When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a rather loud rattling noise coming from the transmission bell housing. It doesn’t start until the car is warm. It is loudest in Park and Neutral, quieter in R, and goes away when I put the car in Drive. I verified it is not coming from the engine with a stethoscope and also with a rubber hose stuck in my ear. The noise is same with compressor on and off. It is loudest at the bottom of the bell housing. Any ideas would be appreciated!!
I have a rather loud rattling noise coming from the transmission bell housing. It doesn’t start until the car is warm. It is loudest in Park and Neutral, quieter in R, and goes away when I put the car in Drive. I verified it is not coming from the engine with a stethoscope and also with a rubber hose stuck in my ear. It is loudest at the bottom of the bell housing. Any ideas would be appreciated!!
May you add sound to the video...? (Could not see it...) Your fluid is correct.... Could it be the torque converter or some other rotating part? have you considered getting a noise diagnostic by a trusted mechanic? Did you put the stethoscope on the transmission to verify where the rattling noise is? (You could also try using "chassis ears" a remote mic you put right on the trans.) And, you are sure it is not exhaust rattle....
I was hoping there was a simple solution, but I’m afraid the cracked flexplate diagnosis makes the most sense. I’ll try to pull an access cover and inspect.
I was hoping there was a simple solution, but I’m afraid the cracked flexplate diagnosis makes the most sense. I’ll try to pull an access cover and inspect.
Would something have to be out of balance to cause a flexplate to crack...?
Last edited by 430SLOwner; 10-28-19 at 11:48 AM.
Reason: ]
I was hoping there was a simple solution, but I’m afraid the cracked flexplate diagnosis makes the most sense. I’ll try to pull an access cover and inspect.
If it is a cracked flexplate let me know. I'll have an extra one next week. If that is the issue the transmission must be removed to replace it.
Would something have to be out of balance to cause a flexplate to crack...?
No. The definition of a "flex plate" is that it flexes to absorb movement in the drivetrain. Over the course of a thousands of miles it develops a crack and that is probably the noise you are hearing. The noise goes away when the flexplate is loaded up with the torque from the engine.
If it is a cracked flexplate let me know. I'll have an extra one next week. If that is the issue the transmission must be removed to replace it.
Thanks for the offer, but I have a new flexplate en route already. $250 for a new one - it’s common with Toyota Land Cruiser or such. Shop says $500 labor to drop the trans and install. I’d do it myself but it’s such heavy work I’m planning to just pay for this one.
The car has 240,000 miles on it. It did get the factory recall transmission years ago before I bought it. I’ll get the old one so I can see the cracks...for fun.
As am I, I have not heard of this ever happening on any 4.0/4.3/4.7 and I'm suspicious that when the trans was replaced they hit/bent/put force on the flex plate at some point during the repair and it resulted in this issue.
Greenskeep is the winner. Thanks for the correct diagnosis. I told my wife, it’ll just be a little 1/2 inch crack between two adjacent holes. HAHAHA. Wrong! My finger is pointing to the only part of the plate that is NOT CRACKED!
The shop said one of the dowel pins was missing. The theory is...when Lexus swapped transmissions during the 2002 factory recall, then lost a pin. The bellhousing bolts are not close tolerance. So the housing was slightly misaligned without the tight fitting dowel pin. 250,000 miles later. Crack head city! This thing was perfectly quiet when the engine was cold, and only started rattling after it warmed up. I couldn’t hear anything going down the road. But it was plainly audible at idle with the windows down. Shop charged $550 to drop the transmission and replace the flex plate and rear main seal. I provided the plate ($250 toyota part).
10-27-19, 05:14 PM
Transmission rattles!
