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-   -   Diff upgrade???? (https://www.rcuniverse.com/forum/hpi-monster-truck-forum-250/3993623-diff-upgrade.html)

Prospeed 03-05-2006 10:11 AM

Diff upgrade????
 
Does anyone know if there is any other differentials that can be used to replace the garbage from HPI. I have an OS 30 in my savage and it consistenly strips either the bevel gears inside the diff or the main gear outside the diff or pinion gear. Please let me know if a diff from a Mugen will fit. Thanks

Dawman 03-05-2006 12:22 PM

RE: Diff upgrade????
 
Do you have the diff upgrade ?

Chronic 03-05-2006 01:20 PM

RE: Diff upgrade????
 
If you don't already have the four gear diffs, do that right away. I'm not aware of a whole diff that can be substituted. I think guys were using Kyosho spider gears until HPI released their four gear version, so they might be a little better. Most of the time, shimming the diff assembly to get a better gear mesh will solve the problem. Mine have held up pretty good without having to shim, but I know people who had to in order to solve breakage issues.

JayC1968 03-05-2006 01:25 PM

RE: Diff upgrade????
 
I saw somewhere on ebay a 8spyder gear diif. I'm not sure where, but the dude has a store and says it will work with the savage. I think it may have been a buggy diff. I do know they were pricey... around $89 per diff I think

Dawman 03-05-2006 01:34 PM

RE: Diff upgrade????
 
ya the spider diff is a buggy diff and that would be the best if it fits . In my savages I use Ofna shafts before HPI came out with the 4 gear.

azzman 03-06-2006 03:21 AM

RE: Diff upgrade????
 
For indistructable diffs:
[link=http://cgi.ebay.com/HPI-Savage-Alloy-Diff-Cup-Case-Housing-4-6-21-25-SS_W0QQitemZ6040893389QQcategoryZ34063QQtcZphotoQQ cmdZViewItem]Get these diff cups[/link]

along with [link=http://www.lightninghobby.com/kyosho_differential_bevel_set_67593_prd1.htm]THESE BEVEL GEARS[/link]

And you may need to shim it with the shims second from the left [link=http://www.lightninghobby.com/kyosho_shim_set_n_67550_prd1.htm]HERE[/link]

Not sure where you can buy those shims by themselves tho.

crop 03-06-2006 03:55 AM

RE: Diff upgrade????
 
no offense, but why kyosho gears? as i heard they are aluminium and very soft, wears faster than steel gears which has been proven by my own experience. if the 30 engine can strip those steel hpi gears it can destroy kyosho gears sooner.

boydie1 03-06-2006 04:43 AM

RE: Diff upgrade????
 
I'm using FLM diff cups, 4 spider bevel gears and GPM alloy diff housings on both my savages and haven't had any problems with my diffs since.
This combo seems to stop all the flex/wear you get in the diffs with the larger engines

double_down 03-21-2006 08:31 PM

RE: Diff upgrade????
 
Is this a pinion gear? http://www2.towerhobbies.com/cgi-bin...&I=LXDLD3&P=ML
I keep stripping this part too. Changed it twice already and it seems like i strip it whenever i do a nose dive off a medium to big jump. Is there anything to keep that from stripping?

cardriverx 03-21-2006 09:00 PM

RE: Diff upgrade????
 
proper shimming is one of the best ways to protect the diffs, and other than that you can get alu. diff cases (i have the GH ones), 4 bevel gear convertion, and some silicone diff oil (it seems a thicker oil helps in my experence).

ozpall 03-21-2006 11:15 PM

RE: Diff upgrade????
 
dont use kyosho gears as they strip faster, the material is too soft. they work and im using them right now but only becasue my LHS had a bunch for like 2 bucks so i bought them but they dont last as long.
get the aluminum diff cases and it should hold up, at least longer than stock.
is not that HPI is garbage like you said, is that they made this stuff to run with their engine not a 30 or 32 like we are doing. if you run such a big motor you better expect to have some carnage.

guitar 03-26-2006 05:01 PM

RE: Diff upgrade????
 
