Loud thunk from the rear....

[mmartin1]

My 97 4Runner Limited 4X4 has just started displaying a problem I'm a bit nervous about. Every once and a while after coming to a stop, I hear a loud thud come from the rear end. It also seems to happen right after I accelerate from the stop. Does anyone know if this sounds more like a transmission problem, or just the suspension in the back making racket when the weight of the vehicle shifts position? If it makes any difference, I did have the rear spring recall done on the car a while back.

Thanks,
Michael

 

[swerks]

Lube your drive line joints!

 

[Thai]

Sorry about late response, i didn't see this thread until now.

The loud thunk in the back is likely the rear suspension. A few things to look at:

1. Insufficient/damage clamping of the rear control arms.
2. Shock assembly (washers/rubber bushings) damaged, resulting in harsh contact with the head of the spring (if front suspension) or body mounts (rear suspension)
3. Shock itself is damaged.

I would say to have a certified mechanic (a good one) check out the rear suspension, concentrating on the rear shocks and it's surroundings.

On some other vehicles, it is sometimes due to gas slushing around in the gas tank. I have not heard of problem with Toyota SUV in this regard...but ya never know.

BTW, make sure you empty out your cargo area to make sure it's not from your stuff rolling around! (My brother once had a rattling noise in his Jeep Wrangler...he thought it was the differential going bad...but it turns out that it was due to a screw driver in his cargo area rolling around!)

Hope this helps...sorry again about late reply.

 

[javacups]

Any luck??

Hi, I wonder if you evern discover what the chunk noise coming from the rear?? I am also experiencing the same problem..thank you so much.

 

[utah_saint]

After reading numerous responses regarding the infamous "clunk sensation" in the 03' and 04' 4 runners, I can finally say that lubing the propellor shaft with nlgi 2 lithium grease will fully eradicate the problem. yes, there are numerous grease fittings along the front and rear driveshafts along with numerous other fittings on the u-joints/ double cardan joints as well. I practically went nuts at every stop light until I decided to investigate further......so I bought some Valvoline synthetic nlgi 2 "lithium" grease and a grease gun from the auto parts store, and pumped
about 15 shots of grease into the prop shaft fitting at the front of the vehicle. In fact, I just kept on pumping until I saw grease expand back out of the fitting. A lot of people don't realize that there is a hollow section of the prop shaft that needs to filled with a certain amount of grease at all times. Otherwise, as you go over bumps and your suspension and or driveshaft expands and compresses, the "clunk" becomes noticeable because there is simply no grease to "dampen" the travel in the component. Now, once you get enough grease to see grease overflow back out the fitting, you should only need to give that particular fitting a few pumps every few months depending on conditions/ useage.
I hope this helps some of you out there. Trust me, I am probably in the top 1% of the mega "anal retentive" crowd and the clunk has not returned in several hundred miles. If you have greased this fitting and the clunk has returned, carefully try it again until the prop shaft is full of grease. Be careful not to use any other type of grease gun besides a manual handheld unit....air guns etc. could create excessive pressure and blow a seal.

 

[yabedude]

utah_saint

I'm an not a mechanic and am quite the layman. Would you have a pic or can you provide another clue as to where I would find the grease nipple?

 

[TechWrench]

Re: utah_saint

I'm an not a mechanic and am quite the layman. Would you have a pic or can you provide another clue as to where I would find the grease nipple?

If you can get under the vehicle, locate the rear drive shaft. About a foot from the end closest to the rear axle there will be a slip joint in the shaft. This joint allows the drive shaft to lengthen and shorten somewhat when the rear suspension (axle) moves up and down. The slip joint is basically a splined shaft that fits into a splined sleeve. On the outside of the sleeve part of the joint should be a small nipple (about 1/2" long and 1/4" round).
This is the grease nipple. A fitting on the end of a grease gun hose is designed to snap over this nipple, and the grease is pumped into the joint thru it. 10 or 15 pumps of grease in this joint should, with a little time to work in, solve your 'thump'.

 

[yabedude]

Mucho Gracious, Amigo!