I know this an age old problem, and I HAVE checked the forums. I could not find a DIY on the motor mounts on the 99 GS400.

I changed my DRIVERS side motor mount recently, but could not get to the passenger side very easily. I have all 3 mounts..(left, right, and transmission), and I want to do the other two.

Is there a special trick to getting to the upper nut on the passenger side mount loose? It looks like I may have to remove the alternator, as well as drop the
lower subframe. The last time I did that, I was on a full wheels-free lift with everything disconnected. The front wheels were removed and I could see the upper nut on the passenger motor mount. The 2 nuts on the lower part of both left and right mounts were disconnected and the engine was clear of the subframe.

I had the front of the engine raised high with wood blocks under the oil pan, and the transmission lowered out back on a hydraulic transmission floor jack. I was scared to go any lower out back because it seemed like the whole engine and transmission was going to fall out.

I just could not get to that upper nut. I believe it is a 17 mm, because it was the same nut on the drivers side.

The transmission mount is easy, but the engine mounts are a pain.

Any suggestions short of taking it into the dealer would be appreciated.

I am here in southern california and I heard that a mechanic named TODD works in a shop out this way. Does anyone know what shop he works in?

Thanks

 

If it's the todd that's well known on clublexus, then he's at TM Engineering. But it seems that his schedule is very tight so I dont know if reaching him will be easy.

Where in socal are you? PM dung0981
He recently changed his engine mount and he was able to complete the project fairly quickly.

 

Thanks so much GSTEG. I am in San Diego this morning, and I wanted to do this before thanksgiving, but I can wait until I talk to someone. I do nearly all of my own work, including the Timing Belt and starter on both of my GS vehicles.

I just don't like this motor mount assembly on the pasenger side. there MUST be an easier way to do this, and I am always willing to learn something.

I am retired military, and have access to the lifts on the MCAS Miramar and the NAS North Island bases. Having good tools and facilities makes most of my work a lot easier.

Thanks again for the quick response.

 

You will get an answer today. My buddy always log onto CL every day. His english may not be the best, so if you don't understand him, let me know and I'll clarify for you.

 

Thanks again. So I assume you are in California as well. I have added you to my list. I may PM you from time to time. My 99GS4 is holding up well after all of these years.

I'm not ready to buy a new one, as this one still runs great. I'm off to the gym for some much needed cardio. I'll check back in about 1 hour or so!

Keep in touch whenever the urge hits.

GSEREP1

 

Hi guys. I don't mean to hijack the thread, but I have a quick question. The dealership recently changed out both motor mounts for me, but not the tranny mount. Is it normal to change the tranny mount at the same time? Is it necessary? Is the tranny mount relatively easy to change? About how long would it take the dealership to change it out? Should I even bother at this point?

e

 

No problem.
The transmission mount is the easiest of the 3 to change. In fact, the "transmission" mount is actually the rear "Engine Insulator". it is just underneath the transmission.

This mount creats stability for the rear of the engine as well as the transmission. When the forward mounts start moving, the rear mount tries to take up some of the slack. It wears just like the two front mounts. The old mount was like putty in my hands. The rigidity in the mount was gone.

Taking a SWAG (Scientific Wild-Assed Guess), I'd say that you couldn't go wrong.

The last time I changed my transmission mount on my old 99 GS, the rubber was collapsed, and was not supporting like it should. I had a high speed vibration out back..(around 70 to 80 mph). It disappeared after those speeds. I tried balancing my tires, but the mount took away the vibration.

Just food for thought.

 

Here is the method to replace the engine mounts on the GS4
1. Remove the cover and the nuts (02 for each side) on the sub-frame support bar
2. Remove the nut on the top of the motor mount( 17mm or 19mm)
3. Remove the bracket, which connected between the engine and engine mount by loosing 4 bolts (12mm or 14mm)
4. lift the engine up. then you will able to remove the engine mounts
Note: You need to do both side of the same time, so you can lift the engine higher, more clearance.
Hope this help

 

Thanks DUNG0981!
I appreciate the quick response both by the web site and by phone. Hopefully I will be able to get to the upper nut and turn it. That has been the problem, but I will give it a try again tomorrow.

I'll let you know my progress!
GSEREP1

 

wow that sounds too easy. There has to be more to it.

 

It sounds easy. Yes really, theres not much to it. Literally about 4 bolts total for the front 2 mounts and another 4 for the transmission mount.

BUT...go try to do the job and you will run into some serious problems. Yes there are only 4 bolts to remove, but there is almost no clearance at all in there. For a small tool maybe it's ok, but these are huge bolts that need a lot of torque to be removed. You need to fit a big breaker bar or impact wrench in there. It's really hard to when you have almost no room to work around and have to twist/turn your hands/arms to fit the tools in there. So that gentlemen...is the hard part

 

It cant hurt to try. I am sure it is not going to be easy, but ill go out with a fight.

 

Keep in mind that jeff has the inline-6. There is a lot more clearance with the inline-6 than there is with the V8. Trust me

 

I was talking about the V8
Trust me, the inline 6 is a snap to change(relatively) compared to the v8.

 

Ah. I only read the first sentence of your post. Yes, the 300 is 23434 times easier than the GS400