M32 transmission rebuild. Pic heavy, parts list

Cruzing12 · May 25, 2024

I'll be updating all the posts as I go... just keep in mind things will be slow or here n there as I assemble and reassemble the posts, thread last updated sept 8th 2024 still in progress.

Page one
Post #3 bearing race removal.
Post #4 input shaft tear down
Post #5 R 3rd 4th gear stack teardown
Post #6 1st,2nd,5th,6th gear stack tear down
Post #7 part number listings

Page two
Post #8 R,3rd,4th gear stack assembly.
Post #9 1,2,5,6th gear stack assembly.
Post #10 input shaft assembly.
Post#11 differential bearings/ shimming.
Post#12 bearing race insert and shimming.

Post #1

Figured this transmission is going to be a project by itself, cleaning the outside, cleaning the clutch jam inside, new bearings, and plumbing for oil cooler hookups.

Out of a 2014 LS est 164k km encased in grease.

I've had this for nearly two years, needing a replacement for my current 2012 LS, with 205k km, that has damaged bearings. Input bearing is starting to get loud, 1st is developing some stick play, and 3rd/ 4th has always wined since buying the car at 147k km but either gears having no play. Shifting is still good, and crisp. Having since gone to a clutch masters stage 1 clutch with aluminum flywheel. shifts are near intuitive now.

Clutch masters aluminum flywheel with stage 1 clutch. Bite is slightly improved/ more progressive. Clutch pedal is heavier. Shifting feels easier on the transmission and is easier to rev match / predict rpm for a cleaner shift. Feels worlds better then the heavy clutch. And as a bonus getting first gear from a cold start in winter is now a non issue blip the throttle 200rpm and it's in

Oil cooling. I magine two 3/8" bulkhead flare fittings, one draw, two supply to input bearing and side bearings via drilling out the pressed in ball. Then crushing the pipes to meter oil will do the trick. As for exterior wise I have a aftermarket "transmission cooler" and am looking into a pump, filter, and some type of temperature relay setup.

Should have room to run a line to feed that there input bearing.

Cruzing12 · Jun 1, 2024

Post #2

Currently if money is no issue ,$5500, one can still purchase a crate transmission through GM via the 2018 sonic platform. Not sure as to what gearing range it comes with or any other vehicle in the line up it could come with, but it should also have a warranty.

Parts... Full gm parts lists in post #7, couple of the gears are coming back as discontinued but may be regional( ie GM depot site sais stocked, gm wearhouse site sais discontinued.) As a back up there's allot of shops in the uk/Europe servicing these transmissions as they seem to be as common as the common cold.

Courtneyracing,co,uk has a exploded view diagram that comes in handy, they sell bearing kits, and parts.

for a little more of a premium, bearing kits, gear sets, and seals can be had via transmission parts online they're also based in the U.K. and last I checked flat rate shipping, via fed-ex 2-3 days, across the pond is around the $60 mark. when ordering the kit the 25mm input shaft version is the one to get, I believe the 27mm input shaft is for older transmission with the smaller end case. but always ask and check in with them before purchase as I have no experience there.

Occasionally on rockauto.com they stock random gears for the transmission based on dealer buyback inventory

As for just bearings I'm currently looking around "123Bearings.com" they stock all the bearings our boxes need, and ship out the USA, cheap prices and shipping compared to the markup from the shops out of the U.K.

There's limited aftermarket support.

4H or 4Q, a company manufactures short throw shift levers.

"SQS racing" makes a 4 speed dog box kit. Built to order. retains the two output shafts/ crown wheel and features a custom input shaft ("adding website")

I ordered a bearing kit from transmission parts online co uk, included the seals and circlips... but the wrong end case bearings. I've cross referenced the measurements and Bearings are as listed for the new end case transmissions.

Differential bearings -....................NP537150 / NP050487 (X2) TIMKEN
Output bearings -."SET 634".NP238750 / NP929800 (X2) TIMKEN 45x88xXXmm
Rear output bearings -....................NP285701 - NP341513..(X2) TIMKEN 25X62X17.5MM
Rear input shaft bearing -.........................EC43082S01H206..(X1) SNR 28X62X17.5MM
25MM input bearing -...................NP259742 - NP378917 (X1) TIMKEN 25x51.3x13.2mm SNR - EC42310S01H200

Sensors, switches, seals, and misc

clutch line holder....gm part# 5535-2049
Revers light switch gm part# 5558-3570
Speed sensor..........gm part# 5556-8130
Turrent seal.............gm part# "at large"
axle seal..................gm part# "mia"
Fill plug....................M18x 1.5
Drain plug................M...........

