• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Worn out u-joint

cdnxj

NAXJA Forum User
Ok... I just want to see if I got this right. There is a popping noise coming from the front and I only (usually) hear it when I'm driving slowly, mostly second or first. I think its the front driveshaft u-joint as it goes into the diff. Now the driveshaft turns all the time right? It's only when I shift the t-case to 4 hi/lo that a vacuum engages the front diff? The u-joint in question is very loose and when I shake it; its the same tone as the sound I hear. Therefore if I replace the u-joint the noise should go away? Any specific type of u-joint I should use/stay away from?

Any help here guys is appreciated as I have a 15 hour drive again on the weekend.

Marty

'91 XJ 4x4, 2 dr, 5-spd 224,500 km and counting. And a Punisher sticker!
 
I got my replacements (I bought 2 of them) years ago at autozone and they came with a lifetime warranty. Now whenever I need a new one, I just got get a warranty replacement for free.
 
People tell me spicer brand available at NAPA are the best. The good news is this will be easy to replace, and you caught it before it broke and did some damage.
 
note the front driveshaft does not turn when in 2H with an disconnect axle front will only turn if axle is connected or if 4H or 4L is selceted
 
crazyray said:
note the front driveshaft does not turn when in 2H with an disconnect axle front will only turn if axle is connected or if 4H or 4L is selceted

OK... So if the front drive ISN'T turning then why would a worn u-joint there make a noise like that? I'm pretty sure I'm not in 4wd as I know that my lever is in 2wd and you would just know, wouldn't you? Then again if the light wasn't on how would you know? Regardless the joint has to be replaced. I have checked all the other u-joints in the front end, and I know that they were replaced when I got the truck as it was a gov't safety thing. It's the only one that is loose. Everything else up there is tight.

Thanx,
Marty

'91 XJ 4x4, 2 dr, 5-spd 224,500 km and counting. And a Punisher sticker!
 
MoFo said:
The '91 does not have a disco axle, so your U Joint is turning all the time.

So (stupid question) does this mean that I have an all wheel drive truck? Then (another stupid question) why would the transfer case have 2h and 4h/lo? I thought that I had it all figured out. The problem is that I have no owner's manual for the thing and the guy I bought it off of has no Jeep experience.

Thanks again guys.

Marty

'91 XJ 4x4, 2 dr, 5-spd 223,500 km and counting. And a Punisher sticker! AND a chrome skull shift knob!
 
No, it's not an all-wheel drive. The axle disconnect is gone so forward motion of the Jeep will make the driveshaft turn, but that is 'residual' from the axles driving the differential. The front output of the t-case isn't engaged.

Don't use the 4H or 4Lo unless you are in conditions where you actually have wheelslip. Rainy roads aren't enough for that, and although 4H works on snowy/icy roads you don't want to use it in patchy conditions if you can help it.
 
Thanks Yucca-Man, I just wasn't too sure how the system worked. I got about 5 different stories from guys I know around here, but your explanation makes alot more sense. It seems to me there are at least a couple of different systems in these things. So long story short here is I need to replace that u-joint asap or it's going to wreck something. I guess it would be best to use one with a zerk so I can grease it?

As for when and where to use the 4h/lo I haven't even thought of it yet. Nowhere I 've gone with it required it. Besides winter here will come soon enough!!!

'91 XJ 4x4, 2 dr, 5-spd 223,500 km and counting. And a Punisher sticker! AND a chrome skull shift knob!
 
Re: Worn out u-joint--how to get owners manual and gen info on w heeling

You can buy an owners manual for your particular year on ebay, you may have to put in a "search favorites" for your particular year until one for your year comes up, but it will be pretty cheap and should at least get you an owners manual for your year.

I got an owners manual for my 90 xj that way.

As for "2 wheel drive, 4 hi, 4 lo." etc Two wheel drive is for street. You could use full time 4 wheel drive if you have it, on street but I've found the vehicle doesn't drive as well with full time.

You can use any drive on dirt, 2 wheel, 4 wheel full time (if you have it)
4 wheel hi part time, 4 wheel lo part time.

In part time drive your front and back axles will each have 50% of the power, and and in turns front wheels will travel less distance than rear , so you will have wheel slip and need to be on a surface where the wheels can slip a little, otherwise you will have wheel chirp (noise) and will use up rubber quicker.

You might get a good book on 4 wheel driving like 4 wheeler's bible, or
4-wheel freedom or harry lewellyns book (not sure of name).

You can find these used on amazon or by looking in bookfinder.com
 
The offending u-joint has been replaced. I took it to a place here called the Jeep Doctor, and they replaced with a Spicer joint that's all shiny... End of problem. I was going to do it myself but they had the wheels off (got new tires today) and it cost next to nothing. Thanks to lapaul for reminding me about eBay, I picked up a '91 manual on ebay.ca for next to nothing. Thanks guys!

Cheers!

Marty

'91 XJ 4x4, 2 dr, 5-spd 224,500 km and counting. And a Punisher sticker!
 
Back
Top