Symptoms:
1) While decelerating in gear, there's a loud and high pitched grinding noise, video for reference:


2) While in 1st or 2nd gear, toggling between acceleration and deceleration with the gas pedal will cause the shifter to bounce around in the center console. This behavior isn't present while in the other gears.

History:
I've had this car for about 6 years now. It's had these problems since the day I bought it. The transmission had a different vin number than the chassis so who knows what its seen or where its been before I bought it.

2015 - main shaft bearing (the bearing opposite of the clutch housing side) busted, brought it to a local shop, they replaced the bearing
2018 - main shaft bearing busted, took it apart myself. Replaced the bearing and noticed that the mainshaft bearing has been making contact with the input shaft's 6th gear for what looked like a long time. There's noticeable wear on the 6th gear where the mainshaft bearing had been rubbing (See arrow in pic #2). I also left the preload pretty loose, I should have shimmed it to be within spec but I really didn't know what I was doing. And I still don't! After this repair the noise was gone for about 5 months. The shifter bouncing issue was still present but not has severe.
Today - The deceleration noise has been back for a few months so it's time to pull it apart and see if we can fix both issues and set the preloads properly.

The trans has been removed from the car and the case has been split:







Some observations: Magnet is relatively clean. Gear oil is relatively clean. I immediately noticed that the two shafts don't appear to be properly aligned when sitting upright. You can see there's nearly a quarter inch offset where the input shaft gears rise above the main shaft's gears. I'm not yet sure how to correct this. I measured the preload on the input shaft and it's less than a millimeter within spec - need to add a slightly thicker shim, it seems.

The main shaft was pretty far from the preload spec. I think that the main shaft needs to be shimmed from the bottom to come up a few millimeters but the bearing housing that it sits on top of doesn't seem to be designed to be shimmed so my assumption may not be correct.

What I'm going to do next:
I have a donor transmission sitting in the garage with a main and input shaft inside of it. The gears have some damage but I will try to put them into the upright resting position as seen in the pictures
above and then try and draw some conclusions from how the height offset looks between the gears on the input vs main shaft in that unit and then determine how to proceed

Anyone have any advice or insight? Experiences to share?

 

Holy crap, what a great post! Thanks for uploading these pictures Butte. We need more people to dig into the 6 speed and spread the word. That quarter inch offset could definitely cause some problems with some of the load bearing side of the gear's free floating. It would essentially turn an 18mm gear into a 13mm gear. I wonder if the shaft moved around or if it sits correctly when assembled. I have so many questions now Also, I hear that disassembly of the 6 speed shifter linkage arms is difficult, did you find this to be true?

 

you just need to follow the workshop manual on the way you get the shift interlocks out... not that difficult really.. I got it right the first time I tried..

 

I'll have to take a look a this . I'm happy to hear that there is workshop manual instructions for the 6 speed. Unlike the inners of the transfer case......

 

One thing I can say for certain is that the mainshaft was traveling along the axis of the shaft (to and from the driver and passenger sides of the car) when toggling load between accel and decel with the gas pedal. This accounts for the bouncing shifter problem and the mainshaft's bearing making contact with the 6th gear on the input shaft.

I've taken the linkage apart, it's tedious to remove the pins that hold the collars to the shafts but I wouldn't say it's difficult exactly. It's made a little bit easier if you have a heat gun. The shifter interlocks took me some time to get right, but if you have some tweezers, a little magnet-on-a-stick tool and some patience to start over a few times then you'll be fine.

 

I see, that explains it! I appreciate the warning about the linkage assembly. I want to be able to install the Albins 3 - 5 by myself, but I don't feel confident enough to tackle the project yet. I have a press, but need a gear puller and new bearings etc..

 

here you go..

http://evoscan.com/manuals/Evo9/GR00...M1222000900126

 

Hi friend I have same problem with my 6 speed gearbox….how did you fixed it? Thanks for your answer😉✌️

 

It ended up being the retention clip on the bearing of the housing end (opposite the flywheel side) of the input shaft. That clip had enough play that it couldn't keep the input shaft in place and on deceleration the input shaft would lean into the output shaft in a way that cause the top two gears to grind together. You can see the retention clip I'm referring to at the very top of the right hand shaft in the first picture. I bought an old junked 6 speed off of someone and replaced the clip and the bell housing (I was concerned about wear on the part of the bell housing that secures the retention clip) and it's been fixed since. Let me know if I can help with any more information.

 

So If I understand you change only this part on the my photo right?😉

 

Good thread for a diy gearbox repair, always something I've wanted to be able to do especially replacing the 3-5 with an Albins gearset in my 6 speed when I blow the 4th gear

 

dont wait for the 4th to blow as it will take whole gearbox out,.... hell took the rear diff on mine too

 

So today I took the gearbox out of the car…my problem was with “locking clip“. on the photo is different between new and old. On the video is shaft with old clip - this was bad!! Thanks for member butte! His information fixed my shaft in gearbox😎

This is the different…upper is old

Old clip in gearbox it has a long distance