Bearing tension... for those who want the tools Kentimpex, Bosch gm tool supplier. it's about $1200 for the spring stacks and the spacers/ inserts to pair with the stacks. or about $2500 for the whole service kit. For myself I will be shimming by hand as it seems to be as tedious as setting up an old taper style wheel bearing or doing the wheel hubs on the mountain bike. Fitting each shaft individually and adjusting based on feel. feel- the assembly should rotate freely but with minor resistance aiming for as close to zero play as possible. followed up with sharpie marks on the bearing surface to view wear patterns.

Gear oil is going to be 3Qts plus cooling system loop. Amsoil "manual transmission and transaxle lube"

Out from a couple days in the parts washer... Laundry tub lol.

Just hit it with a wire wheel, and pending on how the case cleans up I may pursue powder coating the unit. White accessories and black main bell housing.

But the front is heavily stained with grease soaked oxidization so I'll see how it goes. Will be flame treating with a map torch before I send it off so it's as clean as possible for shop.

NotCruzing · Jun 10, 2024

You might find some helpful tips and parts on the European sites

https://www.vauxhallownersnetwork.co.uk/threads/m32-guys-m32-gearbox-thread.649097/

Cruzing12 · Jun 17, 2024

"TO BE REVISED"

Post 3

Pulling the races. Quick and cheap about $50 all in. 2.5", 3.5", and 4.5" pipe. A 3/4" square by 4.5" stock. And a two jar puller.

Having patients to line everything up was the hardest part. The input race came out easy.

For the larger races modifying the case for the tool to fit is necessary and is okay... In that there is material just anti service tactics.

My method of madness. A cordless drill with a 1/16" drill bit to start. Going from left to right, drill in a 32nd or so and using the bearing races as a guild run the drill bit across slowly tensioning it( good welding practice) into the material. Basically dermal it out at a steep angle for diameter. Once in far enough I hit it with a 1/8" drill bit removing the bottom lip for a taper up behind the race.

In hind sight there be careful with the shavings.

With the races out I gave it a clean up...

Races

Pop.

To be continued... I ordered the wrong size of pipe for the other two size of race.

NotCruzing · Jun 17, 2024

Awesome project.

The radiator on our Astra failed. That was a combo engine coolant & transmission oil (probably to save money), mixing both fluids and killing the transmission.

The transmission shop installed a separate (automatic) transmission oil cooler. GM engineered just enough space to stack the 3 radiators (AC, transmission oil, engine coolant), so that must have been an option in early design. You wouldn't know if you didn't try. Maybe the Cruze is similar.

Shop just used plastic stand offs to secure the cooler.

One guy on the Vauxhall forums said that the combo radiator had the advantage of bringing the transmission oil to temp faster. But I think there are a lot of advantages to a dedicated one.

Blasirl · Jun 17, 2024

Cruzing12 said:
I'll be updating as I go... just keep in mind things will be slow.

View attachment 307600

View attachment 307601

Figured this transmission is going to be a project by itself, cleaning the outside, cleaning the clutch jam inside, new bearings, and plumbing for oil cooler hookups.

View attachment 307553
Out of a 2014 LS est 164k km encased in grease.

I've had this for nearly two years, needing a replacement for my current 2012 LS, with 205k km, that has damaged bearings. Input bearing is starting to get loud, 1st is developing some stick play, and 3rd/ 4th has always wined since buying the car at 147k km but either gears having no play. Shifting is still good, and crisp. Having since gone to a clutch masters stage 1 clutch with aluminum flywheel. shifts are near intuitive now.

View attachment 307638

Clutch masters aluminum flywheel with stage 1 clutch. Bite is slightly improved/ more progressive. Clutch pedal is heavier. Shifting feels easier on the transmission and is easier to rev match / predict rpm for a cleaner shift. Feels worlds better then the heavy clutch.

View attachment 307640

Oil cooling. I magine two 3/8" bulkhead flare fittings, one draw, two supply to input bearing and side bearings via drilling out the pressed in ball. Then crushing the pipes to meter oil will do the trick. As for exterior wise I have a aftermarket "transmission cooler" and am looking into a pump, filter, and some type of temperature relay setup.

View attachment 307641
Should have room to run a line to feed that there input bearing.

