m32 rebuild

#1
anyone got any data for rebuilding the m32 box please?
torque settings for diff housing bolts and sequence?
end float for shimming the shafts?
rebuilding one for a friend in his 1.3cdti corsa d. usually problem 6th gear bearing gone at below 40k miles :(
going for the later type end case with larger bearings and better oil ways.
and before you say its not the m32 it is in this one as it's already out in bits.:)
 

evocarlos

Stupid Bollocks
Staff
#7
fitted the revised/new style end case with the larger bearings.
these boxes are so weak when compaired to the F23 :(
i like the new end case and disagree with the comment on the f23 ive got 1 working m32 thats on the charged car and 2 f**ked f23s off na cars :)
an early design flaw that corrected with a 1" squire of 1mm plate mines done 90k miles now 75k of that was with atf and no mod
they all rave about the f40 for its 400nm out the factory support but the big breaning mod pushes the m32 past the 400nm support
 
#8
i was more referring to the size of bearings and shafts as standard on the m32 compaired to those in the f23.
over all the m32 looks to be a budget box with so many failing at low mileage 20-40k miles. still around 2500 a year fail in the uk alone.
you must be unlucky with your f23's or they have had a hard life before you got them as mine have all been fine. mines taking well over 330nm at the moment and i know of many others that are way past 600nm on z20let corsa's.
 

evocarlos

Stupid Bollocks
Staff
#9
i was more referring to the size of bearings and shafts as standard on the m32 compaired to those in the f23.
over all the m32 looks to be a budget box with so many failing at low mileage 20-40k miles. still around 2500 a year fail in the uk alone.
you must be unlucky with your f23's or they have had a hard life before you got them as mine have all been fine. mines taking well over 330nm at the moment and i know of many others that are way past 600nm on z20let corsa's.
they fail cause the oil cant get in or out of the 6th bearing it gets cooked off and then runs hot for a long time the only other thing they suffer from is a bent fork when using short shift and heavy hands
the f23 was new in the car when i bought it :) been a bag o s**te since 25k and now 3rd 1st and rev syncro is muffed
the m32 has been doing 380nm for over a year and past 7000 rpm the small bearings are fine once you have done the mod to let the oil in and out when i put the new end case on there is no sign of significant wear to the snr bearings timkin are the ones that people recommend and timken are the ones that fail the most on the out side :)
i do like the m32 for its ease of serviceability and cost of parts
 
#10
this one had timken bearings on all 3 shafts, both lay shafts had failed or were about too. and both of the larger bearings at the other end showed signs of failing. (both snr)
due to extra vibration and dirty oil from the 2 small bearings giving up. magnet looked like a hedge hog!
still all good now :)
and cheap parts, £277 for a rebuild kit, bearings, seals and end case.
 
#11
all re built and running fine now :)
Hi Gents,
I have also had the 6th gear bearing failure and have just finished installing a SNR bearing kit through my M32 box. I have used the original end case and now need to set the preload on the shafts. I used the original shims and I can't turn the input shaft by hand, I need to use multi grips. Does anyone have info/link on the bearing preload set up procedure and the rolling torque spec?
Vehicle ID
Astra SRI AH Manual MY07 Coupe 6 speed manual.
GEARBOX ID :
M320L850
3650HA 6
0779280C7
 
#13
each box will be different i ended up with 1.2mm on input shaft and 0.9 on the 2 lay shafts.
best way i found to check was only have 1 shaft in the box at a time with no shims and measure end float then fit according shim.
i did manage to prize some info from the local dealer to set zero end float once assembled.
would have liked to have a rolling force figure but couldn't find info on that.
 
#14
each box will be different i ended up with 1.2mm on input shaft and 0.9 on the 2 lay shafts.
best way i found to check was only have 1 shaft in the box at a time with no shims and measure end float then fit according shim.
i did manage to prize some info from the local dealer to set zero end float once assembled.
would have liked to have a rolling force figure but couldn't find info on that.
Can you advise me how to measure the end float.
 
#15
each box will be different i ended up with 1.2mm on input shaft and 0.9 on the 2 lay shafts.
best way i found to check was only have 1 shaft in the box at a time with no shims and measure end float then fit according shim.
i did manage to prize some info from the local dealer to set zero end float once assembled.
would have liked to have a rolling force figure but couldn't find info on that.
1mm shim on the main shaft and 0.9mm on the pilot shafts
i could not turn mine by hand unless in neutral
Yours was also tight.The case must expand a lot when hot?
Do ya reckon the small splash plate mod has helped cool the 6th gear bearing?
What size was your tap for the mod?
 
#16
fit shaft with no shims, 1 shaft at a time, only need a few bolts around the case, with input i used a dial gauge on the top and lifted shaft with pry bar through diff housing. on the lay shafts i use feeler gauges lifting and measuring through diff housing.
 
#17
fit shaft with no shims, 1 shaft at a time, only need a few bolts around the case, with input i used a dial gauge on the top and lifted shaft with pry bar through diff housing. on the lay shafts i use feeler gauges lifting and measuring through diff housing.
Good info
Thanks Guys, I think I am onto it now.
Have done what you said.Installing one shaft at a time and am narrowing down which shaft has too much pre load.
Then onto the splash plate mod
 
#19
Ok corsa,
cheers.
What year is the vehicle you installed the updated case to?
I heard from the bearing supplier that some of their clients had trouble with the new style casing being installed into vehicles PRE 2011.
My chariot is 2007 and was advised against installing the new case. The problems reported were related to the shimming apparently.
Incidentally how is your conversion performing and how tight was the input shaft to turn, could you turn it by hand or did you need to use multi grips?
 
#20
Yours was also tight. The
1mm shim on the main shaft and 0.9mm on the pilot shafts
i could not turn mine by hand unless in neutral
evocarlos do you have dimensions of the splash feed plate, so I can make one?
I have set up each shaft with a rolling torque of 5 foot pound (60 inch pound)
case must expand a lot when hot?
Do ya reckon the small splash plate mod has helped cool the 6th gear bearing?
What size was your tap for the mod?
 
Top