Gearbox Issues

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3diamonds

Well-Known Member
Joined
Apr 21, 2005
Messages
156
Location
Brisbane
Hi all

Well I'm on about my 5 gearbox due to the gearbox housing getting damaged.

The problem is the sleave that the trust bearing for the clutch is on keeps getting torn off the housing. Unfortunately I can't find someone willing to attempt a repair and I'm getting tired of buying gearboxes. The clearances are fine for the clutch and the gearbox is sitting in correct on the block.

So is there anyone that has come across this problem before or know of anyone?

If so do they know of a solution for this problem?

I'm running the short ratio 3.9, 4 bolt box
 
do you have the right length clutch fork?
correct throw on the slave?

there must be an external issue causing it surely
 
DOUGMO said:
do you have the right length clutch fork?
correct throw on the slave?

there must be an external issue causing it surely
the fork and slave are fine
jack of all said:
You have the little tube locators fitted between gearbox and block?
You have the gearbox bolt that is under starter motor and fits from engine side?
the box is sat on the block properly and bolted correctly.

I'm thinking that it could be something to do with the input shaft?
 
The input shaft sleeve gets damaged when the throw out bearing collapses and seizes up. I cant see any other reason for it except for maybe if the input shaft bearing itself gets worn it will elongate a hole in the bellhousing causing some play and clutch plate play.
Im thinking you're either using the wrong type of throw out bearing, or youre not adjusting your clutch properly and theres a constant drag on the bearing causing it to overheat, wear and seize prematurely damaging the sleeve. You can check drag by putting the car in neutral and revving the engine to see if the car creeps forward.
 
Here's a pic I took to compare throw out bearings.

The aftermarket bearing that came with my clutch was a different shape and I took it upon myself to use it as hey, that's what the company supplied with my clutch kit. The thing was crap in no time at all and was making the typical thrust shhhhhhhh noises most of the time it was in. The outer bearing case was worn and the bearing retaining clip was warped. It had so much movement in the bearing cage that it wore unevenly where it pressed into the pressure plate fingers. It also didn't fully seal the ball bearings inside it. There was a big gap in the casing and dust and water entered inside it. As you can see from the pic, don't always trust aftermarket bearings that come with your clutch kit!

The middle bearing is the oem EVO I-III, GSR, GVR4 etc throw out bearing. It has a thin inner sleeve (Mitsu#MD719925, NSK#48TKA3201).
It was later revised by Mitsubishi for a slightly different design with a thicker wall inner sleeve and better sealed bearings (Mitsu#MD749998, NSK#48TKB3202)

I ended up buying a new revised OEM bearing from Meek for $40 when I did the reinstall.
 

Attachments

  • EVO I-III, GSR, GVR4 throw out bearings.jpg
    EVO I-III, GSR, GVR4 throw out bearings.jpg
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Just to go back on what Jack of All asked... you DO have the 2 hollow dowels to locate the gearbox on the engine block. Of the scores of gearboxes I've been involved with in street/race/rally cars, I have never encountered your repeated dramas of breaking the input snout!!
 
^^ Me neither. You dont hang the weight of the gearbox on just by the input shaft sitting in the clutch plate during assembly do you?
Basically get the bugger straight onto the locating pins and bolt the bitch up straight away and never let it sit there under its own weight until at least one or two of the top bolts are in part way.
Easier said than done whilst the block is still in the car I know due to the tight squeeze lol.
 
I can't remeber off the top of my head the bearing thats in it. but I had purchased the twin plate clutch through APC and they suppied the bearing.
After having this happen to me 4 times previously I bought another box at a highly inflated price to what i usually get them for and had APC install the new box. only for it to happen a 5th time after a short period of time.

their solution was get a dog box. i properly could of purchased one by now with the amount it has cost me.

but I'm at a point where I'm keeping the funds towards the car at a bare minimum.

over the years the car owes a little bit of money and doesnt help when you take your car to a shop after you have done the set up that worked fine for years for them to change things with the help of my $$$ and it doesnt run well for very long since.

if I was willing to spend the dollars I'd properly change it to auto and get rid of the drama.
 
DOUGMO said:
if it was fine before the clutch went in you would have to be looking at that as the cause surely?
i had the clutch checked over by Direct Clutches and a Clutch place in Sydney, they both said that there is nothing wrong with it.
 
it might look fine on a bench and clamp loads could test fine,but unless you sent the whole car there it could be hard for them to be 100% I would think
 
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