How to Rebuild an 88/89 KM132 Manual Transmission

[kev]

Then slide a pipe over the shaft and contacted that old inner race.

 

 

And hammer her home

 

 

What will happen is that you will not only seat the new bearing in position, that old bearing race will be pressed in slightly as well…so pull that old race off via your puller

 

 

 

Flip over and install the other bearing inner race…again cone out. I used the same old inner race as a tool.

 

 

 

Input shaft flange prep:

 

Press in your input shaft seal (note the orientation)

 

 

 

[kev]

Fully installed

 

 

Ok, all of the little stuff is done with exception to the speedo gear and extension housing…we’ll do those later…let’s focus on getting the transmission gear train all back together and clear away some parts from your lay down area before they get mixed up.

Grab your main shaft. Follow along with the photos…

 

Starting in reverse order from disassembly..we need to install the 1^st/2^nd gear assembly prior to putting the shaft in the housing. Slide the needle roller bearing from the tail side of the shaft all of the way down to the shaft.

 

 

 

And move on…everything just slides on now.

 

 

Even though I greased the sync good, I still added some oil to the mating surface….probably overkill.

 

 

Snych assembly…make sure you put it on in the right direction!

 

 

 

Bushing:

 

 

 

 

This is as far as you can go until we install the shaft:

 

[kev]

Ok…to prevent this 1^st/2^nd assembly from moving around, I added a zip tie to keep things where they should be. We will pull this off later on…just remember it is there!

 

 

Ok now, slide the shaft in….It barely fits but it goes in…

 

 

Now to put your countershaft in…play with the angles…it fits, just take your time.

 

 

 

 

Lay the housing on its side

 

 

Here is what you will be seeing:

 

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Now to install 3^rd/4^th gears:

 

Reach in thru the input shaft hole and slide on the needle bearing

 

 

Then 3^rd gear

 

 

Now the synchro….remember we need to pull the ring. Note that I labeled the hell out of her:

 

 

Pull the ring

 

 

Slide on the assembly thru the input shaft hole.

 

 

Now work the ring in thru the pan hole, orient and align it correctly. Make sure you indexed it correctly on the key.

 

 

 

Note that I pushed the ring all of the way into 3^rd gear. I did this on purpose…to give us more room to get the input shaft in.

Ok, put on your snap ring…thru the input shaft hole

 

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Now slide on the small needle roller bearing

 

 

 

Input shaft installation:

 

It’s time to install your input shaft. Note the notches on the side again.

 

 

 

Now work it in there.

 

 

 

Pic inside…note I slide the ring of 3^rd/4^th back to the neutral position.

 

 

Well the work on the inside is done

 

[kev]

Back to the input shaft side. Install the outer race of the countershaft bearing…it slides right on. Make sure you install the mating outer race to the inner on the cross shaft..note my markings made prior

 

 

 

Flip around to the other side and install the other countershaft bearing outer race. This will now support your countershaft nicely.

 

 

 

Ok, pick up your input shaft flange cover. I took a dab of grease used to hole the shim in position for assembly

 

 

Set the shim in position on the grease.

 

 

 

Now take the front shim for the countershaft…add some grease to it and put it directly against the outer race of the bearing.

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Now slide on the flange….put a little oil on the input seal! NO GASKET YET…we need to take some measurements

 

 

If your studs are still in, spin a few nuts on them and snug the assembly down…not too tight. I just used some bolts for this because I removed my studs to clean that flange better.

 

 

What you want to do is snug up the fasteners and then back them off to finger tight. We want to slide in a feeler gauge to check the spacing between the housing and the flange. That hole for the shifter fork works perfectly for this.

 

 

What you want is a gap of 0.000 – 0.004”. Mine was within spec (.002). If not, you need to buy a thicker or thinner shim…the larger one in front of the input shaft bearing.

 

Ok, pull off that flange.

 

If your studs have been removed, reinstall them. I used some Loctite here. As well as my shifter fork fulcrum

 

 

 

 

 

[kev]

I’m not too fond of relying on just the gasket, so I used some gasket sealer too. This looks messy in the photos due to the reflection, but it is really a very thin coating.

