Aftermarket front and rear diff?

[D-DUB]

New to the truck world, I picked up the Kraton BLX 6S with a dozen 2 and 3 cell lipo to bash with when its crappy out and I cant fly my quads.

I mostly drive at my local bike track, bashing, and some grass across the street at the park.

I was just out with my son at the park, went from cement, to grass and the front diff blew out.

I wanted to know what you all recommend for a stronger option for front/rear/center.

I pulled the center out, thinking it was the issue, but looks fine. There are however some chunks of metal in the grease, but there are no broken teeth on the gears. I have everything soaking right now to inspect a little closer.

Thanks in advance for the advice.

 

[Peejwk]

New to the truck world, I picked up the Kraton BLX 6S with a dozen 2 and 3 cell lipo to bash with when its crappy out and I cant fly my quads.

I mostly drive at my local bike track, bashing, and some grass across the street at the park.

I was just out with my son at the park, went from cement, to grass and the front diff blew out.

I wanted to know what you all recommend for a stronger option for front/rear/center.

I pulled the center out, thinking it was the issue, but looks fine. There are however some chunks of metal in the grease, but there are no broken teeth on the gears. I have everything soaking right now to inspect a little closer.

Thanks in advance for

You can buy the exb differentials. I just did all three to my talion and drives unbelievably better. They are saposed to be tougher too. Yea be careful when your wheels are spinning a hundred miles an hour and then stop all the sudden, diffs don't like that. Thats what it sounds like happend when you went to pavement

 

[D-DUB]

You can buy the exb differentials. I just did all three to my talion and drives unbelievably better. They are saposed to be tougher too. Yea be careful when your wheels are spinning a hundred miles an hour and then stop all the sudden, diffs don't like that. Thats what it sounds like happend when you went to pavement

Thanks, ill look into those. Any specific place I should look? I don't have a very good hobby store locally. I've been looking around, but not sure who has the best reputation for parts.
Looks like ARA310985 is the part I need? Same for front and rear? I figure at $15 each, I might as well do both.

 

[Peejwk]

Im gonna suggest "just bash it", that's where I got mine. They have a ton of new take off parts and they have the whole bulkhead and diff for 68$ which isn't much more then other places charge just for the diff. Other than that if you don't wanna buy all that, ebay.

 

[D-DUB]

Sounds good, are all the front rear and center diffs the same minus the case?

 

[slick2500]

Sounds good, are all the front rear and center diffs the same minus the case?.

Long story short no. Some models have spiral cut gears some have straight cut gears, some have a different spur, the Limitless has a spool, and each EXB has different diffs.

 

[D-DUB]

Long story short no. Some models have spiral cut gears some have straight cut gears, some have a different spur, the Limitless has a spool, and each EXB has different diffs.

When buying, none of them say front rear or center. How do I know which is which?

Also, just pulled my front apart, looks like the steel diff outdrive sheared off and is lodged in the gear because it mushroomed out.

I also noticed a big gouge in the bottom of the case, is this anything to be concerned aboout?

 

[slick2500]

When buying, none of them say front rear or center. How do I know which is which?

Also, just pulled my front apart, looks like the steel diff outdrive sheared off and is lodged in the gear because it mushroomed out.

I also noticed a big gouge in the bottom of the case, is this anything to be concerned aboout?

View attachment 140555

Oh okay yeah front, rear and center are the same parts on the non EXB models minus the crown gear or spur obviously. IIRC the 6s EXB models have limited slip diffs in the front and center while the rear is open.

Is that the case or the chassis?

 

[D-DUB]

Oh okay yeah front, rear and center are the same parts on the non EXB models minus the crown gear or spur obviously. IIRC the 6s EXB models have limited slip diffs in the front and center while the rear is open.

Is that the case or the chassis?

That is the inside of the case, looks like the ring hit it and took a chunk out.

I have run, 5 packs through this car, first pack, two of the IC5 connectors exploded into a bunch of pieces because they came out of the holder.

Second pack I ripped off the wing (luckily I have a printer, and I printed out a few TPU and PC/PA carbon fiber wing mounts, as I have a feeling this will not be the last time that breaks.

Since then, no issues until the front diff sheared. I was planning on taking it apart this week to shim it, it says to shim it after break in, and I have no idea how much that is, so I just figured now would be a good time. However, from looking at it a little closer, I think it had too much side to side play, and that is what took that chunk out, probably on a side landing and shoved the ring gear into the case because it had enough play.

I just ordered the front LSD, rear open, and center LSD, entire EXB assemblies (case and sway bar) from JBI, it was actually a lot cheaper than anywhere else.

40-50 for a open front BLX diff on ebay, or 65 for the EXB, kind of a no brainer.

