RE: Diff Replacement...Skill Level?
 

Hi, as I'm getting a LST on Saturday:D:D i have been researching a lot on mods and weak spots of the truck. The first mod which i am going to do is the diff cases (before i run the truck) and i am upgrading to silicon oil in the aluminum cases instead.
I am wondering about the same questions which dbmcgee asked and as i am a newbie i don't know what the shim is??
If no trouble, could someone please give me a diagram with the shim circled please!!
Many thanks

RE: Diff Replacement...Skill Level?
 

There is one shim in each diff case, on one of the outdrive bearings. All you need to do is check the gear mesh after you transfer everything to the new cases. If it's not smooth, move the shim to the other side and if that doesn't fix it, remove it entirely. The shim is clearly shown on all the exploded diagrams of the diff's.

RE: Diff Replacement...Skill Level?
 

Hi again, i have had a look in the LST Manual now as ncgrunt suggested. All which i think looks like a shim from how ncgrunt has described it, is a part with the number A6356 (sorry i prepared a large picture showing the differentials but for some reason i couldn't download as a picture[sm=confused.gif])
As you have to change it across to the other side, does it go in between the bearing and another part? (like where it started up at in the instructions, but we have to move it across)
If it is not this part could you please advise me what part it is then? (number or picture would be great)
Cheers

RE: Diff Replacement...Skill Level?
 

Marcy, when you open the diff up to change the case you will not fail to notice a small metal washer like "shim". There is only 1 shim in the diff and as it will be different to everything else inside the diff you will know it's there!;) When you open the diff, seperate both shells carefully removing the top shell upwards, you will then see 2 bearings either side of the diff. Next to one of these bearings will be the shim, take note of what side the shim is on. When you go to reasemble the diff put the shim on the opposite side to where you took it out from and check for gear binding, if you have none good, if you do, take it out altogether and try again until you find the least binding way! I have 1 diff with no shims in and 1 diff with 2 shims in and the gears dont bind at all!!

RE: Diff Replacement...Skill Level?
 

The shim is circled in red. The blue arrow points to where you would place it if it needed to be moved to the other side of the diff.

RE: Diff Replacement...Skill Level?
 

The picture of the diffs makes you think the little red circle seal is on the outdrives outside of the diff. Look carefully, they are on the inside.
Rockman

RE: Diff Replacement...Skill Level?
 

Thanks a lot everyone, you guys are great at explaining stuff!!!!! :D.
I will check the less binding way for both diffs then, thanks MrBill for your advise most appreciated (definitely the bit about how many shims you put each diff)
Also I'm liking the picture Ncgrunt, i thought it was that part and i had a similar picture to you. But at least i definitely know what to do to my diffs now :D:D so thanks a lot Ncgrunt.
All I've got to do now is to decide which oil i'm putting in the diffs (probably something like 50k in rear an 30k in the front, because i heard 50k all round is a bit aggressive).
Do you think 30k (front) and 50k (rear) is a good combo. or not? please advise as i have no experience on oils, and i want a good setup for bashing and racing.
Many thanks

RE: Diff Replacement...Skill Level?
 

Or should i run 3k (front) and 5k (rear)? as i really do not know. Or if there is anything else which other people suggest? but i do not want the oil being to thick as i won't be able to wheelie:(
Many thanks

RE: Diff Replacement...Skill Level?
 

I don't think thick diff oil is going to hurt wheelies. All it will do is lock that diff (or close to it) basically forcing those two wheels to spin together.

Personally I have mine set up with 30k front and 60k rear.

RE: Diff Replacement...Skill Level?
 

Thanks there Ncgrunt, everybody else told me that from other formals, but I as just checking other people's opinion as i do not believe this (what do you expect though, as i have no experience with oils as i never changed the oils in my diffs or springs before, and the fact i am only 14 years old).
So Ncgrunt, how is this setup? can you pull wheelies easily in high or low gear?
Do you think you can do better for what you use your truck for?
Thanks

RE: Diff Replacement...Skill Level?
 

Marcy, it sounds to me like you don't really understand the purpose of the differential. Basically, it's to let the wheels rotate at different speeds while the truck is turning. If you want to know more details, this is a pretty good explanation: http://auto.howstuffworks.com/differential.htm In the LST, the viscosity (thickness) of the diff oil controls how easy it is for the wheels to rotate at different speeds. Thicker oil = more difficult for them to rotate at different speeds, thinner oil = easier to rotate at different speeds.

