Need some help with my rear end.... on the car guys, on the car.

KAIN81 said:
UPDATE/NEWFLASH/IMPORTANT TITLE INSERT HERE

Lincoln Dealership just called back - said it is NOT the wheel bearing, after test driving and putting it up on the lift -they said it is 100% my rear end. And the number one reason they are sure (besides where the sound is coming from) is that the sound speeds up with the pedal, not the tires. Which is what I thought was weird since the begininng.

Bad news: $400 to take it apart and tell me what needs replacing
They call then and I decide if i can get the parts cheaper through work, or if they can.
Then they charge me $400 to put it back together.

Do I have the skills to do the work? I'd wager a 'more than likely' but i DO NOT have the time. As i mentioned, new house, parents on the way and baby due ANY MINUTE. So looks like I'm screwing the pooch on this one.

Good news? I got it in before I did serious damage and f*cked up my entire rear end....

I need a beer.
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800 bucks just to look? I'd check around for a rear diff shop and get a quote before I'd do that. You might be able to get a full rebuild and have a positrac unit installed for a little over 800 bucks, might even be able to regear it if you want. I paid 1800 to a local rebuild shop to have my front and rear diffs on my Chevy truck rebuilt, including new Chevy gears front and back as I changed ratios, plus had an Eaton posi put in, for a price reference.
 
The problem is they can't just pop a cover and look at the diff. Have to drop the whole rear to even look inside.

That being said, you should really just get a quote for a complete rebuild. They shouldn't be fixing anything, but throwing new bearings and seals at it and have a line item on there for gears/spiders if it needs it. The only real question is if the gears and spiders have life left in them or are junk. If the gears are OK then you might want to find a rebuild 28-spline trac-loc and get it thrown in there for fun. The only added labor to them is popping the ring gear off and bolting it down on the tracloc. It should only be an extra 20 minutes or so to do.
 
Kumba said:
The problem is they can't just pop a cover and look at the diff. Have to drop the whole rear to even look inside.

That being said, you should really just get a quote for a complete rebuild. They shouldn't be fixing anything, but throwing new bearings and seals at it and have a line item on there for gears/spiders if it needs it. The only real question is if the gears and spiders have life left in them or are junk. If the gears are OK then you might want to find a rebuild 28-spline trac-loc and get it thrown in there for fun. The only added labor to them is popping the ring gear off and bolting it down on the tracloc. It should only be an extra 20 minutes or so to do.
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Cars got 110 easy miles on it, woman before me was 73. I've had it for 10k of those miles - aggressive at times, but never driven stupidly. Lot of HWY miles to work. And it just started making the noise about 5 days ago or so. Really hoping it's not major surgery. Kumba you seem to know quite a bit about this ****, can you tell me more about what the 28 spline tac loc is? I have no idea on that one. And is it something the dealer can come by?
 
KAIN81 said:
Cars got 110 easy miles on it, woman before me was 73.
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Easy or not, it's making noise now. If you are going to open the rear-end up, just rebuild it. I would just ask them how much to rebuild the center section assuming the gears and carrier are good. Then the only question is if the gears and carrier are any good. You'll find out as soon as they open it.

If it was really driven easily then hopefully they are. If the carrier is shot then just buy a Ford 8.8" 28-spline 'trac-loc'. Search google, they are all over. It will be a bolt-in upgrade for 2000-2002 model years. If the gear is good then you will probably have to either find a junkyard set, ebay set, or buy new from Ford. The gears are specific to that center section.
 
KAIN81 said:
Lincoln Dealership just called back - said it is NOT the wheel bearing, after test driving and putting it up on the lift -they said it is 100% my rear end. And the number one reason they are sure (besides where the sound is coming from) is that the sound speeds up with the pedal, not the tires.
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this make no sense.

the speed of the rear end, the drive shaft, and the wheels are tied directly together. if one of those changes speeds, they all change.

and none of them have much to do with the pedal.
 
