1LikesMugen MBX7
07-13-2013, 07:45 AM
#5146
Just though ill share my findings after i thought ill go on a mission to free up my x7's drivetrain as much as possible lol. Sorry for the long winded post.
Well the difference is huge..even on the bench. I did some research in the onroad forums on how those guys mod their cars to free them up even more. So here is what i did and why.
1: even if you dont want to do the rest, just plain remove the rubber cvd boots from the centre shaft. They put so much tension on the centre shafts..youll get your drivetrain almost twice as free by just removing them. The problem is easy to spot. When you car is apart and the boot on the shaft, the shaft naturally wants to stay straight. Because they are at an angke when fixed to the chassis, they push into the sides of the centre cups and produce friction. Easy fix..throw them away!
2: this is one i found alot of onroad guys experiment with and makes alot of sense. Take your inner wheel bearing and press it between your two fingers. Look at how much it deforms/deflects. So...if you've driven a JQ you'll know exacly about the next issue.
When the plastics are moulded and cooled, it shrinks a minute amount. On the jq you had to ream the arms and stuff forever since they will just bind up. Anyway, that "snap" you feel when you force a bearing into a wheelhub can sometime press down/crush a bearing just enough to cause some drag. So what some of these guys do is, sand or dremmel the seating area of the hub where the bearings go just a hair at the time untill the bearing goes in VERY smoothly, but the hub stil holds on to the outer ring of the bearing. It should just barely hang on in there under its own weight when you turn it upside down. This wont be an issue if you run AL hubs since the tolerances will be way tighter on cnc parts. DONT OVER DO IT, if you do your bearing will spin in the plastic of the hub. They should still go in snug, just not tight or snap in. I did this on all 4 hubs, inside and outside, as well as to a lesser extent, the cenre pinion areas.
3: take your bearings, clean them of all grease, blow them out. Get them super clean and spinning like skateboard wheels lol. All that grease in there just slows them up. Now, once they are super clean, lube them all in some full sunthetic, mobil 1 or similar 5W40 or thinner oil and let the excess drain on some toilet paper. You will feel how much more free they are already.
4: now start reassembling your car. Install ONLY the outer bearing seal on every single bearing..the one that is exposed to dirt so to speak. Smaller ones usually dont have a preference, but i put the seal in and feel which side lets the bearing work more freely. On the large inner hub bearings it is easier, install the seal on the side with the metal part behind the balls..youll see it.
This all made my car so free it is silly compared to stock. Worth a try if you are interested in freeing up your drivetrain. Im sure if one spends some money on lighter drivetrain parts in conjunction with this, it would be insane lol. A free drivetrain means more consistent handeling, better runtime, cooler engines etc.
anyway, thought ill put it out there for the modders out there lol
Well the difference is huge..even on the bench. I did some research in the onroad forums on how those guys mod their cars to free them up even more. So here is what i did and why.
1: even if you dont want to do the rest, just plain remove the rubber cvd boots from the centre shaft. They put so much tension on the centre shafts..youll get your drivetrain almost twice as free by just removing them. The problem is easy to spot. When you car is apart and the boot on the shaft, the shaft naturally wants to stay straight. Because they are at an angke when fixed to the chassis, they push into the sides of the centre cups and produce friction. Easy fix..throw them away!
2: this is one i found alot of onroad guys experiment with and makes alot of sense. Take your inner wheel bearing and press it between your two fingers. Look at how much it deforms/deflects. So...if you've driven a JQ you'll know exacly about the next issue.
When the plastics are moulded and cooled, it shrinks a minute amount. On the jq you had to ream the arms and stuff forever since they will just bind up. Anyway, that "snap" you feel when you force a bearing into a wheelhub can sometime press down/crush a bearing just enough to cause some drag. So what some of these guys do is, sand or dremmel the seating area of the hub where the bearings go just a hair at the time untill the bearing goes in VERY smoothly, but the hub stil holds on to the outer ring of the bearing. It should just barely hang on in there under its own weight when you turn it upside down. This wont be an issue if you run AL hubs since the tolerances will be way tighter on cnc parts. DONT OVER DO IT, if you do your bearing will spin in the plastic of the hub. They should still go in snug, just not tight or snap in. I did this on all 4 hubs, inside and outside, as well as to a lesser extent, the cenre pinion areas.