 

 

 

Lube that seal again with oil

 

 

And install…7-9 ft lbs

 

 

 

Now flip the tranny back over…time to work on the back end.

 

 

First thing is first…get rid of that zip tie we put on earlier

 

 

 

Now slide the center bearing on the shaft…it will go this far

 

[kev]

So now what I did was used the components of the tranny to stack up and take the gap between the bearing and the threads. You could use any old spacer if you wanted as well but the actual components work…note I didn’t put on the gears, just the bushings, etc. We don’t want to load up those synchronizers themselves. I simply want to use the large nut to install the bearing.

 

 

Now using an old driveshaft to hold the main shaft (covered up to prevent debris from coming down on our nice clean transmission and a crescent wrench…drive it until the bearing is seated. Take your time and use judgment, you don’t want to screw up the threads on that shaft. It should install pretty easy though. You’ll feel when it is seated.

 

 

 

Ok..good thing is the hardest parts are done. Bad thing is that we need to shim this dang countershaft. Here is where I made a fundamental error again. I didn’t catch my error until almost fully assembled and I had to tear back down to address. So I’ll try to talk you thru this.

 

First thing you want to do is measure the ‘gap’ between the top of the outer face of the rear countershaft bearing and the housing. I used some markings here.

 

 

I added the original shim too. I can see that it is undersized and fell into the hole….thus knowing I need a thicker shim. Yours may be the opposite!

 

 

I mounted a dial indicator on the end of the shaft.

 

 

Now I set a flat block (my polishing stone in this case) over the housing and shim. And measured the slop.

 

 

This told me the approximate ‘range’ of shim I need. Basically the measured slop is in addition to the thickness of my old shim…in my case. You want to shoot for 0.000” but not create a binding situation! That’s difficult. But the max slop you can have is 0.002”.

 

However, here is where I screwed up! Remember we just installed new bearings in our countershaft and I didn’t take account any potential compression by torqueing the nut at the end of the shaft. You need to account for this and it is not easy! What I did was bought four shims in the approximate range I measured. Then I selected the one that was perfectly flat with the top of the flange. I don’t own a depth mic so I had to improvise.

 

 

I checked my slop again…it was negligible…thus I went with it.

 

 

But again I didn’t take in account any compression during torqueing. When final assembled, I checked my slop again and I was at ~.003” which was out of spec!

 

To account for this; you can try to assemble the countershaft with the gear components temporarily and deliver the torque and then re-measure. This will be difficult because the tranny cannot be locked into gear yet. What I did was that I knew I was .003” out of spec so I had to select a spacer .003” over what I installed…of which was larger than my largest shim purchased. So I had to order some more…coming from Japan….5 weeks lead-time! Dang! When they came in, I measured them, selected the one closest but not greater than .003 over the last one, tore the hole back end of the tranny back apart, swapped the spacer and reassembled. I guess another avenue would have been to select a shim in the front side of the countershaft that we assembled earlier that was .003” over the one installed….but in either case, it resulted in rework. What I’d do if I were you, is find out what thickness shim you need to achieve zero gap in the un-torqued condition and make sure you buy shims that go up to .003-.005” over. Then assemble the rest of the gear train keeping in mind that you will have to recheck your countershaft slop once the countershaft nut is torqued and that it may result in tearing back down and going with a different shim.

 

That is long and drawn out, but I hope you get the point. You want close to zero slop but not binding! When it was all said and done, I had ~.0005” slop but it derailed my project for a long time!

[kev]

Ok moving on. Let’s install our reverse idler shaft now. Put the nut on to prevent thread damage.

 

 

 

Now the retainer

 

 

Using some new bolts…don’t have to but I did, add some Loctite and install…11-15 ft-lbs

 

 

 

Take off that nut

 

 

Back to the main shaft. Note that I used my spacer as part of the system to press in that center bearing….in doing so, it pressed onto the shaft in addition to the bearing…no big deal at all, so I left it there. Install the roller bearing over it

 

 

Next is the reverse gear

 

 

Lube it up…..i didn’t show this on every photo prior but I did lube every mating surface

 

[kev]

Synch assembly installed correctly

 

 

 

And now 5^th gear.

