Drive Angles

[97wr@ngler]

just had a lift put on and they had to weld some square tubing along the frame where the belly pan is. my question is i have alittle vibration when shifting gears, can i shim the belly pan to drop the transmission alittle so there is not so much drive angle?

 

[JPNinPA]

Yep! What type of lift?

 

[97wr@ngler]

Yep! What type of lift?

4in Rough Country

 

[Bounty__Hunter]

The 4" Rough Country kit comes with the proper transfer case lowering kit, and it should NOT be welded to the frame. If they welded it, chances are the nutserts holding the skidplate bolts to the frame spun inside the frame and they wanted an easy fix.

You shouldn't have any vibration after installing that kit (properly).

I would check the condition of your rear driveshaft ujoints and your caster.

 

[97wr@ngler]

The 4" Rough Country kit comes with the proper transfer case lowering kit, and it should NOT be welded to the frame. If they welded it, chances are the nutserts holding the skidplate bolts to the frame spun inside the frame and they wanted an easy fix.

You shouldn't have any vibration after installing that kit (properly).

I would check the condition of your rear driveshaft ujoints and your caster.

I just had the plate off like an hour ago to replace the trans mount and while I was down there I played with the drive shaft and there was no wiggle room

 

[JPNinPA]

The new trans mount may dampen some of the vib and the bad one may have been some of the cause. RC makes a fairly good lift. I'd call them being it was just installed.

 

[97wr@ngler]

The new trans mount may dampen some of the vib and the bad one may have been some of the cause. RC makes a fairly good lift. I'd call them being it was just installed.

I just got done chatting with them and i was told I could put shims around the plate to drop it alittle more

 

[Bounty__Hunter]

How do you know it's your rear driveline?

Consider removing the front driveshaft and see if it changes after a test drive.

 

[ademondad666]

How do you know it's your rear driveline?

Consider removing the front driveshaft and see if it changes after a test drive.

I also have the RC 4" x-series lift on a 97 wrangler. I also have vibrations, now, I have sye/cv driveshaft, and transfer case drop, with out the drop kit, it vibs crazy, with it, its so so, little vibs but blows u joints. iv leveled the front end with 1 3/4" spacer, hoping for improvment, but no. so im also thinking of putting 1" spacer on the back now, since i all ready have them. would riser motor mounts help,or is that only with body lifts? what I want is no drop kit and no vibs. the rear end is pointing at the transfer case, and what iv read is, that is what you want.is it? on the driveshaft, looking with naked eye, it seems to look twisted at the double u joint part. what caused this? new transmission mount too, and no differance. Iv been constantly researching for answers but they all differ.please help, thanks :???:

 

[Jester32]

You want the rear u joint angle as close to zero as possible with a double cardon driveshaft. I would check that first then possibly have the balance of the shaft checked. Its hard to get rid of vibs on wranglers with lift. Such a short driveshaft.

 

[Jason4x4]

would riser motor mounts help,or is that only with body lifts?

I installed them with a 1" body lift to make room for a t-case tummy tuck, but reading the literature that came with the riser motor mounts, it suggests that they can be used without a body lift. The reason you would install a motor lift with a body lift is basically to keep from having issues with the fan shroud and the like as if you didn't raise the motor the fan would stay in the same location but the shroud/grill would be raised up.

If you don't install a body lift but install riser motor mounts, you will be lifting the engine. The transmission/t-case which of course is attached to the engine stays where it's at on the frame, but since the front of the assembly (the engine) is raised the rest will rotate on the crossmember so the back (the t-case) will be pointed down towards the rear axle which will improve your driveline angles. The riser motor mounts are relatively cheap, so I would definitely give it a go to see if it helps your situation. Just remember you're probably going to have to trim your fan shroud if you don't install a body lift (i.e. the fan will move up but the shroud stays where it's at). I just installed a 4" lift (Skyjacker coils/shocks but with full Rough Country X-Flex arms upper and lower and a SYE (and the aforementioned body lift/motor mount lift/tummy tuck) and fortunately I have no vibration issues.

 

[Bounty__Hunter]

I also have the RC 4" x-series lift on a 97 wrangler. I also have vibrations, now, I have sye/cv driveshaft, and transfer case drop, with out the drop kit, it vibs crazy, with it, its so so, little vibs but blows u joints.

I'll pose the same question to you, are you confident that the vibes are from the rear and not the front driveline?

Get adjustable upper control arms for the rear if you don't already have them, and remove the transfer case drop. A SYE and TC drop should never be used together, especially with a 4" lift. Then ensure the rear axle pinion is directly inline with the driveshaft.

Also remove the front driveshaft to see if your vibes change. My guess is you don't have the correct balance between front pinion angle and caster.

 

[ademondad666]

ok well, ill take the transfer case drop off, then measure the rear drive angle. it wouldnt be the front driveshaft in my case?, would it, cause i keep blowing rear u joints. but i will take the front one off to test it. if all fails get riser mounts, if that fails, get my driveshaft balance checked.
and thanks you guys, iv been letting my jeep sit for too long, and being snow is on the way,well we all know how fun that is.:shades:

 

[ademondad666]

I took the front drive shaft off to see, and i dont think that is the case. still vibes, but i havent got the chance to change the rear drive angle yet but it is not zero at all, so when i get the chance that will be next,to adjust it up. do they make rubber riser motor mounts or just poly?