Bad rear hub design….

[JJay18]

Just noticed this when replacing my rear bearings. Its the same with the stock hubs too. The slots in the stub axle go past the bearing allowing dirt inside the hub. My rear bearings were really gritty because of this. All other bearings were fine. Picture should show what I am talking about. Anyone come up with a good fix for this? What about a rubber insert like the diff cups have?

 

[SrC]

Good observation.
And this has been discussed here years back. The dirt that builds up can wear out the inner hub BB's fast. Even much faster with the smaller OE sized BB's/hubs.
Many went to using Rear CVD's. (using the front axles/bones) I did this with several of my Off road rigs. Using the EXB Rubber spacers won't really help IMHO. They belong only at the rear diff's output cups. Using the rubber spacers at the hubs can even bind up the axels. There needs to be a tick of end play with these rear axels, along the whole suspension travel. If using the Front CVD's at the rear, remove the Rubber spacer at the Output cups altogether. Notice there are no EXB rubber spacers at the front diff output cups. Because the front runs CVD's.
Just try to keep the Hub axels clean of any dirt build up. This helps greatly.


Edited.....

 

[JJay18]

Good observation.
And this has been discussed here years back. The dirt that builds up can wear out the inner hub BB's fast. Even much faster with the smaller OE sized BB's/hubs.
Many went to using Rear CVD's. (using the front axles/bones) I did this with several of my Off road rigs. Using the EXB Rubber spacers won't really help IMHO. They belong only at the rear diff's output cups. Using the rubber spacers at the hubs can even bind up the axels. There needs to be a tick of end play with these rear axels, along the whole suspension travel.
Just try to keep the Hub axels clean of any dirt build up. This helps greatly.

I like that idea of the front axles on the rear.

 

[JvG]

Yep, it’s a stupid design.
Been a few years ago but here you go:

https://www.arrmaforum.com/threads/bearings-mayhem.5415/

 

[slick2500]

Yep, it’s a stupid design.
Been a few years ago but here you go:

https://www.arrmaforum.com/threads/bearings-mayhem.5415/

I was literally just going to post this.

 

[JvG]

I was literally just going to post this.

Too bad they still haven’t redesigned that part.
And the Team Durango cups do not fit on the EXB diffs so i had to drill them out which is a pita to do….

 

[JJay18]

I ordered an axle kit from JRC. Comes with the rears as well but still cheaper than ordering the front parts individually.

Too bad they still haven’t redesigned that part.
And the Team Durango cups do not fit on the EXB diffs so i had to drill them out which is a pita to do….

I know! I am new to Arrma but these vehicles have been out awhile now. They are still running the weak ass rear wing mount setup as well. Thankfully RPM just came out with an awesome design.

 

[SrC]

3dRC makes good wing mounts. Many here use them with best results.
If you choose to use Nylon RPM mounts, boil them in water for a few minutes. makes the Nylon more flexible.
As you get better driving skills, you will break W. Mounts less. They are sacrificial parts, that protect the rear shock tower and bulkhead , IMHO.

 

[JJay18]

3dRC makes good wing mounts. Many here use them with best results.
If you choose to use Nylon RPM mounts, boil them in water for a few minutes. makes the Nylon more flexible.
As you get better driving skills, you will break W. Mounts less. They are sacrificial parts, that protect the rear shock tower and bulkhead , IMHO.

I appreciate your advice and experience but I like something which attaches to the chassis brace to be as strong as possible without breaking. The 3DRC mount is too flexible IMO. You can barely tighten down the bolts even because the nuts spin inside the 3drc mount. The updated HD RPM mount system is very strong and triangulates the wing mount. This will add even more strength to the chassis and should not allow the bolts to break or bend. JM2C

 

[slick2500]

I appreciate your advice and experience but I like something which attaches to the chassis brace to be as strong as possible without breaking. The 3DRC mount is too flexible IMO. You can barely tighten down the bolts even because the nuts spin inside the 3drc mount. The updated HD RPM mount system is very strong and triangulates the wing mount. This will add even more strength to the chassis and should not allow the bolts to break or bend. JM2C

View attachment 239892

In theory yes, but the wing mount is still only attached to the shock tower via 2 screws and that will continue to be the weak point. This is the biggest weakness of the Arrma wing mount design, there really should be 4 screws attaching it to the shock tower and not 2. Also while were are on the subject the rear chassis brace should also use 2 screws going into the chassis not just 1.

 

[JJay18]

In theory yes, but the wing mount is still only attached to the shock tower via 2 screws and that will continue to be the weak point. This is the biggest weakness of the Arrma wing mount design, there really should be 4 screws attaching it to the shock tower and not 2. Also while were are on the subject the rear chassis brace should also use 2 screws going into the chassis not just 1.

I think they should at least be m4 bolts instead of m3 and have nuts on the end like the chassis brace uses. I just think this design is the best available so far till Arrma decides to update their design. I like the extra protection the skid plate provides and the back of the RC feels really solid now.

 

[slick2500]

I think they should at least be m4 bolts instead of m3 and have nuts on the end like the chassis brace uses. I just think this design is the best available so far till Arrma decides to update their design. I like the extra protection the skid plate provides and the back of the RC feels really solid now.

Oh yeah, they should at the very least be M4.

 

[JJay18]

I got the front axles in the rear now and they seem to fit ok. If anything they could be a hair shorter.

 

[JJay18]

Well they definitely appear to be binding some. This car is starting to get really annoying. Ive barely driven it since I bought it because ive been fixing small issues here and there. Good news is that the steering is great now lol. I could try the stock diff cups but that means pulling and working on the diff for the 10th time.