input gear nose bearing failure..
Turbo Mini Forums

Whats the like cause?








and can I fix it all before Avon PArk

AlexF

putting cover on wrong ie forcing it , crap in oil,not a matched set, hecical gears putting too much side load on bearing....someone will post more ideas i`m sure ,
going to have to strip box off to clean all the bits out ,new bearing and endcover at least.

Everyone knows that instructions only have to be read if the thing doesn't work....

Well they werent forced and ran fine for 80 odd miles round bedford autodrome in november!!!

Since then i changed the head and done about 500 meters :(

It cant be side load... that bearing takes no side load...


alex

AlexF

what ever it was its fucked

Everyone knows that instructions only have to be read if the thing doesn't work....

True!

Just trying to understand the failure mode... then I can look at ways of stoping it happening again!

I was running no more than 7 psi on the old head and 5psi on the new head!! Doesn't bode well for long lasting boxes!!

alex

AlexF

many moons ago i had this happen , same set up as yours, nipped the the nose bearing on install ran fine for a while , but one of the little bearing had popped out and evenually wrecked the box , changed to s/c drops and smaller nose bearing never had a prob since.

Everyone knows that instructions only have to be read if the thing doesn't work....

maybe I fucked up the install :(


alex

AlexF

Is that the 'turbo' nose bearing?

You didn't do the silly mistake of putting a 'turbo' transfer case onto a standard gearbox (with the std nose bearing) did you?

If the bearing has gone like that (did the rollers disintegrate?), the large 1st motion bearing will need replacing, as will the mainshaft spigot bearing. The mainshaft and/or input shaft may well be shot as a result also.

Nope it was a turbo bearing and a turbo houseing...

I had a quick look inside the transfer casing when I got the engine, as the plan was to rebuild it. It all looked so clean and good (as did the head I pulled off), I just re-set the clearences and put it back together and used it!

The rollers look complete... the brown plastic keeper was broken and missing a chunk.

Alex

AlexF

"The rollers look complete... the brown plastic keeper was broken and missing a chunk."
before you put in on ?

Everyone knows that instructions only have to be read if the thing doesn't work....

no... seperate statement! In answer to Dave's question "If the bearing has gone like that (did the rollers disintegrate?),"

rollers are ok, plastic cage isnt!

alex

AlexF

ok

Everyone knows that instructions only have to be read if the thing doesn't work....

The Cage is just as important on a bearing designed to run a cage as the individual bearing components...
They can break up very quicky, and once they do - that's it - the rollers all move together and overload individual rollers.

You might want to price up 'turbo' bearings before ordering!

"You might want to price up 'turbo' bearings before ordering!"

Yeah that nose bearings about ?55 !!!

Phil.

WWW.TURBO-MINI.COM

so then alex, no mininfinity haynes track day then?

Nope... I think I need to strip the box.

I knew the price of the bearing... I have some spares... but I could just go back to a 9.50 std version!!!

Turbo ones don't seem too good thus far :p


alex

AlexF

what type of bearing is it? does it have a manufacturers name and part no. on it?

its a funny roller type...

no name I've seen, but havent ever looked that closly.

AlexF

It's a special.
I used to order them from BSL - they were around fifteen quid cheaper than MiniSpares!

alex.so your clutch was never fucked then???

just rebuild one of your spare boxes, should be able to get it running by the end of the weekend

Team Racing

nope it wasnt the clutch...

I still need to pull the engine and flush it all out. I cut up the oil filter tonight and it shoud have saved the engine, but the oil in the sump is full of swarf :(

I have a few gearboxs yes... but no time at the moment, I need to work one day this weekend... its going to be tight for avon park!

While the engines out, I might as well do the rings and bearings....

Alex

AlexF

mine went when a bit of crap got in the little oil hole that feeds it and it seized up

Alex which pistons are you using .....
re lack of rings nowadays.

Everyone knows that instructions only have to be read if the thing doesn't work....

20831s std size

I know were I can get some rings :)

Alex

AlexF

I'd leave the rings and pistons intact if i were you - assuming they seem ok...
Good idea to drop the mains / BE shells tho!
That oil pump from Avonbar is excellent aswell...

I'm sure you'll be ok for Avon - shells bed in pretty quick - that's why i suggsted leaving the rings!