Torque Bind, Repair Options, VC Failure Mode

[wagnerku]

1st Time Poster, a student of this site a bit longer...

03 Baja w 5MT NA, 65k miles I bought it at 58k Aug. 08

 

My main question regards mileage and failure modes for Subaru viscous couplers, if I get a used one, does it matter if one has 100k more miles, provided it is still functional. They seem to suddenly go critical rather than gradually wear out. More details below.

 

On a recent 50 mi weekend freeway trip my fun and trouble free Baja first displayed (that I noticed) symptoms of Torque Bind. Subsequent research online, mostly here, leads me to believe the VC in the center diff. is locking when warmed up. Usually, I would turn this over to the reliable independent mechanic we use for our 98 Forester. However times have changed, being unemployed and soon to start school, I have much more time than money and plan to repair it myself. It started with a recent trip to the lake...

 

After 40 min at a steady 75 mph I left the freeway. As I made a soft left into an angled parking space at a restaurant, I felt a repetitive thump-shudder from the fwd passenger wheel area. Same thing fwd-rev and left right. Frequency increasing with wheel rotation, whether clutch engaged or free. No noticeably hard steering that I read about. No problems going straight line. Flashing back to a formative VW Rabbit episode from the 80's, I checked and no worn/torn CV boots or grease where it didn't belong. Receipts form the previous owner did have the dealer clean and repack when a torn boot was found at 39k miles.

 

When I left the restaurant all seemed well. I cut my trip to Lake Michigan short and returned home. I have been able to keep it parked except for a couple 4-5 mi trips.

 

Lot's of trouble shooting help from this board, my independent mechanic, and the local Subaru dealer's parts and service departments...I have checked wheel bearings, CV axles, struts, measured tire circumference, and wear. (Note: 4 new tires at 50k, circumference variation taped at < 1/8" this week, rotated as recommended, pressures good and checked weekly) Alignment is decent, some pull to the left sometimes, seems to come and go with road surface.

 

Although I don't pull doughnuts in parking lots and the tires have been taken care of, the evidence strongly suggests I need to replace the VC and/or or swap the trans.

 

It would be more convenient and easier for me to change out the VC. Instructions here:

http://forums.nasioc.com/forums/archive/index.php/t-381351.html

and here:

http://www.subaruforester.org/vbulletin/f89/center-diffs-how-replace-them-46979/

I can also get to procedures to replace the trans if needed.

 

Please give me your thoughts on these options or anything I may have overlooked in trouble shooting. I am short on Subby owner experience: we got our 1st Subby 2 years back after admiring them for years. I am not a mechanic but come from a hands on engineering background and am comfortable with the work once I assemble find any needed tools I lack and have service procedures.

 

VC Options

Rebuild

STE - Traction Control Technology Can rebuild my VC if the housing is still ok. They were very helpful over the phone. Anyone dealt with them?

 

Used trannies, all from 03 Foresters.

The VC is the same but I don't know if the 5MT in the Forester will bolt up to my Baja, engines being equal. Local dealer and auto recyclers I have spoken with to date don't know for sure. If someone knows or can verify this or point me to a good cross reference, I would appreciate it.

 

Thanks to eadrach, (http://www.ultimatesubaru.org/forum/showthread.php?t=97885) I know the gearing is the same, 03 Forester to Baja The tranny codes look good but is the mounted body code, digit 7 the critical one? I am out of my depth on this part.

US Legacy Outback & Baja MY03-04 TY754VCDCA

US Forester MY03 TY755VC3AA

One within 15 miles with 169k $385 low price high miles, but does that matter with a VC?

One 35 miles away with 49k $650 higher price, lower miles, again do the miles matter with the VC.

[edrach]

Not to rain on your parade, but having just gone through a VC failure in our '99 Forester, I would opt for a new unit (expensive but probably the best alternative). I had three used trannies to select a VC from and all three had a bad VC! I went with a new one from the dealer and had it professionally installed. If you do it yourself make sure you have a hydraulic press. Good luck.

 

By the way, just as a price comparison, I recently picked up a used 5MT for our Forester (from a '99 with a reported 50K miles on it for $550). Too late to install in our Forester, but I'll have a used transmission that I can have checked out and have available if needed.

Edited April 21, 2009 by edrach

[idosubaru]

i guess it depends on your location and finding parts, but i'd have no problem locating a good used transmission around here. i'd opt for a used unit.