Great project.

Consider turning this into a How-To: when you're done.

How-To: Write a Tutorial

Best Manual Tran's Links 20SEP222

How To correct the horizontal backlash of the clutch pedal

Upgrade the bearings on an M32

Cruzing12 · Jun 17, 2024

Blasirl said:
Great project.

Consider turning this into a How-To: when you're done.

possibly, I was going to show the process, here, as I go. Adding in anything I find along the way... post three has just started

Post #3 Continued.

Cruze CTRL · Jun 18, 2024

Hi, Here a description of what you're doing with an intriguing shim guessing method! Sonic M32 Rebuild
"After installing all the bearings, it was time to shim the end case. For this operation, I didn't fully seat the three cups for the end case bearings. I pressed them in about 1/4" shy of the full seated position. I then installed the end case on to the front case with just five bolts and tightened them slowly while knocking on the cover by each bearing with a plastic mallet. When the bolts were fully tightened, I knocked on them all again and then verified that I could easily turn the input shaft through all gears by hand which I could. I also verified there was no apparent shaft play.

Then I measured under the bearing cups with feeler gauges to determine what size shims I needed. I them pulled the cups, installed the shims then put the cups back in. Next I reinstalled the cover with just a few bolts and verified that I could still easily turn the input shaft though all gears and there was no apparent play"

Cruzing12 · Jun 19, 2024

Cruze CTRL said:
Hi, Here a description of what you're doing with an intriguing shim guessing method! Sonic M32 Rebuild
"After installing all the bearings, it was time to shim the end case. For this operation, I didn't fully seat the three cups for the end case bearings. I pressed them in about 1/4" shy of the full seated position. I then installed the end case on to the front case with just five bolts and tightened them slowly while knocking on the cover by each bearing with a plastic mallet. When the bolts were fully tightened, I knocked on them all again and then verified that I could easily turn the input shaft through all gears by hand which I could. I also verified there was no apparent shaft play.

Then I measured under the bearing cups with feeler gauges to determine what size shims I needed. I them pulled the cups, installed the shims then put the cups back in. Next I reinstalled the cover with just a few bolts and verified that I could still easily turn the input shaft though all gears and there was no apparent play"

Thanks for the link, a short thread, but found I overlooked "Courtney racing UK" they unlike transmission parts online co UK, they have individual gears, synchro rings and the needle bearings as well even output shafts if you really messed it up.

I will be updating post #2 with the Courtney racing website. As well placing an order with them. as for the price of a bearing kit and eco 6th gear from transmission parts online is the price of a bearing kit, eco 6th gear and all the needle bearings via Courtney racing.

Also I just remembered there's a UK shop that makes a 4 speed dog box conversion I'll look around and add that in too.

Cruzing12 · Jun 29, 2024

Post #4

Getting some where. Main input shaft teardown.

that sweet smell of gear oil, more surprised how clean the box is but there were allot of metal shards chilling when I took the bearing race off the shaft, further re enforces the planned consumption of alcohol and sitting down one night to profile every single gear by hand.

Heat with a torch and pound with the 1/2" impact. a good set of shop gloves and or double glove it. had the gear cut through the glove no injuries.

The end screw takes a 10mm Allen( same size as the drain plug.) pressing little and unscrewing in steps. Not knowing how strong the threads are I proceeded in 1/8" increments

This was with a 10ton press with a 3" bearing splitter on backing plates....

And this was a fight... I found out the press frame is tweaked so I inadvertently cold welded the 4th gear on the spline trying to get it off on an angle... Hence having to wigle the shaft with a hammer under pressure to get it free. Eventually it came free but was fraught with fun, snaps cracks and air in the cylinder.

Cruzing12 · Jun 30, 2024

Post #5

4th, 3rd, and reverse output shaft tear down.

Lay the shaft down with the bearing over the end of the table, hold said timmies cup to catch the rollers.

Believe this is a 3" bearing splitter, you will need snap ring pliers to pop the ring prior to pressing.

Ran out of room...

And had to finish with the bearing breaker kit.

Bearing holds 4th on... The shift collar tends to pop out just by looking at it without the synchro stack against the ball springs. After loose disassembly there's another spring clip securing the dog on the spline, before 3rd can be pressed off.

Using 3rd to pull the dog off the shaft. For this the press was to narrow so I employed a "3 jaw" six inch puller.

Take some time to lubricate your threads. Makes the threads last longer and cuts out that nails on a chalk board feeling dry steel on dry steel produces.

