Horrid 'thunk' when taking off, and braking?

[jmorgan6]

I took the car for a short drive with the blown motor(actually got pulled over by the cops on the way home because of the noise!)

First thing I noticed was when I took off, almost every time(if not everytime) the rear end would go ka'thunk... and when I let off the gas and hit the brake it would do it again. Sounded like something in the trunk slamming into the back and then going back again. I knew he had some tires in there so I thought that first, but when I popped the hood the tires were wedged in so I really don't think this was the problem.

I first thought u-joint, but im starting to have second thoughts that it may be something more serious?

Something in the diff stripped or broken? I did some searches, but didnt' find anyone with the same symptoms.

Thank you!

Jacob

[Vegascorbin]

Sounds like you have pretty much coverd the usual suspects. Could be loose brake assembly or posably suspension.

Pull the drive line and check U joints. if ok then check rear end pinion while drive line is out.

[MarkRipoll]

I had almost the same problem, it could be your subframe bushings, you can replace them, or use subframe collars.

http://enjukuracing.com/stance...2_138

[!Zar!]

Sounds like you have a sticking caliper.

[positron1]

I had almost the same problem, it could be your subframe bushings, you can replace them, or use subframe collars.

http://enjukuracing.com/stance...2_138

I read that it's the sound of the subframe banging against the car because of old worn out bushings.

[slepys14]

there is no doubt as to what it is "subframe bushings". my s14 did that exact thing when I first bought it. those stock bushings get old and tear. when you put torque on the subframe when starting and stopping it clunks against the bottom the body of the car. those bushings are an easy fix.

[romerider153]

that is deff subframe bushings same thing in my s14 i got collars and it went away for like a week then i guess they settle cause it came back so i gotta try tightening the bolt up some more make sure ur carefully with those studs tho and torque everything back together cause it would suck to snap a stud

[jmorgan6]

Sweet I will check those out! bringing some ramps up today to put under the rear tires(like them a lot more then jack stands!).

My biggest concern was it being something in the drive line, like in the differential. The guy before me had pics of him doing burnouts, and other stupid stuff with the car and he was the one that blew the motor... So who knows how much abuse that driveline took!

Thought it was going to be a nice day to work in the garage....but it snowed last night!@! Yesterday was perfect, but when I hinted at my g/f the idea of 'hey lets go do a compression test on my 240sx with me'.. Well, the look said it all.

[romerider153]

well ramps is going to make it hard to check the bushings and impossible to replace them you need the suspension unloaded and if your on ramps all the weight will be on the suspension

[jmorgan6]

I'm still pulling the motor, so I need the driveshaft out and this guy cant' fit under that car without it jacked up ..

[YuNg1's_240sx]

hey, i am having almost the same problem, except mine is not so loud from the outside. But from the inside, it sounds like if it happened again, the whole rear would fall apart! I talked to my teacher at school about this, and he said right away, after telling him that it makes a THUNK sound when i acc. and suddenly let go of the gas, and when i let the gas go to shift, its the universal joints.I am not sure which one it is, so when u get this fixed can u let me know if your problem went away?

Arash

[jmorgan6]

Will do. Still don't have the drive shaft out yet.. drive shaft 2 Jacob 0.

First attempt I had a small jack, and could only get it up on the first notch on the jackstands. I could only lay down under the car with one hand under there.. Couldn't get the bolts off.

Today, I showed up with a large floor jack from our shop and two ramps that were pretty heavy duty.

Since the car is no longer running, I just figured i'd jack the car up and slide the ramps under the rear tires and let the car back down.. Easy right? The Jack was about 6" short from being able to do that with it on the Diff.. So I set them like that and the repositioned the jack to under each side's suspension and tried gain.. still a few inches short. I couldn't find a piece of wood to save my life either to get a couple more inches.

O well, the good news with the larger jack I can easily get the jack stands up to a suitable level to get under there with both hands and get that dang drive shaft out!@!

Anyway, once I get it out and inspect the u joint i'll let you know. Doing this in a storage building is no fun.

[slepys14]

just replace the subframe bushings, if it has never been done before it is time anyways. I guarantee that is the problem, "they all do it eventually". you can use the collars "easy fix". I went with the energy suspension "pineapple bushings". pretty cheap but you have to pull the subframe to install.