Transmission question

[bmwgolfguy]

I am a newbe to Jeeps and in particular a Cherokee.

I just bought two of em. One for my son and one for me. His is an 01 Sport with 83k on it and mine an 01 with 74K.

My question is this. When the vehicle is in reverse and you slip it into drive with your foot on the brake, there is a very loud/audible clunk. It only seems to do this in this situation alone as just described.

I am told by a reputable mechanic, in fact the guy who sold them both to me, that this is normal. He says this is within Jeep tolerance.

I have no basis to disagree with him as these are my first two jeeps and both do it under the same circumstance. I am a bit nervous about this for a couple of reasons. First, I have been a GM guy for a lot of years and have never dealt with these kind of transmission sounds with any of those vehicles unless there was a problem. Any one GM I think would attest to this. Second, of late, mine seems to slip a little tiny bit upon acceleration and also when coming to a complete stop. When stopping there is a little tiny rattle/slip sensed or heard or felt. Both of my vehicles are automatic transmissions.

I believe the guy who sold them to me who also is a 4x4 shop, but he will work on anything. Is this normal the klunking that is. And should the little tiny slippage that I think I am sensing be cause for concern.

The seller/mechanic has given me a 3 month 3000 mile warranty, so now is the time to speak up. They both are still under that warranty.

Thanks in advance.

[MagicRat]

Check the driveshaft for bad U joints or a bad/loose slip joint. Also, make sure the spring U-bolts are tight.

My Jeep and my '83 Chevy van sometimes clunk a bit too, even though there is noting obvious wrong, except a bit of wear. However, there may be problems. Check it out before the warranty ends. Often this clunk, especially if its bad is NOT normal.

[AlohaBra]

quote: "My question is this. When the vehicle is in reverse and you slip it into drive with your foot on the brake, there is a very loud/audible clunk."

Ok...this is going to be subjective...but yes there is a clunk.

• the Jeep is a noisy vehicle
• when you shift from R to N to D, that reverses the direction of the transmission output shaft and there will be a clunk
• the clunk is the rear drive shaft reversing direction
• there is also a clunk from the leaf spring absorbing the change of torque
• how bad is the clunk? that depends if U-joints are worn or other issues with the suspension or driveshaft

Hope that helps you...others may address your question when they get back from this Memorial Day holiday.

[sector95]

Yup, my 2000 Sport does the same thing....seems to be worst when the fluid is warmed up. It is....the nature of the beast. You bought a Jeep...two of them!...so you'll get a double doses of their little quirks.

Mike
00XJ

[bmwgolfguy]

Originally Posted by sector95

Yup, my 2000 Sport does the same thing....seems to be worst when the fluid is warmed up. It is....the nature of the beast. You bought a Jeep...two of them!...so you'll get a double doses of their little quirks.

Mike
00XJ

Thanks for the reply Mike. My son's (blue one) shifts smoothly with no jerks unless you go from a stop in reverse with your foot on the brake to drive, then there is usually an audible klunk. I am told by more than one person, that is normal.

The part that is bothering me on mine (black one) is there is a tiny tiny hesitation when you start from a standing stop in drive. I can only describe it as a slip. It also does this occasionaly when you stop when the car is in drive. This is very disconcerting to me. Like I said, I am used to GM tranny's and for the most part that is one thing GM seems to do right.

Last time I had it in the mechanic told me everything was tight down there. I am cool with that if in fact this is normal. I just don't want to find out in 2 months I need a whole new tranny rebuild to the tune of a couple of grand.

thanks again.

[AlohaBra]

I think a fluid change might be in order.

[bmwgolfguy]

Aloha:

I checked the tranny fluid when hot and it was clear and full. Does that change your suggestion?

Thanks.

[sector95]

Originally Posted by bmwgolfguy

Aloha:

I checked the tranny fluid when hot and it was clear and full. Does that change your suggestion?

Thanks.

One of the problems of buying a used vehicle is its unknown history....even CarFAX won't find all the glitches (like you found out with your door seal problem).

Me, myself and I like to change all the fluids in any used auto I buy...this way I know: a) it has been done and b) I have a mileage baseline to schedule any future fluid changes. I usually do it myself so my cost is my time plus the fluids. A Jeep, even a modern one, requires you to brush up on your basic mechanical skills to keep the old girl happy.....or have a reliable shop to do the work for you.

Just some things to consider......

Tranny fluid is great stuff and it will last just about as long as the vehicle *if it's normal operating tempurature has not been exceeded*. Once tranny fluid is heated to the point exceeding its limitations, it breaks down quickly and does not recover. The color of tranny fluid is not a good indication of its health either; it will darken as it ages and unless it is fresh out of the bottle pink, you really have no idea how old it is. The old adage of it smelling like "burnt toast" is still a valid way to determine if it has been running at excessive temps. Has the vehicle ever been used to tow? Has it been slogged around in off-road conditions?...these are actions that will trigger a required fluid change on a regular basis. Look in the owners manual in the scheduled service sections to find the actual requirements (I don't have mine handy as write this).

Chances are your tranny fluid is fine....but it wouldn't hurt to change it. Will changing it stop the "clunk" you experience?....I doubt it...it didn't with mine.

The other fluids to consider are the transfer case (very easy to change and uses about a quart of DEXRON II or III tranny fluid) and front and rear differentials. A lot of guys swap out the dino-based axle lube for synthetic fluid....under the guise that it might save some fuel (an almost unmeasureable amount) and also because the factory recommends the synthetic stuff (rear axle) for trailer towing operations.

Mike
00XJ

[bmwgolfguy]

Hey Mike:

Thanks for all your help. When I was a younger fellow, I used crawl around underneath my cars and do a lot of that stuff myself. I have sons now who can do that stuff for me. Thanks.

I will have those fluids replaced as you say, but probably go with the Dex and not the synthetic.

Thanks again.

Kent

[longfellow]

My Jeep does the same thing' but usually only when warming up. Idle is up some at start up. Also everything checks out underneath mechanically sound.
Also had trans cked. out , fluid change , mech ect. found no problems.
Been that way evey since I bought it.

[Raimundo]

Despite of what others say and with all the respet to all of them,,,,when you have a "clunk" something is wrong and it cuold get worse. Check every thing they told you and also check the idle speed. sometimes the jeep's idle increases for cooling porpuses and then you may feel like a "push" when you shift but not a "clunk" no way should be that hard and loud!!!!

[AlohaBra]

Aside from the idle speed, it might be worth looking at the rear u-joint and the play in the rear diff. You can disconnect the rear drive shaft to inspect for wear or excess play.

You can even start it up and try it with the shaft disconnected.

Noises are best diagnosed on a vehicle lift with some one standing underneath.

[Raimundo]

Originally Posted by AlohaBra

Aside from the idle speed, it might be worth looking at the rear u-joint and the play in the rear diff. You can disconnect the rear drive shaft to inspect for wear or excess play.

You can even start it up and try it with the shaft disconnected.

Noises are best diagnosed on a vehicle lift with some one standing underneath.

Hey AlohaBra, now that you mentioned it, if mine has diff. play ,,,, to expensive to fix it????

[AlohaBra]

Actually that can be adjusted, but isolate the problem first.