Take it out of overdrive stupid....

Two weekends ago, I had the privilege of running the Rubicon with the Vintage crew. It was awesome trip as can be read in the post Mortem thread in the outings section.

I'm a little embarrassed to say this but the last morning, before hitting Cadilliac hill, I realized that I had driven the trail to that point in overdrive.

My question is this: have I done some unseen damage to the unit? It seemed to function on the road properly, but is there something I should be worried about?

The upside is that I did notice better than usual fuel mileage on the trail R)...

 

You drove in overdrive!?!?!

You probably grenaded the whole transfercase!!!






Just kidding. You're talking a Warn type O/D right? They (Warn) called it "all range" for a reason. You can use it just fine in any gear, 2wd, or 4wd.

 

Maybe kidney damage from driving too fast over the bumps. No damage to gears though. As long as you didn't slip the clutch too much, no damage anywhere else either

 

I'm new to Jeeps and overdrives on Jeeps but if I understand correctly the OD goes on the back of the t case to alter rear d.s. speed. If this is the case the front d.s. would still be trying to turn at the non overdrive speed causing the front and rear end to turn at different speeds and potentially chew up some stuff. Am I close or way off on my thinking.

 

Forget above post I just saw a picture of how they actually install.

 

A bit off.

As I said, the Warn type overdrives are "all range". Due to their design, they do not put just the rear wheels in overdrive. Working off the PTO on the transfercase, the overdrive engages planetary gears(?) in the tcase, which, through mechanics I don't entirely understand, gives you overdrive in an gear combination. This includes, 2 wheel drive, 4 wheel drive, and 4wheel low.

 

Until I saw an actual picture I had it in my head that the unit went in between the tcase and the output for the rear driveshaft but like they say a pictures worth a thousand words. Makes more sense now.

 

The overdrive replaces the transfer case input gear forcing all power flow to go through the overdrive. When in direct it is just like not having an overdrive as powerflow goes through the "bowl gear" which replaces the stock input gear. When shifted into overdrive mode powerflow goes through the planetary gears then through the transfer case.

As long as the oil level was sufficient and the torque was not high enough to cause damage to the sun or planet gears there should be no issues.


Sent from my iPhone

 

Thanks for the info fellas.

Looking at it, there is a little bit more than usual 90 wt. leaking from around the OD unit. It has always leaked a bit, but it does seem a little excessive at this time. I am going to pull it this weekend just to double check and reseal.

 

Nick beat me, lubrication and, um, proper use of throttle.
They last for years.
My Jeep has been in the family over 30 years with no damage done to the OD behind the V6.
I can think of 2 times in my group that people have broken drive train parts, an input shaft and a powerlock case.
The OD's were fine.

 

Heatseaker I have friends that almost never dis-engage their OD's. As in they leave it engaged while street driving up to 75 MPH. They just use it to lower their gears for gas mileage. They do take it out when they go off road but if daily driving with it in all the time does not hurt it I doubt low speed off road driving would matter

 

Like Nick said, if the lube level is proper, they are a tough unit. Good for a good deal more than their rated 300 ft lbs. Leaving it engaged would put some extra wear on the planetaries but highly likely inconsequential and it would have no effect on anything else.

 

Thanks for all the info guys. As fate would have it, I'm not going to get to tearing the unit out this weekend but I will get after it soon. In the mean time, I took a little preventative measure:

 

heatseeker the thing is trash just pull it and throw it a box i'll pay the shipping and be done with it. Oh and I'm right behind brother!:twisted:
It reallly should havent done any damage if the the gear oil did not get low

 

Fuggin Jim...