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Hu1tik
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Location: Tauranga

TT Gearbox Wanted.

Sun 21 Apr, 2019 5:03 pm

Wanted TT 25 spline gearbox. 

The gearbox is making a bad grinding noise and has no drive in any gears. 
Have taking in out and apart and it all looks okay. Even the clutch wasn't that bad. 

I will rebuild this one over time but was hoping to make it to the Mitsubishi Owners day.

Gearbox
 
BATOOH
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Re: TT Gearbox Wanted.

Sun 21 Apr, 2019 6:09 pm

Hu1tik wrote:
The gearbox is making a bad grinding noise and has no drive in any gears. 
Have taking in out and apart and it all looks okay. Even the clutch wasn't that bad. 

Maybe the bad grinding noise is not the Gearbox, especially if, as you say, It all looks ok. If the clutch is good then I'd be looking at the output shaft into the transfer case. 
 
BATOOH
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Re: TT Gearbox Wanted.

Sun 21 Apr, 2019 6:12 pm

BATOOH wrote:
Hu1tik wrote:
The gearbox is making a bad grinding noise and has no drive in any gears. 
Have taking in out and apart and it all looks okay. Even the clutch wasn't that bad. 

Maybe the bad grinding noise is not the Gearbox, especially if, as you say, It all looks ok. If the clutch is good then I'd be looking at the output shaft into the transfer case. I suppose if the rear drive was lost and the Viscous Coupling (Centre diff) was carrying the load then eventually you might find yourself at Standstill.. Check the Trans case spool and the output shaft...
 
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Hu1tik
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Posts: 40
Joined: Tue 17 Apr, 2012 9:41 pm
Location: Tauranga

Re: TT Gearbox Wanted.

Sun 21 Apr, 2019 8:37 pm

Clutch is okay. 
They are worn but haven't been grided off. Like it doesn't look like metal has been rubbing on metal. 
 
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Hu1tik
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Location: Tauranga

Re: TT Gearbox Wanted.

Tue 23 Apr, 2019 9:14 am

After looking over the gearbox. My best guess is something in the VCU has given up.
 
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box
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Re: TT Gearbox Wanted.

Tue 23 Apr, 2019 12:31 pm

Interesting. Pull it apart. 
Image
 
magn1t
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Re: TT Gearbox Wanted.

Tue 23 Apr, 2019 5:57 pm

It could be the gears in the transfer case stripped...that's if it's not the output shaft or input spool. 
It could be the clutch pressure plate too, the diaphragm split so no clamping force.
As per usual, random swapping of parts isn't very smart.
Need to do tests and measurements first instead of just guessing.


The only time I've seen a "false neutral" in a 5 speed box is with reverse gear, they're made that way for a reason.
Gearboxes are very precious, people will want to hang onto them if they're good.


If there's a problem with a spline, then there's Brian Howatt Engineering, he's made me a new spool (transfer case) and repaired a stripped shaft....makes far more sense than trying to import jap parts from murica.

He's also the man to go see for any balancing.   He's into those off road things that climb up cliff faces.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
BATOOH
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Re: TT Gearbox Wanted.

Tue 30 Apr, 2019 3:11 pm

Wondered if you found the problem yet.

I found a paragraph off a doc     www.3swiki.org/Drivetrain:_AWD _system referring to delamination of the rubber insert in the rear 1/3 section of the tubes of the driveshaft. Apparently estimated at around 500 awhp. "It will feel like you are in a RWD vehicle stuck in the mud" "You may hear a grinding sound" "This type of failure is very hard on the VCU... etc ..and inspect to gear oil for signs of VCU GOO" I have hardcopy and could'nt easily find this on the web. Too much work to scan and send. It would be a bastard to diagnose a failure like this!
 
BATOOH
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Re: TT Gearbox Wanted.

Thu 02 May, 2019 7:56 am

And another thing that constantly amazes me - not that I think it will be a cause to your problems above is the fact that the Pinion wheel inside the transfer case (using terminology from a differential) is simply pressed onto the input spool by immense pressure and it stays put by virtue of that. I realised that when I had the 18 spline spool pressed out and a 25 pressed in. Wow so even those launches that we all do and see are supported through that connection. There is nothing else, no spline, no pin, no keyway no nothin. I keep wondering if it was ever designed to allow a little slippage under the most extreme condition.
 
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Hu1tik
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Location: Tauranga

Re: TT Gearbox Wanted.

Wed 15 May, 2019 10:19 pm

Car is now running again. After pulling the gearbox apart and taking it to the transmission guy. It turned out to the VCU. In that same time sourced anther gearbox that had been rebuilt. 
 
BATOOH
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Re: TT Gearbox Wanted.

Thu 16 May, 2019 3:53 am

Hu1tik wrote:
Car is now running again. After pulling the gearbox apart and taking it to the transmission guy. It turned out to the VCU. In that same time sourced anther gearbox that had been rebuilt. 

Are you big enough to admit to any failing on your part like mismatched front and rear or skidpan action etc or did the VCU just up and fail?
 
magn1t
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Re: TT Gearbox Wanted.

Thu 16 May, 2019 8:59 am

Pics of broken parts for all to see?


A VCU.......the viscous part?
Won't stop the car from moving.


Must be the planetary gears?
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!

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