Big Rock Steel Diff update

[Eno]

Im bummed that I couldnt use the Hot Racing red aluminum diff carrier I bought, as when I mock assembled it the new input shaft /new bearings were actually a little sloppy and not in a way i could shim out.

Same here! Those HR yokes are terrible. So much slop it is ridiculous!

 

[car_006]

Hey bro, yep the steel diff is still holding up sweet as in the Typhon. I can fully recommend it.

Link to steel diff https://www.ebay.com/itm/Arrma-3110...2349624.m46890.l49286&mkrid=711-127632-2357-0
It's completely plug and play. I wish I had one for my Senton as well.

Ok, cool. Thank you. Would it be possible to buy the separate parts and put it together with the old internals?
https://www.arrma-rc.com/part/AR310772
https://www.arrma-rc.com/part/AR310885
https://www.arrma-rc.com/part/AR310886
With these parts. And then instead of the stock diff yoke, using the hot racing part?
https://www.ebay.com/itm/265021531119?epid=27027469575&hash=item3db483a3ef:g:2RIAAOSw8SFgCJbV
Thank you for the help

 

[Eno]

Would it be possible to buy the separate parts and put it together with the old internals?

Yes, that's what I did.

And then instead of the stock diff yoke, using the hot racing part?

No, the HR yokes are crap.

 

[GRC]

Hmm, the Hot Racing yokes fit perfectly with the stock differentials. I don't have the steel diffs, so I don't know if there's any difference.

 

[SrC]

Ah man that sucks balls. Hope you can get it sorted. I wish they would put more diff fluid in at the factory.

Yeah that's an understatement.

 

[car_006]

Yes, that's what I did.



No, the HR yokes are crap.

Ok, I wasn't sure. Thanks, so you run the stock yokes with no problem? And are the exb parts that everyone talks about, just the arrma metal parts? Thanks

 

[parcou]

Same here! Those HR yokes are terrible. So much slop it is ridiculous!

Hmm...I know we can get bad parts at times, but the HR red yoke has been spot on in my BR BLX. I would advise shimming it on the crown side when you install it. Once you put the HR yoke back on you cannot see the mesh to the input but you can feel and hear it if you compare it to stock. After a little shimming to get a better mesh, you will have a great diff with no slop. Then you can tighten the two screws tight (use TL) to hold the yoke which you cannot do on the stock plastic yoke.

They have been spot on....so much so it was not needed I added one to the front for the look of the red

Ok, I wasn't sure. Thanks, so you run the stock yokes with no problem? And are the exb parts that everyone talks about, just the arrma metal parts? Thanks

So you have two flavors and I ran both:

#1
Keeping the stock BR diff, input, etc but use the HR yoke. Please shim it to make sure the crown and the input have a good mesh. It lasts well but is better than the stock plastic yoke that flexes under bashing. You will get a longer life out of your input gear...far more than you will with stock for a $30 HR yoke change.

#2
If you are a real die heart basher, you can still kill your input and spur with an HR yoke...some could be user error landing on power from jumps, big ass heavy tires, etc. I would be the second. #1 was good until I added Trencher belted tires to my BR...heavy tires. So I did change to the Arrma metal diff (rear only) that comes with the metal input. Not always needed but I will still add the HR yoke to keep it all metal vs plastic with this setup. This solved my problem using the heavy-ass belted tires. If I did not do the tires, I would have been cool with #1

Sometimes....we break the equation not the rig
Enjoy

 

[car_006]

Hmm...I know we can get bad parts at times, but the HR red yoke has been spot on in my BR BLX. I would advise shimming it on the crown side when you install it. Once you put the HR yoke back on you cannot see the mesh to the input but you can feel and hear it if you compare it to stock. After a little shimming to get a better mesh, you will have a great diff with no slop. Then you can tighten the two screws tight (use TL) to hold the yoke which you cannot do on the stock plastic yoke.

They have been spot on....so much so it was not needed I added one to the front for the look of the red


So you have two flavors and I ran both:

#1
Keeping the stock BR diff, input, etc but use the HR yoke. Please shim it to make sure the crown and the input have a good mesh. It lasts well but is better than the stock plastic yoke that flexes under bashing. You will get a longer life out of your input gear...far more than you will with stock for a $30 HR yoke change.

