5 speed rebuild

[fwd35]

I finally got a little time to start fixing my new Delica. I bought it with a bad transmission, it would only move in 4th gear, which made it a bit of a challenge driving it into the garage. I was pleased that the transmission came out fairly quickly and I only needed 12 and 14mm wrenches and sockets. After opening it up there is definitely a few striped gears, the input shaft and where it meshes with the counter shaft are both completely gone. On a plus side the fifth gear needle bearing, sleeve and where it runs on the main shaft all look to be in great condition. The 5th gear inner bearing race spinning on the main shaft is a common problem with these transmissions. The other thing I noticed is that the gears don't seem to fully mesh, as seen in the picture of 5th and reverse. the rest of the transmission has the same offset in the gears. This doesn't seem right to me and as I was taking out the main shaft I noticed that it has snap ring bearings but that the snap ring is quite a bit narrower that the counter bore in the case allowing the main shaft to move in and out. hopefully tomorrow I will put it back together enough to confirm this end play in the main shaft. I will also count gear teeth to see if I have the early or later version of this transmission, KM145 or V5M21.
Does anyone know if a different case was used for the snap ring retained bearings vs the flange retained bearings?
Also does anyone know of one of these with a bad 5th gear and main shaft laying around? I could build one out of the two and shipping it to Colorado will probably be cheaper than a new counter and input shaft from japan.

 

[fwd35]

I got it the rest of the gears out. it looks like it has 19 teeth on the input and 28 on the counter, though there is not much left to count on the input. I also noticed that the inner roller on the main shaft was not pressed all the way to the rest of the gear cluster. I don't know if it moved out during disassembly or if it was not pressed all the way on in the first place. Judging by the copious amounts of black RTV and a few rounded off pieces of hardware I figure someone has been into this transmission once before, which seems like a lot of transmission problems for a van with only 138000 km on it. If the bearing was never fully pressed on than that would explain why the gears didn't seem to fully mesh. The first and second gear on the main shaft are able to move in and out about .100 in which might explain the early failure, at least partially anyway.
The counter shaft and other part numbers seem to be the same for Delicas and the Monteros/D50's. So I ordered all of the gears and bearings from a state side transmission shop for the price of just the counter shaft from Amayama and it should be here next week not next month! I'll let you know if everything is indeed the same. I am still looking for a cast aluminum bottom cover for the transmission, the original stamped steel covers allowed for a little flex in the case under heavy load causing the counter shaft to drop slightly and make your gears look like mine.

 

[fwd35]

The new gears came in and montero/D50 parts are exactly the same! I started pressing new bearing on and when I had the main shaft apart The sleeve that the first gear needle bearings runs on was spinning on the main shaft. It looks like the roller bearing that was not pressed on all the way helps hold this sleeve tight on the main shaft. I saw no signs of heat, ware or brinelling (denting from the rollers) on the first gear sleeve so i used a little lock tight sleeve retainer and put it back together with new synchro rings. The cast aluminum cover part # 2502A008 is not avalible even from a dealer in the states so I am waiting for one from Japan through Megazip.

 

[Alpina2002]

Great write up. I’m looking at buying a delica with the same gears worn out. Can you provide information on where you bought the replacement gears and an idea on what it is going to cost you to complete the rebuild.
Thanks
Greg

 

[fwd35]

Hay Greg,
I got my parts from Anaheim Gear in California. they were vary helpful on the phone to make sure I was getting the right parts. And there prices were great, less then 500 for the new gears, bearings, synchros, and gaskets. I am putting in a new clutch and upgrading to an aluminum pan which adds a few hundred more. Are you planning on rebuilding it your self? I have not kept track of my time but labor could get expensive.

 

[fwd35]

Finally got a chance to do some more work on putting together my Delica trans, pesky work was taking up all of my time. Putting in the counter shaft I may have found the reason that the gears didn't properly mesh before I took it apart and also why it failed again so quickly. There is a spacer that goes behind the outer race on the rear counter shaft bearing that was omitted during the previous rebuild. The thrust of the helical gears pushes the counter shaft back during operation so when I disassembled it this race, and the whole shaft, was pushed back against the bearing retainer, I never thought to check for end play on the counter shaft but I bet I would have found quite a bit. Also with the counter shaft pushed back like it was the front bearing would not have been close to being seated in it's cup, allowing the counter shaft to drop and the gears to mesh poorly, even under normal driving. You can see this in the first picture with the .093" space between the bearing race and the rear end of the transmission housing.
So I turned a .091" spacer and now I have the .002" clearance specified in the manual.
(Admin edit: Caution! Should be 0.002" *preload* not clearance.)
The rigid aluminum pan to upgrade this transmission and prevent me from having to rebuild it again is not available any ware. Megazip was back ordered for at least 6 months and even tough-pans, who made a after market strengthening pan out of 3/4" aluminum, seems to be out of business. So I made my own. I used 3/8" steel as it is much cheaper and about the same strength as 3/4" aluminum. Now I am just waiting for some more time to finish putting it all back together.

 

[jpmustblaze]

Awesome job, you are very brave.

 

[Blobby]

Great info! Quick question, is the model of the D50/montero trans different than our km147/v5m21? Not finding one that matches, I’m assuming the internals are the same in what I’m finding which is km145.. ?

