AH3000

A couple weeks ago my 1999 RX300 developed a drive line vibration up front. It went on for a couple of weeks and my wife never let me know about it. I found out when I took the car to a doctors appt when she needed my car. It's pretty bad and has gotten worse.

Normally, I do all my own work, but mostly on RWD cars, so I'm not up on FWD too much.
The RX300 is AWD. I did check the transfer case and it has plenty of oil in it.

As I blew out my knee a month ago and can't bend it, I'm not doing alot of mech work on our cars right now. I took it to the local garage and was told the issue is in the front differential and it would be anywhere from 1000 to 1600 to fix it. I said nope and picked up the car.

Honestly, it feels like a U-joint or something (I've had full size 4WD trucks before) But I'm starting to hear noise from the front end. Trying not to drive it, but had to make a 3 mile run in it today. I didn't go over 35 mph and it's vibrating pretty badly.

I did price out a used diff on ebay for about 300.

I guess I'm looking for advice on how difficult it is to swap one out.
Or what to look for when I pull the diff cover off.. Or info from someone who has had a similar issue

thanks in advance.

carguy07

I have never heard of a front differential on an AWD (AWD not 4WD) car causing vibration. It's incorporated into the transmission, so I would not really call it a serviceable part. I doubt the transfer case would do that either. Are you sure it's not a tire or maybe a 1/2 shaft/CV joint? Any recent damage?

salimshah

Have you checked the cv joints? Both inner and outer on each half shaft.

Salim

AH3000

No damage, I will have to look into the CV joints, as mentioned, I'm sorta side lined so I have to wait for a buddy to drop by. I didn't think diff either. I've had U-joints go out on me before on trucks and it feels kinda similar, so the CV sounds like a good starting point. Time to go read up on them...

trhs75

Sorry to hear about your trouble. This probably isn't it, but years ago my daughter was complaining about a terrible vibration at speed along with noise in her front-drive Olds Intrigue. Turns out she had driven through some fresh tar or something and a LOT of it stuck to the front tires. I poked around with a screwdriver for hours trying to get most of it out. To rule out a tire or rim problem, maybe switch tires from back to front just to see if it changes things. Good luck!

AH3000

Turns out a tooth broke off a gear in the transfer case.

New xfer case from dealer $3600. Used one with same miles 150K, $350. Had a well reputed Lexus guy do the work. Out the door $2000 and some change.

Had to pull the whole transaxle out to get to the transfer case. Got PM done on seals, etc. while it was all out (easy and not that much extra). Said he'd only ever seen it one other time since they came out in 99.

Ended up paying another guy over 500 to **** up the electrical system (he did stop the battery drain but half assed the wiring in the rest of it by wiring around the memory modules) but that's a whole other story.......

Took so long as I was in the hospital and all kind of other stuff got in the way....

kalali

Sorry to hear. How was he able to isolate it to the broken tooth in the transfer case and what could have caused it? Just seems like such an unusual failure mode.

AH3000

Je had seen it once before and you could tell something was jacked up as it would vibrate immediately. what he said was the missing tooth caused the jump or stutter that made the vibration

It was really bad