Manual Gearbox Bearings

mookers

puri puri
Location
Frankston, Melbourne, VIC
First Name
Derek
Drive
CL9 Accord Euro Lux, GE Jazz VTi, Evil Supervillain Chair, Homemade Portable Square Drumkit
If you have a manual and it's got over 100,000 km on it, I would strongly recommend replacing the input shaft bearings the next time you have the box out of the car (most likely for a new clutch).

It's obvious that you'd replace the engine rear main seal and the gearbox input shaft seal because they're right there, and not too difficult to do. But you should really replace the input shaft bearings too.

The bearings in my gearbox were worn enough that the input shaft developed enough play that it caught and fouled the input shaft seal, resulting in an oil leak which then fouled my clutch.

It's a big job to split the gearbox and replace the bearings, but it's also a big job to pull the gearbox out of the car and reinstall it again. Do all the maintenance at one time.

</experience>
 

dwarfmarine

1 AYC Bar
Location
Windsor, NSW
First Name
Cameron
Drive
Previous: Black PFL Legnum
Current: TD5 Land Rover Disco
Seconded.

I had done the clutch in mine not long after the 100'000km service, the usual.. Rear main seal had enough and oily clutch.

6months later input shaft bearing was noisey as buggery so dropped it again and had a full new bearing set put in but I ended up paying g/box removal labour twice unfortunately
For the sake of the $300 for the bearing set, do it all at once.
 

Nitephyre

Flaccid Member
Lifetime Member
Location
ormeau@gc.qld.au
First Name
Matt :)
Drive
1963 Toyota Lite-Stout & 2007 Toyota Blade Master G
Mmm yeah, I think that's this years expense... gearbox bearings, seals & clutch... it's only been rattling for the whole 5.5 years I've owned it :p
 

jungle

3 AYC Bars
Lifetime Member
Location
QLD
First Name
Simon
Drive
1 PFL & 1 FL Legnum
You can be unlucky. I've done 200 000km's (259xxxkm) in my Leggy now and its recently developed the tiniest ( not sure if that's a word) of whines in 5th and 4th only on decal at certain speeds. That said, I've already priced the gearbox bearings and synchro's as I plan to replace the lot while the engine is out(y)
 

6A13TT TYPE S

3 AYC Bars
Lifetime Member
Location
New Zealand
First Name
Adam
Drive
1999 Legnum VR4 Type S
If your splitting the box open to do the input shaft you may as well but a W5M51 Bearing kit and do the lot! because once you have the gearset out it's minimal extra effort to do the remainder of the bearings
A local bearing supplier (South Island Bearings) here in Christchurch sells a kit for 390NZD it includes
both input shaft bearings
both layshaft bearings
both center diff bearings
input shaft seal (Genuine mitsubishi)
left axle seal (Genuine mitsubishi)

@jungle how much are synchros going to cost you as last time I priced them they were drug money. like $140 ea for 1st 2nd and reverse and $100 ea for 3rd-5th so I just bought a good nick evo box with a damaged casing and swapped synchros out of that instead
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
See us for gearbox parts. We have all of them in stock and nothing like those prices. We've rebuilt heaps of evo and vr4 boxes. We recommend the input shaft bearings in them with every clutch pretty much.

There are a few things to watch in these boxes. The input shaft bearings are a problem due to their design. They don't deal with the thrust load from the helical cut on the gear sets very well at all. The output shaft has tapered bearings to deal with this and I've have yet to see problem with these. That said some guys replace the lot because you're there anyway.

There is a company in the US that has developed a tapered bearing replacement for the input shaft and we're evaluating doing something similar but it would only be on gearboxes we rebuild.

The other area of failure is the shift forks. Again we have all these in stock most of the time and we replace heaps of them in vr4s and evos.

Then there are synchros which is more dependent on how particular people are and the type of life the box has had.

Also be careful if you get bearings from anywhere but mitsu. Ntn make the input shaft bearings for example but an ntn6306 is not what you'll get from mitsu. The correct bearing is a heavy duty version and is an ntn6306 v23. You'll find that this is about 3 or 4 times the price of the generic 6306. Again, all in stock.
 

6A13TT TYPE S

3 AYC Bars
Lifetime Member
Location
New Zealand
First Name
Adam
Drive
1999 Legnum VR4 Type S
See us for gearbox parts. We have all of them in stock and nothing like those prices. We've rebuilt heaps of evo and vr4 boxes. We recommend the input shaft bearings in them with every clutch pretty much.

There are a few things to watch in these boxes. The input shaft bearings are a problem due to their design. They don't deal with the thrust load from the helical cut on the gear sets very well at all. The output shaft has tapered bearings to deal with this and I've have yet to see problem with these. That said some guys replace the lot because you're there anyway.

