Rear end noise

liberty2.8 · **Posted:** Fri Nov 14, 2008 2:34 pm

Noticed the other day when idleing around a parking lot that I frequently have a bumping sound coming from the rear end at idle speed. It goes away under acceleration and is only there at idle speed in gear. I just bought this Liberty several weeks ago and it has 50000 on it and I don't know much about its maintanence history. Any ideas what the noise could be?

05infernoCRDL · **Posted:** Fri Nov 14, 2008 2:37 pm

i would first change all your fluids... so you know when they were changed

liberty2.8 · **Posted:** Fri Nov 14, 2008 2:55 pm

Quote:

i would first change all your fluids... so you know when they were changed

I'm gonna get to that soon but what could the bump noise be? Supposedly the dealer changed engine oil as part of their certification process but I checked oil soon after purchase and it was very black.

05infernoCRDL · **Posted:** Fri Nov 14, 2008 3:02 pm

the oil turns black very fast in diesels....

is there a service booklet with all the services signed off on?

as far as the click... i dunno... i am leaving the house right now
and i will see if mine does it too, might be a typical thing

liberty2.8 · **Posted:** Fri Nov 14, 2008 4:18 pm

Quote:

I'd check the u joints for sure

How do you check the u joints? Do they have to be removed? The bump is not on acceleration but in a forward idle... bump, bump, bump, bump, etc. It goes away with any acceleration fast or slow. I guess I need to crawl underneath to see//feel if anything in the drivetrain is noticeably loose.

mackruss · **Posted:** Fri Nov 14, 2008 4:27 pm

"2006 Jeep Liberty 2.8 CRD everything stock for now"

Keep it stock if you can otherwise you'll become paranoid like me

mackruss · **Posted:** Fri Nov 14, 2008 4:55 pm

ATXKJ wrote:

To check Ujoint - you basically "crawl underneath to see//feel if anything in the drivetrain is noticeably loose."

- emergency brake on to lock the rear wheel - tranny in neutral and try to rotate the driveshaft - loose is bad - more definitive is to pull the joint and flex/inspect - but if you go that much trouble you've done the work to replace one.

If you do replace it - get one with a grease nipple so it'll last.
I think NAPA has some - and these are good http://www.4xshaft.com/index.html

and as for completely 'stock' you should probably do an EHM or Provent to keep oil out of the intake - doesn't cause bumps but will clog the intake & kill CAC hoses (check the CRD tech threads)

All the extra money we spend on upgrading our Jeeps really p!sses me off and we pay a premium for the brand. I often wonder if there is a vehicle on the market in this class that offers the "real deal" and no need for any extra expenditure for suspension or drivetrain upgrades.

ATXKJ · **Posted:** Fri Nov 14, 2008 5:07 pm

I'd check the u joints for sure. (there's also a ball joint on the top of the rear end - I don't know how to test that)
And even though you said rear - several CRD's have had loose motor mounts - causes a bump on acceleration.

also - because of the EGR - the oil turns black almost instantly.
the only person who mentioned clean oil - had the SEGR and then flushed the system with fresh oil before an oil change.

ATXKJ · **Posted:** Fri Nov 14, 2008 5:32 pm

To check Ujoint - you basically "crawl underneath to see//feel if anything in the drivetrain is noticeably loose."

- emergency brake on to lock the rear wheel - tranny in neutral and try to rotate the driveshaft - loose is bad - more definitive is to pull the joint and flex/inspect - but if you go that much trouble you've done the work to replace one.

If you do replace it - get one with a grease nipple so it'll last.
I think NAPA has some - and these are good http://www.4xshaft.com/index.html

and as for completely 'stock' you should probably do an EHM or Provent to keep oil out of the intake - doesn't cause bumps but will clog the intake & kill CAC hoses (check the CRD tech threads)

aandlwoods · **Joined:** Mon Jun 09, 2008 4:53 pm **Posts:** 96

mackruss wrote:

ATXKJ wrote:

To check Ujoint - you basically "crawl underneath to see//feel if anything in the drivetrain is noticeably loose."

- emergency brake on to lock the rear wheel - tranny in neutral and try to rotate the driveshaft - loose is bad - more definitive is to pull the joint and flex/inspect - but if you go that much trouble you've done the work to replace one.

If you do replace it - get one with a grease nipple so it'll last.
I think NAPA has some - and these are good http://www.4xshaft.com/index.html

and as for completely 'stock' you should probably do an EHM or Provent to keep oil out of the intake - doesn't cause bumps but will clog the intake & kill CAC hoses (check the CRD tech threads)

All the extra money we spend on upgrading our Jeeps really p!sses me off and we pay a premium for the brand. I often wonder if there is a vehicle on the market in this class that offers the "real deal" and no need for any extra expenditure for suspension or drivetrain upgrades.

Its called a Rubicon...

Rear end noise

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