Like I said, I can't really see diff oil affecting your ability to wheelie if you're using any of the common weights.

I can't really answer the question about the LST wheelies, I'm just on breakin with mine. Most people here have said though that it's very eager to wheelie.

RE: Diff Replacement...Skill Level?
 

Numwiz..Regarding the gaskets for the differentials from Mugen. How do you order these? Do you ask for diff gaskets for the Losi LST or what? Thanks DBM ;)

RE: Diff Replacement...Skill Level?
 

Hi there Ncgrunt, yes you were right about not knowing how a differently works (only had a vague idea about how the power is transfered to the wheels) but thanks to you i know a lot more:D (I like knowing more about how my car works). You are very good at explaining things!!!
Thats what i like to hear, a LST Wheeling[>:], with whatever oil you use
I shall use your set up you advised me as you know your stuff and is obviously a professional, so I'm not going to argue with that LoL.
That is about the end to all my questions about the diffs. Thanks to all you guys especially Ncgrunt!!!, i will have no problems with changing the diffs.
Thanks a lot, you guys are da best!!! LMAO

RE: Diff Replacement...Skill Level?
 

is this one will fit the LST diff case ? [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&W=000591233&I=LXNJ07&P=K]Mugen diff gasket[/link]

RE: Diff Replacement...Skill Level?
 

Not sure if there the ones or not,But I have Changed the Diff Oil a few times without changing the Gaskets with No leaks, (just be Carefull when your changing them)

RE: Diff Replacement...Skill Level?
 

Thanks. I just want to know since I am gonna make an order to tower soon and would want to have some extra gaskets just in case.

RE: Diff Replacement...Skill Level?
 

How important is it to get all the grease out of the dif before going to Silicone diff oil? ;)

RE: Diff Replacement...Skill Level?
 

I just finished replacing my stock diffs with the alumies and I'm now having that harsh gear meshing problem, all I did was open up the only case, take out what was in it put it in the new case exactly how it was in the old case and then seal up the old case, now when I turn the shaft it seems like its binding or grinding, but when I take it apart to look at it, the gear mesh is perfect???

I didn't think this job was difficult at all to do, but now that I don't have smooth turning its turning into a pain in the butt. I opened the old diff case and did not notice any shims, just the bevel gears and bearings. and some grease.

Any help would be great

The Bird Man

RE: Diff Replacement...Skill Level?
 

I moved the shim to the other side as stated above and it improved turning the shaft smoothly immensely. Although it is turning smoother now, there is still some binding when turning the shaft, will removing the shim completely hurt the setup in anyway?

Also since the diffs are so easy to get at, do you recommend using grease or silicone oil? and what weight oil do you recommend?

RE: Diff Replacement...Skill Level?
 

Great! I just removed the shim completely from the rear diff and she's smooth turn now. HOT..
Now I just have to redo the front diff :D

Woot

Thanks Guys

RE: Diff Replacement...Skill Level?
 

I read where some people run different silicone oils in the front & back, you know 30wt in front 50wt in rear or something like that.Why two different weights ? :eek:[:o]

RE: Diff Replacement...Skill Level?
 

You use different weights to make the diffs slip more. The thicker the oil the more the Wheels hook up together, the thinner the oil the wheels will act more independantly. It's user choice, I have 50-50 in mine. If you ask someone that races he might use different weight oils to help with steering etc..

RE: Diff Replacement...Skill Level?
 

MrBillUp.....Thanks very much. DBM :D:D

RE: Diff Replacement...Skill Level?
 

Be sure you're getting 30k, that is 30,000 weight oil. 30 & 50wt (shock oils) are waaaay to light for these diffs.

RE: Diff Replacement...Skill Level?
 

I am running 100k silicone in the rear and 50k in the front of my LST. This way if I am climbing my rear wheels are less likely to spin as easy. Where as in the front when you climb you would want the wheels to turn easier for grabbing.
If you reverse the situation and put heavier in the front and lighter in the rear, your front end will pull you through turns better. Well for all wheel drive anyway. They do that in the sedans.