 

[Growlerbearnz]

The internals are mostly the same (depending on year). The cases and shift mechanisms are different- ours are cable shift gearbox and transfer case, Monteros etc. are remote shift (gear lever out the back of the housing). You could fit an entire Montero gearbox to your Delica as long as your rear seat passengers were good at shifting gears for you ;-)

here's a copy of the Mitsubishi 5-speed Transmission workshop manual. You want book 22A- V5M21. As you'll see, there are quite a few variations and changes to the internals over the years- I strongly recommend disassembling and inspecting your gearbox before ordering any new parts. Genuine Mitsubishi parts aren't expensive if you go through Amayama.com.

Part number lookup is fairly easy on epc-data.com but the mainshaft exploded diagram is a touch confusing unless you're actually looking at a mainshaft at the time.

I found this great step-by-step writeup on a Starion forum.

I recently converted from automatic to manual, and rebuilt the 5-speed before I installed it. My brief writeup is here, including some part substitutions to make the gearbox stronger.

At a minimum you want to replace the input shaft bearing with a new felt-sealed unit, the countershaft taper rollers (and set the preload correctly!), the 5th gear needle rollers and sleeve, the mainshaft rear bearing, and both mainshaft and countershaft nuts.

 

[Growlerbearnz]

So I turned a .091" spacer and now I have the .002" clearance specified in the manual.

You're not going to like this but... that's supposed to be 0.00" to 0.002" *preload* on the countershaft taper roller bearings. The step-by-step part of the manual is unclear about this ("ensure the standard measurement" or some such bollocks) but the table of clearances and tolerances at the beginning is unambiguous.

It caught me out too. A year of driving on the wrong clearance doesn't seem to have damaged the gears, but now I've corrected it (thread here) the gears seem to shift a bit easier, there's less slop in the drivetrain, and the gearbox seems quieter.

 

[Blobby]

Great thank you. I’ve got an ‘87, badge says km147, so I’m guessing I have the old style. Just started the van to listen more closely and it sounds horrible, I’ve definitely got debris pinging around in there and some very worn bearings. Not much warning that this was coming, shifting smoothly always, still is actually but not it driving anymore!

 

[jpmustblaze]

Sucks that there was no warning. You have a petro version correct? How many miles on this transmission? I am curious now as I have a petrol, 1988, and same transmission.

 

[fwd35]

Growlerbearnz. That is unfortunate that I got the clearance backwards. I got my van put back together and have only drove it around the block so far. Looks like ill be pulling the trans back out and making a .004" shim for the front end of the counter shaft. I think this will be easier than taking apart back part of the trans. Thanks for the heads up I would rather fix it right now than have it fail again prematurely.

 

[Blobby]

Sucks that there was no warning. You have a petro version correct? How many miles on this transmission? I am curious now as I have a petrol, 1988, and same transmission.

Yeah, think I missed it cause the catalytic converter shield started to rattle before this, put a hose clamp on it temporarily. Probably would’ve thought more about a noise had that shield not been making a ruckus. Either way very faint until it wasn’t. I’m not convinced of the mileage anymore but odometer says 112000 km. I’ve owned since it had 90k. Yes I have the g63b. My trans has definitely been worked on before, was supposed to be preventive and done by Coombs but I can’t find proof of that on the invoice supplied by the previous owner.

 

[jpmustblaze]

I see, keep us up to date on what you find and I will help if I can.

 

[fwd35]

I pulled my trans out and put in a shim in to fix my error, I had only driven it around the yard so i doubt any damage was done. First I pulled the input cover and removed the spacer so I could use it as a template to cut a shim. A piece of 0.004" shim stock took me from a 2 thou clearance to a 2 thou preload needed. The thing to keep in mind is to measure the gasket and make or use one of the same thickness or else this preload will not what you intended. On this note after I put it back together I realized that I could have achieved the same result by just switching to a thinner gasket.
I put the new shim in between the spacer and the bearing race so that it stayed in place while I put it all back together. The whole process took me a little over half a day to have it driving again

 

[Andy]

Great write up, this is awesome info!

Any idea if Anaheim Gear can cut you a new 5th gear? I recall reading somewhere that the gassers have a 5th gear with a ~0.70 overdrive, seems like that would be a nice and fairly straightforward swap to bring down the cruising rpm’s.

 

[natematos]

A new 5th is doable. Dream Works Garage in Taiwan sells rebuilt transmissions with a new 5th. They say it will drop your 5th gear RPMs by 500 at 100kmph which is crazy. Been wanting to get one for a while now.

 

[fwd35]

A higher 5th would be awesome but I didn't think to look into that when I had mine apart.

 

[natematos]

Bumping this as on Facebook someone shared this link:

FM132 FM145 & KM SERIES TRANSMISSION 5TH GEAR SET: UPDATED FITS FORD DODGE MITSUBISHI (MIT-5)

ford FM132 fm145 km132 km144 km145 D50 transmission 5th Gear Set mit-5 F2TZ7C391A 406585K-1

www.transmissionpartsdistributors.com

It's a .6 5th for the KM145, something that may actually be too far in the other direction. A calculation on the FB thread shows this would put you at 88mph in 5th at 3k RPM with factory tires.

At $70 it's a ton cheaper than buying the $2300 transmission out of Dream Works Garage, but not sure how feasible it is. Honestly I'm surprised this hasn't come up before. The #1 complaint of the manual transmission is it's top speed, for the price this seems like a no-brainer mod.