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Landscaping Professional
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Discussion Starter · #1 ·
Well, it looks like my engine oil leakage issues may finally be behind me, but while the car was on the lift at the dealer, I asked them to see if there was any apparent stiffness in the diff and/or the rear wheel bearings. I have done checks & service of nearly everything engine-related that could possibly affect mileage. My fuel mileage on long cruises has gotten down to under 20mpg (from over 25). And, I've recently noticed groaning from either the diff or rear bearings when driving very slowly with the wheels cut hard in the driveway. The inside wheel has also started slipping, then grabbing suddenly, when making a sharp right hand turn from a stop sign on unlevel pavement.

After checking the free input torque, the tech dropped the diff, opened it up and measured the ring gear lash. It's at .0095" with a service limit of .008". Obviously, the pinion is moving back and forth, and it appears the pinion bearing is shot. Dodge will not allow that component to be rebuilt under a Service Contract, so they will R&R with a new unit. Well, there goes my pin-stamped, date-coded, OEM differential carrier. I guess it's not that big a deal - I'm already on my 4th tranny. The wheel bearings feel just fine.

I plan to dyno the car after it goes back together. I pulled 410 in March - just before I had the halfshaft u-joints replaced under contract. I figure this work might free up as much as 8-10 hp. We'll see...

Anyway - this extended service agreement is really worth every single penny. My car will be 7 years old in 13 more days, and will remain under mechanical warranty for another 4 years. All it costs is $100 per visit. /images/graemlins/applause.gif
 

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Schadenfreude Connoisseur
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I need warranty work done too. I wonder what the dealer will say when I pull it in /images/graemlins/laughing.gif
 

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Premium Member
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1,333 Posts
Dean, now that you have the last of your bugs sorted out, you should
be in top form. I hate it when there is something mechanically 'not right'
about my car. I wouldn't worry about OE matching numbers on the diff, I'm
surprised that you have a 4:1 trans/diff fail rate - maybe that's normal with
your type of racing - I don't know. I think the pinion gear lash tends to
grow over the years, it could be that an adjustment could prevent a bearing failure - but it's hard to tell. With all your problems solved, you'll have
to find something else to focus on. /images/graemlins/headbang.gif
 

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Landscaping Professional
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Discussion Starter · #4 ·
HP said:
...maybe that's normal with your type of racing - I don't know. I think the pinion gear lash tends to grow over the years, it could be that an adjustment could prevent a bearing failure - but it's hard to tell.
Drag cars tend to get wear on one side of the pinion/ring gear set, because all the load is forward. Road racing with big, hot, sticky tires and kick-butt suspension puts a lot of coast-side load on the gear set as well, and works the pinion in and out during downshifting and throttle steering.

HP said:
With all your problems solved, you'll have
to find something else to focus on. /images/graemlins/headbang.gif
Uh-huh!!!!! /images/graemlins/gr_driving3.gif

/images/graemlins/wave.gif

/images/graemlins/supergrin.gif
 

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Discussion Starter · #6 ·
They were 6 years old, with 22k miles of hard use on them - several thousand miles of track time. I had marked the caps and yokes, then rechecked them a couple of weeks later and found that several of the caps were turning in the yokes when they should stay put.
 
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