Always good to have little containers.

And yet another spring clip, holding the reluctor ring down.

Same thing with the "3 jaw" six inch puller, this is only on about 1/4" inch so don't be going ham on it as it's not really on.

Cruzing12 · Jun 30, 2024

Post #5.5

3rd 4th, and reverse output shaft teardown continued.

Next is reverse gear. A simple press on the gear to pull the hub off.

Needle bearings slid off, the roller races on these are steel.

and another spring clip... This one I'm going to note, and see about a new clip. When removing the clip it seemed the bearing race had moved back, or not been fully seated as the clip needed a couple hammer strikes to be removed and has taken on a tapered/ flared appearance.

With the cross plates I had enough to grab the bearing race. A quick pop and there we have it a stripped output shaft. Currently returned the spring clips to their corresponding positions( 4 clips in total, picture doesn't show the second clip located the ridge atop the first spline). And am going to clean the synchros hubs, and gears, as well as find a file to get in and file the teeth clean.

Post 6 will be the 1st-2nd-5th-6th output shaft tear down.

Cruzing12 · Jul 1, 2024

Post #6

1st, 2nd,5th,6th tear down.

I was planning on using the press, but in actuality the 6" 3 jaw puller did most the work.

No clip just a simple press on. One piece synchro.

1 circlip holding the dog on the shaft.

5th gear, I was worried using the synchro splines of 5th gear but it was sufficient to pull the dog off the output shaft.

5th gear and dog off.

Now this isn't on any literature. It's not a snap ring but a thrust bearing with a hold ring

Cruzing12 · Jul 1, 2024

Post #6.5

With the thrust bearing/retainer removed 2nd gear comes off. Needle bearings apears to be the same between 2nd and 5th, playing around the 5th/6th dog callor fits in place of the 3rd/4th callor... Back to topic.

2nd gear, three piece synchro

One clip holding the dog on the shaft

first gear and dog pressed off.

I wasn't expecting the first gear to have a needle bearing thrust washer riding on the back of the pinion bearing

so the bearings you get in a kit are supposed to replace this, I looked things over and it seems like they would work but the flange surface is pretty close to the end of the needle roller path... still checking on this, as this box uses two different output shaft bearings(inner cones)

This is the thrust washer for 1st gear

Can't see anything out far but if you can zoom in there's heavy pitting and cracks missing seems this special bearing wasn't properly adjusted for as majority of wear in on the inner cone instead of center.

All done, I'll have to make some more contacts to see about that special bearing.

Cruzing12 · Jul 1, 2024

*piling information on part numbers

Post #7

Sensors, switches, seals, and misc

Slave cylinder.........gm part# 5556-3645
clutch line holder....gm part# 5535-2049
Clutch line elbow....gm part# 5535-2050
Clutch lineW/accumulator..t# 55
Master cylinder.......gm part# 55
Cylinder to reservoir.....part# 55

Revers light switch..gm part# 5558-3570
Speed sensor..........gm part# 5556-8130
Turrent seal.............gm part# "at large"
axle seal..................gm part# "mia"
Fill plug....................M18x 1.5 8mm hex
Drain plug................M...........10mm hex tapper plug

Gears & Synchros

part numbers are currently listed for the gear box with a PRO code: MZO , I believe to be the LS trim gear box. the LT gear box has a diffrent 1st, 2nd gear ratios, with the eco trim being the same with the exception of sporting a higher ratio 6th gear.

1st gear is integral to the input shaft...........gm part 5549-1654 *input shaft 1st and 2nd gear integral.
1st gear ,output shaft.....................................gm part 5557-7010

1st gear/ 2nd gear selector hub and collar..gm part 55564410
1st gear/ 2nd gear synchro (3pc)...............................................................gm part 55557-4656

2nd gear is integral to the input shaft.........gm part 5549-1654
2nd gear ,output shaft..................................gm part 5519-8420

3rd gear ,input shaft (drives 5th) ..................gm part 5518-2029 * same as 5th
3rd gear, output shaft ....................................gm part 5556-6887

3rd gear/ 4th gear selector hub and collar gm part 5557-0102
3rd gear/ 4th gear synchro (2pc) ...............gm part 5556-9599

4th gear ,input shaft ......................................gm part 5518-2042
4th gear ,output shaft.....................................gm part 5558-0104

5th gear , input shaft (drives 3rd).................gm part 5518-2029 * same as 3rd
5th gear ,output shaft....................................gm part 5518-2032

