aomdedude1

The other day I was driving along and I noticed that I had a very slight humming noise coming from the rear, but I dismissed it thinking it was nothing. My wife used the car the next few days and she told me it was making a weird noise, so I checked it again and sure enough the noise was there.

At first I was thinking this might be the differential making some type of noise, so I lifted the rear and checked the Differential fluid level. I pulled the plug and the differential fluid looks to be in good condition and the level is correct. I went on to check all the rubber bushings in the rear.

They are all not doing so great. The differential bushings are loose, and the drivers side rear lower strut rod bushing (at the knuckle) is so bad that I didn't see any rubber left! I am going to have to replace this but I am not looking forward to putting in the Poly ADUS bushings. Lexus only offers the OEM rear strut rod bushing if you buy the WHOLE KNUCKLE!

Anyway, I now think the noise I heard is actually coming from the passenger side rear wheel.

Here is a video:




My question is, does this sound like a wheel bearing??

I get some side to side movement and also up and down play. The drivers side does not have ANY play compared to the passenger side.

aomdedude1

Is it possible for this to be the CV joint?? How can I test that?

Any Ideas as to how long I can safely ride it like this? I wont have the money in my budget to fix this until mid June!

Greg5OH

what year is your car? if its a UCF 20 roca auto makes oem style sherical bushings you press in (you dont want poly in there, it will bind). Figs engineering also lists the tool that makes this job a breeze. 100 for the tool, 60 bucks for the pair of bushings).
quick check if its wheel bearing-can you pull teh wheel in and out? if it has axial play its wheel bearing. Could be the CV making the noise if its dried out in there for whatever reason (ripoped boot?)

aomdedude1

Sorry, it is a 1994 LS400. Rock Auto was the first place I checked but I did not see any bushings available through there site. Thanks for the information about the tool.

No, the rear has no ripped CV boots and the Drive/CV Axles has no play in them but the Propeller Shaft/Drive Shaft to the Transmission DOES have clockwise/anti-clockwise play in it when I turn it back and forth with my hands.

aomdedude1

So it is now somewhere around three months later and I finally bought all the necessary parts to do the wheel bearing job. All Toyota OEM parts of course that cost me an arm and both my legs. (plus wife was NOT happy lol) So I got under my car today to start the job and I figured that I would spin, what I thought, was the culprit wheel and use a long screw driver pressed up against my ear to listen in. This time I didn't hear the howling noise very strong. Did the same to my differential and heard the noise quite prominently.

So I am starting to think my initial diagnosis was completely wrong. There IS a bit of play in the "culprit" passenger side wheel when compared to the drivers side (good side).

My next move will be to take out the differential and take a closer look.

Does anyone know how likely it is for the differential support bearing to go out? I will take pics and post them as I start digging deeper but I'm done for tonight. Sure hope I figure this out soon and without having to spend more money!

randal

Did you happen to see this thread? -> https://www.clublexus.com/forums/ls4...l-problem.html

aomdedude1

No, I haven't seen that one,but it is an interesting read. Thank you!
I sure hope it is not the whole diff.


After further investigation today after work, I took out all the bolts holding the axle shaft to the differential (six per side). I found a surprise on the passenger side. Here are my findings:

DRIVERS SIDE:




PASSENGER SIDE:



(white match-marks were placed by me for when I reassemble)

Uhm,it's NOT supposed to be like that right?

Also checked differential fluid level and it looks to be spot on right at the top fill plug. All that black oil type substance is actully CV axle shaft packing grease that splattered everywhere while driving. As you can tell the drivers side looks to be completely fine and there is no grease leaking out. Will these axle half shafts need to be replaced or is this part interchangeable/rebuild-able? In case this needs to be replaced,can anyone speak to the quality of aftermarket axle shafts?

randal

Yeah, I think you found the 'smoking' gun. The grease worked out of the RH (passenger) side axle and the CV is probably shot. You can buy a new axle for about $50 but there is a core charge of about $60. I do not know the quality of various brands but Rockauto usually has some decent stuff. Not as good as OEM of course but probably acceptable.

PureDrifter

iTrader: (10)

the axles aren't an overly common wear item, I would either replace both with remanned units, or replace the single axle with a part from a wrecking yard.

aomdedude1

Yeah, I gotta be honest, I was surprised when I saw this and I probably overlooked it in the first place because I never really heard of this happening.

