xj92

Since the last time I posted with with a question about my instrument panel.

I have installed my 4.5in RC lift, with 31in a/t.

I replaced my a/c blower motor, so now my heat works, which it great because it is starting to get cold here in Michigan.

and I just replaced my wheel U joints.

Ever since I installed my lift, I can hearing a grinding/rubbing noise, and feel a slight vibration in the floor/gas pedal, when I'm driving above 40mph.
It happens whenever I let off the accelerator, and then again when I press the accelerator.
It is not a constant noise/vibration, it is just for about a half second or so.
It seems to be within a certain area of the gas pedal, because if I want I can find the sweet spot, and keep the noise, and slight vibration constant.

Just to sum up,
It only happens when I'm driving above 40mph, and I'm accelerating/decelerating, and I pass the "sweet spot" on the gas pedal, I'll just hear and feel it for a half second or so.

I guess my question, is what do you guys think the noise and vibration is coming from, and could it be because I don't have an SYE yet?

i'm sorry if i have not explained my question very well, if anyone has any question about what i'm trying to say, just ask and i'll try to go into more detail.

thanks in advance

Josh

Belto

well im not 100% sure, but you might need a SYE maybe a tcase drop will help, if that helps well you got it.. but people say that the drop is only a temporary fix before getting a SYE.. but I let some1 with more expirience help out..

okcjeeper

Eh could be bad u-joints that were exaggerated upon lifting and altering the angles..but more then likely you will need a TC Drop..Mine did this till I changed u-joints but my u-joints were in very very bad shape before the lift.

xj92

well my RC lift came with the drop spacer that I installed, so I guess my question now is what dose the driveshaft vibration feel like before you guys installed your SYE?

I'm thinking I'm going to do a hack and tap once I get the funds. I have heard of people using the front driveshaft from a cherokee, and usind it for the rear. But the front drive shaft is somuch smaller than the rear, so how dose that work out over time?

fox128

i just put a 3.5 on my xj, and am having the EXACT same thing happening-just like you say, growling/grinding when i let off and get back on the accelerator at 40+. I put a tc drop in as well and it didn't help with that. I took the front driveshaft off and tried it, because it almost sounds like its coming from the front, but that didn't help either. I am also leaning towards the hack n tap, becasue i'm not excited about tearing into my tcase, or i'd esle i'd spend the extra $60 and put the porc sye in. Do we need to buy a yoke to work with a front shaft, or does the hack n tap include one? If you get it figured out let me know, and i'll do likewise, because it sounds like we have the same problem

okcjeeper

Question do either of you have any shims in the rear to adjust the angle of the rear axle/driveshaft?

xj92

I bought the whole leaf spring package, so on the bottom of the RC leaf spring, there is a little shim angling the axle upwards slightly. I think that is what you mean.

thanks for the help

fox128

I put the re 4* shims in right away. I changed my mind once again and might just order the porc sye....it will probably pay just to do it right the first time, even if it will take some more work.

MasterShakeXJ

i shimmed my rear axle after i did my sye. i rode around with like 4" of lift with no sye, the vibes were only bad at certain times but it was managebale. you might want to seriously look into getting one though

okcjeeper

Next question when you guys added shims did you measure how much shimming you needed? Before adding shims you need to measure your angles so you know how many degrees you're off in either direction. I'll try to find a link to directions on doing that..

fox128

no, i didn't do that, i just looked around on here and found someone that reccomended a 4*, and i was kinda expecting to put a sye in anyway and my understanding is you want it shimed with a cv anyway.

So, i changed my mind for the final time and just ordered the AA sye kit from porc. Won't be here for a week though! should give me plenty of time to get my hands on a front shaft anyway

xj92

what type of drive shaft are you looking for? a Tom Woods DS, or a driveshaft from another vehicle?

fox128

i'm going to get a front shaft from another xj for now. if i see a need at some point i'll get a tom woods or something different. for now, i'll stick with the $50 option. I'm actually headed to the jy this afternoon

xj92

OK cool, let me know how much you have to spend, because I think the JY around me over price things.
But what about the front drive shaft being smaller then the rear drive shaft? Will the smaller drive shaft be able to hold up being a DD, and at Highway speeds?

fox128

well, it looks like jeeperscreepers is running a front shaft with 35" tires and apparently its strong enough. as far as being a dd, i'm not too worried, becasue if its good enough for the front it should work fine in the back. if it doesn't work, i'm only out $50 i guess and i'll get a tom woods or something. PORC said i won't have the sye for a week, but i'll let ya know how it goes when i get it installed