There is a company in the US that has developed a tapered bearing replacement for the input shaft and we're evaluating doing something similar but it would only be on gearboxes we rebuild.

The other area of failure is the shift forks. Again we have all these in stock most of the time and we replace heaps of them in vr4s and evos.

Then there are synchros which is more dependent on how particular people are and the type of life the box has had.

Also be careful if you get bearings from anywhere but mitsu. Ntn make the input shaft bearings for example but an ntn6306 is not what you'll get from mitsu. The correct bearing is a heavy duty version and is an ntn6306 v23. You'll find that this is about 3 or 4 times the price of the generic 6306. Again, all in stock.
How often do you see shift forks fail? just from abuse?, rubbish oil? or both?
 

jungle

3 AYC Bars
Lifetime Member
Location
QLD
First Name
Simon
Drive
1 PFL & 1 FL Legnum
As I plan on keeping the car longtime I figured I may as well give the gearbox a complete refresh. And yes I've sorted all the bits through Steve TME
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
How often do you see shift forks fail? just from abuse?, rubbish oil? or both?
In evos heaps. Vr4s get driven easier generally so not as common but you see them wearing a lot so on their way. Get too much wear and bye bye fork. You can get chromoly ones too but likely overkill for most on here.

Oh so answer is abuse really. Especially 3rd 4th
 

6A13TT TYPE S

3 AYC Bars
Lifetime Member
Location
New Zealand
First Name
Adam
Drive
1999 Legnum VR4 Type S
In evos heaps. Vr4s get driven easier generally so not as common but you see them wearing a lot so on their way. Get too much wear and bye bye fork. You can get chromoly ones too but likely overkill for most on here.

Oh so answer is abuse really. Especially 3rd 4th
Good to know!
What do you sell Synchros for? just out of curiosity
 

Scradam

Leaving Skid Marks
Location
WA
First Name
Adam
Drive
Manual Series 2 VR4 Legnum
How long should I expect replaced input shaft bearings to last before becoming constantly audible over a loud exhaust?
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
Not long

Edit: i may have read that wrong, you mean they have been replaced and now you can hear them all the time again. Should last say 80-100k in a modded car.
 

marksanne

Hesitantly Boosting
Location
Netherlands
First Name
Mark
Drive
1999 8G VR2 Galant & 1996 8G VR4 Galant
I broke a clutch fork on my VR2 for the first time a couple of months ago. It was replaced a few years ago when I installed a heavier ACT clutch-kit (it's the V6 N/A 5-speed gearbox mated with the VR4 engine, all power to the front wheels. The gearbox internal cope just fine with the added power, but the stock V6 N/A clutch & pressure plate are no match. Evidently the stock forks don't like the (much) added pressure. Not sure if the VR4 and V6 N/A forks are the same though.
 

adaxo

Idling at the Lights
Location
UK
First Name
Adam
Drive
Legnum VR4
See us for gearbox parts. We have all of them in stock and nothing like those prices. We've rebuilt heaps of evo and vr4 boxes. We recommend the input shaft bearings in them with every clutch pretty much.

There are a few things to watch in these boxes. The input shaft bearings are a problem due to their design. They don't deal with the thrust load from the helical cut on the gear sets very well at all. The output shaft has tapered bearings to deal with this and I've have yet to see problem with these. That said some guys replace the lot because you're there anyway.

There is a company in the US that has developed a tapered bearing replacement for the input shaft and we're evaluating doing something similar but it would only be on gearboxes we rebuild.

The other area of failure is the shift forks. Again we have all these in stock most of the time and we replace heaps of them in vr4s and evos.

Then there are synchros which is more dependent on how particular people are and the type of life the box has had.

Also be careful if you get bearings from anywhere but mitsu. Ntn make the input shaft bearings for example but an ntn6306 is not what you'll get from mitsu. The correct bearing is a heavy duty version and is an ntn6306 v23. You'll find that this is about 3 or 4 times the price of the generic 6306. Again, all in stock.

Hi Steve, I send you email few days back regarding your upgraded clutches but not heard back and sort out clutch here in UK, may it end up in your spam box, anyway can you give me the price for set of bearings mentioned by Adam
both input shaft bearings
both layshaft bearings
both center diff bearings
input shaft seal (Genuine mitsubishi)
left axle seal (Genuine mitsubishi)
also my second gear was notchy all the time so possibly im after synchro for that too
as my gbox is currently in pieces it will be wise to change all bearings while I'm there, r you happy to arrange post to UK?
 

TME_Steve

3 AYC Bars
Lifetime Member
Location
NSW
First Name
Steve
Drive
2010 nt did pajero tow car / 2000 6spd gc8 wrx tarmac rally car / 2000 Manual Subaru Outback 2.5 just a car
Yeah mate can do. I didn't see an email but I'll check spam folders.
I'll put it all together for you and pm you :)
 
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