Spec-R Gear diff review
07-13-2010, 07:21 PM
#286
At the recent MSRA Beat the Heat race in Memphis I ran 100 wt Losi oil in mine and another front runner ran 1000wt Mugen diff oil. This was on 150 ft straight with unlimited esc 17.5's. I ran the diff with the stock innards, but it leaks after a few runs. I gotta get that fixed. I smeared 6636 AE diff grease on the seals and around the outdrives, but it still leaked after the first day of racing. I heard I should try green slime, but I haven't been able to try it yet. It leaks around the outdrives, but not through the pulley/gasket.
. 100 is pretty heavy shock oil
07-14-2010, 02:14 AM
#289
Hi, Can anyone recomend a differant O ring, as im having a little leaking from the outdrive.
07-14-2010, 03:23 AM
#290
Tech Adept
I wouldn't run anything that says WT. It's not a true rating. If I use shock oil or diff oil, it's much better stating its CST value. 100WT can mean anything. I purchased an Atomic 34T version that arrived yesterday. As far as I see it, 1000 - 5000cst is the range that should be used by looking at all the messages.
The big problem with my car on carpet is the 'hooking' into tight corners, where the car pivots way too much off throttle and that was with a recomended ball diff set with zero slip and associated grease. I'm pretty sure now, the problem turned out to be that the diff motion was so free that the car off throttle had too much rotation even with a rock hard front end and a spool, so its not always good to have a super free rear diff. I'm sure the diff needs some resistance, so the car doesn't have too much variation on and off throttle.
The big problem with my car on carpet is the 'hooking' into tight corners, where the car pivots way too much off throttle and that was with a recomended ball diff set with zero slip and associated grease. I'm pretty sure now, the problem turned out to be that the diff motion was so free that the car off throttle had too much rotation even with a rock hard front end and a spool, so its not always good to have a super free rear diff. I'm sure the diff needs some resistance, so the car doesn't have too much variation on and off throttle.
07-14-2010, 04:19 AM
#291
Tech Adept
How much do you guys polish the back of the diff gears? and what grade wet and dry are you using? I've just built mine used 1500 wet and dry put it all together with green slime and filled with 1000cst oil and boy is it tight compared to the standard ball diff.
07-14-2010, 06:16 AM
#292
Tech Adept
I did the same as you. Lightly sanded the back of the gears with 1500grit paper and filled with 1000cst oil. It is tighter than a free ball diff, but it shouldnt be much tighter. What you may have to do is loosen the screws so that they're not very tight, just done up until they lock, as I noticed the screws done up very tight made the gears too tight inside.
07-14-2010, 08:14 AM
#294
Mine is on its way, its for my TRF416X which is my Mod class car, I wonder why do you guys sand the back of the gear diff? Any other tips to bulletproof it? Can somebody also post some pics on which exact area to be sanded?
07-14-2010, 08:59 AM
#296
Tech Adept
07-15-2010, 12:07 AM
#300
Tech Adept
my gear diff set just arrived... unfortunately without any build instructions. Is it available online or can someone post it? appreciated...