First post: 2001 LX470 (1 Viewer)

[faganism]

Hello! First, thank you to this community. I have learned much from you since I purchased my 2001 LX470 in February: A one-owner, 189K, rustless (Texas). I've done the obvious things. Had the water pump and timing belt changed. I have replaced the AHC globes and fluid.

I do need some help.

--I have the dreaded "clunk" and my local Toyota dealership said I had severe backlash in the front differential carrier assembly (41110-6A171). I ordered a new one from IMPEX in Japan. After my dealership installed it, I still had the clunk. Their claim is the product was defective. However, I called a Lexus dealership in Dallas--they said it probably isn't defective and that it was likely installed incorrectly because parts like that require shims to get the geometry right. Can anyone speak to this?

--While I am keeping the AHC--the new globes and fluid made a vast improvement--the ride can still be very harsh. What are some other aspects of the suspension that may need replacement? Front and rear coil springs? Please help.

Thank you for any insights you can offer. I will give as detailed information as I can.

Best,

Faganism

 

[BullElk]

My first thought on the clunking is diff bushings need changing and drive shafts need greasing. Never heard of replacing the entire diff.

As others have said before that know much more than I, the harsh ride with new globes may be due to air in the system that needs to come out.

 

[faganism]

My first thought on the clunking is diff bushings need changing and drive shafts need greasing. Never heard of replacing the entire diff.

As others have said before that know much more than I, the harsh ride with new globes may be due to air in the system that needs to come out.

Thank you! I have done the greasing on the six zerks. The bushings are all OK. I can verify the clunk is caused by a backlash in the front diff. But the fact they are saying this brand new one is "defective" makes no sense. I don't think they are installing it right. Since buying the whole new assembly, I see that the pinion and bearings can be replaced ... that is like $125 versus the $1,000 for the whole assembly shipped express from Japan; if I had gone through the dealership it would have been $3,500, and taken a month to be delivered.

 

[diabetik81]

Thank you! I have done the greasing on the six zerks. The bushings are all OK. I can verify the clunk is caused by a backlash in the front diff. But the fact they are saying this brand new one is "defective" makes no sense. I don't think they are installing it right. Since buying the whole new assembly, I see that the pinion and bearings can be replaced ... that is like $125 versus the $1,000 for the whole assembly shipped express from Japan; if I had gone through the dealership it would have been $3,500, and taken a month to be delivered.

Did you check the bushings on the front diff mounts? If you ordered a complete assembly and it's still clunking it likely wasn't the diff to begin with.

 

[faganism]

Did you check the bushings on the front diff mounts? If you ordered a complete assembly and it's still clunking it likely wasn't the diff to begin with.

Thank you. Yes, those check out fine. It is visibly and audibly backlash in the diff.

 

[RapidRob]

It seems that you have been very thorough and are mechanically competent , but just to be sure I'll ask if you're checking for slack at the wheels or right where the axle comes out of the housing? Don't let bad axles or flanges fool you. Just something to consider.

 

[faganism]

It seems that you have been very thorough and are mechanically competent , but just to be sure I'll ask if you're checking for slack at the wheels or right where the axle comes out of the housing? Don't let bad axles or flanges fool you. Just something to consider.

Thank you, the flange area is the source of the slack and noise.

 

[CALIFORNIAGOLD]

02 with 260k, I have the typical clunk when shifting into drive and when hitting the throttle after a light coast. Vibrations are also obvious while in drive and at a stop. Shift to neutral and vibrations gone. Ive been driving with 2nd start engaged lol and it helps quite a bit. With that being said, I have worn diff bushings and I am in the middle of swapping everything out right now. This kit is going on as we speak: Front Differential Mount Bushing Kit - Fits 98-07 IFS 100/470 (DIFF100BKITOEM) - https://cruiserteq.com/front-differential-mount-bushing-kit-fits-98-07-ifs-100-470-diff100bkitoem/

 

[CALIFORNIAGOLD]

Worn CV splines and flanges can also give you a big clunk.

 

[RapidRob]

Thank you, the flange area is the source of the slack and noise.

We may be talking about two different flanges. I was referring to the very outer ends of the front axles, which is the drive flange that the axle mates with. A very common place for problems. I think you are saying that the slack is clearly at the point that the driveshaft from the transfer case enters the diff. If that's positively the location then someone needs to go back inside the diff and do it right. Very slight chance of the new part being defective but I've heard that
NEW stands for Never Ever Worked!

 

[faganism]

We may be talking about two different flanges. I was referring to the very outer ends of the front axles, which is the drive flange that the axle mates with. A very common place for problems. I think you are saying that the slack is clearly at the point that the driveshaft from the transfer case enters the diff. If that's positively the location then someone needs to go back inside the diff and do it right. Very slight chance of the new part being defective but I've heard that
NEW stands for Never Ever Worked!

