Car Lurches Forward And Clunks When Releasing Gas Pedal

[housedogg]

Hello all,

I have a 95 LS400 and for some reason when I am on the Highway doing about 50 or so and I go to release the pedal, the car kind of lurches forward and makes a clunk sound. I took it to Lexus and they said it was the bushings on the transmission and rear diff. I had them change the trans bushing but it didn't really help but it only cost $125 but to change the rear diff, they quoted me $600 and I didn't want to pay that right now. My question is, does that sound like what the problem could be or has anybody else experienced that? Also as a side note, my antenna doesn't go up or down anymore. All I hear is the motor turning but nothing is happening and they quoted me $500 for that. Is there a cheaper solution? Thanks..

[aarman4]

For the antenna, go to www.ebay.com and search for a Lexus LS400 antenna replacement. Pretty easy job for anyone who has even a little bit of mechanical aptitude. You should be able to do it for under $20. www.lexls.com has a tutorial for replacing it, you only need to use half the tutorial from lexls, as his is for the whole dissassembly and rebuild of the motor, all you need is the telescoping antenna.

[nc211]

Hopefully this is just a mount problem, but the lurching forward and the speed that it happens makes me think of the off-throttle-shock syndrome. I had it too. The car's computer cuts the fuel too quickly when you take your foot off the gas, creating a buckling feeling in the driveline, which makes you feel like you're personally lurching forward. It's reverse torque through the driveshaft. I've attached the TSB for the issue, which you may want to print off and take to your dealership. Ask them about the "Off-Throttle-Shock" problem caused by this TSB, which is aimed to fix it, and it does indeed fix it. But it's not cheap. Run a search for the stalling after highway speed, or key words off-throttle-shock, you'll see lots of good info. If it is indeed your computer, you can buy second hand ecu's for the fix. Additionally, let the dealership know that you're aware of the fact that out of ALL TSB's ever issued for the car, this is the ONLY one that is highly recommeded by Lexus to be performed. It has caused a few complaints to the NHSTB.

Additionally, welcome to the club! Great question for your first post! I recommend posting up the repair suggestions from your dealership here first, before authorizing the repair. These cars ain't cheap to fix at the dealership, and my personal experience is that some stealerships will dance around the real problem "and in your wallet" before actually adressing the real problem. Sometimes you have to really needle them. Not all, but sometimes. Since you're way over the pond, and we dont have a lot members from your area, we don't really have a lot of stories about your dealership yet.

PS: Might want to correct the year of your car in your profile. It shows a 94', but you're saying you have a 95'. Two totally different set ups.

41.pdf

[raymsixsix]

Hopefully this is just a mount problem, but the lurching forward and the speed that it happens makes me think of the off-throttle-shock syndrome. I had it too. The car's computer cuts the fuel too quickly when you take your foot off the gas, creating a buckling feeling in the driveline, which makes you feel like you're personally lurching forward. It's reverse torque through the driveshaft. I've attached the TSB for the issue, which you may want to print off and take to your dealership. Ask them about the "Off-Throttle-Shock" problem caused by this TSB, which is aimed to fix it, and it does indeed fix it. But it's not cheap. Run a search for the stalling after highway speed, or key words off-throttle-shock, you'll see lots of good info. If it is indeed your computer, you can buy second hand ecu's for the fix. Additionally, let the dealership know that you're aware of the fact that out of ALL TSB's ever issued for the car, this is the ONLY one that is highly recommeded by Lexus to be performed. It has caused a few complaints to the NHSTB.

Additionally, welcome to the club! Great question for your first post! I recommend posting up the repair suggestions from your dealership here first, before authorizing the repair. These cars ain't cheap to fix at the dealership, and my personal experience is that some stealerships will dance around the real problem "and in your wallet" before actually adressing the real problem. Sometimes you have to really needle them. Not all, but sometimes. Since you're way over the pond, and we dont have a lot members from your area, we don't really have a lot of stories about your dealership yet.

PS: Might want to correct the year of your car in your profile. It shows a 94', but you're saying you have a 95'. Two totally different set ups.

Wow, my '95 LS does that. I just thought it was the car being 13 y/o lol. I've contacted Lexus of Tampa Bay for more info ie price. I'll post what I find out.

[housedogg]

Hello all,

I have a 95 LS400 and for some reason when I am on the Highway doing about 50 or so and I go to release the pedal, the car kind of lurches forward and makes a clunk sound. I took it to Lexus and they said it was the bushings on the transmission and rear diff. I had them change the trans bushing but it didn't really help but it only cost $125 but to change the rear diff, they quoted me $600 and I didn't want to pay that right now. My question is, does that sound like what the problem could be or has anybody else experienced that? Also as a side note, my antenna doesn't go up or down anymore. All I hear is the motor turning but nothing is happening and they quoted me $500 for that. Is there a cheaper solution? Thanks..

Cool, thanks for the information. It is very helpful and I will check out ebay tonight when I get off work.

[housedogg]

Hopefully this is just a mount problem, but the lurching forward and the speed that it happens makes me think of the off-throttle-shock syndrome. I had it too. The car's computer cuts the fuel too quickly when you take your foot off the gas, creating a buckling feeling in the driveline, which makes you feel like you're personally lurching forward. It's reverse torque through the driveshaft. I've attached the TSB for the issue, which you may want to print off and take to your dealership. Ask them about the "Off-Throttle-Shock" problem caused by this TSB, which is aimed to fix it, and it does indeed fix it. But it's not cheap. Run a search for the stalling after highway speed, or key words off-throttle-shock, you'll see lots of good info. If it is indeed your computer, you can buy second hand ecu's for the fix. Additionally, let the dealership know that you're aware of the fact that out of ALL TSB's ever issued for the car, this is the ONLY one that is highly recommeded by Lexus to be performed. It has caused a few complaints to the NHSTB.

Additionally, welcome to the club! Great question for your first post! I recommend posting up the repair suggestions from your dealership here first, before authorizing the repair. These cars ain't cheap to fix at the dealership, and my personal experience is that some stealerships will dance around the real problem "and in your wallet" before actually adressing the real problem. Sometimes you have to really needle them. Not all, but sometimes. Since you're way over the pond, and we dont have a lot members from your area, we don't really have a lot of stories about your dealership yet.

PS: Might want to correct the year of your car in your profile. It shows a 94', but you're saying you have a 95'. Two totally different set ups.

Hey thanks for the warm greeting and for all the information. I will check out the TSB and see what is has to say and I will call Lexus promply after I read it and post their answer here as well. Actually I do have a 1994 LS400 as well as a 1995. Kind of a his and hers thing. We love the cars...