#2
If you are a real die heart basher, you can still kill your input and spur with an HR yoke...some could be user error landing on power from jumps, big ass heavy tires, etc. I would be the second. #1 was good until I added Trencher belted tires to my BR...heavy tires. So I did change to the Arrma metal diff (rear only) that comes with the metal input. Not always needed but I will still add the HR yoke to keep it all metal vs plastic with this setup. This solved my problem using the heavy-ass belted tires. If I did not do the tires, I would have been cool with #1

Sometimes....we break the equation not the rig
Enjoy

Cool, thank you for all the help. I think I am going to go with 2 in hope for longevity and hard bashing. Sometimes I have rough landings, too

 

[parcou]

Cool, thank you for all the help. I think I am going to go with 2 in hope for longevity and hard bashing. Sometimes I have rough landings, too

It's a cost the CNC Metal diff/crown with the metal input will last. Keep in mind that I do not want anyone to speed money they do not need. The HR yoke can work if landing without power and just getting better as an RC'er...the HR yoke is a cheap FIRST step. If you do #2, still shim it so you have a good mesh. For example, Arrma diff comes assembled and ready to drop if. I still took mine apart and added a shim or two. Like my Infraction and Kraton with metal gears, I did not have the sound of feel to be certain the mesh was SOLID. After adding the shim, it has a deep gear mesh sound, with still good spin but the mesh was sure to never slip!

We are here when you get to that point and have questions....

 

[morrjr71]

Same here! Those HR yokes are terrible. So much slop it is ridiculous!

I didn't have that issue at all: mine were not sloppy and had near perfect gear mesh.

 

[car_006]

It's a cost the CNC Metal diff/crown with the metal input will last. Keep in mind that I do not want anyone to speed money they do not need. The HR yoke can work if landing without power and just getting better as an RC'er...the HR yoke is a cheap FIRST step. If you do #2, still shim it so you have a good mesh. For example, Arrma diff comes assembled and ready to drop if. I still took mine apart and added a shim or two. Like my Infraction and Kraton with metal gears, I did not have the sound of feel to be certain the mesh was SOLID. After adding the shim, it has a deep gear mesh sound, with still good spin but the mesh was sure to never slip!

We are here when you get to that point and have questions....

so I think I am going to go with the arrma metal diff and the hot racing yoke. I then need the diff case, the ring gear, the input gear and the yoke. will I need shims or anything else? I would like to just upgrade it to hopefully prevent the purchasing of any more diffs and the truck being down.

 

[morrjr71]

It's a cost the CNC Metal diff/crown with the metal input will last. Keep in mind that I do not want anyone to speed money they do not need. The HR yoke can work if landing without power and just getting better as an RC'er...the HR yoke is a cheap FIRST step. If you do #2, still shim it so you have a good mesh. For example, Arrma diff comes assembled and ready to drop if. I still took mine apart and added a shim or two. Like my Infraction and Kraton with metal gears, I did not have the sound of feel to be certain the mesh was SOLID. After adding the shim, it has a deep gear mesh sound, with still good spin but the mesh was sure to never slip!

We are here when you get to that point and have questions....

I didn't need any shims on the CNC steel diffs I recently put in my Typhon 3s. I carefully checked them before installing them, and the gear mess was smooth as glass with absolutely no play of any kind and nothing was too tight. I was pleasantly surprised at how well they came from the factory.

 

[parcou]

so I think I am going to go with the arrma metal diff and the hot racing yoke. I then need the diff case, the ring gear, the input gear and the yoke. will I need shims or anything else? I would like to just upgrade it to hopefully prevent the purchasing of any more diffs and the truck being down.

Yes if you go that way... 3 items

https://www.amainhobbies.com/arrma-...ssion-module-set-ara311072/p-qqqctqtqyzzcqctz

And yoke
https://www.amazon.com/gp/product/B07MPZCTK2/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

And shims (test it first) shimming is different for each RC
https://www.amainhobbies.com/arrma-washer-4-12x15.5x0.2mm-ara709052/p707217

I didn't need any shims on the CNC steel diffs I recently put in my Typhon 3s. I carefully checked them before installing them, and the gear mess was smooth as glass with absolutely no play of any kind and nothing was too tight. I was pleasantly surprised at how well they came from the factory.

@car_006 It comes ready to go so like Morrjr said you might not or no need to shim. For me....again me, my dif spun like a ten-speed on freewheel...I did not like that. I wanted more mesh and bite since my 6S metal diff gears did not spin like that in a forever spin. Could have been my purchase....they all are different.

So Car I do not want to frighten you shimming may not be needed. I have come from an experience that shimming has been bad on some Arrma rigs and I prefer to have a PHD in shimming and check my own and adjust.

Will it work out the box, damn right it will. I just like to get a little more fine-tuned....you do not. But as you get into this hobby, you will want to learn and get a feel for mesh, shimming, etc. I've had too many bad experiences I just cannot ignore it. So just sharing my point of view....not law here it is drop and play when you get the diff so go for it

Keep us updated!

