level7

iTrader: (3)

THE PROBLEM:
Everytime there is a distribution of weight via accel and decel there is a fairly short series of clunks like:

clunk-------------clunk-------clunk----clunk.

I thought for sure the new motor mounts I installed today would do the trick, but no dice. Nice mounts by the way, (thanks wanklin) no vibrations and it did make my shifting easier. When I finished the install I took it for a drive and could not understand why this problem persists. I'm getting real serious right about now.

OK, I have walked away from the car, calmed down, and ready for even more troubleshooting. The problem is I am at a loss with things to try, I feel like I have inspected everything.

WHATS BEEN DONE ALREADY:
New diff bushings
New pillowballs in the rear suspension
Removed and inspected PPF for cracks (installed in correct position)
New Noltec motor mounts
New aftermartket trailing arms
New aftermarket toe links

FYI: I do not want to solve this problem via any braces, I feel that is only a band-aid to the real problem.

I havnt asked for help here in years since I have become self sufficient with my FD, (thanks to you guys) but this is beyond my knowledge, and the search well has just about dried up. For the love of anything good and logical, please, somebody lend me a helping hand.

Thanks fellas
Chris

rynberg

Did you check on the trailing arm bushings?

level7

iTrader: (3)

Im sorry, I forgot to add I replaced the trailing arms and toe links as well.

maxcooper

The toe link bushings in the rear suspension are also wear items.

I also replaced the front upper A-arms recently, after finding that mine were bad, AND that the ball joints on the used set I bought were also bad. I guess the front upper ball joints wear out, too. And the lowers also wear, but both my set and the used set of lower arms I bought were still okay, which indicates to me that the upper ball joints wear faster. I think the front ball joints are especially noticable on braking, since braking stresses them substantially. On further reflection, I doubt it is your front ball joints since you mentioned that you also get clunks on acceleration.

And I once found a loose oil cooler bracket clunking around in front of the driver's side front wheel, behind the fender liner. I have upgraded to an aftermarket oil cooling system and I guess I didn't remove one of the brackets. It was held in place with just one bolt after the cooler swap, and eventually came loose and started to swing around. It is unlikely that you have the same issue, but it could be something similar just flopping around.

-Max

maxcooper

Oops, well I guess it isn't your toe links then.

-Max

maxcooper

My rear-lower-inner bushings (a pillow ball suspended in rubber) were also slightly loose. But the rubber keeps them from clunking very much.

-Max

maxcooper

Check exhaust piping for evidence of banging on something?

-Max
Sorry for post-whoring, just trying to help

level7

iTrader: (3)

Be a ***** all you want Max, I appreciate any suggestion.

Try to imagine that you have two pendulum *****, one in each hand, one representing the front of the car, the other the rear. Letting the ***** drop...hehe...would represent decceliration. They would tap until force ran out. Hard to analogize but yeah.

level7

iTrader: (3)

I did check for any exhaust issues, even changed the gaskets while i was in there. Oil coolers are secure, however I have not replaced any front suspension arms or bushings since ive owned the car. It feels more dramatic then what your discribing but who knows, at this point I need to figure out my options.

Thanks Max

level7

iTrader: (3)

What about old coils and shocks? The stock R1 shocks are still on the car with a set of H & Rs that where also on it when i bought it almost 7 years ago.

After more searching I was looking into flywheel problems, my question is what are symptoms of needing to resurface?

Thanks

dgeesaman

iTrader: (7)

Flywheel surface only affects clutch engagement issues like shuddering.

Perhaps you should look for play in the differential pinion bearings. Drop the rear end of the driveshaft, and if there is any play whatsoever you know it needs rebuilt (bearings rebuild). If you're not sure, it may help to drain a little of the diff oil and look for metal dirt or flakes.

Coils almost never go bad, and if they did they wouldn't clunk. If you have them removed for any reason definitely inspect the rubber mounts.

You might also have a loose baffle in your fuel tank, or a loose item in the spare tire, jack storage, etc.

Dave

poss

iTrader: (5)

Check your differential. My stock unit has had some slop ever since I've owned it due tto the helical gears wearing. It makes a clunking noise when going from accel to decel.
Jack up the rear end, set the e-brake, put the car in neutral and try to rotate the drive shaft back and forth. If you have excessive play, that may be your problem.

level7

iTrader: (3)

My friend Matt is going to give me some lift time at his shop tomorrow morning. That way I can really get in there and inspect. The jack stands, on your back with a flashlight thing starts to get old over and over

Dave and poss, thanks for the replies. Im going to check the diff fluid and see how it looks. It was changed last in Nov 05 and it looked fine. I will check everything from the driveshaft to the diff as you guys suggested as well. If I have time I will pull the rear coils out to see if the rubber mounts are still good.

