jeepfool41

i HAVE A 99 GC,4.0 SELEC TRAC.WHEN PUT INTO 4WD i AM GETTING a terrible grinding noise and jumping.someone told me the dana 30 was bad for pinion bearings so I swapped out the entire front diff. same noise,then i purchased a used 242 tcase,swapped it out,same noise.no noise at All IN 2WD,BUT SOON AS IT GOES INTO 4WD IT STARTS AND IS A BEAR TO GET OUT OF 4WD

TXstiGuy

Welcome I say it was the chain but you said you changed the case is the driveshaft seated properly and are the u joints good did you check for play in them when you replaced the case

mudfrog

Are you sure the gear ratio is the same in both axles? I test drove a suburban once that had mismatched gear ratios. It jumped and grinded like you described.

jeepfool41

ujoints are good driveshaft is seated,ratios are the same 3.55.even bought new rear tires today to match the new front ones in case that was throwing the final ratio off

TXstiGuy

maybe it's just a pos then nah i'm kiding. Man i'm not sure unless the replacement case is bad too.

jeepfool41

im starting to think it is a pos,of course its my wifes pos.and she wonders why i like my lifted xj better.think you are right on the bad case,nothing toi engage and disengage in the front diff.so im leaning toward my replacement case being bad too.just my luck i get one with exactly the same problem as my original

TXstiGuy

Man it happens i'm guessing salvage yard. I had to replace the aircon control in my xj "***** by the way" went through four of them

jeepfool41

havent had a chance to pull the transfer yet because its my wifes daily driver.she called me on her way home from work tonight said it was starting to make the noise in 2wd as well.i guess when i get home from work after midnight tonight im gonna pull the front driveshaft,see if that helps get her by till this weekend when i can try another tcase

jeepfool41

hey guys,i know this is probably a stupid question,but is there any way my front drive shaft could be causing these troubles?

jeepfool41

OK guys,stumped here. tore apart the original front diff,no problems,took apart the original tcase,no problems,could it possibly be the driveshaft?

OverlandZJ

I had a guy want me to swap in a 242 in his WJ, he had the same symptoms. He bought and had waiting a new replacement transfercase.

When i got under and started working i noticed the front driveshaft had a blown CV joint at the front output. This is common from the little i looked into it.

I'd pull the front shaft and take a good look at it... but you said it had typical ujoints?

jeepfool41

sorry,i mis-spoke,it doesnt have typical joints,just meant the joints(cv's) didnt have any noticable problems.really the shaft is the only thing left,i guess it has to be it,ive already ruled out every other component

dave1123

How about the splines in the front driveshaft? They could be whipped.