The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Kiggly Racing
Please Support STM Tuned

Slight Grinding noise

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

vr4joe

10+ Year Contributor
69
0
Mar 4, 2012
Everett, Massachusetts
What going on guys?

I finally just bought a GSX tonight. I'm really excited to get back into the car scene. I recently sold my 95 3000GT VR4 last summer and really missed the AWD turbo scene.

I just picked up a 98 GSX and it is in great shape besides the clear coat. When i test drove the car i didn't hear anything wrong with the car. But on the way home ( 2 hour drive back home ) i got on it a couple of time and now i'm hearing a slight grinding noise. It only happens with i accelerate in 2nd, 3rd, 4th or 5th. As soon as i take the my foot of the gas, the noise stops. When i'm in 1st i also do not hear the grinding noise. Anytime when the car is 'under stress' is seems to make this slight grinding noise.

Could this be the throwout bearing making this noise? i feel like this is a transmission thing.

Let me know what you guys think.

Thanks,
Joe
 
i know the TOB are known to potentially fail Happened to me twice and I had a louad chattering/grinding sound before I changed it out. Eventually the syncros were bad so I got a whole new tranny. I did however put tranny fluid in first and it did ease the grinding. Try checking the fluid it could just be low. if fluid is ok most likely its the bearing which go for 20-30 bucks and easy if you can do it yourself. I know mechanics tend to rape you when it comes to dropping the tranny and stuff
 
It's certainly a slight grind when the car is 'under load'. I was thinking on flushing our the tranny oil but it wasn't doing this during the test drive. Either it started doing this when the car warmed up, or i messed up the throw bearing while doing some slight rolling awd launches in 1st.

I just didn't want to tear into the tranny if this was a simple issue. Believe me, I don't mind taking this thing apart... looks soooooo much easier than working on my VR4. There is so much more room to work, it is unbelievable. Your parts are so much cheaper as well. Wish i bought a dsm a long time ago. LOL

PS the tranny shifts like a dream, no grinding at all.
 
Its ###### the TOB mine was doing the same thing I replaced the TOB and now it never makes a sound, Id make sure if you do go to replace the throw out bearing you should replace anything else while u have it out, I changed out my clutch and everything while i had it out.
 
I would agree with the throw out bearing, but it's just a wild guess. I don't want to scare you but another possibility is an internal transmission bearing. It could be so many things. Any other info you can give on this like where does it sound like it's coming from? I know that can be hard to figure out. How much hp does this car have?
 
The car is completely stock. I bought the car off the original owner, he was 62 and rarely beat on the car. The only reason why he was selling it was because he was having a hard time getting in and out of the car. The car has 117k on it with the original clutch. The tranny shifts like butter in every gear. Again, when i test drove the car it wasn't making this sound. As soon as i did a couple of rolling 1st gear launches i could hear the grinding noise on the way home. The sound is def. coming from the engine bay and it only happens when the car is under load. The slight grinding sound happens in all gears while accelerating except in first gear and in reverse. As soon as the push in the clutch, the noise stops, if i let my foot off the gas , the noise stops. It only happens when the car is under load ( accelerating) except in 1st gear, it's weird. Also if I put it in a gear higher than it should, the noise is louder. ( when driving at 30mph and a put it in 4th or 5th). It's funny the clutch grabs really well and i'm surprised its the original clutch. That only tells me the guy certainly took very good car with the car and didn't push it to it's limits. This is the very first gsx that i've ever seen completely stock! It literally still has the stock air box and air filter.

I understand it's very hard to say exactly what is wrong with the car until i take it apart but i was hoping this might have been a common problem that DSMs have and i didn't want to waste my time taking everything apart, finding out it was something simple.

I did a lot of searching and found many causes of this slight grinding under load but they varied from simply changing the gear oil to rebuilding the tranny. It's a lot easier when someone else has the exact issue and telling me what to look for.

I really appreciate the help guys, this forum is very organized and i think I'm going to have a lot of fun hear. It's great to be back into the car scene, it's only been about a year but it felt like eternity.

Here's another clue. If i'm driving in 1st gear at 15 mph i don't hear the noise. If i'm driving in 2nd gear at 15mph I do hear the slight grinding noise.
 
No definite answer huh? well I might be able to start taking it apart this weekend depending on how cold it will be out there. Its suppose to only be around 10-15 degrees this weekend.... yuck!
 
Hey guys, I've finally been able to figure where the grinding noise is coming from. It almost sounds like its coming from the rear end or driveshaft. Again, the noise only happens when i'm under load. (3rd, 4th or 5th gear). When I accelerate in 1st or 2nd gear, I do not hear this noise. Could this be the carrier bearings going out? I jacked the car up and tried moving the driveshaft to find any play. There's alittle play with it but not enough to cause the issue. Again, it's not a vibrating issue, sounds like a slight grinding noise only when I'm in a higher gear or going up a hill.

Any suggestions?

Also, something seems to be loose underneath the car, and could also be the same issue. Let's say I'm driving in 3rd gear and I take my foot off the gas pedal really quick and then press the gas pedal again, I hear a high pitch clunking sound every time I do this procedure.
 
Pull the drain plug and check too see if there's any metal pieces on the plug or in the fluid. Small metal Shavings will be normal. X2 on throwout bearing. Maybe either synchros too?
 
-first, hello

-second, you said the sound might be coming from the rear of the car? hows the fluid level/quality look in the rear differential?

