Rear Diff. Leak
03-27-18, 01:43 AM
#1
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Rear Diff. Leak
Rear differential has developed a small leak at the front of the housing, appears to be the seal where U-joint shaft connects to the differential. Shop told me if the seal is the problem, I will be looking at a $400-$500 bill. My ‘02 LS430 only has 112,000 miles. Is this a common issue on a 16 year-old car?
03-27-18, 03:02 AM
#2
Lexus Fanatic
I don't think it's common, but did they say what they recommend, if it isn't the seal? Did they see it when it was on the lift? Was the fluid changed out at 90k? In the big picture, if it's $400, imho it's worth it to address, unless you would be topping it off regularly (what I did with my Volvo in college)...
03-27-18, 08:30 AM
#3
Rear differential has developed a small leak at the front of the housing, appears to be the seal where U-joint shaft connects to the differential. Shop told me if the seal is the problem, I will be looking at a $400-$500 bill. My ‘02 LS430 only has 112,000 miles. Is this a common issue on a 16 year-old car?
03-27-18, 03:26 PM
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I had the fluid changed around 100k miles. It has only leaked a couple of drops in my garage, but that’s too much for me. I crawled up under it and it definitely looks to be coming from the seal. I wiped it off really good three days ago and it still hasn’t dripped any in the garage. I have an appointment to take it in to the garage next Tuesday. I suppose if it was an old pickup or cheap car I wouldn’t worry about it, but this car is our baby. I have four vehicles, and this is the only one with any sort of leak. I put valve cover gaskets on the Lexus about 4 years ago. $400 is a lot to spend to fix a small leak, but it can only get worse.
04-04-18, 05:13 AM
#6
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Repair shop determined that the leak is from the seal where the driveshaft yoke enters the differential. It’s just an $18 part from Lexus, but shop says it’s a 4-5 hour job, mainly because the exhaust system has to be dropped/moved in order to replace the seal. My 16 year-old exhaust system is in perfect condition. The idea of screwing with it bothers me. I’m wondering if I should just live with the leak and have the fluid level checked periodically unless it gets worse. Opinions welcome!
04-04-18, 05:22 AM
#7
Lexus Fanatic
You definitely could live with it if you top it off, I did so with a Volvo 8 years. It just depends on how bad the leak is...because that would determine how often you need to top off...you may not even have the vehicle long enough for it to matter. It's like high cholesterol on a dog--they do measure it with a blood test, but they do not treat it, because the dog doesn't live long enough for it to matter....there are various human issues too that are like that...
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sajack (04-04-18)
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04-04-18, 07:29 AM
#8
Repair shop determined that the leak is from the seal where the driveshaft yoke enters the differential. It’s just an $18 part from Lexus, but shop says it’s a 4-5 hour job, mainly because the exhaust system has to be dropped/moved in order to replace the seal. My 16 year-old exhaust system is in perfect condition. The idea of screwing with it bothers me. I’m wondering if I should just live with the leak and have the fluid level checked periodically unless it gets worse. Opinions welcome!
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sajack (04-04-18)
04-08-19, 01:09 AM
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I finally got another garage to look at this and they said that the vent on top of the differential was stopped up, that I didn’t need a seal. They cleaned it out, didn’t even charge me anything. After 6 months it hasn’t leaked a drop. Sometimes it pays to get a second opinion.
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04-08-19, 10:27 AM
#10
I finally got another garage to look at this and they said that the vent on top of the differential was stopped up, that I didn’t need a seal. They cleaned it out, didn’t even charge me anything. After 6 months it hasn’t leaked a drop. Sometimes it pays to get a second opinion.
05-10-21, 08:27 AM
#11
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Rear Pinion Seal Replacement LS430
Just finished replacing a leaking rear differential seal on a 2001 LS430. Here's a summary:
- Loosen clamp on downstream cat where it Ys into two exhaust pipes...I had to pry the slotted pipe away a bit to free it from the corrosion at the fitting.
- Unhook the 2 "rubber bands" on the bumper end of the muffler. Used a 2x4 to move the muffler towards the outside body hook and easily removed the rubber band (reverse process for installation) and then moved the muffler the other way to remove the 2nd rubber band...thread a long shoestring through the rubber band and pull down to clear the hook on the muffler (reverse process for installation).
- Unhook the rubber holding clamps on the tail pipe (spray with a lubricant to make them slide off easily and the rotate the exhaust assembly to free from the cat, taking care not to place too much tension on the forward exhaust system.
- Remove shielding and loosen/remove carrier bearing bolts.
- Remove 3 bolts holding the rubber disc to the pinion yoke...will take a bit of light prying to get the bushing shoulders out of the pinion yoke. Slide the drive shaft towards the transmission to clear the pinion pilot shave and then secure it up out of the way.
- Un"Stake" the pinion nut using a narrow regular screw driver tip, but BEFORE you remove the nut (see NEXT step)...mine took about 150-180# of torque to remove so if you're not using an impact be sure to reinsert the bolts to loosen the nut so as to not put too much pressure on the pinion gears.
- COUNT the number of turns (mine was 8.5 turns) the nut comes off, so when you put the pinion yoke back on, the crush spacer and pre-load are maintained. Autozone has an online repair manual for the pre-load specs if you prefer that method. My pinion nut took a 36mm deep socket that I had to grind down slightly to fit between the nut and the pinion yoke (e.g., made a "thin" wall socket).
- Remove the pinion yoke...I used a long flat blade screw driver to pry out the old seal...don't pry against the pinion shaft. I reinstalled the new seal using a 2" PVC union to seat the seal 2mm inside the seal rear-end housing.
- Examine the pinion yoke to see if the seal cut into the machined surface too much. Mine was lightly grooved so I cleaned it up a bit with a light touch of emery cloth and reassembled with gear lube...so far no leak. I couldn't fine a repair sleeve for the pinion yoke, so if yours is too scarred, you may need to replace the yoke.
- Reinstall the nut the original number of turns and re"Stake" the nut.
- Reverse the above steps and top of the differential with the fluid recommended in your owners manual.
07-14-23, 05:57 PM
#12
I finally got another garage to look at this and they said that the vent on top of the differential was stopped up, that I didn’t need a seal. They cleaned it out, didn’t even charge me anything. After 6 months it hasn’t leaked a drop. Sometimes it pays to get a second opinion.
07-16-23, 06:52 PM
#13
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