View Full Version : Fulltime 4wd
86isuzu
11-05-2007, 08:04 PM
92 Ranger 2.9L A4ld, dana 35 front
Ive got a crappy electric transfer case that wont shift. i was gonna drop in a manual in the spring, but for now, would it be possible to hardwire the electric into 4hi for the winter months? no 4wheeling just snow.
bad idea?
Wicked_Sludge
11-06-2007, 02:14 AM
you can unbolt the shift motor from the rear of the case and manually shift the case into 4hi if you want....but if you have auto hubs then i'd advise against it.
have you tried cleaning the shift motor as advised in the tech library?
rickcdewitt
11-06-2007, 10:37 AM
bad idea the ttb is not ment for extended high speeds(55 or more)it will burn up the stub shaft and its roller bearing
4x4junkie
11-06-2007, 05:04 PM
bad idea the ttb is not ment for extended high speeds(55 or more)it will burn up the stub shaft and its roller bearing
That's not true. Keep things greased properly and it'll be fine.
As for running in 4WD all the time, I would expect you'll occasionally hit dry patches of pavement, which wouldn't be real good for the system if you ever had to make a fairly sharp turn.
True, you can unbolt the motor and turn the shaft by hand (or with pliers/Vise-Grips), although there is no detent for the 4HI position, only 2HI, and 4LO. You'd have to try to rig something up to hold the Vise Grips in the right position probably.
brendank69
11-06-2007, 06:23 PM
bad idea the ttb is not ment for extended high speeds(55 or more)it will burn up the stub shaft and its roller bearing
That's a really common misconception. The u-joints are the same style as the ones in your rear drive shaft; there's no problem with them spinning that fast. The ring and pinion is of the same design as the r&p in the rear end; it doesn't care if it spins that fast. The spindle bearings, although small, are not weight bearing and should be greased with the same grease as the wheel bearings.
If you're frontend is reasonably maintained, there should be no problem running it at highway speed. The only time that an inner spindle bearing will "burn up" is if it was starved for grease and on it's way out anyways.
IIRC, the manual actually states that highway travel in 4x4 is fine up to 55mph or so.
The only issue, as junkie suggested, is transfer case(front-rear axle) bind in 4x4. This is really only an issue if you're making turns.
Ranger5.0
11-06-2007, 06:51 PM
Whew, thats a reliefe, ive been watching this thread and when i read that its not good to "over speed" the front axle it got me thinkin. When the snow flys, my hubs are locked for about 4 months straight, and many times im in 4 high whipin down the highway at 100kmh. I have never had a problem with anything, but i got worried for a second.
86isuzu
11-06-2007, 07:26 PM
have you tried cleaning the shift motor as advised in the tech library?
yeah, i cleaned it and replaced the motor. replaced the switch itself and determined no power to the switch. i think its that 4x4 power box or whatever behind the driver seat.
thanks for the responses, i guess ill just drop a manual in after the snow melts. just leave it in 2wd, could be difficult to keep it in 4hi as 4x4junkie mentioned
AllanD
11-06-2007, 07:35 PM
Whew, thats a reliefe, ive been watching this thread and when i read that its not good to "over speed" the front axle it got me thinkin. When the snow flys, my hubs are locked for about 4 months straight, and many times im in 4 high whipin down the highway at 100kmh. I have never had a problem with anything, but i got worried for a second.
You and me both...
My brother locks his hubs the first time in the fall that he SEES a
snowflake and doesn't unlock them until spring when the last of
the snow has melted, though if the roads are clear and he needs
to make any lock highway runs he unlocks them as a concession
to fuel economy.
AD
rickcdewitt
11-07-2007, 08:35 AM
That's not true. Keep things greased properly and it'll be fine.the stub shaft bearing a very small bearing i woulden't want to run my truck on the freeway with the hubs locked in,or take it apart and grease it all the time. like i said going over 55 woulden't be a good idea.
rickcdewitt
11-07-2007, 08:44 AM
That's a really common misconception. The u-joints are the same style as the ones in your rear drive shaft; there's no problem with them spinning that fast. The ring and pinion is of the same design as the r&p in the rear end; it doesn't care if it spins that fast.who said anything about u joints or r&p?that wimpy bearing gets loaded every time you turn with the hubs locked in,especially in 4x4.
