1999 Other Jeep Models Drive train noise.

GOLFIAAM41

MEMBER
1999 JEEP
V8
AWD
AUTOMATIC
95,000 MILES

I have a 1999 WJ Grand Cherokee
When I come to a stop under medium to hard braking, once the truck has stopped and settles, there is a release of pressure that has been put on the drive train that causes a shock wave back through the drive train of gears slamming. I have few thoughts here,
1.(The suspension bushings are letting the axles move to much and once the pressure is gone from the stop it releases)
2. (There is some bad u joints, but does not make since to me on those causing it)
3. (The torque converter is not disengaging when I let of the gas until I have came to a complete stop, which sends a shock through the drive train)

5 Replies

SERVICE WRITER

MECHANIC
9,123 POSTS

By chance do you know what fluid is in the transfer case?

There was a problem with the transfer case on these (type 247) that was cured by changing the oil.

75W-140 synthetic gear lube and A container of Mopar Trac-LOK Lubricant (friction modifier). They had specified atf-3 or atf -4, but found that caused problems.

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Wednesday, January 14th, 2009 AT 6:24 PM

GOLFIAAM41

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I will check the transfer case out and change the oil.
Are the any other parts IE tranny, axles that could cause the issue I am having. Just incase the oil change does not solve the problem.

By they way thank you for the help!

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Wednesday, January 14th, 2009 AT 8:08 PM

SERVICE WRITER

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This is one that I wish I could test drive.
My suggestion may or may not help, but should be done regardless because of similiar ones I've read about.

When I read the description, my first thought is the brakes not releasing right. That can make a nasty sound/feeling.

I would be curious if this was put on a lift and run, if the noises could be replicated.

The Grand Cherokee's have had rear differential problems.

While the u-joints should get done, I agree that it doesn't make sense. IF there there were bushings that bad, I would think there would plenty of more symptoms. IF the converter was not disengaging, I would think it would stall the truck.

IT may help to have someone outside the truck listening for the general area while you pass them and brake. IT may become more evident in narrowing this down.

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Thursday, January 15th, 2009 AT 4:33 AM

GOLFIAAM41

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Thank you,
You said they have differential problems, is it the spider gears, ring and pinion, bearings?
Spider gears would make some since to me but want to make sure before I go in so I will be able to replace all if needed.

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Thursday, January 15th, 2009 AT 11:04 AM

SERVICE WRITER

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The right transfer case oil is the Chrysler bottle labeled NP 247 fluid, the right rear diff fluid is the 75w140 Synthetic with bottle of friction modifier also from Chrysler.

I didn't write that right in my previous post.

From what I understand, It seems that these aluminum housings tend to expand vertically when hot, so after a long road trip the side bearing preload is too tight and destroys the bearings. The cure is to set them up with no preload take about.005 off each OE shim and you should be real close.

It's been a long time since we have had one apart so I can't say specifically which parts are the problem child. We have replaced them with a rebuilt unit or used unit since then.