Bringing the camera too just incase I find anything visualy suspect.

level7

iTrader: (3)

UPDATE:
Put the car on the rack this morning and here is what I found out.

With the car in the air, I fired it up and tried to see if I could replicate the clunk while the suspension is at rest. I could, so that OFFICIALLY RULED OUT ANY SUSPENSION COMPONENTS.

PHYSICAL:
My friend was under the car with a pry bar trying to press various parts of the drivetrain as I blipped the throttle in first gear. No difference or movement at the diff area but when he got to the trans and pryed, it got much better! He was prying it from the top of the trans toward the ground.

VISUAL:
When giving throttle in first, my friend was saying the trans was flexing up and down (sky to ground) but the new motor mounts where holding well. (this was with no prying)

I can only conclude that there may be something wrong in the trans internaly? but what? Any other ideas? I wanted to run it by you guys before I get under there....again.

FYI: I have a JDM trans with ACT pressure plate and factory disk. Thanks

poss

iTrader: (5)

Have you checked your PPF for cracks?

level7

iTrader: (3)

Yeah, removed and inspected, no cracks, lined up and bolted correctly.

dgeesaman

iTrader: (7)

Nice thinking with the suspension diagnostics. Although you wouldnt have found me under that car

IMO, the tranny housings should be plenty rigid to avoid flexing. There are some dowel pins in there too. If it were flexing youd have gear oil everywhere.

To rule out tranny internal damage, I would drain it and remove the main gearbox pan. If there is metal in there on the magnet, youve found something to go on. But Im not sure if its a likely scenario.

level7

iTrader: (3)

Bump for the weekday people.

Im going to have more lift time coming this week, so I am going to try what Dave suggested and check the transmission internals. I am still reaching for any other ideas if anyone wants to chime in.

QUESTION: Can a RX be driven with the wrong counter weight or would that just make everything unbalanced and explosive?

mad_7tist

is the shifter assembly/body hitting and popping on the trans tunnel?

level7

iTrader: (3)

Thanks for taking a shot. The trans is totaly clear of hitting any part of the tunnel, even when it is torquing up and down on throttle.

poss

iTrader: (5)

This is going to sound like a no-brainer, but your transmission shouldn't be moving up and down, especially if you are on a rack and no load is placed on the wheels.

Make sure the PPF is tight and adjusted properly. as mad_7tist suggested, it may be the transmission hitting the tunnel. Loosen the front PPF nuts, pull the trans downward and re-tighten the nuts. IIRC, the FSM has some specs on how to adjust it.

dgeesaman

iTrader: (7)

Does the motor rock forward and backward when the tranny tilts up and down?

They almost have to, to create the effect you describe.

Dave

cozmo kraemer

I had a very similar problem and it was related to the trailing arms. What kind of trailing arms did you install? My trailing arms had a bolt in the side that bolts into the lower I-arm. This bolt can be threaded in and out of the aluminum shaft that makes up the trailing arm. When this bolt had threads exposed, I would get clunking related to throttle inputs. I could see how it would make these noises even when in the air because of the force applied to the wheels.

Make sure that bolt is threaded all the way into the trailing arm. This type of arm is supposed to be adjustable, but adjustment can only be done from the hiem joint end, where there is a jam nut.

An alignment tech, aligned my car, exposed threads on this bolt, and caused the noise...took me 2-3 weeks to find it.

In my troubleshooting (very similar to yours) I replaced the shocks/springs with coilovers, had just done the pillowballs, motor mounts, and diff bushings, replaced my ppf and checked every other suspension bushing...turned out to be the problem I described above.

If you search my user name I have a thread on my troubles and eventual conclusion...

poss

iTrader: (5)

Just for clarification, "no load" as in no torque applied to the wheels.

nashman69g

iTrader: (3)

I have a similar problem...I got under the car and had my friend load the drivetran and I what I found was the drive shaft has a bit of play if twisted back and forth. This in turn causes a cluck sound as the driveshaft loads the diff. If u twist the driveshaft back and forth u should be able to hear a lighter version of the sound... Another way is to have a friend or whomever load the third and reverse gear syncros, without depressing the clutch, alternating between them. You should then see and hear the clunk.