Transfer Case Drop Worries

S

Salhuerta

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Joined
Aug 20, 2020
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Phoenix
Hi everyone! I recently installed a 2.5in lift on my 04 TJ. This caused it to have slight vibrations at around the 15-20mph range. I purchased a 1in transfer case drop kit to have installed, but after reading some horror stories, I am starting to think it might not be a great idea.

Should I:
1. Install the 1in t-case drop and call it a day
OR
2. Install the 1in t-case drop and save up for a SYE
OR
3. Not install anything and live with the vibrations (this seems like the worst idea)

I should probably mention I definitely cannot afford a SYE at the moment...

I have so many questions and I just need your advice - thank you in advance!
 
The worst option is to not do anything.

Install the drop and save up for a sye, driveshaft and arms.
 
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Wouldn't the other option be to buy at a minimum adjustable lower control arms so you can adjust the pinion angle? That will also get rid of your vibs.
 
jjvw said:
The worst option is to not do anything.

Install the drop and save up for a sye, driveshaft and arms.
Click to expand...
Thank you jjvw, now my question to you is... am I at all limited from wheeling or driving while I have the t-case drop? I say this because it could be a while before I save enough for a SYE...
 
Wildman said:
Wouldn't the other option be to buy at a minimum adjustable lower control arms so you can adjust the pinion angle? That will also get rid of your vibs.
Click to expand...

I've never been clear on how well that actually works. But if so, then buy arms before the sye and ds.
 
Salhuerta said:
Thank you jjvw, now my question to you is... am I at all limited from wheeling or driving while I have the t-case drop? I say this because it could be a while before I save enough for a SYE...
Click to expand...

Never having done a t case drop myself, all I know is that more people drop than don't when confronted with vibes. I also don't know what these horror stories are, except from those who would complain that going lower is the wrong direction.
 
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There's nothing wrong with a tcase drop other than the slight loss of ground clearance. Changing the rear pinion angle is not the cure for this issue.

Installing a set of 1" taller rubber motor mounts or Savvy's 1" motor mount spacers would do it too though that's kind of a PITA job if you don't have help.

Installing a SYE kit into the tcase and replacing the rear driveshaft with a new CV/double cardan driveshaft works too and is a great upgrade but it's expensive and not really needed/a bit premature for just a 2.5" suspension lift.
 
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I had vibes after a 2.5” lift and dropped the TC a half an inch using washers. Got rid of some of it so I changed the u joints which got rid of a little more. Finally I installed a one inch MML and used my rear upper control arms to do some fine tuning and that finally got all the vibes out. Start simple with the TC drop and if that works your good. If not go to the next thing.
 
Do a MML or buy some thick washers at Lowe's and drop the skid just enough to get rid of any vibes. I've done both of those ways many times and the SYE and adjustable arms too. They all work.

p.s. If dropping the t-case skid 1/2" with washers hampers it's offroad abilities, you need to choose better lines.
 
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If it were me I would go with the 1" motor mounts for your 2.5" lift. And there is a way to roll your rear diff up a bit without adjustable control arms by using cam bolts and opening up the slot on the rear diff axel side control arm mount. It not a common solution but it does work.
 
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Thank you all for your suggestions - it seems I have found another small issue (this always happens). I bought a t-case drop kit that comes with the six spacers and bolts to lower the skid plate but it seems like there is another plate attached to the front of the transfer case plate (see photos).

Do you all think I am okay to remove the front portion when droping the transfer case? I noticed other TJs dont have this front part so I figured its not absolutely necessary to have it.

Let me know your thoughts!
IMG-1884.jpg
IMG-1885.GIF
 
That front plate will move I'd think as you put the drop on. It is a transmission skid plate to protect your transmission pan from damage. I wouldn't remove it IMO.
 
Wildman said:
https://4xshaft.com/blogs/general-tech-info-articles/tail-shaft-conversion-kits
So you have to match the angle of the output on the t-case to the angle of the pinion. It's been too many years since I have done this but I did it on my YJ after I did a lift on it with wedges between the leaf springs and axle.

In theory this is suppose to work.
Click to expand...
While this is true, a U joint can only operate any so many degrees before it creates vibes. Not sure what the exact number is for a 1310 but if you exceed this number you will still have vibes(even if they are the same angle).
 
Wildman said:
That front plate will move I'd think as you put the drop on. It is a transmission skid plate to protect your transmission pan from damage. I wouldn't remove it IMO.
Click to expand...
The thing is the kit only comes with the bolts and spacers to lower the transfer case skid plate, not the front part. Im thinking the front skid plate will flex a little if I only lower the back part? Or should I maybe stick some washers in there for the front too?
 
Lou said:
While this is true, a U joint can only operate any so many degrees before it creates vibes. Not sure what the exact number is for a 1310 but if you exceed this number you will still have vibes(even if they are the same angle).
Click to expand...

No arguement there. I just know I was able to get rid of my vibes on my YJ by adjusting the angle so with such a small lift I would think the u-joints would be fine. But maybe not.
 
Salhuerta said:
The thing is the kit only comes with the bolts and spacers to lower the transfer case skid plate, not the front part. Im thinking the front skid plate will flex a little if I only lower the back part? Or should I maybe stick some washers in there for the front too?
Click to expand...

I don't see why that front plate won't bend a little as you lower the main skid plate. It's just going to slope a little. I guess if you start to add the drop and that plate won't bend you could get washers and longer bolts but I try it without doing that first.
 
Wildman said:
I don't see why that front plate won't bend a little as you lower the main skid plate. It's just going to slope a little. I guess if you start to add the drop and that plate won't bend you could get washers and longer bolts but I try it without doing that first.
Click to expand...
I'm going to give it a shot tonight - thanks for the advice! I'll update you all in the after lol
 
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