Correct, flange at the driveshaft. I spoke with a guy at Lexus in Dallas, and he said shims are required to get the proper alignment, but that is the point of buying a new assembly, that should already be done. So something is wrong. Waiting to hear back from IMPEX in Japan, they have filed a defective part claim with Toyota. This is bumming me out so bad. So much time and money and I feel like I'm driving a timebomb around.

Once I get this sorted out I need to get the suspension dialed in. Already replaced the AHC globes and fluid--major improvement but it is still pretty rough. Not sure if it requires coil springs. Seems unlikely I would replace the shocks because those are part of the hydraulic system.

Ah well. Thank you for your insights!

 

[shane431]

Do you have techstream? And where in DFW are you located. Maybe I can help.


Never mind. I see Tyler. Sorry man.

 

[Brandon Ryder]

I still have clunk but the majority of mine came from cv shaft to outer flanges.
Pay attention to cv shaft rotation against the knuckle.


After new cv axles and new outer flanges


Old cv splines. Notice tops are sharp. Flange looked similarly sharp.

Vs new splines. Notice tops are flat. These fit tightly into the new flange. Resulting in no rotation of the cv shaft vs knuckle in the above video.

Edit to add:
The remaining clunk for me likely comes from the transfer case. Its really not much of a clunk and maybe it's within the design of the 100 I don't know. Never drove one new. The clunk is one of those mysterious 100 issues that's hard to diagnose over the internet and may have multiple contributing factors. It COULD be, worn CV shafts, front Diff bushing, front diff backlash, front propeller shaft, transfer case backlash.
If they replaced your entire front diff, I would confirm the axles were serviceable. If so. I would want to see a video, like mine above so we can identify the source.

 

[RapidRob]

I looked up the part number that you listed, I didn't realize that you got the entire diff including carrier housing. If that's correct it should be ready to run out of the box. If your clunk is identical as before, then I'd have to suggest that some thing else has to be wrong. Triple/Quadruple check how the axles feel where they go into the diff, CVs, and outer flanges. Sometimes slack in a drivetrain can be hard to pin down. I'm surprised that some of the members here who repair these trucks for a living haven't piped up yet. I have a lot of general experience but some of these guys are TLC gurus.

 

[faganism]

Do you have techstream? And where in DFW are you located. Maybe I can help.


Never mind. I see Tyler. Sorry man.

Hello. Thank you for your message. No, I don't have a techstream. I live in an apartment and we aren't allowed to work on our cars here. I am relying on my local Toyota dealership and it's not going well. They don't seem to know what they are doing and don't seem to care. I have never met a more incurious group of people.

 

[faganism]

I still have clunk but the majority of mine came from cv shaft to outer flanges.
Pay attention to cv shaft rotation against the knuckle.


After new cv axles and new outer flanges


Old cv splines. Notice tops are sharp. Flange looked similarly sharp.
View attachment 3647631

Vs new splines. Notice tops are flat. These fit tightly into the new flange. Resulting in no rotation of the cv shaft vs knuckle in the above video. View attachment 3647637

Edit to add:
The remaining clunk for me likely comes from the transfer case. Its really not much of a clunk and maybe it's within the design of the 100 I don't know. Never drove one new. The clunk is one of those mysterious 100 issues that's hard to diagnose over the internet and may have multiple contributing factors. It COULD be, worn CV shafts, front Diff bushing, front diff backlash, front propeller shaft, transfer case backlash.
If they replaced your entire front diff, I would confirm the axles were serviceable. If so. I would want to see a video, like mine above so we can identify the source.

Thank you, this may come in handy at some point but I know with certainty there is an issue with my front diff assembly and that is the issue I am focused on right now.

 

[faganism]

I looked up the part number that you listed, I didn't realize that you got the entire diff including carrier housing. If that's correct it should be ready to run out of the box. If your clunk is identical as before, then I'd have to suggest that some thing else has to be wrong. Triple/Quadruple check how the axles feel where they go into the diff, CVs, and outer flanges. Sometimes slack in a drivetrain can be hard to pin down. I'm surprised that some of the members here who repair these trucks for a living haven't piped up yet. I have a lot of general experience but some of these guys are TLC gurus.

I appreciate the help, yes. It has been very disspiriting. The Toyota dealership doesn't seem to know what they are doing and they don't seem very energetic about identifying a solution. I can only do so much as a non-expert. The dealership has said definitively that the backlash is in the assembly itself. I just have to wait and see what IMPEX has to say regarding the claim they filed with Toyota in Japan.

 

[RapidRob]

I appreciate the help, yes. It has been very disspiriting. The Toyota dealership doesn't seem to know what they are doing and they don't seem very energetic about identifying a solution. I can only do so much as a non-expert. The dealership has said definitively that the backlash is in the assembly itself. I just have to wait and see what IMPEX has to say regarding the claim they filed with Toyota in Japan.

It's strange to say but I guess you just have to hope that the parts were defective.
I don't have anything else, Good Luck.