tranny issue/noise

[taino787]

97 GST Spyder






My problem started when I was driving my car about 60mph (I was not dogging it at all. just driving normal) While driving I heard a loud bang(like hammer striking metal) comming from the engine, followed by several popping sounds(like loose bolts in a coffee can) I stopped my car and looked in the tranny area and floor for any signs of fluid leaks, but no MT fluid was leaking.

It was late and I was just a block away from my house so I decided to drive the car slowly and park it at home. The tranny shifted fine, (but I did not go past the 2 gear.) I kept a slow speed because the popping noise gets worst with speed increase.

While at home I moved the car back and forth a few times and I have noticed thet the poping only occurs when I when the car is rolling.

On top of the popping, I can also feel a strong bump every rotation (feels almost like I had bump in my tire, but im sure I dont) I also noticed that the whole engine moves (small pop) at the same time that the bump occurs. All the noises stop when the car stops rolling. I lifted the front of the car and had my neiigbor put the car in gear and found that the noise comes from the transmission.

If I turn the car on and get into any gear, the noise will come back on as soon as I start taking pressure of the clutch, withgout the vehicle moving. Noise stops as when car is not moving or a few seconds after the transmissions is taken out of gear and placed In N.



Any ideas ???????

 

[Old Mitsu Tech]

I'm not psychic, but I wonder if you could have knocked a tooth of either your pinion or ring gear. It's kindof rare, but without hearing it that would be my thoughts.

Mark one of your tires and see if it happens once every revolution. This would indicate ring gear. More than that could be pinion.



Good Luck

 

[taino787]

After a couple of days without messing with the car, I started it today and noticed that the clucth pedal has no pressure at all.

It goes all the way down and won't come back up. I can press it and i'm able to start the engine, but I can not get into any gears.

 

[majik2k5]

Sounds like the throw out bearing. My friends went bad on his 1g, and the symptons were identical.

 

[Pandagonier]

Had the same problem once. Check and make sure your transmission bolts are tight and not missing. Had all of my bolts either missing or about to fall out. There was like a 1/4" gap between the tranny and engine. Got some new bolts from Mitsu put them in and it worked perfect minus a bad TOB...but thats a different story.

 

[taino787]

i will check the bolts today. the pedal pressure went back to normal.

 

[taino787]

I check the bolts and they were tight and all accounted for. but i will have someone doublecheck.

 

[taino787]

when I asked my friend to double check all the bolts for me .. we found that my front motor mount is broke. I never had any issue with vibration or any of that.

When the problem started, that that loud bang I heard could have been the motor droping..(just a theory)

Do you think that broke mount is the cause of my problem?

 

[jeremy19984g63]

i had a 99 gst that had done so many hard pulls that the rear mount broke in three pieces and the front one had stretched. had no vibration, but did have a small knock when accelerating and decelerating. also i have seen these transmissions throw teeth off a gear and exit casing

 

[taino787]

just thought about CV joints/axles/shafts???maybe???

 

[taino787]

it was the 1-2 gear shaft that went to shit. looked like a slushy.


I had a 1G tranny around. i sarted to look and compare the exteriors, exterirors were slightly different (mounts) but decided to open it just for kicks and to my surprise the internals were identical. same gears, teeth counts, synchros etc. the only difference was the diffrenetial, I used the 2g one because the 1g was not compatible with my 2g CV input shafts.