5th gear/ 6th gear selector hub and collar..gm part 5556-3746
5th gear/ 6th gear synchro (1pc)…...............gm part 5555-6581

6th gear (39 tooth),input shaft.....................gm part 5518-2048
6th gear (29 tooth),output shaft...................gm part 5518-2049

"ECO" gear set
6th gear (44 tooth), input shaft....................gm part 5518-3245 *coming back as expensive
6th gear (27 tooth),output shaft...................gm part 5518-2045 *coming back as discontinued

Needle bearings

1st gear

2nd gear gm part 5518-0108

3rd gear gm part 55180108

4th gear gm part 5556-5314

5th gear gm part 55180108

6th gear gm part 5556-5314

R gear

meganh92 · Jul 1, 2024

Cruzing12 said:
I'll be updating as I go... just keep in mind things will be slow.

Post #1

View attachment 307600

View attachment 307601

Figured this transmission is going to be a project by itself, cleaning the outside, cleaning the clutch jam inside, new bearings, and plumbing for oil cooler hookups.

View attachment 307553
Out of a 2014 LS est 164k km encased in grease.

I've had this for nearly two years, needing a replacement for my current 2012 LS, with 205k km, that has damaged bearings. Input bearing is starting to get loud, 1st is developing some stick play, and 3rd/ 4th has always wined since buying the car at 147k km but either gears having no play. Shifting is still good, and crisp. Having since gone to a clutch masters stage 1 clutch with aluminum flywheel. shifts are near intuitive now.

View attachment 307638

Clutch masters aluminum flywheel with stage 1 clutch. Bite is slightly improved/ more progressive. Clutch pedal is heavier. Shifting feels easier on the transmission and is easier to rev match / predict rpm for a cleaner shift. Feels worlds better then the heavy clutch. And as a bonus getting first gear from a cold start in winter is now a non issue blip the throttle 200rpm and it's in

View attachment 307640

Oil cooling. I magine two 3/8" bulkhead flare fittings, one draw, two supply to input bearing and side bearings via drilling out the pressed in ball. Then crushing the pipes to meter oil will do the trick. As for exterior wise I have a aftermarket "transmission cooler" and am looking into a pump, filter, and some type of temperature relay setup.

View attachment 307641
Should have room to run a line to feed that there input bearing.

Following

Oldguycruze12 · Jul 9, 2024

I’m following also
In the process of doing the same
No shop press
Did all my tear down with a 8” three jaw puller

XtremeRevolution · Jul 10, 2024

This is an absolutely amazing thread. I greatly admire your dedication to documenting this process. I’m sure this will be a lifesaver for someone down the road. I’m very impressed.

Cruzing12 · Jul 12, 2024

XtremeRevolution said:
This is an absolutely amazing thread. I greatly admire your dedication to documenting this process. I’m sure this will be a lifesaver for someone down the road. I’m very impressed.

Thank you.

Trying to figure it out, spaming some posts to space out the picture load on the thread. As the 1,2,5,6th tear down is coming

About have everything I need for the front end suspension refresh I'm needing to do Hoping to have the transmission back together to swap by then. As the current unit is indeed developing some 3rd/4th stick play.

Currently thought I'm a little hung up on shop space and time, so I haven't tore down the 1256 shaft to know if I need any parts, so disappointing. But I do have a parts basket going on GMPARTSGIANT they have both "ECO" 6th gears, 1st/2nd synchros. Hoping to get that squared away before sticker shock scares me off lol.

ECO 6th gear set and pair of synchros comes to $300 flat. Just picked up 4qts of amsoil for $106. Going to be a pretty penny and I haven't even contacted a shop about powder coating yet.

Did some driving with the animals today noted average highway speed is 110kph engine rpm 2600 feel as though 2000rpm would fair better as I find I down shift to 5th for hills as it is. And I feel even with a bigger gap between 5th and 6th shouldn't be a problem with the aluminum flywheel as rev matching is just that easier

Have to dust out the cob webs and do the math to see what the theoretical rpm drop would be with the gears.

Cruzing12 · Jul 13, 2024

Update to post #7 added synchronizer part numbers and needle bearing part numbers.

July 16th,
Just tried filing one the gears and it's not happening. Just going to avoid that elephant... I mean I'll be employing a oil filter with the cooler setup so ... LoL.

M32 transmission rebuild. Pic heavy, parts list

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