77olds

Looking to hear from anyone who has had that problem.

When I first start driving while my XJ is cold, there is a rattle that I only hear while in motion, and it sounds like it's coming from the front end somewhere. It's constant with speed, doesn't seem to get any faster or slower, just stops when I get to about 5mph and is inaudible above 40mph.

Sounds exactly like a chain being dragged across a piece of metal. More noticeable in 2wd than 4, and it goes away completely after about 5 to 10 miles and doesn't come back until it gets cold again.

I'm pretty sure my transfer case chain is stretched, but I wanted to hear from people who have had to replace their chains to know of my symptoms line up.

cruiser54

I'm gonna bet your engine mounts and trans mount are shot, allowing teh exhaust pipe to vibrate against the trans/transfer case crossmember.

77olds

Nope, mounts are good. Exhaust doesn't shake or rattle or come into contact with anything, and even if it does, that's not the sound.

I'm pretty much positive that it's the t-case chain, the noise changes when I put it in 4. Just wanted to hear from others who have had this problem.

weebur

You might want to drain the fluid in a clean pan and check the condition with a bright light and a magnet for metal particles.

peep

You can see the TCase chain thru the fluid drain hole. (Refill with Dextron Type Trans Fluid)
Check it for slop.
The chain can be replaced by pulling the rear casing off the TCase while the TCase is in the vehicle.
Have you considered any loose fasteners of the flywheel to the torque converter. Can be checked by dropping the lower cover.
I do assume all other fluids (differential?) are up to snuf and all universals driveshafts and axles are in good shape. Any accompanying vibrations?

77olds

I looked it over really well, nothing is loose. Haven't inspected the chain, I'll do that tomorrow. I have access to a hoist so that's not a problem at all.

rompnXJ

you'll know when your chain is stretched 'cuz you'll get this loud popping/banging sound when throttling hard in 4 wheel, especially low range.

Here's a lazy way to check it, it's how I found my stretched chain.

unbolt the front driveshaft from the axle. put it in 2H, grab the front driveshaft and quickly spin it 1/4 turn back and forth by hand, if the chain is stretched you'll hear it slapping against the case.

if it needs replacing get a wide kit and don't look back.