Transfer case lowering

[driver007]

When you lower your transfer how is this being done. I have heard about it but do not understand how it is being done. Could someone explain for me.

 

[Saddle Tramp]

Typically the case is lowered by adding a spacer between the bottom of the frame and the top of the cross member/skid plate that the transmission mount is bolted to. Spacers are usually about an inch or so in thickness with a hole in the middle for the bolts and of course the bolts are longer to make up for the extra length. When the transmission is lowered it reduces the angle of the drive lines from the transfer case to the pinion yoke reducing vibration an u-joint wear.

 

[BajaEdition]

I often winder about guys who lower the T case.
you spend a lot of time and effort to raise a jeep with a lift, and then spend more money to bring the T case down and destroy some of the clearance you gained with the lift.
Yes it does make the driveshaft angles decrease and help with driveline viabration, but it is a step backward. The alternative is to get a double cardon driveshaft and clock the pumpkin to match the angle.
Just a thought.

 

[Darren9975]

^x2 you lose a lot of clearance.

 

[1986cj7]

I often winder about guys who lower the T case.
you spend a lot of time and effort to raise a jeep with a lift, and then spend more money to bring the T case down and destroy some of the clearance you gained with the lift.
Yes it does make the driveshaft angles decrease and help with driveline viabration, but it is a step backward. The alternative is to get a double cardon driveshaft and clock the pumpkin to match the angle.
Just a thought.

How about degree wedges what is the opinion on these I'm thinking of installing these on my jeep and wanted to get any feedback on if they help or not instead of using a Transfer Case lowering kit? And how much is needed 4,6,8?

 

[BajaEdition]

Degree wedges are good for what they do. and that is to realign a axle to a small degree. however do not just use them unless you know how and why to align a axle.
In the front they commonly are used to set the caster.
in the rear we use them mainly to adjust the pumpkin angle to the angle of the t case,
with a regular type of drive shaft we need this angle to be near perfect to not get driveline vibration, if useing a double cardon joint we need that angle to be in relation to the drive shaft.
Buying a CV style shaft and clocking the pumpkin is something a lot of guys want to get around because it can cost 4 plus Bengamens but it is the correct way to handle the problem and will result in a longer u joint life.

A single cardon needs to be aligned like this

a Double Cardon (cv) needs to be like this

however I give it 2 degrees to wrap a bit

 

[Niedhogg]

Degree wedges are good for what they do. and that is to realign a axle to a small degree. however do not just use them unless you know how and why to align a axle.
In the front they commonly are used to set the caster.
in the rear we use them mainly to adjust the pumpkin angle to the angle of the t case,
with a regular type of drive shaft we need this angle to be near perfect to not get driveline vibration, if useing a double cardon joint we need that angle to be in relation to the drive shaft.
Buying a CV style shaft and clocking the pumpkin is something a lot of guys want to get around because it can cost 4 plus Bengamens but it is the correct way to handle the problem and will result in a longer u joint life.

A single cardon needs to be aligned like this

a Double Cardon (cv) needs to be like this

however I give it 2 degrees to wrap a bit

Interesting thread, as I have just lowered my Transfer Case with home made 2" spacers.. this was just the easiest and cheapest way for me right now, with where I'm at, not at home and building this Jeep in a backyard and not my shop, but you're saying I can use these double cardan joints (or what I've always called velocity joints) in the rear, like in almost all front shafts. Which means a guy could, technically, take a front driveshaft out of.. say, an FSJ, and re-size it for the rear shaft on a CJ, and then install a set of wedges on the rear axle to correct the angle. That doesn't sound too bad to me to gain back that 2"..

 

[Sasquach]

You were able to lower it 2" without the valve cover hit the firewall? without the fan hitting the rad? and without the T case lever hitting the cutout in 4L?
You motor mounts must be crying too.

 

[Niedhogg]

You were able to lower it 2" without the valve cover hit the firewall? without the fan hitting the rad? and without the T case lever hitting the cutout in 4L?
You motor mounts must be crying too.

Well, the valve covers clear just fine, I haven't installed the fan, and, I need to change my signature, I don't have the low range Q-Trac... ...but thanks for the heads up on the fan, didn't look to be an issue so far, there's actually a 2" spacer on the pully and I'd bet there's at least 6" to the rad from there.. I'll have to check now..

 

[Sasquach]

Well, the valve covers clear just fine, I haven't installed the fan, and, I need to change my signature, I don't have the low range Q-Trac... ...but thanks for the heads up on the fan, didn't look to be an issue so far, there's actually a 2" spacer on the pully and I'd bet there's at least 6" to the rad from there.. I'll have to check now..

I was thinking I6 and the AMC 304 must not be so tightly packed in, there is very little room between the firewall and the radiator with the I6.

 

[Darren9975]

2" sounds extreme to me, you will lose all ground clearance, my valve covers are close with no drop.

 

[driver007]

Thanks fellows. I now understand that really what is happening is your tilting your motor to lower your Transfer Case .

 

[1986cj7]

Degree wedges are good for what they do. and that is to realign a axle to a small degree. however do not just use them unless you know how and why to align a axle.
In the front they commonly are used to set the caster.
in the rear we use them mainly to adjust the pumpkin angle to the angle of the t case,
with a regular type of drive shaft we need this angle to be near perfect to not get driveline vibration, if useing a double cardon joint we need that angle to be in relation to the drive shaft.
Buying a CV style shaft and clocking the pumpkin is something a lot of guys want to get around because it can cost 4 plus Bengamens but it is the correct way to handle the problem and will result in a longer u joint life.

