So the Firestone mechanic says I have problems with my rear differential

[CPA]

I have a GMC Savana Custom van and for some time I have been hearing a clickety sound coming from the back. Took the van in last week and the mechanic says that it is coming from my rear differential (which i think I have five, sorry if this is wrong I am not a car guy and I think this is what he told me), and that it is caused by some bad bearings. He said he couldn't repair it because it is highly technical work. So my questions:

1) How long can I go with it like this before I have serious problems?

2) what serious issues can this cause?

3) How much would it cost to get it fixed?

4) Anything I can do to short-term fix it?

 

[notfred]

5 Differentials, huh? Is your van by any chance 10 wheel drive?

New differential in my car was about $300, and about $200 labor to put in. I took it to a specialized rear end place.

Your van is highly unlikely to break down on the side of the road any time soon due to a noisy diff.

There's nothing you can do about it w/o pulling the rear end apart.

 

[Brutuskend]

The differential is the thing that the rear axles come out of.

There can be only one!!

You can have the lub. changed and maybe have thicker lub. put in. That MAY prolong it's life somewhat.

They use 90 weight....

 

[Evadman]

Notfred, your vehicle has a drop out center section. GMC's do not. They are a little more to repair. CPA: you most likely have a 10 bolt rear axle. These are super cheap and easy to find parts for. it should not be too bad to repair, but notfred's estimate is very low. (IMHO)

How long will it last? That depends. If it is just a bearing, it could go for quite some time as long as it stays fully lubed. If the bearing is making noise because there is no lubrication, then it could go very very soon.

<edit>
I like the smell of 90 weight. Everyone else says it smells bad. I disagree.

And repairing a diff is not highly technical work.

It does however require specialty tools and half a brain to set the pattern up correctly.

 

[Bignate603]

My rear differential in my Caddilac locked on me. The rear wheels would no longer turn and they literally had to drag it onto the flatbed truck to take it to the shop. They dropped out the whole axle and got me a used one off a wrecked caddilac. Don't remember the price but it wasn't too bad.

 

[notfred]

Originally posted by: Evadman
Notfred, your vehicle has a drop out center section. GMC's do not.

You know I'm not a Chevy guy

 

[Brutuskend]

Originally posted by: Evadman
Notfred, your vehicle has a drop out center section. GMC's do not. They are a little more to repair. CPA: you most likely have a 10 bolt rear axle. These are super cheap and easy to find parts for. it should not be too bad to repair, but notfred's estimate is very low. (IMHO)

How long will it last? That depends. If it is just a bearing, it could go for quite some time as long as it stays fully lubed. If the bearing is making noise because there is no lubrication, then it could go very very soon.

<edit>
I like the smell of 90 weight. Everyone else says it smells bad. I disagree.

And repairing a diff is not highly technical work.

It does however require specialty tools and half a brain to set the pattern up correctly.

ACKKKKK it smells NASTY!!!

At least old used 90 weight does.

 

[Evadman]

Originally posted by: notfred

Originally posted by: Evadman
Notfred, your vehicle has a drop out center section. GMC's do not.

You know I'm not a Chevy guy

I know. That is why I did not smack you For those that do not know, or are stuck in one brand, there are 2 main styles of centersections. Drop in and GM (I know it has another name, but I can not think of it) Drop in's like ford's 9" are one piece. Instead of a diff cover like on a GM type axle that has to be removed, you remove the entire front section onf the diff where the pinion is (driveshaft side) 8 bolts (or however many) and you can pull the section out and can set the gears up on a bench or something. On GM style, you have to set the gears up in the vehicle because the section does not come out. it is one piece with the axle.

 

[CPA]

So how can I make sure it is lubricated enough.

God, I feel so embarrassed asking these questions.

 

[notfred]

Originally posted by: CPA
So how can I make sure it is lubricated enough.

God, I feel so embarrassed asking these questions.

If it's not leaking, you're probably fine on oil. I think your mechanic would have mentioned if it was leaking.

 

[Bignate603]

Originally posted by: CPA
So how can I make sure it is lubricated enough.

God, I feel so embarrassed asking these questions.

You'd have to crawl underneath and actually get at the diffential. If you don't know what you're doing it won't be the easiest thing in the world. Anyways, I also think diff fluid smells nasty, I had it all over my garage from my caddilac the day it blew up on me.

 

[CPA]

Originally posted by: notfred

Originally posted by: CPA
So how can I make sure it is lubricated enough.

God, I feel so embarrassed asking these questions.

If it's not leaking, you're probably fine on oil. I think your mechanic would have mentioned if it was leaking.

No it is not leaking.

 

[Evadman]

Originally posted by: notfred

Originally posted by: CPA
So how can I make sure it is lubricated enough.

God, I feel so embarrassed asking these questions.