3: take your bearings, clean them of all grease, blow them out. Get them super clean and spinning like skateboard wheels lol. All that grease in there just slows them up. Now, once they are super clean, lube them all in some full sunthetic, mobil 1 or similar 5W40 or thinner oil and let the excess drain on some toilet paper. You will feel how much more free they are already.
4: now start reassembling your car. Install ONLY the outer bearing seal on every single bearing..the one that is exposed to dirt so to speak. Smaller ones usually dont have a preference, but i put the seal in and feel which side lets the bearing work more freely. On the large inner hub bearings it is easier, install the seal on the side with the metal part behind the balls..youll see it.
This all made my car so free it is silly compared to stock. Worth a try if you are interested in freeing up your drivetrain. Im sure if one spends some money on lighter drivetrain parts in conjunction with this, it would be insane lol. A free drivetrain means more consistent handeling, better runtime, cooler engines etc.
anyway, thought ill put it out there for the modders out there lol
07-13-2013, 08:37 AM
#5147
Tech Addict
iTrader: (19)
I took the boot covers off the shafts and they do help free it up very much. I would not remove the bearing covers, even if inside. I know bearings are cheap these days, but I wouldn't want to DNF because of a $1 bearing. These engines are powerful enough that will will probably not see much of a difference in speed and runtime.
07-13-2013, 08:41 AM
#5148
I took the boot covers off the shafts and they do help free it up very much. I would not remove the bearing covers, even if inside. I know bearings are cheap these days, but I wouldn't want to DNF because of a $1 bearing. These engines are powerful enough that will will probably not see much of a difference in speed and runtime.
My mbx7 is now as free as my mates TKI3.
07-13-2013, 09:09 AM
#5149
if you use teflon oil the bearing is very fast
07-13-2013, 11:06 AM
#5150
Tech Master
iTrader: (3)
When I receive a new shipment of bearings, I methodically clean out the grease and place a few drops of CRC bearing oil in each bearing. Removing the grease and the shaft boots alone makes a huge difference. I think a car with grease-packed bearings feels noticeably sluggish. Everything Sideshow Bob said is coherent with my experience.
07-13-2013, 03:56 PM
#5151
Freeing up the drivetrain is entirely dependant on how much wrenching time you want to spend and what kind of track you run. It's just that simple.
Boots were placed on the center shafts to keep grease in and dirt out to prolong CV life due to their odd angle. If you remove the boots you'll have to clean and replace CV's faster. If you remove grease from the bearings you'll have to re-oil bearings more often since oil is a thinner lubricant that displaces quicker. Etc.
If you remove the inside wheel bearing shields on the axles you could actually use the oiling holes on the carriers....though I've seen the outer wheel bearings completely lockup once they get dirt in them because the balls are so small, so I'd be hesitant to remove any shield.
Most of my racing is also on outdoor tracks that get super dusty and cars get gummed up with loamy clay... though someone who runs a damp clay indoor with no dust may have a completely different take.
Boots were placed on the center shafts to keep grease in and dirt out to prolong CV life due to their odd angle. If you remove the boots you'll have to clean and replace CV's faster. If you remove grease from the bearings you'll have to re-oil bearings more often since oil is a thinner lubricant that displaces quicker. Etc.
If you remove the inside wheel bearing shields on the axles you could actually use the oiling holes on the carriers....though I've seen the outer wheel bearings completely lockup once they get dirt in them because the balls are so small, so I'd be hesitant to remove any shield.
Most of my racing is also on outdoor tracks that get super dusty and cars get gummed up with loamy clay... though someone who runs a damp clay indoor with no dust may have a completely different take.