 

 

There will be a lot of slop between the ID of 5^th gear and the shaft…that is coming next

 

 

This is for 88/89’s only. There is this custom spacer with a split needle roller bearing around it. I believe the earlier ones don’t have this custom spacer and it resulted in a loss of preload from the main nut causing failure. This was a mod in 88/89.

 

Install the two piece needle roller bearing on the spacer

 

 

Stop here on this shaft until you get that countershaft torqued up and check your slop. I didn’t; so you may see the thick c-clip and main nut installed in later pics…ignore them!

 

Let’s move on to the reverse idler

 

Put on both needle roller bearings

 

[kev]

And the gear

 

 

 

Washer

 

 

Nut…don’t torque it yet

 

 

Back to the countershaft

 

Install the spacer

 

 

Gear

 

 

I put a little oil in here due to the splines

 

 

Ok before you go further…remember that we need to install that one shift rod in combination with the big gear at the end of the countershaft!!!

[kev]

So, grab your 1^st/2^nd and 3^rd/4^th forks….lube them up and install them in the appropriate grooves in the synch outer rings.

 

 

 

 

 

Might as well lock her in reverse and 2^nd now. Slide the 5^th/reverse collar down to engage reverse

 

 

And 1^st/2^nd down to engage 2^nd

 

 

Now…lube the lower shift arm hole closest to you in the tranny pan

 

 

Put the first spacer in between the shift rods now that you have easy access…Lube it!

 

 

[kev]

Lube the upper hole good

 

 

Lube the appropriate shaft…it’s 1^st/2^nd . It’s the one with the notch in it!

 

 

Start it down the hole closest to the bottom of the pan

 

 

Now slide on the gear of the countershaft

 

And slide down the rod until it enters the holes closest to you in the forks

 

 

Wiggle them down

 

 

 

 

Ok, install your new countershaft rear ball bearing.

 

 

Install your countershaft nut….I used a new one…still available from Mitsubishi. Torquing the nut will install the bearing!

 

[kev]

Tighten the nut down…see how it seated the bearing

 

 

Now torque her down…the tranny is locked from earlier but you’ll need your restraint bar to hold the tranny. 116-137 ft-lbs

 

 

Now before you go any further…re-measure your countershaft end play! Make sure it is .000-.002”…preferably on the minimum side. You might have to disassemble back down to that shim and install a different one!!!! I don’t have pics of this but it is the same as before with the dial indicator. I used a small crow bar under the large gear of the countershaft in the pan area to ‘flex’ the shaft to measure the end play.

Only when you are comfortable that you achieved end play within spec, should you move on to torqueing the other two nuts. First the reverse idler; 15-43 ft-lbs

 

 

Naturally it is a castle nut so you need to align a notch to a hole…while still in your torque range!

 

 

Put in a new cotter pin…just like this so it doesn’t hit anything

 

 

 

Back to the main shaft. Install your large c-clip. Note the manual tells you to measure this and select a c-clip of the proper thickness…unfortunately Mitsu has discontinued all of these suckers! So I just had to reuse my original. I honestly needed one a mil or so thicker but what could I do? I didn’t want to try to fabricate one of these…may lead to more problems than reusing the original.

 

 

 

You should have pretty much no slop in your gear train now. Even though I measured a mil or so gap prior to installing the clip, I didn’t notice any slop after installing it…that is a good thing. Remember that the nut goes on next and is added security. I felt it was low risk by not having the exact right thickness c-clip.

 

 

Now for the nut. Mitsu discontinued it as well. I bought an aftermarket one thru manualtransmissionpart.com, but it wasn’t the right one! Note the lack of crimp collar. So I didn’t use it, and reused the original. If you were looking closely earlier, I used the new nut as a tool to seat that countershaft bearing!

 

[kev]

You may have to clean up the threads a little of the nut being reused especially around the crimps…get it nice and clean and burr free

 

 

But a little lube on the threads and spin it down…it went this far by hand!

