Help! Speedo stops working?!

Hi All,
About 2 weeks ago I replaced my stock Speedo pinion drive with a 34 tooth. I have a 98 XJ and I just moved to a RE 4.5" lift and 31x1050 tires. I just noticed tonight that my speedo stops working when I make hard turns. It stops moving and then catches up in a few seconds (it's very noticable). I did have problems with the initial install where the O-ring broke and ATF was leaking out for about 50 miles. I replaced the O-ring and no more leaking.
Any help on what could be causing this would be appriciated. I don't know if it's related but about 3 days ago (after an off roading trip) there is a loud sound coming from the front drivers side. It sounds like a spring creaking as the suspension moves up and down. I thought it was normal for springs breaking in.

TIA,
Rough

are you sure that thedrive was put back in the right position?

I'm sure, I've been driving it in that position for 2 weeks and it seem to read about 1-2mph fast at 70MPH so it's about right for my tires. I also triple checked it when I was putting it back in with the new O-ring. It took about 3 trips and 4 different size O-rings to find the one that worked. I started from the right diameter and then worked from thickest to thinnest. I went with the thickest O-ring of the right diameter.

Rough

Still sounds like you either need to make sure the cable is screwed into the xfer case or the back of the speedo, or the gear housing needs to be rotated to engage the gear further.

I will check on all of that tomorrow when it's light out. Anything else I should be checking?

Thanks,
Rough

make sure the wiring is secured into the housing and not able to pull out when stratched.

Well 98 is electric. A few things to check. Like the others have said indexing, inspect the plastic gear itself for damage, wiring shorting out the output, or if some other gauges are affected it could be TSB 08-15-99 (I think) which was for the cluster connections getting oxidation.