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[jbruvoll]

Hi all,

Just got my WJ back from having Rusty's 4.5" advanced lift kit fitted. Took it down the fields and into the forest - all well until I headed back up and had to use more power to get things up hill. About half-way up something went 'clunk' in the front end and I lost front drive. Now there's a slight grating sound from the front, which varies with speed (obviously all I've done so far is park it up as carefully as possible).

So - on the basis of me having no clue whatsoever what I'm doing - I've had a look underneath, couldn't see any leaks or any obvious external damage. I guess I've either broken the front diff or the drive shaft from the transfer box to the front. What's the easiest way of finding out which?

I'm wondering whether the changed angle in the drive shaft has somehow shortened the innards, putting excess stress on the bits left to connect with the diff. Does that make sense? Rusty mention that certain drive shaft types need a replacement kit (advice that I elegantly ignored at the time of purchase) - how can I see which type I have, i.e. what does a "Rezeppa" joint look like?

Given that the kit has just been put on, what else could have been cocked up, leading to this?

Thanks a lot in advance for your patience with a total newbie.

Best regards
Jan

[scrw]

expect it will be the CV in the driveshaft gone pop. 4" is really the limit for the rear CV joint. Take the shaft off and inspect it, 12 8mm bolts to remove it. New joints are around £30 each on ebay, and if you don't fancy doing it any decent garage will have it done in less than an hour.

[scrw]

repezza is a cv joint at both ends BTW, which is what you will have

[DarthLandy]

The CV on your truck has past the limit of operation. It is under tension all the time you drive on a +4 lift. When you off road you take it past that point and it breaks. Options are. Drop the transfer box but this will ultimately change all the prop angles. New prop with a double cardan UJ on one end this needs to be at the tranfer box not at the axle. You may suffer prop vibe after this in fact i guarantee it. You will then need to suss the degree xof twist on the drive flange from the front axle to eliminate. It can be a right pain. Or go single UJ prop (on each end) and again suffer prop vibe but more than the double cardan one. Double cardan both ends is a big no no.

Hope this helps (been there done that). 

[DarthLandy]

Me and Scrw have both been down this road btw

[scrw]

dropping the TC actually makes the problem worse as it increases the TC end CV angle. I have just gone down to a 3" lift and refitted a CV shaft. I did have a double DC prop on mine and got rid of vibes apart from at around 55mph, double DC shafts mean you can run the stock pinion angle on the front axle, but you will still see some vibes, especially if you stick with the 247 transfer case as it is a variable output, going to a 242 transfer case with real 4x4 output gets around this issue some more.

Wanna buy my tom woods driveshaft?  tis for sale.

I did try to live with a 4.5" lift but I do motorway commuting and the vibe was bugging me, so I have gone back to a 3" lift and a cv shaft, and will keep a spare TC end CV in the truck for when I blow it. I am looking at making up a hybrid CV to stop the rear going pop so often (standard rear outer with front inner parts)