Locking the centre diff vs oil

[CoolRunning]

I know there is a benefit for having a centre diff to unload the front end and stop it rolling over when you're attempting to turn (Yeti) but I've noticed the RR seems to be a bit squirrely off the line and doesn't hook up quite as well as a Yeti with no centre diff.

I don't run on grass or asphalt and try to keep the trucks to dirt only so would I be benefitted going to a centre locker?

I know thick oil would help all round but not give me a solid drive to the front like the Yeti so I'm wondering if the RR would then crawl a tad better and hook up better for dirt usage. I am ok with drifting my trucks around turns etc and it's my preferred style as I'm just having fun and not racing a clock.

What do you guys think?

Any issues with the mod (Ascender locker etc) damaging the centre diff or putting too much stress on the front gearbox etc? I love how tough the truck is stock and want to keep it solid.

 

[CoolRunning]

Ok...I tried oil. I have to say this thing is a MAJOR PITA to pull apart. A Bomber or SCX10 is a cinch in comparison. Huge pain. A Yeti is easier in many ways. IFS sucks. I've owned the RR since the day it was released which is about 10 days off 3 months and I've been meaning to pull the centre and front diffs and grease them because of all the stories about dry diffs and failed bearings etc. My RR had plenty of super sticky, tacky grease in the front and the centre was also fine though it had less. There is no need to grease the RR unless you feel like a night in getting greasy and annoyed at all the BS you have to take apart.

Anyway...the oil which was decently thick didn't really do a great deal (it felt nearly like when it had no oil in it) and I wanted less diff action so I ended up packing both the centre and front with thick grease. All the gears looked new, the bearings all felt fine, there was no slop and nothing needed shimming etc. It's had a lot of miles and many sessions at various BMX tracks. Loads of hours of driving.

Once everything was back together it was noticeably better and you could hear the tighter diff action. The truck tracked straighter and just drove better; it didn't seem to want to just spin out off the line either which I found frustrating. I like it like this and think I want to try locking the centre diff now...anyone know which part it is?

If it wasn't for all the bits, I'd probably lock the front as well to see how it went as with a sensored motor it probably would be pretty awesome as a KOTH bouncer style machine. I think this is what I like particularly. Bouncing and jumping and climbing over stuff and going hard in a straight line. Apart from racing my son drifting around BMX tracks I don't care that much for cornering that hard. The Yeti and RR kind of bugged me how they were so hopeless going over things compared to a SCX10 and Bomber; I feel that I may have an option now for some rock bouncing which is close enough to crawling.

The gears all look beefy and everything looks like it would take some serious power and hopefully the punishment locked diffs would add. The universals and driveshafts are about 3 times the weight of the Axial HD WBs so they should also be decently tough. Everything on the truck is beefy apart from the main/centre gearbox casing but the gearbox is simple compared to the Axial units so maybe this is fine. It hasn't caused any issues thus far anyway.

 

[TheLetterJ]

I used VTR332000 (front locker for a Twin Hammers) to lock the center diff in my BR. I immediatly noticed a few things... the truck will now wheelie, or even backflip if you stay in it on flat ground (3s.) No more "pizza cutter" action of the front tires while trying to accelerate, and it actually goes straight when you punch it instead of pulling left. Maybe the most surprising thing is that my BR actually corners BETTER with the center locked, as I can easily kick the back end out and let it slide vs having to either scrub off your speed before entering the turn, or trying to stick it and flipping over instead. I was surprised that the RR didn't come that way. I have not tried the front diff locked, and likely never will on my BR, but I could see how it could come in handy in some situations for the RR.

 

[CoolRunning]

I've ordered two of the lockers as even with thick grease it still diffs out too much. It's definitely better but still not enough to get over logs or rocks etc where a Bomber would go. I'm going to lock the centre and test it and then the front though I'm not 100% sure about the front as a long term thing. More for experimental reasons as I don't want a locker chewing out the gears because of bulkhead flex. If it doesn't handle 'too badly' and it doesn't start eating gears it'll stay. We'll see anyway but the centre is a definite as I'm over the power going every which way but where there traction is!

 

[84yoda]

I put racers edge diff lock in my center diff today. I haven't run it yet but it feels exactly what I'm looking for. Acts locked up but you can only spin opposite way using tools and even then its still hard/slow to spin. I didn't want to lock my center diff yet and this is probably the closest you can get before locking it. In the front, I got some macks ear plugs thats a soft silicone putty.

 

[CoolRunning]

How did you find locking the front? Any reliability issues?

It's a bit of a bear to tear the centre and front apart so I'm loathe to do it twice...if it's not chewing apart I'll give both a go at the same time.

 

[84yoda]

I haven't pulled the front diff out yet but I'm not locking it. Im going to see how the macks ear plugs feel, it should be softer then what I'm using in the center but that's that I want up front.

 

[CoolRunning]

Update:

It was a waste of time putting thick grease in the centre diff as it leaked out. My lockers came in today and when I pulled the centre diff down, all the grease had squeezed out the inside end where the dogbone holder comes out of the gearbox housing and spider gear area. I had packed it full to the brim, wiped the excess that came out when I bolted it together and slowly drove it around at first. It was obvious where it had come out.

I installed the centre locker and the difference was night and day different. The RR immediately didn't turn quite as well or quite as tightly as before (it could easily turn inside a metre before) and you could hear the front tyre slip a bit on dirt but man did it hook up better.

This is how the RR should have come from the factory. Before, the RR could start heading left off the line then rapidly snap right or just start an uncontrollable pirouette...this could honestly happen at a great variety of speeds and it was far harder work to keep on it compared to the Yeti. I knew it was all down to the centre diff which has added loads more grip and far more predictability. It drifts better and no longer does that silly snap one direction, snap another and then piro thing that was frustrating with the stock slow servo.

It's a bargain mod and well worth a go at only $6. I'll update this thread if I have any reliability issues.

I'm now pondering doing the front as I got two lockers. The handling is not the thing holding me back; rather I don't want to venture down the Baja Rey hole with the front diff chewing itself up due to the extra stress as I've had trouble free motoring so far.

 

[tolofrhr]

Quick question. I have the Baja Rey. Whats the easiest way to gt to the center diff? Take off the chassis plate or remove the body and go in from the top. Neither looks like fun. Oh god so many screws......:x

 

[CoolRunning]

I've tried once by leaving the body on and pulling the roll cage off and once going in through the cage sans body...I am not planning on trying to pull off the cage again if I don't have to as it was not simple or in any way pleasant with the RR. I ended up unscrewing the front part of the body as I couldn't get it off without undoing the front strut brace area and undoing the shocks.

TBBH, the truck is a PITA to pull apart compared to an Axial Truck (SCX10, Bomber, Yeti) and cage removal was no easier than going in from the roof and sides. Leaving the cage on was at times a bit fiddly when undoing the front end and totally dismantling the diff but not so bad that I want the cage off again. Thank god the thing is incredibly tough and very much maintenance free on 2S thus far as I don't enjoy working on it.

I no longer run the body as I found it impossible to clean and it ironically got just as dirty as running no body.

If/when they are released, I will definitely put in a billet front diff simply so I don't need to pull it apart every 3 months even if the plastic bulkhead holds up ok! :ror: