2004 AWD Differential Repair

[romeroom]

I was offered a free 2004 AWD Vibe. The main problem is a confirmed rear differential problem needing repair. Mechanic quoted the person giving me the car $2,200 for the repair. I would need to make a 720 mile round trip to get this car; it will reportedly drive at a max speed of around 65 mph.

I have performed all repairs on my cars for many years. I have never repaired a differential.

I would like some advice on what to do. How difficult would it be for me to repair/replace a rear differential? What is the approximate cost of parts?

Thanks.

[Salsa Guy]

You can get a rear diff off a Matrix also. I've seen them used for $1000 or so. Them problem with these rear diffs is that the seals will leak and eventually run out of fluid then the rear diff will go bad. There's a lot of information on this site about that and the cost seems to be inline. If you buy a used one check the fluid level first to make sure it was well taken care of.

[romeroom]

You can get a rear diff off a Matrix also. I've seen them used for $1000 or so. Them problem with these rear diffs is that the seals will leak and eventually run out of fluid then the rear diff will go bad. There's a lot of information on this site about that and the cost seems to be inline. If you buy a used one check the fluid level first to make sure it was well taken care of.

So, am I correct in assuming that you can't just replace the parts "inside" the "pumpkin", especially if there are parts in there that are not damaged?

BTW: The year of the vehicle is 2003. My mistake.

[Salsa Guy]

I know nothing about repair them. It seems like a tall order even with the proper docs and tools.

[joatmon]

I guess it depends on what else is wrong with the car that the current owner doesn't think that it is even worth the $2200 to repair. I mean, if it would be worth $3000 without the problem, then they should get it fixed and sell it to turn an $800 profit. Is the reason it won't go over 65 believed to be because of the differential, or are their engine/tranny problems as well?

Differentials are not all that hard to work on, although I haven't actually worked on a modern (21st century) one. Looking at the pubs, it seems straightforward to replace. Rebuilding it might be a challenge, individual parts can quickly add up to exceed the cost of a used one from a wreck.

If you do get one from a junk yard, then try to get one with at least some token warranty. Also, most yards will drain engines/trannies/differentials when they pull them, so it might be difficult to see if it had fluid in it when it was removed from the donor car.

My gut reaction is jump on it! but if you do and it turns out to be a money pit, then don't blame me

[romeroom]

... Is the reason it won't go over 65 believed to be because of the differential, or are their engine/tranny problems as well?

I'm going to try and contact the mechanic that diagnosed the problem to get more details.

[romeroom]

(The person I'm getting the car from lives about 300 miles away. She's having the car checked today to try and figure why it won't go past 50 or 55 mph. If its a transmission problem, then I probably won't go get it.)

QUESTION: Can this car be towed safely behind my AWD Astro van?

Using a (two wheels off the ground) dolly from Uhaul is a possibility. However, the rules online say the axle would have to be disconnected. Which axle would that be? The rear one is shot anyway.

I could use a full car carrier trailer as a better option; however, the cost is significantly higher.

Please advice.

[joatmon]

I'll leave it up to you to figure out if an Astro van can safely tow anything as heavy as a Vibe.

The books say to only tow an AWD vibe with all four wheels off the ground. I suppose if the differential is shot and you disconnected the the driveshaft connecting the rear differential to the transfer case, you could risk towing it on only a front wheel dolly, but then again, if the rear differential should seize up, it would be an "interesting" trip.

I have towed rear wheel drive vehicles with all four on the ground with the driveshaft removed. I don't think the differential is as sensitive as the tranny, and the precaution about towing an AWD vibe with all four wheels off the ground is probably to prevent the rear wheels pushing the transfer case and tranny, not about potential damage to the differential. But thats just a guess

[romeroom]

I'll leave it up to you to figure out if an Astro van can safely tow anything as heavy as a Vibe.

The books say to only tow an AWD vibe with all four wheels off the ground. I suppose if the differential is shot and you disconnected the the driveshaft connecting the rear differential to the transfer case, you could risk towing it on only a front wheel dolly, but then again, if the rear differential should seize up, it would be an "interesting" trip.

I have towed rear wheel drive vehicles with all four on the ground with the driveshaft removed. I don't think the differential is as sensitive as the tranny, and the precaution about towing an AWD vibe with all four wheels off the ground is probably to prevent the rear wheels pushing the transfer case and tranny, not about potential damage to the differential. But thats just a guess

Thanks you much for the advice. The Astro can tow a lot, so I'm not sure that would be a problem. But I'm thinking the cost of gas and dolly/trailer rental could easily approach $400 round trip. Need to think this through.

