This has been a slow project... and not just because I'm lazy. I've never put one of these things together, so putting it together from a box of parts takes time. Inspecting and researching each little piece, I keep turning up minor problems as it goes together. So I'll put the trans together a little way, then find another little part or two I need to order... then it's on hold for several days. But I've made progress:


Here's where I left off last time. You can see the inner bearing races for the rear bearings on both the main shaft and the countershaft. I'll start stacking things on top of that one at a time:



If anybody is reading through this as a guide, that's good. That's why I'm putting this together. But take it with a grain of salt. I've assembled plenty of transmissions over the years- most from Case backhoes and John Deere tractors. But never a T56. When you go back together with a transmission, if you're unsure about what part goes on the shaft next, a lot of times you can take a close look at the wear patterns on adjoining parts. That doesn't translate well into photos, but a lot of times you can see where there's a shiny area where two parts ride against each other. I've had to rely on that in a few cases here since I've yet to run across a single detailed assembly guide for this 2004-2006 Dodge Ram SRT-10 version of the transmission. I think the 2004-2006 Viper transmission are basically the same, with a slight difference in the tailshaft housing that I'll cover later. But take this with a grain of salt. And if I've put something together wrong here, I'd welcome any corrections:

Install the 6th gear thrust washer. Big side toward the rear of the trans.




Set 6th gear and the roller bearing in place:


Install the blocker ring. No thrust washer for this roller bearing because it rides on two nice smooth surfaces (6th gear thrust washer and the 5/6 synchro hub):



Set the 5/6 synchro hub and shift fork into place, and tap it gently down with a punch until it seats. Notice that slider is darker than the stock piece. That's a new slider from AMP because the old one had some chewed up teeth. Same part as used by the Camaro/Mustang/Corvette versions, so hub assembly is the same. Make sure you align the blocker ring with the synchro keys as you tap the hub assembly down into place:



Once the synchro hub is tapped into place, install the snap ring to retain the synchro hub, and the snap ring on the 5/6 shift fork:


Actually I ended up sanding that snap ring a little bit since a thrust washer will ride against it. A thrust washer that I almost left out...

 

Don't forget this little thrust washer that lays on top of the snap ring like I almost did. You don't want a plastic roller bearing race riding against the jagged ends of a snap ring...

Also install the 5th gear blocker ring:



Install 5th gear and the roller bearing. Then install the thick thrust washer and snap ring.



Tap the 5/6 driven gear into place. Apparently this is very tight on some transmission, but not on this one. It was a little tight, but I was able to tap it into place with a small hammer and a drift. If it was any tighter I would've had to make a proper pusher tool. This 5/6 driven gear rides right against the inner bearing race for the rear main shaft bearing:




Put the Reverse synchro in place along with the reverse shift fork. This goes right up against the 5/6 driven gear (and the 5/6 driven gear holds that stupid little retainer for the reverse synchro keys in place). The reverse synchro hub just slid into place. Seems like it should've been tight, but I don't really care. Splines look good... it'll work. Also install the plastic reverse thrust washer.

This reverse synchro is what held me up for a while. I had the hub apart to inspect everything and turn the hub around. You can turn these around once for a rebuild as only one side is actually used. There's a goofy stamped steel retainer that holds the synchro hub keys in place. The old one was loose... had to order a new one that would stay in place. So far this is the only thing I've seen in the design where I'm really unimpressed. It's a cheesy little part- and if it fails, it'll likely take out the whole transmission as synchro keys get churned through the gears. So I was careful with it. It'll work. But it's a **** design, and it could've been better with minimal cost/effort. Same part as used in all other T56 transmissions. [/rant]

Once the synchro hub is in place, install the snap ring to retain it, and set the roller bearing on top. This roller bearing can ride against a snap ring with no thrust washer because it has a metal retainer. There's no room for a thrust washer, so I'm assuming this must be right..



Install the Reverse blocker ring, wave washer, and the snap ring for the reverse shift fork:



Install the reverse gear, thrust washer (same as used on the countershaft), and snap ring. This is the new reverse gear from USA Standard Gear. Which by all accounts is made in China:



Like I mentioned earlier, the teeth on the engagement teeth on the original revers gear looked pretty nasty, which is why I replaced it. I've read several accounts of T56 transmissions not fully engaging reverse due to insufficient travel of the reverse shift fork, and kinda assumed that that's what I'd find with this transmission. But that's not what I found... it engages fully. No reason to make any modification. So I can't say why the original reverse engagement teeth were chewed up, but there's no need to modify the shift fork position here.

Reverse seems to be a weak point with any T56. So I guess I'll just be careful with it:

 

Also I found a turbo- arrived a couple days ago. I've researched different ideas on what I'd want for a turbo, and it appears to me that no matter how much research you do, a lot of it comes down to guess-work, trial & error, etc. when it comes to getting the right turbo. So I came up with the following criteria:

1. A reasonable guess at the correct size and configuration. Should be used on an engine of similar size, with similar horsepower.
2. OEM quality. No remans, no made-in-china bullshit. Needs to be built by a major turbo manufacturer, and in good condition.
3. Not German.
4. Cheap. Because I don't like spending money. And I'm kinda just screwing around with this project.

I found this little turbo on Ebay, for a late-80's Isuzu Imark turbo. A pretty rare car, 1.5L gas engine with a turbo. This is a brand new IHI RHB5 turbo that's apparently been sitting in a box for 20+ years. Hard to say why, but apparently those Imark's are pretty rare, so maybe they never sold it. Regardless, IHI makes turbochargers for just about every Japanese engine out there. There are dozens of versions of the RHB5 used on both gas an diesel engines, anywhere from about 80 to 130 horsepower. Including but not limited to Mazda, Massey Ferguson, Toyota, Ford, Isuzu, Yanmar, Subaru, and Shibaura. So this is as good a guess as any... and it's new in the box for $71.

