TC Drop: Should I do it?

[71jimmy]

I'm in the process of putting a six inch lift on my '71 Jimmy. Springs in front (tuff country) and in the rear I'm thinking shackle flip with 2 or 3 inch blocks (depending which levels it out) and having my stock rear springs re-arc'd. I'll be running 35x12.50x15 Mud Terrains on 10x15 rims. It will never see hard core rock crawling!

I'm contemplating dropping the Transfer Case an inch. The advantage I see is it would reduce the drive line angle a bit. Can someone give me the pros and cons in doing this? Is it worth it? What kind of things do I need to consider before I do it? Is it necessary with a six inch lift?

Also, as mentioned, I'm looking at the ORD shackle flip. Anybody know if they take into account the natural tendency for the axels to shift when lifts are installed? Are they made so that the axels remain centered in the wheel well?

As always, thanks for the help!

And I know
As soon as I get the rear lifted I'll post some!

[CrashEd]

On my mud truck i used the stock hangers and just cut the bottem out and fliped the shackle. Then i welded two braces across the top of the stock hanger. I run 40s on it and its all hard core. It leaves the house on a trailer and jumps in the mud full bore. Its done this for a long time and never had a problem. Its got a 383 strocker and it will sling the mud

Droping the transfer case. i think it would help the back drive shaft but hurt the front. It wouldnt be a strait drop it would have a angle to it unless you droped the motor too.

If your running a devorced transfer case then it would work.

[cobinder]

The more arch in your springs and more the flip kit will move it forward.. Flat springs and it won't move an inch. Lottsa arch and it will move close to an inch. ORD does make a zero block that you can move the axle if back needed. I think it moves it an inch might be an 1 1/4". With a 6" lift the flip kit will help your rear driveshaft angle, so I'd stay away from the TC drop

just my 2$ worth

[special-K]

I don`t get the t-case drop thinking.I`ve never done it.Matbe there`s a benefit on a Jeep or other "length-challenged" 4wds.The rear shaft needs the least help in the angle department and that`s the one it helps.The short little front gets a steeper angle from a t-case drop(is that good?).I have an HEI distributor and the last thing I want is to put that thing into the firewall any more than it is,now.Can`t imagine with a big block and dropping the t-case.I have the drop-kit in spare parts from when I did my 6"lift.I figured go with the right stuff that was offered.That was just a waste of money.

[1969k10stepside]

I havent done this to either of my 4x4s.When I installed my lift kit on my 71 4x4 it had t case drop information but it said it was only for the newer models(73+)

[Zoomad75]

When I did mine with a shackle flip my driveline problems were fixed. The shackle flip with stock springs rotated the pinion up slightly, but just enough to ease the angle problem I had before. The PO stacked a bunch of cut down add a leafs to make up for the stock springs sagging.

Remember that ORD's standard flip kit gives about 4" of lift with stock springs. Adding 2" or 3" blocks with re-arching the stock springs might net you 8". It all depends on how much arch is added to the stock springs.

You might be better off with the flip kit and a 2" spring to eliminate the blocks and keep it level with the front 6" springs. After running it a while if the rear sags a little you can use a ORD zero rate to gain back an inch.

I really hate blocks, but understand them in a budget build. Problem is the taller the block the more leverage the spring has and you can get some nasty spring wrap even on the street. Keeping a soft stock spring would make it more prone to this. Not to mention the pinion angle adjustments you will probably need to make with the taller blocks. If you are going to order the ORD flip kit, call and talk to the owner. He will point you in the right direction.

[Eliasj123]

Install a 1" drop tc kit.. It will definitely help with the drive line angle.
Have you thought about installing a CV or a double cardan on the side of the transfer case??

A 6" lift is a big jump. So, you'll have to doing things to help off-set the new height. The rear drive shaft angle is more important than the front because you'll be using it all the time and it's going to have most of the stress. You may have to angle the axle's pinion by either shimming it or cutting the spring perches and resetting them.. The pinion angle should be 2 degrees below the transfer case output shaft. The 2*is for axle wrap when power is applied to the axle..

Like someone said... Consider how much room you have in your engine bay when you do the drop. Typically, you only need to consider the room you have or don't have between the firewall and the engine. Also, the tranny linkage or gear shifter will need to be adjusted..


Elias

[2wdBlazer]

I have 6 inch suspention with no issues. No t case drop.

[71jimmy]

Thank you one and all!

I think the consensus is that I don't need a TC drop. I didn't really want to do it anyway unless it actually did something. I didn't realize it would only help the rear driveline.

I'm thinking of doing the shackle flip because of better ride quality and articulation (that's what iv'e read anyway). I had thought about buying 2" tuff country springs to go with the shackle flip, but they are as expensive as the 6" tuff country springs with the additional cost of the shackle flip. But, as Zoomad75 mentioned, if the 2" springs will help to reduce spring wrap it might be a good investment, since I may have to spend money on "fixing" the spring wrap problem if I don't do it right.

Thanks again for the help.

[special-K]

Remember...Better off road articulation generally means poorer on road handling.

[Zoomad75]

Originally Posted by special-K

Remember...Better off road articulation generally means poorer on road handling.

I can say this with my shackle flip. My on road performance was not affected by the flip. I didn't notice any excessive leaning in corners or any other problems. I'm using stock springs that have 32 years of use on them so they are VERY soft.

All I noticed after the change is how much less harsh the ride was out back. Yes my 4" rough country springs ride pretty tight up front but when driving through dips, over speed bumps and curbs the rear just walks over it.

Granted everybody else's results may vary based on a number of variables. But the softer ride in back is not so soft that it requires the use of a sway bar or anything. My truck does see highway duty every now and then and even at 70-75 mph it's not that bad. No different than before the flip.