07-13-2013, 10:51 PM
#5152
I literally left the centre diff's bearings shielded, the rest all one shield. Imo if you are getting dirt inside the bulkheads or hubs you have other problems. I have noticed with a "stock" bearing..still greased, that the large wheel bearing will lock up in anycase. The grease just attracts and holds on to that dirt untill you sit with some nice oily clay in your bearing. Conversely, ive found that when im lazy and not servicing bearings..to a point where they are basically dry...the run better than when they were greased..although they might be slightly gritty. I rarely replace diff bearings...they keep on going forever, proof that they aren't really that prone to get serious dirt in them.
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I also think the oiling holes where placed in the hubs for that exact reason. Anyway, my car is stupid free and i race on some dirty tracks. Ill report back no matter what the outcome.
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I also think the oiling holes where placed in the hubs for that exact reason. Anyway, my car is stupid free and i race on some dirty tracks. Ill report back no matter what the outcome.
07-14-2013, 12:09 AM
#5153
I literally left the centre diff's bearings shielded, the rest all one shield. Imo if you are getting dirt inside the bulkheads or hubs you have other problems. I have noticed with a "stock" bearing..still greased, that the large wheel bearing will lock up in anycase. The grease just attracts and holds on to that dirt untill you sit with some nice oily clay in your bearing. Conversely, ive found that when im lazy and not servicing bearings..to a point where they are basically dry...the run better than when they were greased..although they might be slightly gritty. I rarely replace diff bearings...they keep on going forever, proof that they aren't really that prone to get serious dirt in them.
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I also think the oiling holes where placed in the hubs for that exact reason. Anyway, my car is stupid free and i race on some dirty tracks. Ill report back no matter what the outcome.
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I also think the oiling holes where placed in the hubs for that exact reason. Anyway, my car is stupid free and i race on some dirty tracks. Ill report back no matter what the outcome.
Last edited by PERROTTO; 07-14-2013 at 12:19 AM.
07-14-2013, 03:45 AM
#5154
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I just cut the front nipple off the front of the boot. Leaving most of the folded part of the cover intact, but it is clear of the bone. If the car is assembled just remove the fuel tank to get to the front boot.
07-14-2013, 05:28 AM
#5155
I have mine like this but you could leave som more on there if you wanted to.
07-14-2013, 01:26 PM
#5157
I literally left the centre diff's bearings shielded, the rest all one shield. Imo if you are getting dirt inside the bulkheads or hubs you have other problems. I have noticed with a "stock" bearing..still greased, that the large wheel bearing will lock up in anycase. The grease just attracts and holds on to that dirt untill you sit with some nice oily clay in your bearing. Conversely, ive found that when im lazy and not servicing bearings..to a point where they are basically dry...the run better than when they were greased..although they might be slightly gritty. I rarely replace diff bearings...they keep on going forever, proof that they aren't really that prone to get serious dirt in them.
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I also think the oiling holes where placed in the hubs for that exact reason. Anyway, my car is stupid free and i race on some dirty tracks. Ill report back no matter what the outcome.
Also, on the topic of cvd wear. The ones in the wheels are basically exposed and take alot more dirt than the centre ones, and they keep up fine. I forgot to mention. If you are adamant to have a bit of protection on the centre cvd but without the drag, just cut the front of the boot off so that all that is left is the back part and a lip over the efde of the cvd. That way you have the pin covered at least...like in the wheels.
I also think the oiling holes where placed in the hubs for that exact reason. Anyway, my car is stupid free and i race on some dirty tracks. Ill report back no matter what the outcome.
I run my CVD without boots and the front one wears out pretty quick. I'd say you'll have to replace them after 20ltrs because all the parts wear out and it gets sloppy. The rear one stays fine for a longer time because the angle isn't so steep.
07-14-2013, 03:29 PM
#5159
Anybody no which hole has to b enlarged on the 6 rear hubs?
07-14-2013, 10:12 PM
#5160
how many degrees of front camber do everybody run?