If it needs to be replaced at some point, it's very similar to the RHB5 turbos used on the Isuzu 2.8L diesel engines. And nearly identical to the RHB5 turbo used on the early/mid 90's Ford Probe and Mazda MX6.

 

Ok, I installed the little reverse gear and snap ring on the countershaft. Also installed the spacer, roller bearing, other spacer, and snap ring onto the output shaft. Reverse gear on the countershaft was a little tight, but not too bad:





Also removed the bearings, reverse idler, and shaft. Cleaned everything up and reassembled. Based on the crud and rust in the tailshaft housing, I think this transmission was sitting in a damp corner of some parts room for a few years before some mechanic got a hold of it. Everything in the tailshaft housing was good though, except I replaced a shift fail bushing:



I haven't seen any evidence so far that this transmission has ever been apart before. No scraper marks or sanding pad marks on the gasket surfaces. No parts that weren't OEM. Looks like they just swapped in a new transmission at some point and never returned the core for whatever reason. I also triple-checked the travel on the reverse synchro hub, since lots of T56's seem to have a problem with the engagement there. I could get away with grinding/spacing the reverse fork back about .040" if I was ambitious. But that's really not much, and a little clearance for max travel probably a good thing. I'll leave it alone.

So now this project is on hold until I get a few more parts. Tailshaft is ready to go on, but I want to check the fit of a few parts first.

The tailshaft on this transmission is really an oddball design, no longer available anywhere. Only made for 2005 and 2006 far as I can tell, and only in the SRT-10 trucks. This thing has the same tailshaft as the Viper car transmission, but for 2005 and 2006 they increased the OD of the slip yoke to 1.885" (car version was 1.680). They also added a goofy vibration damper on the back of the tailhousing. The drive shaft yoke was a little hard to find, but still available from Dana/Spicer as part number 3-3-02231X. Seems to be the correct size anyway... hopefully it fits. Bushing appears to be in good condition, but I want to check that with the new yoke before I install the tailshaft housing. It's not clear exactly what rear seal this thing is supposed to take. I ordered two of them from two different sources, and got the Viper car version both times. So I looked through a Timken catalog and found a seal that should be the right size and configuration- used in Ford transfer cases from the late 90's through the 2000's. And of course after I ordered that seal, I found reason to believe that Mopar part number 5166053AA is the correct seal... but there's no way to be sure without just ordering the seal and checking it. So I'll probably just use that Timken/Ford seal I ordered unless I see any problems with it. If something ins't right, I'll order 5166053AA. Also ordered a bronze bushing for the shifter- the plastic one wasn't totally shot, but it's seen better days.

I've never dealt with Mopar vehicles much at all over the years. I did work on some of their diesels at a Cummins dealership for a few years, but that's not really Mopar. Gotta say that I'm really NOT impressed with their parts availability or documentation. Their parts book uses photos that are flat-out WRONG in several cases (shows a two-piece countersshaft in this transmission for instance). Part numbers appear to be correct, but in many cases you'd never know until you order them. And lots of the parts just aren't available anymore. This transmission is only 14 years old. You'd never have this problem with a GM. And rarely with a Ford though it may be a little more difficult to track down the correct part.

 

Not much left to show on the transmission. The Dana/Spicer yoke fits. Tailshaft bushing is good. That Timken seal for a Ford transfer case fit like it was made for this transmission. So the transmission is all together. Only thing left on the transmission is that I'm going to do a mod to the reverse lockout solenoid spring.




Just in case anybody runs across this thread, trying to figure out what parts are needed for this oddball version of the T56... I kept a spreadsheet. As you can see, most of the parts I needed are the same as a Camaro T-56. Others would be shared with the Viper T56 from 2004-2005. The only thing unique to the Ram SRT-10 T-56 as far as I can tell is the extension housing and bushing, rear seal, and drive yoke:

 

This is cool to me.

I saw this thread at the end of last year and it's part of what gave me inspiration to start my unconventional(though not as unconventional as yours): putting a Mitsubishi 4d55t into my Mazda b2600i. Thanks for the thorough documentation!

 

Thanks. I'm looking at this Nova as a tinkering platform for whatever idea I feel like trying. Been throwing around the diesel idea for a while now. If this proof-of-concept pans out as well as hoped, this Yanmar may eventually make it into a different vehicle, replaced by a GM L9H engine or the like. We'll see. But first the Nova will clatter like a utility tractor

Got a thread for your swap? I'm not familiar with the 4D55T, but I gather from a quick google search that it's an IDI motor with a Bosch VE pump, used in Ram 50's and Rangers in the 80's. Should be a good fit.

 

i started on here but I guess it's still pending approval. It's also here: https://www.oilburners.net/threads/my-current-obsession-1991-85-mazdabishi.84990/

 

Yeah, I'm not sure how that pending approval thing works. I bothered a couple of mods about it and never got an answer. For the first half dozen posts or maybe 10, they wouldn't show up at all on this forum. For DAYS... until some mod somewhere approved them. Then they'd show up. Pretty frustrating, and I suspect it's why there are so many threads here abandoned after one or two posts.

There's probably a minimum number of posts set up in the forum software, such that your posts won't show up without mod approval until you hit that number. The board works fine for me now... just didn't at first.

 

Here it is!
My build thread