I doubt that bearing is all that loaded unless the transfer case is also in 4WD. I suspect manuals say not to drive faster than 55 MPH in 4WD because it's supposed to be slippery if you are using 4WD and you guarantee at least one wheel is going to slip during a turn. Handling is affected, more at high speed than at low speed.
And that bearing may be small, but it's larger than some of the transmission bearings. Have you ever seen a gear bearing? How about the bearings inside your U-joints (it's much bigger than those)?
rickcdewitt
11-07-2007, 10:07 AM
lets just say if you treat them the way i do you'll wind up having a problem
projectnitemare
11-07-2007, 10:18 AM
MAKG had just said what I wanted to say. Your driveshaft u-joint needle bearing rotate much faster than the axle shaft; how fast depends on your axle ratio. Those bearings have a torque load on them where spindle bearings do not; they are just reducing friction in the spindle and keeping the shaft aligned. Although not the smartest of ideas, I have done over 80mph in 4x4; there are no problems. As MAKG said the reson it is stated to stay 55mph and under is if the roads are slippery you shouldn't be going fast to begin with. On top of that the binding the does occur in a 4 wheel drive will create some handling issues.
Matt
brendank69
11-07-2007, 01:18 PM
MAKG had just said what I wanted to say. Your driveshaft u-joint needle bearing rotate much faster than the axle shaft; how fast depends on your axle ratio. Those bearings have a torque load on them where spindle bearings do not; they are just reducing friction in the spindle and keeping the shaft aligned. Although not the smartest of ideas, I have done over 80mph in 4x4; there are no problems. As MAKG said the reson it is stated to stay 55mph and under is if the roads are slippery you shouldn't be going fast to begin with. On top of that the binding the does occur in a 4 wheel drive will create some handling issues.
Matt
Correct, The reason for the 55mph limit is to prevent the driver from losing control. If you need 4x4, it's likely that you shouldn't be doing 55. With that said, I've also done over 55 for extended periods in 4x4.
55mph is not some magic barrier where your spindle bearing is going to explode if you go above it. There is a negligible difference in the stresses applied to the spindle bearing at 55mph and, lets say, 65mph.
Like I said before, if you maintain your vehicle in a reasonable manner, you won't have a problem. That's quite a bit different than taking it apart to grease it "all the time".
tanbuddy
11-07-2007, 03:44 PM
My motor gave me trouble before and wouldnt shift at all into 4wd. I took it off and used a vice grip to put it in 4 hi. I threaded a bolt into one of the t case motor holes to keep the vice grip from moving out of position.
I cut the 2 main wire that go into the motor and put them on a battey and found the motor moved, so i ran 2 wires up to the cab and put the motor back on the t case. When i need 4wd now i have a swich to send juice to the motor and listen for it to move into 4 wheel
4x4junkie
11-07-2007, 07:19 PM
I've put probably 2000 or more miles on mine at freeway speeds and above. Not once have I ever seen any sign of heat or stress on those bearings (it's only about once every 2-3 years I regrease them, too--- which is when I do the routine wheelbearing service & repacking that you're SUPPOSED to do every so often).
All 3 (Ford, Dodge, GM) at some point sold millions of trucks with factory full-time 4WD systems that used the exact same bearings in their frontends too... I can't seem to recall seeing all those trucks always blowing their spindle bearings out all the time... :icon_confused:
Wicked_Sludge
11-08-2007, 11:14 PM
your spindle bearings also see around 3-4 times LESS revolutions than your driveline. with 31" tires, your driveshaft rotates 651 times per mile....or 651 RPM at 60MPH...thats really quite slow.
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