5 speed rebuild

fwd35 · Post by **fwd35** » Mon Sep 03, 2018 9:12 pm

I finally got a little time to start on 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 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? shipping it to Colorado will probably be cheaper than a new counter and input shaft from japan.

Post by **Growlerbearnz** » Tue Sep 04, 2018 4:14 am

Hmm. That *is* a lot of movement. I'm having trouble picturing what you mean about the snap rings- the input shaft bearing and mainshaft rear bearing are the two I can think of that have snap rings, usually the snap ring drops into the case and the retainer (the front cover on the front bearing, the metal retainer plate on the rear) presses on the bearing outer race. Any chance of more pictures when you get further inside?

fwd35 · Post by **fwd35** » Tue Sep 04, 2018 11:54 am

Your right, the bearing retainer for the main shaft has a counter bore cut in it that rest on the outer race and holds the bearing in place. Have any tips on getting that bearing off the main shaft? I cant get it to come out far enough to grab onto with a puller.

Post by **Growlerbearnz** » Tue Sep 04, 2018 2:21 pm

I stood the gearbox on its bellhousing, and pressed the mainshaft down through the bearing. You could probably use a hammer and drive the mainshaft down as well- it would wreck the bearing, but you're replacing it anyway right?

This is presuming you've already removed the input shaft with front bearing, and the laygears.

A pinion-separator style bearing puller is super handy for some of the bearings.

fwd35 · Post by **fwd35** » Tue Sep 04, 2018 2:59 pm

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 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.

fwd35 · Post by **fwd35** » Wed Sep 19, 2018 9:07 pm

The new gears came in and the montero/D50 parts that I was able to get domestically 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 upgraded cast aluminum cover, part # 2502A008, is not available even from a dealer in the states so I am waiting for one from Japan through Megazip.

Post by **Growlerbearnz** » Wed Sep 19, 2018 10:44 pm

That pressed-on bearing isn't supposed to be *that* pressed-on, the giant retaining nut at the end of 5th gear is supposed to hold the whole stack of sleeves etc tight, even the ones in front of that bearing. Very odd- or maybe just manufacturing tolerances.

(It's bad engineering on Mitsubishi's part though; you don't rely on friction to stop something turning on a shaft, you *pin it*.)