Vibration when I hit the gas pedal...

[calvynandhobbs]

My 98 TJ sport had a 1" MML and a SYE with Tom Woods driveshaft for the 4" lift to keep the angles correct. I think I remember you having a 4" lift in your TJ. Did you do anything for your driveshaft angles with that lift (t-case drop, etc.)? If not, I'm surprised you didn't have problems already.

[Coqui]

Yes, RCA 4" n2.0 lift kit came w/TC drop....nothing else to adjust DSline. Any suggestions on MML?

[gearhead1985B]

Wow gearhead thats a ton of work which could all be avoided if you switch to superflex joints. It would fix your binding issues, and the fittings are on the caps so you would never have to pull the shafts again. Just grease and go. They are $60 each but it will be the last joint you buy for a while.

not really concidering how often i go through u joint straps i break at least one in weekend of hard wheeling i would be fine if i could use ubolts on the tcase end but i have no room to get a wrench behind the yoke unless i pull the tcase skid life would be a lot better if i would add a 1" tcase drop but i would lose an 1" of clearance and i like not ever dragging my belly and my fix is better than super flex joint i am just going to install a hp d60  and remove the lp d44 and that will reduce my ds angles enough and add some 1350 joints i will be good (yes i know 1350 has less of an operating angle but i will be running lees droop and more up travle  to even it out)

ex of light wheeling
http://www.youtube.com/watch?v=aURyHLMm8Fs&feature=plcp

hard wheeling (not me the camera ran out of memory but i ran it right after this run and i took pretty much the same line)
http://www.youtube.com/watch?v=AGxozFHu5l8&feature=plcp

[Mayhem]

Yes, RCA 4" n2.0 lift kit came w/TC drop....nothing else to adjust DSline. Any suggestions on MML?

I have JKS and they seem to be very well made.  With 4.5 RE lift I have MML, SYE, and Tom Woods driveshaft.

[JohnC]

not really concidering how often i go through u joint straps i break at least one in weekend of hard wheeling i would be fine if i could use ubolts on the tcase end but i have no room to get a wrench behind the yoke unless i pull the tcase skid life would be a lot better if i would add a 1" tcase drop but i would lose an 1" of clearance and i like not ever dragging my belly and my fix is better than super flex joint i am just going to install a hp d60  and remove the lp d44 and that will reduce my ds angles enough and add some 1350 joints i will be good (yes i know 1350 has less of an operating angle but i will be running lees droop and more up travle  to even it out)

ex of light wheeling
http://www.youtube.com/watch?v=aURyHLMm8Fs&feature=plcp

hard wheeling (not me the camera ran out of memory but i ran it right after this run and i took pretty much the same line)
http://www.youtube.com/watch?v=AGxozFHu5l8&feature=plcp
[/quote]

Sounds like a good plan. I run 1350's on my hp D60 and have 18* on my drive shaft and 5* caster. I went to 1350 yokes on both the ds and pinion and have a ton of clearance (angle wise). I have more clearance with the 1350's than with the stock 1330's that I snapped almost every time i wheeled hard. I havent broken anything since the switch and run a 1350 superflex to give it even more clearance. You shouldnt have any issues with operating angle but if you do rotate the knuckles before you install the axle. Just dont go below 3* positive.

[kirksjeep]

I know it is more $$, but the SYE and new driveshaft is the way to go.  Besides fixing the driveline angles it also seals the back of the transfer case in the even you have to pull the rear driveshaft due to damage on the trail. 

[calvynandhobbs]

I know it is more $$, but the SYE and new driveshaft is the way to go.  Besides fixing the driveline angles it also seals the back of the transfer case in the even you have to pull the rear driveshaft due to damage on the trail. 

x2 on this statement. With a SYE if you blow a rear driveshaft ujoint or mangle the rear driveshaft you can remove it and front wheel drive yourself out of the woods. Without it you lose your t-case fluid. Just an added security when on the trail.

[gearhead1985B]

I know it is more $$, but the SYE and new driveshaft is the way to go.  Besides fixing the driveline angles it also seals the back of the transfer case in the even you have to pull the rear driveshaft due to damage on the trail. 

or go the real expensive route atlas

[JohnC]

I know it is more $$, but the SYE and new driveshaft is the way to go.  Besides fixing the driveline angles it also seals the back of the transfer case in the even you have to pull the rear driveshaft due to damage on the trail. 

x2 on this statement. With a SYE if you blow a rear driveshaft ujoint or mangle the rear driveshaft you can remove it and front wheel drive yourself out of the woods. Without it you lose your t-case fluid. Just an added security when on the trail.

Or you can just do what I do and get a cap, which installs over the end of the tcase and do the same thing for a whole lot cheaper than an SYE.

[skibum]

The only reason manufactures installed the slip yoke into the Trans or T case was because it was cheeper and it worked fine for a stock vehical. Once you start to modify the rig then the stress on the tail shaft housing becomes to great and wears out quickly causing leaks at the tail shaft seal from wearing brass bushings and bearings in the tail shaft housing. Installing a SYE benifits in many ways but more so for short wheel base vehicals like the CJ's,YJ's &TJ's to extend the drive shaft a few inches to help reduce the operating angle. The NP231 and other Jeep T Cases are weak at the tail shaft area compaired to a 1/2 & larger truck T Case housing and also the angle of the rear drive shaft is not even close to a short wheel base jeep. What im trying to say is a standard slip yoke in a Fullsize 1/2 & up truck will hold up to more abuse than a standard slip yoke in a jeep but still will wear out. A SYE is a stronger design and will outlast any standard slipyoke off the tail shaft. Ford installed alot of Slip yokes in there drive shafts. Guess they felt it was worth it. GM, Dodge & Jeep just went the cheeper way. I do have to say you rearly see a leak at the tail shaft on a SYE style setup.

BTW we went far off the subject of "Vibration when I hit the gas pedal"  LOL

[Coqui]

Still chasing the vibration gremlin that happens at around 25MPH and higher…. 

Transmission Mount looked good after removal and inspection.

Installed new Spicer ujoint rear DS.

What’s wired about the vibration is that it only happens while pressing the gas pedal.

[kirksjeep]

I would look at the pinion angle if it is only when on the skinny pedal.  When accelerating the pinion wants to tip up.  If you have adjustable control arms you might want to tilt the pinion down a degree and see if it helps.

[skibum]

If the vibration was not there before you went wheelin then something is warn or loose. There is nothing better than a good visual inspection. If you did not see anything the first time then go back again because your missing something.

[Coqui]

Right on, Looking into a bent TC output shaft.

[Coqui]

Removed rear DS, took the jeep for a spin on 4hi......no vibrations.

Returned home got under the jeep noticed output shaft is bent and whobbly.

Anyone have a spare TC output shaft for NP231J that I can buy?