Kraton To all EXB owners who had good luck and bad luck with the rear diffs?

[luis41510]

Hey guys so just wanted to know peoples experience with their kraton exb. Did you guys shim or did it come correctly shimmed ? How long did you run it before you realized something was wrong. Thanks guys really wanna hear how it went with your kraton exb.

 

[walloftvs]

Mine came shimmed as per spec from ARRMA. I put the lsd plates in after the 1st pack just for additional strength and have had no troubles since then. I also replaced the fluid in all three diffs, not because they were all half full but rather because I intended to up the viscosity in them.

I suspect that this "problem" is really blown out of proportion by a vocal minority. That being said, I did order a set of spare gears for when I eventually blow a diff - just like every other truck I've owned. Truck has a TP 4060 / MMX8S setup running on 6s, so more power than stock but not insane like some of the huge 1/5 8s motors.

 

[bicketybam]

Stock rear open diff. Had the correct number if shims. I changed the configuration after 8 packs, but no LSD plates. Still going strong.

 

[TpPartsRcXtreme]

I decided to run a rtr diff, didnt last more then 5 packs ( and not internal, but ringgear and pinion ) so a shimed open LSD, so far 2 packs no issiues. And would never change the lsd mid and front..its kind of the idea with this car, its handeling..

 

[Surchaufeur]

Me i didnt even ran the truck with the rear open diff i bough a v4 diff shimmed it trowed it in the front trowed the front exb diff in the rear never had an issue then i received the LSD from horizon and did the 6 star plates conversion for the rear i own the exb for now a month a few weeks still no issues. But i have to ssy i did some little mods here and there who cost almost nothing exept a rear gearbox housing from hot racing i found used for 40$

 

[Engineer]

I had no issues when I shimmed under the cross pin. Recently I added 12x18 shims under the sun gear but haven't run it much other than in the driveway.

 

[Notorious J]

Horizon just emailed me to say that my replacements are shipped. They're sending complete open and lsd kits so I can choose which way I want to go. Doesn't really matter cause I can break anything. Need to change my name to Destructo J???

 

[jym73]

So far, the only bad luck i had with my EXB is with 2 ? threadlocked screws on the servo mount, both head stripped, and don't talk me about MIP, my hex srew drivers are still in good shape and not rouneded. I even spent some time to melt the threadlocker on ohter screws to avoid to have bad surprise. So, i'm waiting for a GPM servo mount now as the arrma one is way too overpriced. And as you can understand, i still don't have run it yet

The rear diff. has the slip plates, both front and rear are shimmed with the input gear, with few more mods.

 

[Astronought]

Horizon just emailed me to say that my replacements are shipped. They're sending complete open and lsd kits so I can choose which way I want to go. Doesn't really matter cause I can break anything. Need to change my name to Destructo J???

My rear diff didn't "break" per se, but the gears were ground down to the point where they would start skipping (It had the correct number of shims), I still haven't gotten my replacement from Horizon, buy I did snatch up an EXB center diff from JRC.
I cleaned it out, switched the diff plates order to circle-star-star, filled with 10k oil and slapped on the ring gear from my busted rear diff and kept trucking!
I honestly cannot feel a difference between the open diff and the LSD diff with the circle-star-star plates. I'd recommend running it that way at least until we get better diff gears, metal diff cups or some other more permanent fix.

 

[EXwannaB]

I've had my front and my rear diff both fail after 5 packs arrma is replacing both with lsd's rear diff had only 2 shims instead of 3 and the drive for the slipper plate on the back of the sun gears sheared off in my front diffs

. Other than that the truck takes a thrashing chassis is still straight.

