Front Transaxel problem?????

:confused: I was on lunch break from jury duty yesterday and noticed a bad metal ticking/ grinding sound coming from my front end... First i thought it could be my trans but there was no slipping and it was shifting fine! It would almost completely stop when my jeep did.... but not quite.. I held the brake down and lightly stepped on the gas and the sound would come back.... Since the vehicle is all time 4WD I decided to pull my emergency brake and slightly press the gas.. When I looked under my jeep and noticed the front driveshaft was spinning and the noise would increase when of course it shouldnt be spinning at all. I am pretty sure that its the front transaxel... any other ideas as to what the problem is and how much it may cost me to fix would be greatly appreciated before I bring it to the mechanic!!! thank you

Look for stripped splines on the cv joints at the axle ends or a broken ujoint there.

could also be a broken diff spider gear pin in the diff case.

JD

If you're front wheels aren't turning and your front driveshaft is spinning, then several things could be wrong with it. Check to see if the axle joints are broken. If you have U-jointed axles, the damage will be obvious. If you have CJ joint axles and see movement on the inner side of the joint, then the axle is broken. I would HIGHLY recommend that you not drive the vehicle until you figure out what it is. If you have a quadra-trac (full-time all the time) and you're front axle is broken, then you might be overloading the limited slip mechanism in the T-case. It's a viscous coupling for a NP249 case (93 - 98) and a gerator pump for a NP247 case (99 and newer). Either way, you can ruin the T-case if you keep driving it that way. I'm guessing that you might have a broken axle shaft or differential gears. If you take the wheels off and spin one by hand (with the vehicle in park), then the other wheel should spin the other direction - or the driveshaft will spin. Check both wheels - if on even one of them neither the other wheel or the driveshaft spins, then you either have a broken axle shaft or broken differential gears. An axle shaft should run you around around $150 or so. If this is the problem, I would recommend that you buy a U-jointed replacement (assuming the CV broke) as the U-jointed axles are far stronger. They should be around the same price. (My 93 GC had CV joints - NP249 w/no low-lock, and my 98 has U-joints). It's hard to say about the gears. It's quite unlikely that you would have broken those I would think - but you can easily find out by removing the front diff cover (draining the fluid out) and inspecting the gears. Make sure the wheels are off the ground so you can spin the wheels to see the backside of the gears if you do this. Good luck.

Posted by tinman1973 - 12-02-2004 at 02:58 PM:confused: I was on lunch break from jury duty yesterday and noticed a bad metal ticking/ grinding sound coming from my front end... First i thought it could be my trans but there was no slipping and it was shifting fine! It would almost completely stop when my jeep did.... but not quite.. I held the brake down and lightly stepped on the gas and the sound would come back.... Since the vehicle is all time 4WD I decided to pull my emergency brake and slightly press the gas.. When I looked under my jeep and noticed the front driveshaft was spinning and the noise would increase when of course it shouldnt be spinning at all. I am pretty sure that its the front transaxel... any other ideas as to what the problem is and how much it may cost me to fix would be greatly appreciated before I bring it to the mechanic!!! thank you

You might possibly have a broken pinion shaft in the front differential. It's not all that common, but I have seen them shear off before. Then again the splines to the bolt on yoke of the front differential could be stripped.

It would be impossible for the splines on the slip yoke (yoke attached to front drive shaft which slides into transfer case) to be stripped. Because then the drive shaft wouldn't be moving at all.

I doubt very seriously if the problem would be with your CV (constant velocity) joints or which ever type of U (universal) joints it is your front drive shaft does have. Being that there all universal joints, just different types. When those go out depending on the severity you would experience anything from a clunking noise when first engaging the transmission into gear. Or the worse case cenerio the drive shaft falling out and laying on the ground. In either case and also if your drive shaft itself is broken I can't see how that would enable the shaft to spin freely.

I would say most likely that it's absolutely a problem concerning your front differential as the other poster's have also implied.

To clarify, I was referring to the AXLE shafts - not the driveshaft. Obviously, if the joints in the driveshaft were broken (especially with a Full-Time T-case), then the symptons would be different and the driveshaft would probably have fallen off of the vehicle already. I agree that the splines in the driveshaft slip-yoke or the pinion shaft could cause the problem, but I highly doubt the splines would fail. The weakest link in a D-30 front end is the axle shafts. On the D-35 I blew-up, the pinion shaft sheared in half leaving the splines on both the yoke and the driveshaft in perfect condition.

Far as the axles go. Sorry, yes I did think you meant the driveshafts, not axle shafts. And you might notice right in the first sentance opps maybe second sentance, I wrote the following.

but I have seen them shear off before.

Meaning of course the pinion. Which I had just mentioned the line before that.

Thanks for the clarification. Sorry I misunderstood.

Gotcha. Yeah, either way it's definitely a strange failure. If it is the pinion shaft splines, that would certainly explain it. I imagine a very loud sound would accompany it if that helps. The only failure that might not be super audible might be an axle CV failure - tho I would guess it might crunch pretty good when it blows.