 FWD [ 78,000 miles ] cabin air filter had never been replaced; it was ugly.

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Thanks for the tip, the top mount is easy. I searched and found someone in the ES forum posted this image for lower engine mount.