I think we might be losing something in translation here. Since the noise depends on whether the car is accelerating, deaccelerating, or coasting, (I.E. where you put the pedal) that usually means it's a bearing related to the gears. The force exerted by the pinion and ring gear have a lot of angular force. The gears are literally trying to push away from each other when loaded up. If a bearing was bad, it could easily allow them to move out of alignment and not mesh right. A little movement can make a lot of gear wine.
 
Kumba said:
I think we might be losing something in translation here. Since the noise depends on whether the car is accelerating, deaccelerating, or coasting, (I.E. where you put the pedal) that usually means it's a bearing related to the gears. The force exerted by the pinion and ring gear have a lot of angular force. The gears are literally trying to push away from each other when loaded up. If a bearing was bad, it could easily allow them to move out of alignment and not mesh right. A little movement can make a lot of gear wine.
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Correct. While it is true everything is connected, what you can't see is where the force is being applied, and how it pushed on the parts. Even though you can't see the movement, the force is there. The force changes according to how much the engine pushes to the wheels (gas pedal pressed down) vs no power being transferred (gas pedal partially down, constant speed on flat ground, engine power vs wheel drag are countering each other equally) vs how much power the wheels push towards the engine (gas pedal up, coasting in gear). Plus, the more parts involved, the more slop is induced as each part has a tiny bit of give in it. This little bit of slop is expected, must be there and must fall within tolerances, but it does allow for wasted movement within that part that causes the part to wear differently according to whether force is being transmitted from the engine to the wheels or from the wheels to the engine. And then you are adding force directional changes, from when the rotational force from the driveshaft is twisted 90 degrees to spin the wheels. An engineer can give you the math behind it if you're really interested.

An analogy - interlock your fingers like they were gears, then twist the left hand to move the right hand. When you push down with the left hand the fingers stay interlocked but you feel the force on the tops of the fingers on the right hand. When you twist the left hand up, you now feel the force on the bottoms of the right fingers. Even though the fingers are locked together in the mesh, where you feel the pressure changes. Works the same way, more or less, in the rear diff.

Even parts positioning makes a measurable difference. A Ford 9 inch rear end positions the pinion gear 0.75 inches lower on the ring gear than the Chevy 12 bolt, which is enough to cause the 9 inch to use 3-4 percent more power to operate than the 12 bolt, all else being equal.
 
Alright - 24HRS LATER - the dealer got back to me. Said it needs a set of Pinion Bearings & Caps - and a set of carrier bearings - fluid and a few gaskets I believe. The big ticket items are the two sets of bearings. I'd wager a guess that both do not need replaced and only have minor wear and tear -- however, with it already a part, it's a matter of 'might as well'.
So they want: $400 to take it apart. $400 in parts. and $400 to put it back together.... $1,200.00 sheckles.

She was nice enough to give me ALL of the part numbers, so I'll call my parts distributor on Monday and see if I can beat any of her pricing. Bad news is - kid is due on Thursday, they say they can only HOPE to have it done by Wednesday. My family arrives Thursday afternoon and I need to pick them up. Sh*t.
 
KAIN81 said:
Alright - 24HRS LATER - the dealer got back to me. Said it needs a set of Pinion Bearings & Caps - and a set of carrier bearings - fluid and a few gaskets I believe. The big ticket items are the two sets of bearings. I'd wager a guess that both do not need replaced and only have minor wear and tear -- however, with it already a part, it's a matter of 'might as well'.
So they want: $400 to take it apart. $400 in parts. and $400 to put it back together.... $1,200.00 sheckles.

She was nice enough to give me ALL of the part numbers, so I'll call my parts distributor on Monday and see if I can beat any of her pricing. Bad news is - kid is due on Thursday, they say they can only HOPE to have it done by Wednesday. My family arrives Thursday afternoon and I need to pick them up. Sh*t.
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That's not too far off the mark for the work being done. An independent shop would likely charge 200-300 less, but on the other hand the Lincoln dealer should be providing you with a loaner while the work is being done especially since your service advisor is a chick and you're needing the car back to bring a new baby home. I'd tell them that they have the job if they provide a loaner.
 