 

[Surchaufeur]

I've had my front and my rear diff both fail after 5 packs arrma is replacing both with lsd's rear diff had only 2 shims instead of 3 and the drive for the slipper plate on the back of the sun gears sheared off in my front diffsView attachment 101222. Other than that the truck takes a thrashing chassis is still straight.View attachment 101223View attachment 101222

i really think why the LSD diffs are failing is because it needs more shims than what arrma has decided to put. For example i have 2 shims behind one sun ger and 3 behind the other and diff still spin smoothly maybe i can put 3 on both sides but on my center diff if i try to put an extra shim the diff starts to lock up so i think its a matter of tolerances. Shim the diffs until they bind and remove the shim you added and close everything for good. The pin should be almost completly inside the sun gear if its not snapping the walls like you just did can happen

 

[EXwannaB]

Thanks for the info ill have to shim the internals when everything comes off backorder. at least arrma is doing their due diligence and helping out the guys who have had the issue
Thanks for the info ill have to shim the internals when everything comes off backorder. at least arrma is doing their due diligence and helping out the guys who have had the issue

 

[jondilly1974]

My stock open EXB diff didn’t last very long, maybe a full pack. My cup side sun gear stripped quickly. Mine had two small and one large shim behind each pin.

Next I was told I needed to add more small shims behind each sun gear. I was able to get 0.7mm of shims behind each sun gear and still the cup side stripped.

Next I tried a well shimmed V4 RTR diff. It held up fine but I really wanted the better ring and pinion of the EXB.

Next I tried a front EXB diff in the rear with the LSD setup. This worked ok but I didn’t like the LSD effect. Stock 3 shims behind the pins. No stripped gears.

Decided to change the order of the LSD plates per the Arrma directions and this did help open the diff a little, but still too stiff. I stripped gears.

Now I am running my open EXB diff with 1.75mm of 12x18mm shims behind the sun gears plus the stock 3 small shims behind the pins. This setup is super smooth and open like I feel a rear diff should be. I’m running 15k fluid and so far so good.

 

[Pat_ranch]

Rebuilt, shimmed, lsd'ed before I ran it. No problems (ok, fried steering servo, but my fault for not setting ends)

 

[Harri]

I've now broken rear diffs four times. I guess I've driven around 25 packs so far. The most durable configuration has been the one with 18x12 shims, which lasted 13 packs. Nothing else has broken. HW 4985 + Max6 combo.

 

[Andrew7xX]

I've been running EXB diffs in my Max6 / 4985 Mojave and they've been great. The pinions needed some shimming, both in the front and rear, they were very sloppy, I used 8x10mm shims, .01mm thickness. Brand new open diff units with the fluid changed out, nothing inside the diff messed with. I'd guess around 6 hours of runtime so far. I have some LSD plates but the truck handles so good already I don't want to mess with it yet.

When I first saw the Kraton EXB manual, the diffs didn't show the ARA709060, only the ARA709059. When they revised the exploded diagrams they added the ARA709060 shims to the diffs, that's the only change as far as I know.

 

[insomnia77]

Is there a pole tool? I think this thread should be stickied.

 

[MChammer]

I was really concerned about my diffs when I bought this truck after reading about all the issues. I am returning to this hobby after about 15 years, saw Kevin Talbot’s video on the EXB, and had to have it. I watched a ton of videos and read a bunch of stuff about the diffs before opening mine up to inspect them, wanted to make sure I knew what I was doing. Both had the correct number of shims and everything was nice and tight inside the diff, no play in the output shafts. I topped off the front and rear with 20k and center with 500k. I did have side to side play of the diff inside the diff housing on both front and rear, so I shimmed both with ARA709031 to get the crown gear tight to the pinion, now there is no play that I can feel. Running MMX8s/1717 combo. So far there have been no issues, have not tried 8s yet. So much power, I can Tokyo drift all over the pavement with stock tires, its hilarious. Love this truck!

 

[RWE2500]

Mine has been great stock. I did check shims and had all 3. Have ran about 20 packs so far with no issues. Have spare diffs just in case.

 

[dk3000]

Didn't get through one pack. Both sun gears are worn down. And I have 3 shims on each side, 2 big 1 small.