 

[slick2500]

That is the inside of the case, looks like the ring hit it and took a chunk out.

I have run, 5 packs through this car, first pack, two of the IC5 connectors exploded into a bunch of pieces because they came out of the holder.

Second pack I ripped off the wing (luckily I have a printer, and I printed out a few TPU and PC/PA carbon fiber wing mounts, as I have a feeling this will not be the last time that breaks.

Since then, no issues until the front diff sheared. I was planning on taking it apart this week to shim it, it says to shim it after break in, and I have no idea how much that is, so I just figured now would be a good time. However, from looking at it a little closer, I think it had too much side to side play, and that is what took that chunk out, probably on a side landing and shoved the ring gear into the case because it had enough play.

I just ordered the front LSD, rear open, and center LSD, entire EXB assemblies (case and sway bar) from JBI, it was actually a lot cheaper than anywhere else.

40-50 for a open front BLX diff on ebay, or 65 for the EXB, kind of a no brainer.

That does sound like what had happened. Usually you see marks like that in the chassis.

 

[D-DUB]

Well, upon further inspection. I found another issue.

The set screw for the motor gear came out, apparently chewed around the motor mount, and spit out.

Luckily I took all of this apart and noticed some marring around the motor mount, and when I turned the gear, the set screw just fell out.....

Shouldn't that grub screw have some threadlocker on it?! I cant believe this just fell out after five packs....

Could this be what caused my drive cups to shear if there is that much play in the gearing? Its a good half inch of play between the output shaft and the gears D shape input. Super loose fit. Makes me also think that with about 1mm, that gear has to be off center. Not sure how much that matters.

 

[slick2500]

Well, upon further inspection. I found another issue.

The set screw for the motor gear came out, apparently chewed around the motor mount, and spit out.

Luckily I took all of this apart and noticed some marring around the motor mount, and when I turned the gear, the set screw just fell out.....

Shouldn't that grub screw have some threadlocker on it?! I cant believe this just fell out after five packs....

Could this be what caused my drive cups to shear if there is that much play in the gearing? Its a good half inch of play between the output shaft and the gears D shape input. Super loose fit. Makes me also think that with about 1mm, that gear has to be off center. Not sure how much that matters.

View attachment 140604

View attachment 140605

View attachment 140606

Yeah it should be thread locked in there, and it looks like your center diff might be leaking.

 

[D-DUB]

Yeah it should be thread locked in there, and it looks like your center diff might be leaking.

Not a trace of threadlock on that grub screw, granted, its pretty chewed up at this point.

Diff was low on fluid from what I have seen others put in, but when I took it apart, the seals were fine and it didn't appear to be leaking out the side or the output shafts.

There was a ton of grease on the motor gear when I first got it. Like completely covered, and it slung all over the wires and inside of the body after the first run. Was pretty annoying.

 

[slick2500]

Not a trace of threadlock on that grub screw, granted, its pretty chewed up at this point.

Diff was low on fluid from what I have seen others put in, but when I took it apart, the seals were fine and it didn't appear to be leaking out the side or the output shafts.

There was a ton of grease on the motor gear when I first got it. Like completely covered, and it slung all over the wires and inside of the body after the first run. Was pretty annoying.

Production and assembly errors are getting more and more commonplace with everything now days it seems. I worked at a furniture store and the amount of product that came in with manufacturers defects was getting out of hand. I would say a good 10-20% of the stuff had something wrong with it lately.

 

[D-DUB]

Production and assembly errors are getting more and more commonplace with everything now days it seems. I worked at a furniture store and the amount of product that came in with manufacturers defects was getting out of hand. I would say a good 10-20% of the stuff had something wrong with it lately.

Yea I was a aerospace materials manager for 15 years. 5-15% is pretty standard for a company that poorly manages their vendors and does not want to charge the vendor, or eat the cost to do the work to make up for it. Its a simple solution, but still ends up on the customer either in the way of defective product, or increased cost.

Knowing that I cant trust anything on the ARRMA RTR's ill be piecing together kits from now on, or completely going through before I run it.

 

[slick2500]

Yea I was a aerospace materials manager for 15 years. 5-15% is pretty standard for a company that poorly manages their vendors and does not want to charge the vendor, or eat the cost to do the work to make up for it. Its a simple solution, but still ends up on the customer either in the way of defective product, or increased cost.

Knowing that I cant trust anything on the ARRMA RTR's ill be piecing together kits from now on, or completely going through before I run it.

RTR does not mean ready to run, it means ready to rebuild.

 

[D-DUB]

RTR does not mean ready to run, it means ready to rebuild.

That explains it! Haha.

I am use to BNF drones (Bind and Fly) that are good to go until you do something dumb.

I suppose launching something that is supposed to be on the ground into the air is technically in that ballpark...