Telco - I was wondering why they didn't offer one, especially under the circumstances. I'm going to check to see if i can get any of the big ticket items through work any cheaper than they are retailing them. If I can't - or it's marginal, then I'll tell them just to go ahead w/ the rental car being the contingency. Thanks.
 
KAIN81 said:
Telco - I was wondering why they didn't offer one, especially under the circumstances. I'm going to check to see if i can get any of the big ticket items through work any cheaper than they are retailing them. If I can't - or it's marginal, then I'll tell them just to go ahead w/ the rental car being the contingency. Thanks.
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Considering that Timken has a rebuild kit for $230, I would imagine you could put together the parts kit for less then $200. It's probably a pretty standard collection of bearings and seals that Ford used. They usually don't re-invent the wheel to much on these type of things. Instead they'll spend the money to re-design the gears and carrier and center so that it's an 8.0" rear instead of just using a tested 8.8" design they have long since paid for.

If you are trying to put in all OE parts then you are going to pay a premium for Timken/SKF parts. Contrary to popular belief OEM is not the only quality option. It is a good place to start.

Try calling a drive-train shop. Tell them the car you have and what the dealer said it needs to rebuild it. Have them give you a quote on just rebuilding the center section. Since you seem to have one of the rare mythological dealers what will let you buy your own parts, maybe they can just do the R&R work. Save you some coin from the dealer pricing on parts and labor to rebuild the differential.
 
At this point, unless the work is already being done I'd say hold off on the car for now. Since the baby is due this week, concentrate on that. A rear end howl is more annoying than anything else, and can actually go for years before it becomes a problem. Once the baby is here and settled in, you can pick this one back up. If it just started howling, and it isn't very loud yet, it can go a couple more weeks without concern. Once you have the major stressor of an incoming kid out of the way you can tackle the rear end without feeling like you are under a time limit.
 
Telco said:
At this point, unless the work is already being done I'd say hold off on the car for now. Since the baby is due this week, concentrate on that. A rear end howl is more annoying than anything else, and can actually go for years before it becomes a problem. Once the baby is here and settled in, you can pick this one back up. If it just started howling, and it isn't very loud yet, it can go a couple more weeks without concern. Once you have the major stressor of an incoming kid out of the way you can tackle the rear end without feeling like you are under a time limit.
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Couldn't agree more! Take care of the family first, you have some miles before it gets really serious.

YMMV.
 
Telco said:
At this point, unless the work is already being done I'd say hold off on the car for now. Since the baby is due this week, concentrate on that. A rear end howl is more annoying than anything else, and can actually go for years before it becomes a problem. Once the baby is here and settled in, you can pick this one back up. If it just started howling, and it isn't very loud yet, it can go a couple more weeks without concern. Once you have the major stressor of an incoming kid out of the way you can tackle the rear end without feeling like you are under a time limit.
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I agree with you both - I took the car in thinking it was a quick wheel bearing and I would get it back last Friday. They had to take the rear end down and apart to diagnose it - so I'm all in now. Thankfully I pressured them into giving me a rental car while it's in the shop since they cannot give me an exact time of how long they will have the LS. Very nice of them to step up and take care of that under these circumstances, especially since I did not buy my LS from them and haven't ever gotten any work done here. Gotta appreciate good customer service in times like this for sure. I'll keep you updated.
 
Got the car back on Tuesday - yes it took them much longer than I'd hoped - but was finished sooner than they had thought. Car is silent as the day I got it - runs smooth, no sound, no shake, and just over all feels more solid. Here is a pic of the issue that caused it all:
photo_zps5389f3dd.jpg
 
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