[joatmon]

surprisingly relevant, stumbled across this from yesterday in a general google news search for Vibes
http://www.emcperth.ca/20120524/lifesty ... icy+repair" onclick="window.open(this.href);return false;

"Hi Brian,

This winter I had to change a rear wheel bearing ($550 job) and couple of weeks ago the right rear wheel bearing (on my Pontiac Vibe). Now, after over $1,100 in repairs, I'm hearing a whining sound from the rear and had it in to my local mechanic, who identified the sound as coming from the rear differential. The next step being suggested is to drain and replace the oil in order to see just what is in the old oil and see how the new oil may help. What are your thoughts on this issue? Given that the power train is the same as the Toyota Matrix, is the differential a Toyota part? Is this a common problem on the Vibe and the Matrix? The car has only about 140,000 km on it. I assume it should be looked after fairly soon, would you suggest replacing the differential with a used one or repair the unit? What kind of money are we looking at? Thanks. I drove my 1990 Corolla AWD for 18 years and never had to replace any bearings or differential."

Yours truly,

Greg

In my shop we've seen problems in Matrix/Vibe rear ends, usually related to axle seal leaks or noises caused by bearing and gear failures. Used assemblies from salvage yards run around $1,300 to $1,600 depending on condition and a new crown and pinion gear set with seals from GM is around $1,055. The side bearings are serviced separately so it would be worthwhile to have it torn down to see exactly what's wrong. Refilling it with a good quality synthetic axle oil is recommended. As the Pontiac Vibe and Toyota Matrix represented a joint venture between GM and Toyota, most of the driveline parts are the same.

Changing the oil is unlikely to resolve the noise but its condition may tell you what you'll find inside the axle. If the oil is speckled with metal particles and filings you're going to be replacing some hardware inside the rear differential.

Keep in mind taking a noisy rear diff apart is kind of like opening Pandora's Box. You're pretty much committed to fixing it and few dealers keep the parts on hand so there may be a delay of a day or two to get you back on the road. Some of these all-wheel-drive compacts can suffer from lack of maintenance because not that many of their drivers consider the needs of replacing the fluid on a regular basis. If the vehicle's rear axle isn't exposed to a lot of submersion in water (as in backing down a boat launch ramp) a good rule of thumb is to replace the gear oil every three years or 75,000 km or so. If it is in water from time to time, the fluid should be replaced at the end of every boating season.

[Salsa Guy]

^That pretty much sums it up. As I may have stated before most Quick Lubes don't even notice they are AWD/4WD so they won't check the fluids. I had to insist to one grease monkey to check the Transfer Case and rear diff. fluid. He keep telling it doesn't have one and keep telling him it's 4WD. Finally he looking and ofcourse it did have one.

I'm willing to bet 95% of the rear diff. failures is becaus ethe fluid leaked out, Common issue.

[romeroom]

Joatmon & Salsa Guy: Thanks for your input. Right now, a non-dealer will be looking at the car sometime next week in an attempt to figure out what is keeping the car from going no faster than 55 MPH. If the transmission is also a problem, then I'm going to abandon the idea of getting the car--even if its free.

[romeroom]

Discovered that the reason for the poor acceleration is due to a malfunctioning, plugged catalytic converter.

I'd like your opinion on a 3 issues:

1. Is there a potential for serious harm if I drive the car 320 miles with a plugged cat?

2. Diagram pics online almost show the Vibe having two converters. Doubt it. Can someone explain?

3. Catalytic converter replacement: I plan on doing it myself. The price of a universal cat that reportedly fits the Vibe is cheaper by almost $200. Any suggestions/opinions?

Thanks.

[Salsa Guy]

If you decide to drive it with a bad plugged CAT could cause damage. Take a hammer and screw driver to it and knock a few holes in it. It may be loud but at least your not back pressuring the engine.

They describe the down pipe, off the exhaust manifold, as a pre-CAT. If you added a header to the engine it would go away. I heard guys taking the PRE-CAT material out of there in hopes of some performance gains but it doesn't help much. Yes it does have 2 CATs but the pre-cat rarely has issues.