Well, it sucks that I found this out just as the last of my parts came in. A1-Cardone re-manufactured axles are only around 40-70$ each after the core charge, so I'll just go ahead and place an order for them. Since I already have all these parts sitting in my house, I'll make an attempt to slap them on even thought I, in all technicality, do not need every part. At least, I will be riding around on a nearly 100% refreshed rear-end. (that sounds odd...)

My rear strut bar bushings are shot and I ordered new ones from Swell Lexus (yes, I purchased the entire knuckle). I used the Club Lexus discount, so I suppose it could have been a lot worse. Also, I have no idea how old the brake hoses are so I got replacements along with rotors all around. OEM in the front and Rock Auto Brembo specials for 17$ each in the rear along with Akebono pads all around. I did this in hopes to cure my steering wobble on braking. Feels like warped rotors so it should be the ticket. Also, my rear Diff bushings were completely shot so I picked up some new ones along with front strut bar bushings (also shot) and Daizen poly sway bar bushings.

I'm hoping this all goes to tighten up my old worn out suspension and give a little sportier feel to the uncompromising comfort ride that Lexus originally built in. They were waaaaay too conservative with this car. Has anyone seen just how skinny/thin the rear sway bar is!? Its like a twig, no wonder there is so much body roll!

PureDrifter

iTrader: (10)

if that's the case you should return/cancel the knuckles and buy the polyurethane carrier arm bushings instead. no squeaking/creaking and they get rid of some of th factory slop (due to compliant rubber bushings).

Addco sells a rear sway bar for 1st gen LS400s, requires minor fitting (drilling out the end links iirc) but helps a fair bit.

aomdedude1

Im all for saving money. Do you know what the ride quality is like for the Adus poly lower bushings?.... and you probably have a damn good point. Because those rubber bushings will probably end up going bad in a little while anyway and they wont help so much with my goal of giving the car a slightly better feel in the corners....

PureDrifter

iTrader: (10)

i've got coilovers, 20s, and some hard parts. I honestly didn't notice any difference in NVM after installing them.

aomdedude1

I spent the day doing some hardcore work taking stuff apart on the LS400. I had some trouble taking the axles off the car so I decided to just take the entire differential off. I know this is slightly overkill, but I want to take off some of the rust with a wire wheel and respray the diff along with some of the rusting out sub-frame. It sucks because there is practically not a speck of rust on this car from the rear wheels forward. It just looks like a bunch of salt over the years ended up getting flung up to the rear area of the vehicle from all the brutal north eastern winters.

So here are some pics of the disassembly:


Getting ready to lower. All bolts that mount the diff to the sub frame were loosened up. I needed to go out and buy a 12mm hex head to remove the two bolts you can see in the picture.

.

As you can see, the axles that were stuck to the diff were hitting the exhaust. At this point I started to think about what I had gotten myself into! But after removing the rubber exhaust supports and slowly and carefully lowering the exhaust and supporting with two jack stands, I managed to continue the lowering process.






Removing the propeller shaft was a major pain since I had the axles still attached. You need to be very careful at this step because the prop shaft has a nipple/receiver that the rod on the end of the pinion slides into. I took a pry bar and carefully pryed the shaft out. I went back and forth between prying and pulling the differential rearward and eventually the two separated.



OPPS!!!
The differential fell off the rear jack, but it was not as eventful as this photo makes it seem. The differential only slid off the jack and moved about three inches down. No loud boom or crash!


After getting things back in position, I continued lowering:


As you can see, if you are going to remove the diff with the stuck axles attached to the diff, you need to remove the diff at an angle. I unbolted the axles from the hub and banged that portion out no problem.



My reward!!! Please note, that if you are going to remove the diff in this manner, it will completely destroy your axles.Thankfully rebuilt A1-Cardone units are on there way for me.

Well anyway, after getting the diff out I banged out the stuck portion of the rear axles:

aomdedude1

Now here is the part that I really need some serious help and experienced advice with. After the differential was taken out and the rear axles were completely detached, I spun the differential by hand and guess what? There it was the noise!!! I will shortly be posting a video of the noise. It sounds as if there is a bearing issue inside the diff somewhere. The problem is that I am not 100% sure if this is just normal gear noise or not??!

There are two versions of the video and I will post them both. In the first video, the differential had all of its fluid inside is and was freshly off the vehicle. In the second, I drained the fluid and opened up the diff to have a look inside. I tried taking a picture of the drained gear oil but it did not come out good enough to see the small METAL FLAKES in the fluid. There were tiny silver and some brass color flakes in the fluid.

I will be uploading the videos shortly: