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Hello all. New to the forum but have been lurking a few weeks looking around. But not new to Tamiya. I built a Wild Willy and Hornet back in the early 80's as well as several carpet racers. Still have all of them and love them. Dropped out of the hobby a bit during college and early career but then saw the TXT-1 when it was first released and bought one. Love it. Dropped out again for a bit with family and work but back now and my issue is that I stripped some of my TXT-1 transmission gears. I understand the truck is long discontinued and original parts are difficult to source. From what I can gather reading other posts here related to the topic, is it correct to say that TXT-2 or Agrios parts are mostly interchangeable with the TXT-1? And would anyone happen to know if the transmission gears in particular are cross compatible? Or, are there any aftermarket gears available?   

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Yes, I believe they are the same thing. I’d just check the parts numbers to be sure. 
 

You'd probably have to put them on back order with someone as they aren’t overly common though do turn up on ebay now and again. (There’s a set on eBay just now listed as juggernaut, txt 1&2)

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I blew the differential gears in my TXT-1 a couple weeks ago - had replacement parts off ebay shortly thereafter. I've found the following helps the driveline survive...

1. Don't run heavy tires with foams
2. Avoid "crazy" power combinations (I run dual Reedy 17T brushed motors with a 2S lipo and it's plenty of power without being a reliability issue)
3. Modulate throttle and avoid high-traction surfaces (grass/pavement)

The TXT can't be driven like an SMT10 or the new Losi monster truck, it's just not built for bashing. But if you love Tamiya and want a big truck, they're awesome fun and unique.

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37 minutes ago, Mr. Horsepower said:

From what I can gather reading other posts here related to the topic, is it correct to say that TXT-2 or Agrios parts are mostly interchangeable with the TXT-1? And would anyone happen to know if the transmission gears in particular are cross compatible? Or, are there any aftermarket gears available?  

Welcome to the forum. The drivetrains between the TXT-1 and TXT-2 Agrios are virtually identical and all the gears should interchange. The TXT-1 uses a solid spacer (ME7) on the 40T gear the pinons mate to, while the TXT-2 uses a shim (BA10) and a stack of 3 o-rings (BA16) but the gears themselves along with the rest of the gears in the transmission and axles should be the same. The only other difference is the TXT-1 use 15T pinion gears and the TXT-2 uses 19T pinion gears to compensate for the smaller tires on the newer truck.

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Thanks guys- I'm grateful for all the insights and info. 

After looking through the manual and checking part numbers I just ordered a bunch a different gear sets and bags from eBay. I also discovered that the kit came with two sets of transmission gears so I already have a new old stock set.

Unknown Driver, thanks for the tips. The stripped gears are completely my fault as I was messing around with a 3S lipo .... Yes, I realize that was dumb. May I ask which 2S lipos you run?

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Yes, the kit does come with an extra set of trans gears, have a few sets still lying around but have never needed them.  I've found the TXT drivetrain to be very stout over the years and I run them pretty hard.  My TXT-2 runs an 1/8 scale brushless setup with 2200kv motor on 2-3S and never an issue...except for the differential case screws backing out, this is a very common issue and the number one reason diff gears get stripped.  If you hear a click when accelerating, STOP immediately and tighten the diff case (of course you have to dissasemble the axle, but if you catch it early enough the gears will be fine).  Unfortunately Tamiya used tiny M2 screws and even loctite doesnt help keep them together when making any sort of power. 

The other weakness is the driveshafts, they get nice and sloppy in short order.  I run Traxxas Revo driveshafts in all of my TXT-based trucks and those things are bullet-proof.  Other than that enjoy the truck, it's a great platform and one of my favorites.  Hoping they do a TXT-3 in the future, mostly so parts become common again.

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3 hours ago, 87lc2 said:

Yes, the kit does come with an extra set of trans gears, have a few sets still lying around but have never needed them.  I've found the TXT drivetrain to be very stout over the years and I run them pretty hard.  My TXT-2 runs an 1/8 scale brushless setup with 2200kv motor on 2-3S and never an issue...except for the differential case screws backing out, this is a very common issue and the number one reason diff gears get stripped.  If you hear a click when accelerating, STOP immediately and tighten the diff case (of course you have to dissasemble the axle, but if you catch it early enough the gears will be fine).  Unfortunately Tamiya used tiny M2 screws and even loctite doesnt help keep them together when making any sort of power. 

The other weakness is the driveshafts, they get nice and sloppy in short order.  I run Traxxas Revo driveshafts in all of my TXT-based trucks and those things are bullet-proof.  Other than that enjoy the truck, it's a great platform and one of my favorites.  Hoping they do a TXT-3 in the future, mostly so parts become common again.

+1, I run my TXT with Revo drive shafts, (I've also converted my Juggernaut 2 to use traxxas slayer Pro shafts, which fit the shorter wheelbase without modification). 3S is my standard battery for my TXT, 2S is 'pedestrian' and 4S (Yes, I tried it on 4S, just because it was possible) is way too much power to drive, but the trans held up OK.

As spares are getting short, It's time for a TXT / JuggClod 3 :)

img33435_7182021120204_1_1100_.jpg

 

I also  made a custom drive shaft for my TXT trans (Bottom one in the image is stock, mine is loctited and pinned rather than using splines, with a steel hex), to make it easier to fit the REVO drive shafts:

img33435_7182021120204_7_1100_.jpg

 

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I'll 2nd Mad Inventor - I wasn't going to get into the weeds, but I'm also running Revo driveshafts. Great mod for reliability - I got mine from a guy on ebay that made them custom with the correct yolk on the transmission side so you don't have to grind/clearance the bejeezus out of everything.

For LiPos - I just run my race packs, which right now is a 5000 mAH ProTek 100C shorty. I run buggy/truck/short-course indoors in the winter, so all summer those packs just sit. It's nice to get a cycle on them from time to time.

I may turn the timing down on my motors to compensate for the added pop from the LiPo though. I was shocked at how much faster the truck was 'just' from going to a LiPo pack.

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3 hours ago, Mr. Horsepower said:

Thanks all. Just to clarify, are the driveshafts the parts the the universal joints attach to from the transmission and to the axle?

Yep

 

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It took me a while but I have the truck running again. I forgot how much fun it is to drive!
 
198814295_ScreenShot2021-11-01at8_11_54PM.png.1b8f4f1ce4bacbd5ceede21b569abc67.png2096560143_ScreenShot2021-11-01at8_09_47PM.png.9b8f2c71dd28ef4d4c38a7c43a43d275.png
 
It turns out there were two different problems. The first was a small 8x5 (MR3) ball bearing that totally disintegrated on the end of the long 27T gear in the transmission. It was completely in pieces when I disassembled the gear box. The inner and outer races and carrier were all free parts within the bearing groove. Most of the balls were in the hollow section of the gear. As a result of this the gear was able to wobble on the shaft and it got munched up pretty good. Thankfully it was the only gear that had any damage- the others were fine, even looking at them closely under magnification. I tore the whole assembly apart, tossed all the old ball bearings, cleaned everything and then reassembled with a replacement gear and fresh grease throughout. 
 
The other problem was a broken star shaft in the rear differential. All three shafts had fractured near the hub. Interestingly the gears themselves did not show any sign of damage.
 
245969338_ScreenShot2021-11-01at8_13_23PM.png.513cb40e839a6688b1189ec26c84ecbb.png
 
I basically took apart the entire drive train just to look everything over. No other major issues found. I did end up replacing many of the phillips head screws with socket heads.
 
For the rebuild I removed the old Super Rooster and black onyx Speed Gem motors I had in there and installed a Traxxas velineon 3S system. So far I’ve only run it on 2S and 8-cell NiMH packs which is a hoot. I’m not even sure I want to run it on 3S. 
 
844685949_ScreenShot2021-11-01at8_20_16PM.png.882b2fd727d4b311b21aeb0f215c4a8a.png
 
As a side note, as others already mentioned the kit does include a spare set of transmission gears. I had completely forgotten about them. I had to dig through my attic to find the box and once I opened it up it was kind of like a time capsule. I had some other spare parts in the box including parts bags, axel housings, a spare gear case and spare decal sheets. 
1667135011_ScreenShot2021-11-01at8_10_06PM.png.e41ad3a3c74136b69b66e4c4fe0177c7.png
 
I do love Tamiya packaging and artwork. But it’s a shame how difficult it is to find certain parts for this thing now. I was able to get some spare gears and other driveline components but it took a fair amount of digging around and multiple different international sources. I think many of us want to keep these old trucks running. It’s too bad Tamiya doesn’t keep more stock of so many critical items. Then again, it is twenty years old this month I believe.
 
And, Mad, after going through the mechanics and drivetrain, it made me really appreciate your various modifications and enhancements. 
 
Thanks again to all for the help and advice.
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Looks great!  Nice to see another TXT back up & running.  As you said, definitely a shame Tamiya parts support is not better for these trucks.  I run my TXT-2 often and it rarely has any issues, but it's always in the back of my mind, "Can I find xxx part if I break it?"   Good luck with it, they are a ton of fun.  

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Glad to hear you got it all up and running again. I do like those axle guards you've got, my TXT runner is still running the stock one at the front. It's on my list of 'things to do' to try and make some star shafts from steel at some point. I've broken the several star shafts. I think all it needs are 3 pins loctited into a drilled steel bush (I've got a rotary table and a milling machine I can use to drill the 3 holes spaced exactly 60 degrees apart). If I manage it I'll let you know. 

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Thanks guys. 87, you're absolutely correct. It really is a ton of fun. Mad, if you ever did go through the trouble of creating steel star shafts I'd buy some for sure. Ditto your steel drive shafts.

The axle guards, transmission skid plate and other aluminum bits were from New Era Models. Looks like they are still around on eBay but don't seem to stock that stuff anymore. But I'm guessing you have the skills and ability to machine your own from steel... B) The New Era ones were well made though. Very nice machining and chamfered edges similar to the stock frames.

1053800570_ScreenShot2021-11-02at2_35_34PM.png.8d94eaf399073c4fd33d5f06db1a5d39.png

 

 

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Can Juggernaut wheels/rims be used on a TXT? It appears that the hub locking holes are smaller on Juggernaut wheels so that you could actually mount them but the E3 wheel hubs would slip within the hole span when shifting from forward/reverse. Can Juggernaut B5 hubs be mounted as a direct replacement onto TXT-1 MD7 brass axle hubs?

886602069_ScreenShot2021-11-10at12_32_51PM.thumb.png.98724ba19bc60772e44a03254636a1c3.png

 

977129353_ScreenShot2021-11-10at12_34_14PM.thumb.png.e923933e48f1b307e4218b7c97eb67b6.png

 

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Yes, the 12mm brass hubs will fit Clod, Jugg, TXT-1, and TXT-2 adapters with no issues.  

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12 hours ago, Mr. Horsepower said:

Can Juggernaut wheels/rims be used on a TXT? It appears that the hub locking holes are smaller on Juggernaut wheels so that you could actually mount them but the E3 wheel hubs would slip within the hole span when shifting from forward/reverse. Can Juggernaut B5 hubs be mounted as a direct replacement onto TXT-1 MD7 brass axle hubs?

 

 

 

 

Yes and no. The hubs fit the brass adapters no problem, but the juggernaut E5 part is a lot thinner than the TXT E3 part. The TXT stub axles are longer to accommodate it. You can fit the wheels using clod buster stub axles (These are identical to juggernaut 2 axles), but the downside to doing this is that it moves the wheels closer to the centreline of the truck. This will make it less stable in the corners, but more importantly I suspect it will makes the wheels rub on the 4 links and the axle guards at full steering lock. 

I went the opposite way with my juggernaut 2 and fitted TXT wheels, hubs, and stub axles to it, to move the wheels further apart from the centreline of the truck, to make it more stable and stop the wheels rubbing on the axle guards.

 

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Forgot about that.  @MadInventor is right, the TXT-1/-2 adapter is thicker than the Clod/Jugg.  You'll need Clod stub axles as he said.  

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That all makes sense. Thanks guys. 

I'm going to experiment with a few types of small adapter rings to see if the Jugg 1 wheels can be modified so that the E3 drive hubs fully engage the smaller locking nibs. Should be a relatively easy mod if I can find the right size adapter ring. Unfortunate since they are otherwise identical to TXT-1 wheels. I'll report back how it works.

 

apcar06e.thumb.jpg.c147eb1cb8a53b74c6ed7887357f1cf6.jpg

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That could work, but seeing how many drive pins I've stripped from wheels in the past I'd say you better get them perfect.  Another option could be CPE adapters, I believe they are made to fit both TXT & Clod style wheels and should work on any length stub axle.  Check their site to be sure, but I've used them on both in the past.  

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If you go the CPE route, make sure to buy the aluminum adapters, the 3D printed plastic ones are junk. 

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Did not know about CPE. Clearly this is the best solution. However, it seems they only have the 3D printed ones available. I've sent them an inquiry about aluminum. Thanks for the tip!

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No problem!  The 3D printed ones will get you by on stock or near stock power, but I've heard they don't take to upgraded power or abuse very well.  If that's all they have might be worth a shot, but if Brett can still make aluminum ones that's the way to go. Good luck. 

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