When getting a universal cat I'd stay with a good quailty one. Many times from what I've seen you'll need to add a bung hole for the rear O2. Another issues is they buy an el-cheapo and fight P0420 codes all the time. You get what you pay for.

Here's a questions: Why is the CAT plugged? Excessive oil blow by? Running rich? Althought I doubt it, is the pre-Cat is plugged?

Goodluck. You may check out this site or MO for pics of the exhaust.

[joatmon]

gmpartsdirect.com shows the cost of the exhaust assembly that contains the main cat for the AWD is about half the cost of that pipe for the base non-AWD. Add in the part with the precat and its still quite less than for the non-AWD. Don't know what shipping is from them, and you'd have to ship back the bad one to get the core charge back, but it might be worth pricing out the part from both local GM and Toyota dealers to see if it would really be worth the cost of an aftermarket cat + labor

[romeroom]

If you decide to drive it with a bad plugged CAT could cause damage. Take a hammer and screw driver to it and knock a few holes in it. It may be loud but at least your not back pressuring the engine. ...

I would like some other's opinion on this method...

Which of the two cats would need the holes?

[Salsa Guy]

If you decide to drive it with a bad plugged CAT could cause damage. Take a hammer and screw driver to it and knock a few holes in it. It may be loud but at least your not back pressuring the engine. ...

I would like some other's opinion on this method...

Which of the two cats would need the holes?

LOL, it would be the 2nd one just before the 2nd O2 sensor. Before you start punching holes in things make sure you know what's going on. I'd just replace the CAT before the drive or install a "test pipe".

[romeroom]

If you decide to drive it with a bad plugged CAT could cause damage. Take a hammer and screw driver to it and knock a few holes in it. It may be loud but at least your not back pressuring the engine. ...

I would like some other's opinion on this method...

Which of the two cats would need the holes?

LOL, it would be the 2nd one just before the 2nd O2 sensor. Before you start punching holes in things make sure you know what's going on. I'd just replace the CAT before the drive or install a "test pipe".

Since I've never been under one of these cars, Can someone tell me the approximate dimensions of the "test pipe"; I would need to bring tools with me. Suggestions with that would be great.

Tell you what: If any of you can help me out with simply suggestions on this temporary test pipe fix, I will take and post pictures.

[Salsa Guy]

Here a diagram. There's also some pics and video of the exhaust buried deep on MO and maybe some on here.

http://matrixowners.com/index.php?/topi ... m-diagram/" onclick="window.open(this.href);return false;

[romeroom]

Well, went to pick up the car yesterday and just arrived home. Sure enough the car could not go much past 55 MPH. I drilled a couple small holes ahead of the cat converter and was able to go 65 - 70 while maintaining around 3000 RPM.

Interesting: Before I left for the trip home, I decided to check the oil. It was very dirty and way high on the dipstick. Decided to change the oil (in parking lot of hotel.) I drained 7 quarts!!! Don't know how that happened and didn't want to ask.

QUESTION: There was not CEL code. Shouldn't a messed up CAT thrown some kind of code?

[Salsa Guy]

Did you do check the muffler or tail pipe for a plug, or a damaged exhaust pipe some where (I know it too late now). If the CAT or exhaust system is plugged some where, the exhaust gases that get to the O2 sensor are all good.

With your car engine running 3K at 70 mph is about normal.

Good Luck with the repairs

[romeroom]

Did you do check the muffler or tail pipe for a plug, or a damaged exhaust pipe some where (I know it too late now). If the CAT or exhaust system is plugged some where, the exhaust gases that get to the O2 sensor are all good....

Are you suggesting that an obstruction may exist between the O2 sensor past the CAT and the tailpipe? And that the CAT itself is likely OK?

[joatmon]

Are you suggesting that an obstruction may exist between the O2 sensor past the CAT and the tailpipe? And that the CAT itself is likely OK?

possible but unlikely, unless you can see some major dent or deformation in the exhaust pipe

[Salsa Guy]

Are you suggesting that an obstruction may exist between the O2 sensor past the CAT and the tailpipe? And that the CAT itself is likely OK?

possible but unlikely, unless you can see some major dent or deformation in the exhaust pipe

I've heard of these CATs plugging before and we went off what a mechanic said (according to you). I have no idea if the exhaust is damaged because I didn't see it. Hopefully you'll just need to replace the CAT and repair the rear-end. The other issue is why did the CAT plug?

[romeroom]

Moving this to a new post called: Exhaust Problem