Manual Hub Mileage Increase?

[warmonger]

I recently replaced my factory auto lockers for a set of MileMarker manual hubs. Interestingly enough, I noted a marked improvement in gas mileage. Since my gas mileage hasn't changed since the day I bought my X brand new almost 2 years ago, this tells me that my autolockers haven't worked correctly since the day I took delivery of my truck. I found this rather interesting and was wondering if anyone who has done this experienced the same thing or is it a fluke? I have seen close to a 2 mpg increase in gas mileage since the install. This leads me to believe the hubs were not fully disengaging when they were supposed to.

[Philosopher]

I haven't noticed anything like that at all.

Um ... congrats! I guess.

[warmonger]

Philosopher,

Actually it kind of irks me. It means I could have been getting better mileage for the last almost two years and haven't. Money wasted, know whut I mean?

[Philosopher]

Originally posted by warmonger
Philosopher,

Actually it kind of irks me. It means I could have been getting better mileage for the last almost two years and haven't. Money wasted, know whut I mean?

Oh I definitely hear you, that would piss me off too. But since adding all the stuff to my truck I haven't noticed any loss of MPG and one of the last things I added was manual hubs.

[xoc]

I doubt they are to blame.

If they were engaged, and turning the front axles and driveshaft, you should have felt it long ago (dull heavy steering, different handling, more noise and vibration).

I lose a lot more than 2MPG when locked, usually closer to 4 or 5.

[evergreen]

are the milemarker hubs better than the warn manuals, or just less expensive. and does switching from the factory auto hubs to manuals void the warranty? i only have 20k on my rig and don't want to get screwed.

[warmonger]

XOC,

Actually there was a noticable steering difference. I noticed the steering wheel turned freer, in fact so much so that I jacked the truck back up and checked the bearing adjustment in the front end. There is no doubt in my mind that there was something wrong with those hubs. I had no idea this was abby normal until I replaced them. I've only driven my X so I've never experienced any different.

As for the hub quality difference, none that I know of. A hub is a hub is a hub. The quality of the MM is comparable to any Warn I've seen, so in my opinion, it is just a matter of choice and personal opinion.

[xoc]

How many times did you have the stock hubs off when repacking the wheel bearings ? Did you lube the hubs as well ? Could you never hear the stock hubs engaging and disengaging ?

[warmonger]

XOC,

Lubricating the hubs is a no-no. If you pack them with grease, they will cease to operate. As for feeling them engage and disengage, now that I think about it, I can't recall ever having felt them disengage but one time when I put the truck in reverse on a nasty sand hill and that was jsut a couple of weeks prior to the manual hub installation. I felt them disengage and reengage briefly when I had to go into reverse to back off of a tree root.

[xoc]

Originally posted by warmonger
XOC,

Lubricating the hubs is a no-no. If you pack them with grease

Packing them no, but periodic lubrication of auto and manual hubs is very important. That's steel on steel in there, and it will cause a lot of wear and noise if not lubricated correctly.
If you submerged your Xterra as often as I've seen on your website, and never did any maintenance to the locking hubs, that may be the culprit.

[Toy Man]

I recently drove about a 100 miles to off-road event. Warn hubs not engaged on the way down but I forgot the disengage them on the way back. About a 4.5 mpg difference, some of which could be attributed to the fact that I was drving 5 mph faster on the way back.

[Philosopher]

Originally posted by evergreen
are the milemarker hubs better than the warn manuals, or just less expensive. and does switching from the factory auto hubs to manuals void the warranty? i only have 20k on my rig and don't want to get screwed.

Check out Matt Peckham's thread on the MM hubs.

[evergreen]

i think i am going with the mm hubs. sound like a stronger unit. from the looks of the other posts, the warn's instruction blow. thanks for the info philosopher.

[warmonger]

One important note regarding Warn hubs. Warn actually has a reason for building their hubs the way they do. Warn has built-in breakage protection in their hubs. By using the cheaper metal, it helps prevent, although not perfectly, the hand-grenading of diffs by building a weakness in the hubs in the hopes that they break before a VERY expensive diff breaks. Although it is no where near perfect, a hub is cheaper to replace than a front chunk. There is a purpose to it, although with the low hp output of a Nissan, it really isn't much of an issue. BTW, if you use a stronger locker in the front end, you decrease the odds of diff breakage. The bolt-in units such as PowerTrax will hand-grenade in spite of the hub weakness. One of the off-road magazines even went so far as to test Warn hub fuses and found that most of the time, the PowerTRax blew before the hub fuse did. But in the case of ARB and Detroit lockers, the hub blew but the diffs didn't. Just a little food for thought.

[evergreen]

that is some damn tastey food for thought. never looked at it that way. does changing to manual hubs void the warranty?