Different front and rear axle ratio

[JLANEF]

I have seen this question before but with conflicting answers. I’ll try again..

I installed, (just about done), new front axle with 4.10/11 gears. Due to the virus complications my rear axle is not going to be done for at least a couple weeks. My question is simple. I have a 1999 TJ with stock automatic transmission and stock transfer case. I will have 4.10 up front and 3.07 in the rear for a few weeks. Can I drive the Jeep with the front driveshaft installed, but The transfer case always in 4 high? Or do I need to remove the front drive shaft?

Thanks for the help.
jeff

 

[mrblaine]

I have seen this question before but with conflicting answers. I’ll try again..

I installed, (just about done), new front axle with 4.10/11 gears. Due to the virus complications my rear axle is not going to be done for at least a couple weeks. My question is simple. I have a 1999 TJ with stock automatic transmission and stock transfer case. I will have 4.10 up front and 3.07 in the rear for a few weeks. Can I drive the Jeep with the front driveshaft installed, but The transfer case always in 4 high? Or do I need to remove the front drive shaft?

Thanks for the help.
jeff

2 high only with the rear shaft in. 4 high with the rear shaft out.

 

[JLANEF]

Thank you for the quick response. Since I am OCD, let me ask for absolute clarification. 2 high only with rear shaft in, and front shaft in. 4 high only with rear shaft out and front shaft in. Thanks again!

 

[InfamousCanadian]

You need to isolate the differentials from one another. To do this you need to remove one of your driveshafts. So choose if you want your Jeep to be front wheel drive or rear wheel drive and remove the other driveshaft.

 

[JLANEF]

This seems to be in conflict with @mrblaine. Doesn‘t the transfer case isolate them in 2 high?

 

[InfamousCanadian]

This seems to be in conflict with @mrblaine. Doesn‘t the transfer case isolate them in 2 high?

It does. Mr Blaine is absolutely correct. However for peace of mind I would pull one of them. If someone accidentally shifts it into 4x4 it could be disastrous.

 

[Denverdean1]

Let me try and make it simple to understand:
Front wheel drive (4.10 gears)
-rear shaft needs to be removed. (So no power is being sent to rear axle)
-transfer case needs to be in 4-wheel drive. (So it's sending power to front axle)
Rear wheel drive (3.07 gears)
-front shaft is suggested to be removed. ( So you don't accidently engage both axles)
-Transfer case needs to stay in 2-wheel drive ( with both shafts in and different gear ratios, putting it into 4-wheel drive would cause binding and very bad stuff)

Decide what gear ratio you would like to use for the time being and go from there

 

[CharlesHS]

IF you choose to drive on the front differential gears and remove the rear driveshaft; do you have a SYE installed? In my '98 XJ 4.0L AX-15 when I pulled the rear DS I could drive without the possibility of a leak due to the SYE.
IF you donot have a SYE installed... I would verify that the transfercase gear lube does not leak out while driving the Jeep around. I know there was a output bearing/seal redesign that was supposed to resolve the leaks, but for piece of mind... I always verify that it is not leaking when the DS is removed.

 

[mrblaine]

This seems to be in conflict with @mrblaine. Doesn‘t the transfer case isolate them in 2 high?

It is in conflict and the t-case does isolate them from each other in 2 high. I always assume folks are not idiots and I have never seen or heard of anyone accidentally shifting the case from 2 high to 4 high. My response is based on you needing the rig drivable.

You can run both shafts. Don't use anything but 2 high.
If you want to run one shaft, 2 high for the rear shaft being in, 4 high with the front being in.

 

[Steel City 06]

Just know you can't accelerate very quickly from a standstill in front wheel drive. You can drive as fast as is normally safe, but it is very easy to break even a 35 inch tire free if you're a little heavy on the gas or the clutch in 1st gear.

Not usually a big deal, but just be aware of it. I drove in front wheel drive for about a month before I got my new driveshaft.

 

[JLANEF]

Thanks to all. I will be very careful to stay in 2 hi. Hopefully it will only be a couple of weeks.