If it's not leaking, you're probably fine on oil. I think your mechanic would have mentioned if it was leaking.

true. hoipefullyt hey would have mentioned it. If you want to check, it is relitively easy, but not as easy as checking the engine oil. There is a plug on hte back of the diff. (on your rear axle, located betweent he 2 wheels there is a large center section. this is the diff. the driveshaft goes intot he other side of it)

There should be a plug about 1/2 way up the rear cover. if youa re on flat ground, undo that plug and stick in a piece of paper towel. the level should be just below the plug. the plug is usually square drive. instead of having a head it will accept a 1/2" ratchet extension with no socket. (usually)

Also, most oil change places will check for free since they want to sell you on getting it changed.

 

[Brutuskend]

I've always checked fluid level by sticking my little finger in the hole, bending it downwards and then checking if there is fluid on the tip.

Same way with manual trannies.

 

[Evadman]

Originally posted by: Brutuskend
I've always checked fluid level by sticking my little finger in the hole, bending it downwards and then checking if there is fluid on the tip.

Same way with manual trannies.

but then he would have gotten the "smelly" stuff on him, and that is not right!

 

[Brutuskend]

Originally posted by: Evadman

Originally posted by: Brutuskend
I've always checked fluid level by sticking my little finger in the hole, bending it downwards and then checking if there is fluid on the tip.

Same way with manual trannies.

but then he would have gotten the "smelly" stuff on him, and that is not right!

Hehe true.

 

[iamwiz82]

CPA, does your rear end have a limited slip differential? If you just had the fluids changed the place you had it done at may not have added an LSD additive.

 

[Brutuskend]

Originally posted by: iamwiz82
CPA, does your rear end have a limited slip differential? If you just had the fluids changed the place you had it done at may not have added an LSD additive.

WOW...that takes me back.....

 

[CPA]

Originally posted by: iamwiz82
CPA, does your rear end have a limited slip differential? If you just had the fluids changed the place you had it done at may not have added an LSD additive.

No it doesn't.

LSD Additive??? oh boy, that doesn't sound good.

So how much to get this puppy fixed or should i just try to sneak it through a dealer and trade it in?

 

[iamwiz82]

you dont need limited slip additive if you dont have a limited slip differential.

 

[Evadman]

Originally posted by: CPA

Originally posted by: iamwiz82
CPA, does your rear end have a limited slip differential? If you just had the fluids changed the place you had it done at may not have added an LSD additive.

No it doesn't.

LSD Additive??? oh boy, that doesn't sound good.

So how much to get this puppy fixed or should i just try to sneak it through a dealer and trade it in?

Were you planning to buy a new vehicle anyway? As for cost, call around and ask how much for a rebuild on a 10 bolt rear axle.

 

[PG]

Originally posted by: Evadman

Originally posted by: notfred

Originally posted by: Evadman
Notfred, your vehicle has a drop out center section. GMC's do not.

You know I'm not a Chevy guy

I know. That is why I did not smack you For those that do not know, or are stuck in one brand, there are 2 main styles of centersections. Drop in and GM (I know it has another name, but I can not think of it) Drop in's like ford's 9" are one piece. Instead of a diff cover like on a GM type axle that has to be removed, you remove the entire front section onf the diff where the pinion is (driveshaft side) 8 bolts (or however many) and you can pull the section out and can set the gears up on a bench or something. On GM style, you have to set the gears up in the vehicle because the section does not come out. it is one piece with the axle.

I thought all mid 80's and up Mustangs had the same Ford 8.8" which does NOT have the same design as the 9". The 8.8" has a back cover and does not have the drop out center section.

 

[CPA]

Originally posted by: Evadman

Originally posted by: CPA

Originally posted by: iamwiz82
CPA, does your rear end have a limited slip differential? If you just had the fluids changed the place you had it done at may not have added an LSD additive.

No it doesn't.

LSD Additive??? oh boy, that doesn't sound good.

So how much to get this puppy fixed or should i just try to sneak it through a dealer and trade it in?

Were you planning to buy a new vehicle anyway? As for cost, call around and ask how much for a rebuild on a 10 bolt rear axle.

I had taken it to a Toyota dealership and they actually noticed it and dinged my on my trade in because of it (5K trade-in value), while a Ford dealership didn't (9K trade-in value).

 

[Evadman]

I thought all mid 80's and up Mustangs had the same Ford 8.8" which does NOT have the same design as the 9". The 8.8" has a back cover and does not have the drop out center section.

That is correct about the 8.8 not being a drop out center section. It was an assumption on my part that notfred's mustang was a 9" baised on the price of his rebuild. I am not 100% sure what center section he has, or what came in his year mustang. I am not even 100% sure what year his 'stang is.

I had taken it to a Toyota dealership and they actually noticed it and dinged my on my trade in because of it (5K trade-in value), while a Ford dealership didn't (9K trade-in value).

$4k for that?!? Owie. Guess your getting a ford

 

[Iron Woode]

CPA:

did he not tell you which bearings he thought were going? There are several different bearings in a rear axle. If it is a wheel bearing then your looking at an hour or so to fix. At least thats how long it takes me, in between eating and drinking a coke.

Non drop out center section axles are called Salisbury axles. Most axles are that type. Drop out ones are easy to swap gears with. Mopar 8 3/4 and Ford 9 inch are the most common drop out center axles.