DOES ANYONE MAKE A POSI TRACKTION DIFF

Chronic 03-26-2006 05:18 PM

RE: Diff upgrade????
 
Posi-Traction is a fancy trademarked(GM) name for a limited slip differential. You can get limited slip action by putting heavier oil in the diffs.

I think you are asking about locking the rear axle. Where both axle shafts are essentially locked together. They call them diff lockers, but they are actually like mini'spools for 1:1 cars. A rear differential locker has a locking and unlocking action, where these are always locked, or "spooled" together.


As far as the Kyosho gears, I really know nothing about it. I was just repeating something that I heard at the LHS. This is my first Savage and it came with the four gear setup, so all I've done is rebuilt it back to factory a couple of times.

guitar 03-26-2006 06:11 PM

RE: Diff upgrade????
 
I AM SORRY WHAT I MEANT IS MORE LIKE THE DETRIOT LOCKERS .

Dawman 03-26-2006 06:18 PM

RE: Diff upgrade????
 
yes they make a locker for the diff

Chronic 03-26-2006 06:20 PM

RE: Diff upgrade????
 
Then No, there aren't any actual lockers on the market that I know of. It's either fully 100% locked all of the time, or your other choice is to taylor the diff action for your intentions with thicker oil. Actually, something like 300k diff oil gives results similar to locking it, but will still allow diff action under extreme conditions.....which can lead to less broken parts.

Chronic 03-26-2006 06:21 PM

RE: Diff upgrade????
 
Dawman, who makes an actual locker for the Savage?

guitar 03-26-2006 06:27 PM

RE: Diff upgrade????
 
THE FIRST 8TH SCALE MT BY KYOSHO CALLED THE USA-1 HAD 3 LIMITED SLIP DIFFS FRONT BACK AND CENTER WHERE THE GEAR REDUCTION WAS BUT THEY HAD A SET SCREW THAT YOU COULD TIGHTEN DOWN ON A FLAT ON ONE OF THE GEARS AND IT WOULD LOCK THE WHOLE DIFF DOWN .

Dawman 03-26-2006 06:48 PM

RE: Diff upgrade????
 


ORIGINAL: Chronic

Dawman, who makes an actual locker for the Savage?
Maximizer makes one and I have one laying around but can`t remember who made it.

Chronic 03-26-2006 06:59 PM

RE: Diff upgrade????
 
A locker, like the Detroit for 1:1 cars, locks the axle shafts together under power, but unlock when no power is sent to the diff. That unlocking allows for tighter turning when you aren't feeding it gas. When you're pulling the trigger it would lock the shafts, but when you released the trigger it would behave like an open diff. The "lockers" that are on the market lock the shafts all of the time like a spool would in a 1:1 car. The term "locker" is a little misleading to someone who is used to the terminology surrounding 1:1 vehicles as it's different than a locker for a real car, but it does lock the diff, so it fits the application I guess.....

guitar 03-26-2006 07:00 PM

RE: Diff upgrade????
 
THANK YOU FOR THE INFO . JOHN

Dawman 03-26-2006 07:04 PM

RE: Diff upgrade????
 


ORIGINAL: Chronic

A locker, like the Detroit for 1:1 cars, locks the axle shafts together under power, but unlock when no power is sent to the diff. That unlocking allows for tighter turning when you aren't feeding it gas. When you're pulling the trigger it would lock the shafts, but when you released the trigger it would behave like an open diff. The "lockers" that are on the market lock the shafts all of the time like a spool would in a 1:1 car. The term "locker" is a little misleading to someone who is used to the terminology surrounding 1:1 vehicles as it's different than a locker for a real car, but it does lock the diff, so it fits the application I guess.....
Well , the manufactures call them lockers , they lock the diffs .

jcam54 03-26-2006 09:05 PM

RE: Diff upgrade????
 
Hey man read your thread and found these later while looking for a new spur gear hope this is what you were looking for.

http://store.savagess.com/product_in...49d38f8ec19313

Dawman 03-26-2006 09:15 PM

RE: Diff upgrade????
 
Thats like the one that I have .


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