Whats going out in my trans?

[GSXftw]

91 GSX, I have never been into my tranny. Its obviously time but Id like to know whats going on and what I will need. I plan on rebuilding everything but Im on a budget at the moment.
For about 3 years now its made a noise on decel at highway speeds, as soon as you give gas it goes away. Its kind of a metal rattling, and you can feel it also in your feet. It hasnt really gotten worse until recently, and what I hope is related is Ive been fighting some phantom knock for about a year, down low 2-3k, even does it on free revs. I hooked up a stethescope to listen, and in the bellhousing area theres a definite wirring noise at idle, and when you rev it itll sound really horrible with the stethascope on... like metal hitting on metal. When you push the clutch in and put it in gear and rev it goes away, and it is not I REPEAT NOT the throw out bearing. Also my transfer case is untouched and stock, and theres play in it. With the car in the air the wheels can turn a 16th before the driveline turns. Thanks in advance guys

Sounds like input shaft bearing, no thanks to the input here

 

[JackM]

The input shaft bearings never go bad. I would check the intermediate shaft end bearings as they are a common problem.

If all of that looks good, then I would say you have the typical 'womp womp' noise. It's normal for cars with removed balance shafts, light flywheels, or aftermarket clutch disks. It can also be caused by balance shafts out of time.

What is happening is the engine harmonics and torsional whip from the crank is getting past the clutch and into the drive-train. Without anything to absorb this, the harmonics end up in the drive shaft and make the noise you hear.

If you want to try to replace your intermediate shaft end bearings in the trans first, here is a list below of what you will need:

DSM CV Seal Output - Driver Side – Jacks Transmissions LLC
DSM CV Seal Output - Pass Side – Jacks Transmissions LLC
DSM Input Seal – Jacks Transmissions LLC
DSM Output Shaft Seal – Jacks Transmissions LLC
1 Drain Plug Washer, Gasket, Seal – Jacks Transmissions LLC
1 Fill Plug Washer, Gasket, Seal – Jacks Transmissions LLC

Need 2 of these:
Dowel Pin – Jacks Transmissions LLC

Need 3 of these:
DSM Fork Roll Pin – Jacks Transmissions LLC

Need 2 of these:
End Nut – Jacks Transmissions LLC

Need 3 of these:
Genuine OEM Mitsubishi Trans Fluid – Jacks Transmissions LLC

End Bearing BOTTOM – Jacks Transmissions LLC
End Bearing TOP – Jacks Transmissions LLC

A quick Google search on how to disassemble your trans can be easily found. That could give you more of an idea of what you are getting in to.

Good luck!!

Jack

 

[eclipsh]

I had worn springs on a clutch friction disk that did something very similar to what you're describing. They rattled like crazy every time the engine decelerated or I did engine braking. If I used a stethescope on any part of the engine or tranny it sounded horrid. It carried through all the metal very clearly. Have you looked at the clutch?

In my case once the clutch was out it was very obvious one of the springs was loose as I could freely move it around with a finger and bounce it back and forth. Free revving it sounded like the whole drive train was rattling around and ready to come apart.

 

[97grnrs]

im having same noise. i found this http://www.dsmtuners.com/forums/dri...-help-diagnose-transmission-noise-videos.html

 

[GSXftw]

Ive actually been through 2 clutches and many mods since this noise started. The stock clutch came out and a stage 2 kevlar fullface sprung on stock FW went in, ran it for 3 years, then Just recently I pulled the engine, did a BSE and XTD stage 4 (unsprung 6 puck) and 11 lb chromolly. Its just always kinda been there... balance shafts or not. Thanks JackM Ill see what I can find out and update

 

[4pistons]

This thread may help ID it ...

http://www.dsmtuners.com/forums/dri...idanza-6-puck-now-having-noise-vibration.html

Rick - '91 GSX

 

[97grnrs]

pop the end case off and check that synchro. i just checked mine today and thats the problem with my rattle

 

[GSXftw]

This thread may help ID it ...

http://www.dsmtuners.com/forums/dri...idanza-6-puck-now-having-noise-vibration.html

Rick - '91 GSX

Good info. Honestly maybe it is just vibration from off balance clutches... it started doin it pretty much right after my first clutch upgrade, stock fw and fullface kevlar...

pop the end case off and check that synchro. i just checked mine today and thats the problem with my rattle

good to hear. Id love to see if it was the 5th gear ring but it mostly rattles IN gear, 5th included, so cant really put pressure on the 5th gear ring...