Outer Limits 4x4 Board

G'day all.. thought I would share trivia this with all interested parties.

Just had my gearbox / transfer case overhauled ... picked it up today... Breif history.. ex mines ute, no real knowledge of prior 4WD usage.. noise in gearbox... in for repair.

One of the problems were two stuffed bearings in the transfer case. From over use... no... from driving on hard surface. no... wait for it.... rather from not being used regularly enough!!

The bearings taken out were what I can say ... lumpy when spun. Looking at the bearing, where the races had been sitting idle, there was extensive pitting causing hollows in the metal. The previous owner had not used the 4WD functionality much at all, with the lubrication of the transfer case being caused by the rotation of the gears, my box was highly under lubricated to the point of being dry. Corrosion had set in totally stuffing the bearings. They had not seized as the box works fine (albeit noisy) since I have been going off road, but sufficiently damaged to warrant an overhaul.

Bottom line... if buying a 2nd / 3rd hand truck, and it is a few years old with no off road usage.. sus out the transfer case first.. you may be in for a bad supprise. Body may look great but the transmission may be stuffed.

The guy who rebuild the box, manual transmission specialist, was telling me of a heap of 4wd's that he has serviced, having never had 4wd engaged, with similar probs.

Cheers

Rainsey

Same goes for front axle/diffs and manual hubs. Books recommend locking hubs once a month and going for a drive to lubricate front driveline components.

I have heard about the same thing with air con's

Eric

Yer, it happens alot.

Espically years ago when rich people bought their 4wd's to drive around in the city, the transfer cases used to pack it in.

scout392 wrote:I have heard about the same thing with air con's

Eric

Yep you are correct. What I was told by an AC mechanic is that in the gas is also an oil component that lubricates the seals of the compressor. No use causes the seals to stuff up, hence the escape of the gas hence the no go of the air con.

Re the gearbox and transfer, the mechanic stressed that at least once a month, not only lock the front hubs but get out on a patch of dirt for a hour at least and engage 4WD.

So now I have a good sound technical reason for telling the missus that I have to go play in the dirt.... otherwhise it will cost me money not to!!

Cheers

Rainsey

It happens with any machinery that is not run and is subject to vibration. Its called peening (yes like what happens when you a piece of metal continuously with a ball peen hammer.)

No use of the AC causes the seal to stick to the shaft, when u do finally turn it on it rips the seal and u loose your gas.

Q. Do you have to lock the hubs in to lube the front diff? if you use 4wd without locking the hubs in, (like backing a trailer slowly up a drive way) the that turns both your transfer and your front diff.

?

I would expect that to be fine. Everything rotates then. It may be good thought to check that your free wheel hubs dont seize also.

Stackson45 wrote:Q. Do you have to lock the hubs in to lube the front diff? if you use 4wd without locking the hubs in, (like backing a trailer slowly up a drive way) the that turns both your transfer and your front diff.

?

except your hubs were not made to be run for periods of time without them being engaged, so if you were to do highway speeds with the hubs unlocked in 4x4 you'd run the risk of cooking the grease in the hubs, or damaging the spindle, because the stub shaft isn't being held in one place by the free wheeling hubs, so it might thrash around.

Was down at the local 4x4 shop the other day when one of the staff pointed out a landcruiser (newish one - dont know what model) that had the front drive shaft removed completely.

Apparently its a full time 4x4 so owner wanted to get better economy by no having to turn the front shaft & axles?

Staff guy said this is very common with the soccer mum 4x4 driving set these days.

in regards to AC,


alot of new cars have their AC pump clutches wired to reverse gear, so when you slot the car in reverse it runs the pump to keep it luuubed up.

Jes