-third, can you do a drag test? 1st gear with clutch in held to the floor, rev to 7100-7400 rpm and see if she budges(if so there's a slight drag problem)

-fourth, I recently replaced my clutch disc/pressure plate and before I did, same thing as you described I could be in 2nd or 3rd gear and gas and let off and then reapply gas and I would hear a clunk( turned out to be the springs held onto the clutch disc itself the rivets had become loose and wasn't holding it tight in place anymore)

just a thought.:hellyeah:
 
Thank you so much guys for the responses.

I took it out one more time, and I'm certain it's a transmission issue. The slight metal grinding sound goes away when i push in the clutch. My question is, why does the grinding sound only happens (while driving) in 3rd, 4th, and 5th gear and not the lower gears. The car shifts through all gears like butter and no grinding between shifts. In-fact this GSX shifts the best out of all Mitsubishi's I've ever owned.

A loose clutch spring could be the case, since when the car is under more load, the noise is present. When I drive the car in 1st or 2nd, the grinding noise is not present. It's funny. Many people have had this same issue, but all the threads never end in a conclusion. I promise once I find the issue, I will let everyone know. :)
 
OK guys. I finally got to work on the car this weekend.

I dropped the transmission and replaced the TOB, clutch and pressure plate. I took her out for a spin this morning and she still is making a noise. On acceleration in 3rd, 4th and 5th gear I can still hear a slight grinding noise coming from either directly underneath me or in the rear. I flushed out both transfer case and rear diff with new 75w90 GL-5 Gear oil. I know i heard Redline is the best but none of the stores around here carry this in stock. I took the car for a spin again and the grinding noise got louder!

I'm thinking on flushing out both t-case and rear diff again and filling it up with Redline Shockproof. Do you guys have any idea what is cause this noise? Have anyone of you found that the Redline stuff really quiet things down? I want to know before i order 2 qts of this stuff.

Thanks,
Joe
 
Motor Mounts? I never though of this being the issue? How would worn motor mounts cause this noise? I thought i was getting closer to the issue, knowing that replacing the t-case and rear diff oils made the issue worse.

I'm at a lost here.
 
ok motor mounts that are worn out is were i would start the first thing i thaught is something is loos sounds like you have a axle rubbing on something and considering its a awd check your front and rear mounts or better yet just start the car and pull the throttle body and c how much you rock if its alot replase them and test drive again
 
Ok so today I popped the hood and reved the engine a couple of times to see any motor movement. There was alittle bit of movement, but that is what to be expected, I believe. I visually check all three tranny mounts when I dropped the transmission and all of them looked to be in pretty good shape. I took her out again for a test drive and I'm still hearing the grinding noise. It's very slight only when I accelerate in 3rd, 4th and 5th. 5th being the worse at low speeds. It only happens when I press the gas pedal (accelerating) I also hear a howling sound when I am decelerating. I'm wondering if these are two different issues or they are related. Both issues only make sounds with the car is in gear. When I push the clutch in, no sounds. It's quiet. (therefore not bad wheel bearings )Are they any DSM pros out there that can lend a hand.

I'm at a lost, there are many, many thread on DSM tuners that sound like they all have similar issues but they never end with a resolution.

Anyone???
 
I already flushed out both the T-case and Rear Diff with Valvoline 75w90 GL-5 gear oil

Here's a video. The slight grinding sound almost sounds like gears meshing together irregularly. You will hear it in the clip. Every time I accelerate you'll here the grinding. Every time I decelerate, the noise stops. It's very faint but you should here it.

[ame=http://www.youtube.com/watch?v=Ux27-SpYtgM]Mitusbishi Eclipse GSX slight grinding noise - YouTube[/ame]


Thanks Guys
 
When you took the trany out, did you check the axles?, I got one bad axle, the boot (transmission side) was damaged, but the inner gears were bad causing a grinding noise when accelerating, but the noise was always there (when accelerating), when it was clutched there were absolutely no noise at all.
 
When I removed both front axles, both seems to look in pretty good shape. The boots were in perfect shape. Grinding noise only happens in higher gears. (3rd-5th) The noise is louder when I'm in 5th at low speeds while accelerating. You can hear it in the video, every time I let my foot of the gas, the noise stops.
 
OK guys! Finally found out where the noise is coming from! It's coming from the transmission! I jacked the car up off all fours and had someone shift the car into 3rd,4th and 5th gear while I was under the car. Sounds is defiantly coming from transmission. What part in the trans is causing this noise? I attached a video on me under the car, near the transmission.

Will this need a full rebuild?

Gsx Transmisson Noise - YouTube
 
When I replaced the clutch and TOB. Everything seemed to be tight and fine. The only thing i didn't do, was resurface the flywheel. It seemed to be in decent shape. I know it will shorten the life on the clutch. This noise was doing this before I replaced the TOB and clutch as well.

Here's a better video of the car going through all the gears.

I pulled the transfer case off to rule out the T-case, Drive shaft and Rear differential.

It certainly is coming from the transmission since it was still making the noise. In this video I shifted through each gear. Notice, you do not hear the "grinding noise" in 1st gear. In 2nd gear you can start to hear it, and it just becomes worse in 3rd, 4th and the 5th gear being the loudest. Video below.

GSX Transmisson Noise_2 - YouTube

What could this possibly be?
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top