 

[car_006]

Yes if you go that way... 3 items

https://www.amainhobbies.com/arrma-3s-blx-mega-front-rear-transmission-module-set-ara311072/p1335206?utm_source=transactional_email&utm_medium=e-mail&utm_campaign=order_complete&utm_cid=4109717&utm_content=/arrma-3s-blx-mega-front-rear-transmission-module-set-ara311072/p-qqqctqtqyzzcqctz

And yoke
https://www.amazon.com/gp/product/B07MPZCTK2/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

And shims (test it first) shimming is different for each RC
https://www.amainhobbies.com/arrma-washer-4-12x15.5x0.2mm-ara709052/p707217

@car_006 It comes ready to go so like Morrjr said you might not or no need to shim. For me....again me, my dif spun like a ten-speed on freewheel...I did not like that. I wanted more mesh and bite since my 6S metal diff gears did not spin like that in a forever spin. Could have been my purchase....they all are different.

So Car I do not want to frighten you shimming may not be needed. I have come from an experience that shimming has been bad on some Arrma rigs and I prefer to have a PHD in shimming and check my own and adjust.

Will it work out the box, damn right it will. I just like to get a little more fine-tuned....you do not. But as you get into this hobby, you will want to learn and get a feel for mesh, shimming, etc. I've had too many bad experiences I just cannot ignore it. So just sharing my point of view....not law here it is drop and play when you get the diff so go for it

Keep us updated!

Cool, I will thank you so much for the help!

 

[car_006]

So I ordered the steel diff crown gear, the steel input, the diff case, and the hot racing yoke. They should be here Friday so I will let you guys know how it works out.

 

[mxfan69]

So its great some have had good luck with the combination of the full exb diff set put into a Hot Racing carrier but some of us have not. And its not from a lack of proper shimming, its from bad tolerance interactions between the two branded parts. The stock plastic arrma diffs fit well in the HR yoke, the exb diff fit fine in the stock plastic yoke. The issue is in the exb’s input shaft and the machining on the HR yoke. I’ll take picture and post at some point, but its not a “shim’able” issue, its laterally sloppy, and stacking shims just pushes the exb input shaft further away (inbound) from the HR yoke’s bear seat and makes the lateral movement worse.

 

[Velodromed]

So its great some have had good luck with the combination of the full exb diff set put into a Hot Racing carrier but some of us have not. And its not from a lack of proper shimming, its from bad tolerance interactions between the two branded parts. The stock plastic arrma diffs fit well in the HR yoke, the exb diff fit fine in the stock plastic yoke. The issue is in the exb’s input shaft and the machining on the HR yoke. I’ll take picture and post at some point, but its not a “shim’able” issue, its laterally sloppy, and stacking shims just pushes the exb input shaft further away (inbound) from the HR yoke’s bear seat and makes the lateral movement worse.

Well if that’s the case then I’ll just run the metal diff in the stock plastic yolk. I only got the HR metal yokes to help preserve the stock diff with its plastic ring and input. Actually…this may be the way to go as it will also cut some of the weight gained from the metal ring and input. I’ll keep the HR yokes for my other cars with stock diffs.

This post helped motivate me to take the plunge lol. Parts will be here in a week

 

[mxfan69]

Well if that’s the case then I’ll just run the metal diff in the stock plastic yolk. I only got the HR metal yokes to help preserve the stock diff with its plastic ring and input. Actually…this may be the way to go as it will also cut some of the weight gained from the metal ring and input. I’ll keep the HR yokes for my other cars with stock diffs.

This post helped motivate me to take the plunge lol. Parts will be here in a week

EXACTLY what I ended up doing. My little road basher has the HR red yoke with a plastic/plastic stock Arrma diff and my Big Rock that was 6s for a while has the EXB diff parts in a stock Arrma plastic yoke. And as a testimony to the later, has held up just fine to 6s power. Now for other issues the 6s power caused, thats a whole diff’erent (pun intended) conversation lol

 

[Velodromed]

EXACTLY what I ended up doing. My little road basher has the HR red yoke with a plastic/plastic stock Arrma diff and my Big Rock that was 6s for a while has the EXB diff parts in a stock Arrma plastic yoke. And as a testimony to the later, has held up just fine to 6s power. Now for other issues the 6s power caused, thats a whole diff’erent (pun intended) conversation lol

That’s good to hear and helps. Thanks!

 

[car_006]

So I built and installed my exb diff yesterday with the hot racing yoke. Everything fit perfectly, no shims, and the mesh was perfect. There was no movement at all. I will be running it when I get my new shock tower and I have a chance. I will let you all know how that goes. By the way, I used 100 weight oil for the front diff, I will also let you know how that feels.