Hey guys,

Follow me on a journey as I tear down my TRE tranny and try to identify the cause of my noises and less than ideal shifting.

Tranny Background:
• Rebuilt by TRE on 10/29/2014 with 4.11 final drive and Evo 8 3rd and 4th ; currently with 15K miles
• Long story - https://www.evolutionm.net/forums/ve...l#post11577208


Issues:
• Noise at idle similar to input bearing noise; clearly audible while stationary and very noticeable against a drive-through wall.
• Whining noise at freeway speeds similar to xfer case whine; no whine before transmission rebuild and xfer case checked 3 times – never low on fluid.
• Slight rough engagement at the top of the 3rd gear shift.


My background
• Currently own – Evo IX, Galant VR4, and a Montero
• Have owned – 4 DSM’s, and Evo X, a Lexus IS 350
• Have 20+ years’ experience building Mitsubishi cars, including 4 DSM motors and transmissions with zero failures over 50k miles. (Not professionally, just for myself, family, and friends)




Initial tear down and thoughts:

The Center Diff bearings are shot! major scaring on the races and on the bearing surface, this may be where my whine at freeway speeds are coming from! Looking through my TRE invoice, these were not billed or replaced. I’m unsure if they looked fine when Jon inspected the tranny and the damage occurred after, or if Jon just missed them, at any rate, I will be replacing these.

No obvious cause of the noise at idle, bearings on the input shaft look ok, but I will replace all major bearings for the hell of it, also all needle bearings will be replaced with the exception of 1st as Jon installed his HD 1st gear bearing instead.

Something a bit odd that I may need the help of the community to solve:
It’s obvious that Jon replaced 1st & 2nd synchro’s, however judging by the large color difference in the other gear’s synchro’s it appears 3rd, 4th,5th, and reverse were not changed….again, only judging by the large difference in color. I’ve decided to replace 2nd, 3rd, and 4th while I’m in there, so I will do my best to measure the wear on the current synchro’s against to the new units I receive.

Stay tuned, I will update the thread as I go, may need your help as well

 

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And a question.....can you describe the input bearing sound and when it occurs ( ie in gear 1000- 2500 under load etc shrill increasing low pitched whine etc you get the idea

Does it go away when the tranny warms up ?

Trying to diagnose my car, 05 MR dont think it is transfer case whine as it is not present when the car is warmed up for 15 minutes before driving.

Thanks in advance

 

If you are referring to my whine at freeway speeds, there was no difference when warm, a very low volume whine audible around 50-80mph, not very loud, passengers couldn't here it unless I pointed it out.

 

Input shaft noise at idle while stationary confirmed to be a bad Throw out bearing.

Only 15k on a OEM bearing that is prepacked with grease and sealed...

Not sure I can find a higher quality TOB bearing though

 

What fluid was used? Maybe incorrect shim size

 

My original TOB started making noise like that. I think it was the first year. Guess what? 135K still have it and the original clutch in there.

 

Only four types of fluid used:

Motul 300
Mitsu oem 75-85 (6sp)
Amsoil 75-110 (during Alabama summer)
Redline 75-85

TRE shimmed the tranny, I'll double check when I re assemble with new bearings and synchros.

 

What's your point, live with the sound?

 

from 35 years of tranny building. maybe 50 dsm and evo transmissions.
replacing those diff bearings will do nothing. they are fine. replace bearings when you see pitting. spots that look sand blasted. even severely worn bearings never make noises. I have taken a transmission apart were oil was dirt black and multiple bearing just fell apart when cases were opened. yet this trans drove fine and was quiet. whining noises come from gear teeth issues. noise at idle on these transmissions comes from 5th gear mating loose on the shaft. I suspect the flywheel is too light and doesnt absorb enough energy. this energy of each engine pulse fires into clutch and into the trans. the weak link is the fifth gear splines and they loosen up. this plays havic on 5th gear syncro as well. they are always the most worn. shep made a 5th gear with double syncro but that made no difference. it wears out both syncros just as fast from the vibration. half the transmissions 8/9 i take apart have this issue. (evo 4 trans is devoid of it, I personally prefer these)

 

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I've had several OEM TOB's not have any issues. It's possible you just got a bad one.


What Jerry said is also possible. Make sure 5th gear still has a slight press fit onto the shaft, as well as all the other gears.


I agree with Jerry on the center diff bearings, they actually don't look that bad. Used, yes. Bad, no. And bearings don't make the noise you described.

 

Well, a bit late, I already removed those bearings, one was cut off

I'll check gear fitment and report back!

 

You guys think (based on color) that 3, 4, and 5 synchro's were replaced?

1 &2 are so much brighter/cleaner looking, so I really have no other way to tell but to buy new ones and measure the outer and inner bores.

 

Post pics, how do the synchro stops and engagement teeth look, as well as the teeth on the sliders and the gears? I don't distinctly remember the color of mine, and I even put my trans together myself...lol. FWIW, the 1-2 and 5-r synchros sit in the flui, which could keep them cleaner. On jacks website, they appear to all be the same color..
http://www.jackstransmissions.com/co...-9-rebuild-kit

Need moar pics.

And FWIW, I would have replaced the center diff bearings too. I was just commenting that they weren't bad in the sense they were making noise.

Also, that poor trans is dirty as f#ck inside