 

Now the tricky part…torqueing this sucker to 181-195 ft-lbs per the manual. I guess you can go different routes with this. What I did was buy a crows foot – 1-9/16” was the closest I could find. You kind of have to drive it down on the nut a little. But what happens when torqueing is the crows foot expanded and slipped. Rather than trying to find/construct another tool, I simply tack welded a bar across the crows foot while it was over the nut.

 

 

Now torque her up! I had to even reinforce my support bar for this! I took her to the max torque.

 

 

 

We can crimp now or go back to the last two shift arms. I’m just going to show the crimping now even though I did the arms first…doesn’t matter.

 

Crimp your nuts in two places for both the countershaft and main shaft

 

 

 

 

[kev]

Ok, back to the shift arms. Put in the other lubricated spacer now

 

 

Now lubricate and slide in the last fork

 

 

Lube 3rth/4^th shift rod…and the holes it travels thru in the housing.

 

 

Install it…needs to pass thru the holes in all three forks

 

 

Next go for the 5^th/reverse…again lubricating the shaft and holes

 

 

We’ll come back to the roll pins. Lets put on the last bearing

 

Install the c-clip

 

 

 

And the bearing

 

 

Using a pole, I drove it down carefully

 

 

[kev]

Don’t forget the 2^nd c clip

 

 

Ok, all we need to do is to pin the shift rods to the forks and we are done with the gear train!

 

I bought a set of high strength M5x22mm roll pins

What you want to do is to drive them in the forks/rods in the orientation as shown. This is very critical! If you drive them in 90 degrees out, the C shape of the roll pin will flex and cause deflection when shifting!

 

Oh make sure the holes align in the forks/shafts…slide the shift collars back to neutral if the tranny is still in the locked state from torqueing.

Use a drift punch and drive the pins in

 

 

 

 

 

[kev]

Last but not least….the ball bearings, etc for the shift rods…

 

Coat the ball bearings in oil and install them in the three holes in the outside of the housing

 

 

 

 

Now the springs…tapered side in first…I was very critical to put all of these items in the same location that they came out from…remember the marked bin earlier?

 

 

 

Now, put a little gasket maker on the threads of the set screws and install them

 

 

 

Set them to the exact same position that you removed them from. You can double check the values from the manual to see if they are in the approximate range if you’d like…mine were a little off but I liked how it shifted prior so I set them right back to where they were.

 

 

Now fill the holes with RTV

 

[kev]

Little gasket maker on the flange and the gasket

 

 

 

Ok…set her aside while we focus on the extension housing

 

Extension Housing Assembly

 

Starting point…all cleaned really good (and in my case painted)

 

 

Here is how clean it should be on the inside

 

 

Inspect that shift arm good!

 

 

 

 

 

Now clean up the flanges…Note that I covered the areas to minimize debris

 

 

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Recleaned again and ready to move on

 

Oil the shifter rod good!

 

 

 

 

 

Flip over and install the rear seal. I added a little RTV to the outside.

 

 

 

 

 

Cleaned up

 

 

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Oil the inside good

 

 

Oil the holes for the shift rods

 

 

Ok taking a break, switch over to this sucker. I don’t think I showed removing this little lever thing earlier, but if you did remove yours…here is how to reinstall

 

 

Flanges again:

 

 

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Take a dab of RTV on the bolts

 

 

 

 

 

 

 

Cleaned up

 

 

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Speedo Assembly

 

I had to buy both seals for the speedo…I just went thru Mitsu. And some more roll pins..high strength M3 x 16mm

 

 

Make sure your parts are all nice and clean

 

 

Oil your inner seal

 

 

And put it in

 

 

 

Oil your rod slightly and install

 

 

 

 

Install the roll pin in the housing

 

 

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Slide on the gear and install the last roll pin

 

 

Lube the outer o-ring and install

 

 

FINAL ASSEMBLY

 

OK, just about done

 

 

Take your shifter rod and go to the right and back…just like during disassembly

 

 

 

And slide the extension housing into position while holding the rod

 

 

Now engage the rod into the forks of the shifter arms…you’ll feel it

 

 

Install your bolts and tighten then to spec..11-15 ft-lbs

 

 

Don’t forget the tabs for the reverse light switch wire..I almost did