4 speed rebuild/normal wear? (1 Viewer)

[Highrlr]

I just disassembled my 4 speed trans for new bearings and seals. This is the first one I have had appart, so I was hoping some of you could look at the internals, and give me your opinions on if this all looks like normal wear, and if these parts are serviceable yet. Thanks in advance!!

 

[Highrlr]

Some more

 

[Highrlr]

The areas I am really wondering about are some of the gears where it almost appears as the metal has migrated some from onto the outer edge of the gear. Mainly on the counter shaft gears, but also on 2nd gear up on the main shaft.

Shift forks all look pretty good, but I'm wondering if the one that looks somewhat ground down is supposed to look that way, or if it's wore down and needs to be repaired?

 

[Filipebates]

Hello @Highrlr ! Hope all's well

Yea I would say that looks like normal wear. For the shift forks, they got plenty of life still in them
For the gear's teeth, I would file away the material that's already chipping away, however for this one below I would start maybe considering getting a new part:

As you can see, the wear on the teeth is around 1/4, maybe a little less of the total area of contact...


Overall I would say this is normal wear and tear

 

[peesalot]

The first pic in post #2 , that gear is done IMO, some of those teeth are almost half gone.

 

[Eurasiaoverland]

A couple of questions.

Why are you rebuilding it?

What is the purpose of the vehicle it came from?

The first picture with the worn straight cut teeth, and the second picture in your second post are the reverse and reverse idler gears. They look worn from impatient shifting into reverse, but they are still fine to run.

The peening over of material on the first gear and layshaft (countershaft) teeth could be filed off and the gear will still run. The counter input gear on the front of the layshaft looks pretty worn. What do the input shaft teeth look like?

Show us the index teeth on the gears, and the bearing surfaces on the gears and layshaft.

I'm guessing that is a very high mileage gearbox. I would say it's OK to chuck back together to keep an old beater running. If I was building a gearbox to go in a cherished vehicle I want to drive for another 20 years, I would put everything you show in your pictures in the scrap bin and buy a new H55F.

EDIT: I've somehow strayed into the 40 Forum, I thought I was commenting on a 70 Series question. Maybe an H55F is not a simple solution. Also, your shift forks look fine.

 

[Highrlr]

A couple of questions.

Why are you rebuilding it?

What is the purpose of the vehicle it came from?

The first picture with the worn straight cut teeth, and the second picture in your second post are the reverse and reverse idler gears. They look worn from impatient shifting into reverse, but they are still fine to run.

The peening over of material on the first gear and layshaft (countershaft) teeth could be filed off and the gear will still run. The counter input gear on the front of the layshaft looks pretty worn. What do the input shaft teeth look like?

Show us the index teeth on the gears, and the bearing surfaces on the gears and layshaft.

I'm guessing that is a very high mileage gearbox. I would say it's OK to chuck back together to keep an old beater running. If I was building a gearbox to go in a cherished vehicle I want to drive for another 20 years, I would put everything you show in your pictures in the scrap bin and buy a new H55F.

I acquired this transmission in a bulk purchase with various other parts. Not sure how many miles are on it, or how it performed/drove. I rebuilt my 3 speed t case, and figured I would rebuild this as well to install in my '67 fj40. I do love my FJ, and plan on keeping it for the foreseeable future, and just want everything as good and problem free as I can get it all. The truck is a "toy" at this point, and will only be driven maybe 1000 miles a year if lucky.

 

[Highrlr]

Input shaft looks pretty good as far as my untrained eye can tell.

 

[Highrlr]

And some more of bearing surfaces, and index teeth, hopefully some of what you asked for, Eurasianoverland.

 

[Highrlr]

And a few more

 

[Eurasiaoverland]

Agreed, the input shaft looks great. Are those index teeth on 3rd gear (I think; third photo in your latest post) broken off, or is that how they come on an H42? (I am only familiar with the H41/H55F) The rest of the index teeth that you show look OK.

I don't believe you can buy new H42 layshafts, so I would probably file the peened over material off the teeth and run it. That second gear might be slow or noisy to shift, but for a vehicle doing so few miles, I doubt there will be anything problematic with the transmission. Just my amateur opinion though.

 

[Highrlr]

Agreed, the input shaft looks great. Are those index teeth on 3rd gear (I think; third photo in your latest post) broken off, or is that how they come on an H42? (I am only familiar with the H41/H55F) The rest of the index teeth that you show look OK.

I don't believe you can buy new H42 layshafts, so I would probably file the peened over material off the teeth and run it. That second gear might be slow or noisy to shift, but for a vehicle doing so few miles, I doubt there will be anything problematic with the transmission. Just my amateur opinion though.

I was curious about those teeth as well. I'm thinking that is how they come though, as there are no signs that anything broke off of that gear (jagged or shiny metal, etc). And I did not find any particles or pieces in the case, oil looked good, and a fairly small amount of shavings on the magnet.

 

[pb4ugo]

I haven't run a stk 4 speed in yrs, but I have read a critical spot for wear is on the output shaft where the tcase gear rides.

 

[Highrlr]

I haven't run a stk 4 speed in yrs, but I have read a critical spot for wear is on the output shaft where the tcase gear rides.

I actually have a brand new output shaft to install. Mine isn't worn terribly bad, but didn't want the gear to be clunking on there.

 

[Highrlr]

Thought I would share pics of the puller I purchased for $30, from home depot. I made the two attachments that fit in the snap ring grooves out off scrap steel and nuts I had laying around, and with the various length extensions in the kit, it worked great!!

 

[Highrlr]

I would love to build a puller to install the output shaft bearing, that resembles the Toyota SST. I am having troubles envisioning how it works however, anyone have detailed photos of that tool?

 

[Eurasiaoverland]

I have covered a full H55F rebuild in my build thread. I made an SST here: Post in thread 'Last of the BJs: 1989 GEN BJ60 restoration, 15B-T swap' Builds - Last of the BJs: 1989 GEN BJ60 restoration, 15B-T swap - https://forum.ih8mud.com/threads/last-of-the-bjs-1989-gen-bj60-restoration-15b-t-swap.1297034/post-14780566

 

[Highrlr]

I have covered a full H55F rebuild in my build thread. I made an SST here: Post in thread 'Last of the BJs: 1989 GEN BJ60 restoration, 15B-T swap' Builds - Last of the BJs: 1989 GEN BJ60 restoration, 15B-T swap - https://forum.ih8mud.com/threads/last-of-the-bjs-1989-gen-bj60-restoration-15b-t-swap.1297034/post-14780566

Thank you, that is exactly what I was looking for!!