H42/H55 transmission Rebuild Tools (1 Viewer)

lelandEOD · May 10, 2018

I’ve decided to rebuild my H55 and want to source the appropriate tools (bearing and gear pullers or suitable substitutes for the factory SSTs) necessary take this transmission apart and rebuild it correctly. I have a couple large generic gear pullers but they won’t work as there’s not enough length to pull against the input and output shafts. I’m curious if anyone can share part numbers of off-the-shelf pullers or other tools I should have to make this rebuild easier. I’ve been around long enough to know that jobs like this are usually much easier if you just have the right tools on hand. Dremeling bearing races and yanking on gears with pry bars doesn’t sit well with me.

And... tech threads without pics, suck.

So Far, the disassembly has been relatively uneventful with the exception of one transfer case bolt head that was rounded and I was unable to get it loose. I ended up drilling it out and will have to use a broken bolt extractor to remove the remnant. Looks like this case will be getting at least two time-serts as one other bolt galled the threads when I pulled it.

Living in the Past · May 10, 2018

I have a H55F from a BJ42 I need to replace the input shaft. Figure might as well rebuild it and the transfer case. The front counter shaft bearing looks to be the hardest to get at without the factory SST puller. I pieced together some pullers I had from HVAC fan hub pullers to practice on a parts H42 I have. Doing a search on the internet finding something that would work for that bearing seemed to be the hardest to find. Buying a cheap puller and grinding the arms to fit probably end up breaking the arms. Most those pullers have three arms evenly spaced. The case has two openings for arms 180 degrees apart. Be curious what people had used for that bearing. Exposed bearing on the back shaft shouldn't be too hard to adapt something for or a buy a bigger puller. Do you have a press to assemble the transmission?

lelandEOD · May 10, 2018

Living in the Past said:
I have a H55F from a BJ42 I need to replace the input shaft. Figure might as well rebuild it and the transfer case. The front counter shaft bearing looks to be the hardest to get at without the factory SST puller. I pieced together some pullers I had from HVAC fan hub pullers to practice on a parts H42 I have. Doing a search on the internet finding something that would work for that bearing seemed to be the hardest to find. Buying a cheap puller and grinding the arms to fit probably end up breaking the arms. Most those pullers have three arms evenly spaced. The case has two openings for arms 180 degrees apart. Be curious what people had used for that bearing. Exposed bearing on the back shaft shouldn't be too hard to adapt something for or a buy a bigger puller. Do you have a press to assemble the transmission?

Good info!
I think I can modify my existing gear puller with longer intermediate arms (for lack of a better term) that will allow me to reach the 5th gear output gear and bearing. I am much more worried with how I'm going to get the front input and countershaft bearings out.

Yes, I have a 20-ton press in the shop which I think will do the trick. It's a little disheartening that these things are so hard to get apart. We ought to start a 'mud loaner tool program!

lelandEOD · May 11, 2018

Not sure how I’m going to figure out what needs to be replaced inside this box. I don’t see any missing teeth or other apparent damage to either the gearsets or the synchro hubs and rings.

Not sure what the correct term for this part is but I think it’s the gear spline that the Synchro hub sleeve slides over. It looks to have some wear on it it’s teeth:

This transmission was made in late 1997 so it’s not like it’s that old. But it did come from the mine truck and I assume it was not well cared for.

The only potential defect I found with the gears is on the the input shaft gear. Looks like it ran a small bit of debris through the countershaft. Whatever it is, it’s wedged in there pretty good as I couldn’t get it free with my pick. Either that, or it’s a manufacturing defect of some sort.