A single cardon needs to be aligned like this

a Double Cardon (cv) needs to be like this

however I give it 2 degrees to wrap a bit

I know this is a newbie question, But what all is done to clock an axle I know what clocking a Transfer Case is. Is clocking the axle flipping it over and rewelding spring preches on the top of the axle I'll have to save up for th e $400 but want to get a good plan in place. And also what needs to be done for the front axle to correct the angle? I'm thinking there is some brake work that is going to have to be done rerouting the brake lines and maybe flipping the brake drums not that sure?! Thanks for the advice!!!

 

[CJim7]

I know this is a newbie question, But what all is done to clock an axle I know what clocking a t-case is. Is clocking the axle flipping it over and rewelding spring preches on the top of the axle I'll have to save up for th e $400 but want to get a good plan in place. And also what needs to be done for the front axle to correct the angle? I'm thinking there is some brake work that is going to have to be done rerouting the brake lines and maybe flipping the brake drums not that sure?! Thanks for the advice!!!

Rotating the axle requires cutting off the spring pads, moving them slightly on the axle tube, and rewelding them to get the desired angle on the driveline. Nothing is flipped over....its just a slight relocation of the pads. Check out Jims attachment and look at the difference in the two pinion angles. The bottom picture shows what would be an axle that has been rotated for use with a CV driveline. The top picture would be an axle that is basically in the stock position.

Typically the front end doesn't need anything done to it as far as driveline angle. The front shaft is much longer then the rear and doesnt suffer the angle change the rear does. In addition, the front isn't going to be engaged during high speed driving, so if there is misalignment of the driveshaft, you would never know it.

 

[BajaEdition]

One more point about the front is the front axle is set at a fixed angle to set the steering caster. So it is set for steering safety

 

[Sasquach]

You guy's with CJ7 's crack me up, you don't even know what a short drive shaft is. Cut almost a foot off yours and then you got a 5 rear shaft.

 

[BajaEdition]

Yes Allan, they don't know what having to deal with short is.

ok, just for a bit of info

when the jeep was set at the factory, it was set to some specks,and when they did so the set the angle of the drive lines to the angle of the front axle. You have a very little degree of variance in this angle so that you get max U joint life. then the rear was set according to the drive line angle.

these two angles were engineered into the design of the Jeep.

so we go to lift. and we suddenly get vibration. The vibration caused because we got passed the operational range of the u joints.

A quick fix is to drop the t case but that may get us into a range, but both the U joints are working at different angles, which is bad and causes premature failure of one of the joints. It also puts more angle on the front drive shaft. However we do not feel this unless we are in 4x4 and that is usually at slow speed, we still are stressing the u joints, just we do not feel it as the shaft is not traveling at a speed to cause vibration.

as I have stated, this is a cheap fix, but in the long run it is not the correct fix and causes more stress than it relieves on more than the drive shaft u joints, it also causes stress on the entire drive line especially bearings setting them up for failure.

the correct way to handle the problem is to leave the drive line angle alone. Your front drive shaft is usually long enough to put up with the increase in angle, the rear is the one that is effected the most as it is usually much shorter in Jeeps. The correct way is to add a CV style drive shaft and raise front of the rear pumpkin so you get correct geometry.

 

[CJim7]

You guy's with CJ7's crack me up, you don't even know what a short drive shaft is. Cut almost a foot off yours and then you got a 5 rear shaft.

I remember my CJ5 driveline very well....it was scary-short.

 

[seyit]

Degree wedges are good for what they do. and that is to realign a axle to a small degree. however do not just use them unless you know how and why to align a axle.
In the front they commonly are used to set the caster.
in the rear we use them mainly to adjust the pumpkin angle to the angle of the t case,
with a regular type of drive shaft we need this angle to be near perfect to not get driveline vibration, if useing a double cardon joint we need that angle to be in relation to the drive shaft.
Buying a CV style shaft and clocking the pumpkin is something a lot of guys want to get around because it can cost 4 plus Bengamens but it is the correct way to handle the problem and will result in a longer u joint life.

A single cardon needs to be aligned like this

a Double Cardon (cv) needs to be like this

however I give it 2 degrees to wrap a bit

Hi Baja;
Sometime ago I swapped a T-98 to my 1962 CJ5 with DANA 18 transfer.( I keep the stock T-90 with the stock DANA 18 though) and as shown in "figure 2" I adjusted "0" degree.But while driving on highway every time the vehicle sprang downward a disturbing sound occured.It was something like when the fan touches the radiator shroud.( It wasn't the case though)Then I put degree vedges to achieve some degrees more than "0"
That sound was to some extend reduced ,but when the vehicle is loaded and while crusing on highway it occurs (slighter now) when the weight presses the springs downward.
I want to increase the degree of the vedges a bit more.If it still keeps I want to shift back to T-90
Any suggestion here will be greatly appreciated.

 

[1986cj7]

Rotating the axle requires cutting off the spring pads, moving them slightly on the axle tube, and rewelding them to get the desired angle on the driveline. Nothing is flipped over....its just a slight relocation of the pads. Check out Jims attachment and look at the difference in the two pinion angles. The bottom picture shows what would be an axle that has been rotated for use with a CV driveline. The top picture would be an axle that is basically in the stock position.

Typically the front end doesn't need anything done to it as far as driveline angle. The front shaft is much longer then the rear and doesnt suffer the angle change the rear does. In addition, the front isn't going to be engaged during high speed driving, so if there is misalignment of the driveshaft, you would never know it.

Thanks for answering my simple question, and bearing with my Limited knoweage!!!!!