Diff oil vs grease

[MattW123]

I am in the process of repairing the front diff on my Losi lst xxl2e. It currently has grease in it. I have 3 questions:

 

1. Should I clean out all the old grease and replace with new grease/oil, or is it fine to leave the old stuff in?

2. Should I use grease or should I use diff oil? 
3. Which grease or oil would you recommend; weight, brand etc?

 

Thanks. 

[Kukynas]

1. Yes

2. oil

3. 50k cst and any brand

 

that’s setup I use in my 3xl-e

[MattW123]

2 hours ago, Kukynas said:

1. Yes

2. oil

3. 50k cst and any brand

 

that’s setup I use in my 3xl-e

Thanks. What’s the best way to clean the grease out? 
 

Just wanted to check if there is anything I should consider in terms of the oil not leaking out? Assume the diffs are similar in yours to mine. 

[Kukynas]

I’m using Aceton based alcohol but pretty much any cleaning alcohol should work, there should be standard rework sealing kit available to buy under LOSA3505 order code

[tomzac66]

Can of De-greaser foam, then spray with WD40 then wash off soapy water and dry, dryings important or the diff oil will turn white as it reacts with any water.

Probably over the top but I have loads of time on my hands.


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[MattW123]

3 hours ago, Kukynas said:

I’m using Aceton based alcohol but pretty much any cleaning alcohol should work, there should be standard rework sealing kit available to buy under LOSA3505 order code

Thanks. Would that def fit the xxl2 do you know?  The part number to include the seal in the exploded view http://www.losi.com/ProdInfo/Files/PartList_PartsExplosion_LST2.pdf shows b3539. 

[Kukynas]

yes according to HH, the old LOSB3539 is discontinued and replaced by the one I posted https://www.horizonhobby.com/product/cars-and-trucks/car-and-truck-accessory/all-surface-parts/front-rear-diff-seal-set-(2):-lst-lst2-aft-mug-mgb-losb3539

[MattW123]

19 minutes ago, Kukynas said:

yes according to HH, the old LOSB3539 is discontinued and replaced by the one I posted https://www.horizonhobby.com/product/cars-and-trucks/car-and-truck-accessory/all-surface-parts/front-rear-diff-seal-set-(2):-lst-lst2-aft-mug-mgb-losb3539

Thanks so much!

[Kukynas]

1 minute ago, MattW123 said:

Thanks so much!

 

no problemo 😉

[ChimChim]

hi, just stumbled across this thread. With regards to diff oil, what weight for front, centre and rear diffs please. I bash ny truck, play on loose rough surfaces, old quarries, sand etc.

 

Thanks for info

Edited November 20, 2020 by ChimChim

[Bajadre]

Depends how much ballooning you get Chim i get a lot of front ballooning on the truggy so use a thick middle 100,000 weight etc when i have my savvy XL think i was running 40,000 front 80,000 middle and 60,000 rear stopped a lot of tyres bursting off on 6s lol  

[ChimChim]

Thanks Bajadre, yeah balooning is annoying. I have just bought some louise ST Pioneer wheels that are belted to stop the balooning. The diff oil weights from research are very subjective.  I want to look after the gears etc,  ive seen people are saying 10k front and centre with 7k rear. Thicker oil to revent balooning as gives power to both wheels, thinner gives more traction to less resisted wheel. 

 

Ive also seen 30k front and centre with rear being 50k.

 

I guess its trial and error. Would you know if the 10k oil front and centre and 7 rear I s too thin for the xxl2e?

 

Thanks for your responce

 

 

[Bajadre]

yeah Chim a lot is trail and error took me a while and a lot of bottles of core rc diff oil to get mine right for the pumptracks we use  the losi is quite a heavy truck like the savvy XL so i would go thicker buddy 👍

some good info in this lot chim seems people tend to use around 20,000 to 40,000 on the xxl2e

https://www.rctech.net/forum/monster-trucks/882974-losi-xxl2-e-27.html

[m4inbrain]

13 hours ago, ChimChim said:

I guess its trial and error. Would you know if the 10k oil front and centre and 7 rear I s too thin for the xxl2e?

 

 

Those numbers are commonly referenced, but they originate in buggies. They don't really apply to big stuff. 

 

Arrma Kratons for example generally run 200-500k in the centre, 70k front, 30k rear. It's not necessarily trial and error, it's about how you want your truck to react to throttle and steering inputs. It's a tool for tuning your truck, with nice side-effects like preventing diff outs (front ballooning) and cooling for the diffs.

 

 

10k in the centre on a monster truck is nowhere near enough though. As mentioned, a Kraton runs anywhere between 200k to 500k, X-Maxxes run up to 20 million (and yes, it's not really liquid anymore). The part in regards to thicker centre fluid making the car more nervous to drive is pointing to wheelies. With the front unloading less, more power goes to the rear = wheelies. 

 

edit: as a side note, i ran 100k/50k/30k in my XXL2e, felt good. But i like wheelies. 

 

 

Edited November 21, 2020 by m4inbrain

[ChimChim]

Thanks for your replies, has helped me. I like wheelies too lol, but may try a non wheelie approach for now.  i have 60k and 30k silicone fluid here already. I will get some 50k and 25k, and play around. 60f 50c 30r see how that goes.