13 replies to this topic

[Tiho76]

Owner of Japanese export 97' mini here.

I'm having a problem changing from 2nd to the 3rd gear, especially when engine is cold. Shifter is moving freely, no obstruction at all. It gives the grinding noise like I've never pressed the clutch, and only after second or third retry it goes properly in the 3rd gear. Only after prolonged usage, let's say after 30min of driving, problem is not repeating. Where should I start looking at? Thanks.

[Steam]

Sounds like the sybchro is on its last legs. If you go 2nd to neutral then double clutch and slide into 3rd it should shift alot quieter and better.

[bpirie1000]

Yip syncro on its way out afraid.

Gearbox out jobbing for that repair.

Engine out gearbox off ..

Syncro change it self is a 20minute job. Getting to it though is the head ache..

Edited by bpirie1000, 08 October 2023 - 06:21 AM.

[mab01uk]

This is a common problem on the later Minis (see link below), as said for a full cure the gearbox needs to be rebuilt and then to only use the correct 20/50 oil suitable for a Mini engine/gearbox.

 

2nd Gear Crunching - Mpi 1999:-

https://www.theminif...ching-mpi-1999/

Edited by mab01uk, 08 October 2023 - 08:14 AM.

[Spider]

Given the issue is present when cold but fine when it's warmed up, I'm thinking it has an unsuitable oil in it.

Worn baulk rings usually behave the other way, OK-ish when cold, terrible when hot.

[Tiho76]

Castrol 20W50

[coopertaz]

if all other shifts ok, including reverse, then would agree baulk rings worn

[Shooter63]

Yip syncro on its way out afraid.

Gearbox out jobbing for that repair.

Engine out gearbox off ..

Syncro change it self is a 20minute job. Getting to it though is the head ache..

Wow, if you can strip and rebuild a gearbox in 20mins that's going some, even if you charged £150.00 plus parts you would make healthy living and would be snowed under with work.It took me 4hrs just to clean all the parts and re assemble the main shaft into the box.

Shooter

[bpirie1000]

Yip syncro on its way out afraid.

Gearbox out jobbing for that repair.

Engine out gearbox off ..

Syncro change it self is a 20minute job. Getting to it though is the head ache..

Wow, if you can strip and rebuild a gearbox in 20mins that's going some, even if you charged £150.00 plus parts you would make healthy living and would be snowed under with work.It took me 4hrs just to clean all the parts and re assemble the main shaft into the box.

Shooter

3 hours 40 to get to the syncro....

20 mins to change..

3 hours 40 putting it all back together.

[LD_Framework]

Sorry Guys, I write here avoiding open a new post due my problem is related to the gear change, but i have problem to put the 4th gear instead. Everytime I put the 4th there is a crunchy noise like the clutch doesn't work, but only from the 3rd to the 4th. Before strip the engine off the car any suggestion? what should I check? Mini 1991, 1300 cooper carburettor, 35k miles, never change the gearbox. 
Is the syncro working only from 4th to 3rd and not the way around? what possibly can be? 

Thanks!

Edited by LD_Framework, 09 January 2025 - 09:55 AM.

[LD_Framework]

Really you're telling me that the only options I have here is to get the gearbox out? Help!!!!

[Spider]

There was what I believe to be a machining issue with the gearcases by around that period. They would cause either 3rd or 4th gear baulk ring to wear prematurely, or even burn out. Given your issue is on 4th gear, which suffers the least wear, I'd say your gearcase has this issue. What I've found was that the Shoulder for the Mainshaft Bearing was machined around 0.020" too deep, and this pushes the whole Mainshaft up in to the 1st Motion Shaft (4th gear) by that amount. This them means that when in Neutral, and all gears other than 4th, the Top Gear Baulk Ring has pressure on it, causing it wear prematurely. These normally float and only have pressure on them when actually shifting. I fix them by first measuring the gearcase to see how far over they have been machined, then putting a shim in to bring the Mainshaft back to where it should be.

[LD_Framework]

There was what I believe to be a machining issue with the gearcases by around that period. They would cause either 3rd or 4th gear baulk ring to wear prematurely, or even burn out. Given your issue is on 4th gear, which suffers the least wear, I'd say your gearcase has this issue. What I've found was that the Shoulder for the Mainshaft Bearing was machined around 0.020" too deep, and this pushes the whole Mainshaft up in to the 1st Motion Shaft (4th gear) by that amount. This them means that when in Neutral, and all gears other than 4th, the Top Gear Baulk Ring has pressure on it, causing it wear prematurely. These normally float and only have pressure on them when actually shifting. I fix them by first measuring the gearcase to see how far over they have been machined, then putting a shim in to bring the Mainshaft back to where it should be.

This means that I have to disassembly all the gear case (removing the engine), disassembly all the gear components, measure the case shoulder (where the main shaft is inserted) and then re-assembly all with a shim (if there is a problem there), is this right? 
Where I can get the right distance? in a few words how can I be sure is the right or wrong distance? What number should be? Can't find it in the manual! thanks again !

[Spider]

This means that I have to disassembly all the gear case (removing the engine), disassembly all the gear components, measure the case shoulder (where the main shaft is inserted) and then re-assembly all with a shim (if there is a problem there), is this right? 
Where I can get the right distance? in a few words how can I be sure is the right or wrong distance? What number should be? Can't find it in the manual! thanks again !

 

You won't find this info in any workshop manual.

Post #12 here;-

 

https://www.theminif...ild-remote-box/