Do I already have some of these upgrades?

[OnceKnotty]

Im in the process of shopping around finding everything I need to do for my jeep to handle all the new modifications. Well I read some guys saying they have things like driveline vibration with a 3 inch lift and need to lower the transfer case or put in an SYE. Im at 4.5 with 33s right now and dont have a problem with that so is it possible thats already been done, how do I tell? And things like if my gearing/axles etc. have been upgraded. I just bought the jeep not that long ago and I dont know much about them so Im slowly learning, and if something is already been done then I definately want to pay money for something thats already installed. Any help is appreciated.

 

[blondejoncherokee]

whether you have a sye or not, or t case drop or not, etc, if youre at 4.5 with 33's , then dont mess with anything. dont change a single thing. if you do you will end up with vibes forever and be totally pissed at the jeep. if you get vibes ever start with driveshaft u joints and tires rebalanced and go from there. ive had my vibes for months now and ive only barely diminished them, didnt have any on 33's with the same setup, now i do...

 

[blondejoncherokee]

i meant if youre at 4.5 and 33's with no vibes dont change a thing...

 

[JNickel101]

for the TC drop, you are looking for about a 1 inch "bar" (or spacers) between your frame-rail and your cross-member. cross member runs side to side, holding your transmission (and transfer case) up.

for an SYE...look at your rear driveshaft. if it has 2 u-joints and a "double cardan" joint at the transfer case end, then thats good if you only have one u-joint at each end of the rear driveshaft, you dont have an SYE.

http://images.google.com/images?hl=en&q=double%20cardan&safe=on&um=1&ie=UTF-8&sa=N&tab=wi

there's some pics. google search, and the infamous search functions are your friends. pictures help a lot.

Like Jon said, if it ain't broke, dont fix it!

Oh and for axles and gears....

there's a good rear axle ID chart. up front, you most likely have a dana 30. for gears, you either pop the cover, count the teeth on the ring gear, divide by the number of teeth on the pinion...or spin your rear tires 1 rotation, and count how many times your driveshaft spins....that will give you your gear ratio. Can be tough though, because 3.55, 3.73, and 4.10 are pretty close.

If you have an auto tranny, most likely you have 3.55. tow package? 3.73 5speed manual? 3.07

those are just very rough generalizations - there's no definite way to tell unless you count!

good luck, keep posting...

 

[OnceKnotty]

wow thanks for all the info guys! Well the transfer case is lowered I can see that now. Im going to a 6.5 instead of 4.5 lift so thats why Im asking all this, I'm just trying to see what I will need for it to handle the extra couple of inches. I dont see the double cardan oh well. I'll have to check the gears when I can get it on the lift at work.

Would I need new gears to run 35s cause thats as big as I'll ever go.

 

[OnceKnotty]

no? yes? maybe?

 

[JNickel101]

Most people go to 4.88 gears or even 5.13s (heck, even more sometimes) for 35s.

I highly suggest if you're going with 6.5" lift, you get an SYE and new Driveshaft. It will make your life much easier. Also, you'll get that inch of ground clearance back (you can get rid of the TC drop once you go with an SYE).

What rear axle do you have???

 

[gijosiahh]

it depends what gears are in the jeep right now. if its stock gearing, then yes, you will need to regear

 

[OnceKnotty]

I have a D35 in the back.

And I just looked I do have the double cardan connecting the driveshaft to the transfer case! yay

Im gonna check the gears as soon as I get a chance to throw it up on a lift.

 

[JNickel101]

your front driveshaft will have the DC....

so you're saying you have both a TC drop AND an SYE/DC rear driveshaft?

 

[OnceKnotty]

if what im reading from you guys is correct then yes.

the double cardan should be on the front driveshaft?

I'll just take a few pics of under the body so you could have a peek. That might be a little easier.

 

[OnceKnotty]

Heres one of the jeep while im at it!

 

[blondejoncherokee]

yah you have a tc drop and sye. you could go pretty tall with that setup, or pull the drop and shim the leaf packs

 

[OnceKnotty]

what is shimming the leaf packs mean