 

keep your tires matching, rotated properly and change your fluids and you shoudln't have future problems. the VC's rarely fail.

[mdjdc]

If you are feeling the shudder from the front end of the car, I highly doubt that the VC is bad. The first thing I would do is put in a new CV half shaft on the side that went bad at 39k. It is very likely that the joint got crud in it before it was repacked and it is now worn out. I just had a very similar situation and I too thought that my VC was bad. No torn boots. I replaced both my half shafts and now I have no problems at all turning. This is a very easy and much less expensive repair and worth it to help to rule out an expensive tranny repair.

[idosubaru]

great point MDJC. i didn't read the entire thread, it was kind of verbose. so i missed any talk of axles.

 

if you have axles problems, that could easily be your issue. if the axles were replaced that is an important item to check. best bet is to avoid any aftermarket axles and use Subaru or MWE only. search/read here if you're wondering why. it's covered over and over

 

good luck and maybe it's something less ominous!

[nipper]

I'm going with looking deeper into the axles. This is awfully early for a VC to go bad, especially if all the tires have always matched. I mean it is possible, but really unheard of.

 

 

nipper

[wagnerku]

Thanks for the axle suggestion. I will pursue that before going any further. I have read the positive endorsements for the MWE axles. They are on my list.

 

I am also looking at a Dorset Axle. MIBearings LLC, next day for me no core. http://www.subaruaxles.com/Subaru_Axles.html Any one know how these are?

 

They are new and "fully balanced". When I asked about vibration problems the sales rep. candidly said Dorset addressed a few complaints and made a fix a year back. No complaints since then. If I go with the Dorset axle, I will provide feedback on it's performance.

 

Guilty as charged on the verbosity. I can go overboard on detail trying to avoid leaving out something that may prove to be important. Thanks for patiently reading through it all.

[nipper]

The axle issue isnt really a problem with balance. Its a matter of the tolerance being too tight and transmitting engine shake at idle while in drive. It isnt a issue i recall with manuals.

 

There is nothing wrong at all with too much detail, its all data.

[mdjdc]

I have a manual and I used an off brand of axle. Te drivers side fit perfectly, but on the passenger side the inner joint was a little loose on the tranny output shaft. As a result, I had some weird shuddering in second gear. I replace both with a better axle and now the problem is completely gone.

[idosubaru]

i would go with known success rather than reinventing the wheel. MWE and Subaru are known good axles.

 

Actually for your vehicle being so new I'd just get a used axle, I bought one the other week for your vehicle for $35. Yours is new enough that finding a good axle with good boots is easy and cheap and no risk of crap after markets.

 

Whether you get a good axle or not from those guys doesn't say anything about the company. No one says all aftermarkets suck. You have as good of a chance of getting a good axle as a bad one.

 

And what do you expect from a salesman? "Yeah, our axles aren't that good, we have a lot of returns.":lol::lol:

[Gloyale]

If you are feeling the shudder from the front end of the car, I highly doubt that the VC is bad. The first thing I would do is put in a new CV half shaft on the side that went bad at 39k. It is very likely that the joint got crud in it before it was repacked and it is now worn out. I just had a very similar situation and I too thought that my VC was bad. No torn boots. I replaced both my half shafts and now I have no problems at all turning. This is a very easy and much less expensive repair and worth it to help to rule out an expensive tranny repair.

 

+100

 

VC units rarely fail, espescially with that low milage.

 

50k is right in the range of CV failure though, espescially if the boot has been torn before.

[wagnerku]

I replaced the front right half axle today and the symptoms are still there. I can add now that the further I drive it, the worse it gets. This is not a noise, it is a periodic impulse. After 5 miles it feels like a flat spot going around with the tire, another 5 miles and the flat spot gets bigger.

 

NOTE - did go with a new aftermarket shaft, Dorset. through MIBearing LLC. Just looking at it next to the OEM shaft, I am not confident it was machined and assembled to the same standard as the Subaru. Internally, it may be fine and may give decent service life, but I will try OEM or MWE next time.

 

Based on what I am learning about heat cycles and VC failure, i.e. that it can occur from cumulative heat cycles as well as the catastrophic event, I'm leaning towards a new VC. My tranny is still young and the ones I have found so far don't give me a warm fuzzy. I did change out the transmission and rear diff. oil. The rear diff oil was very clean with the tranny oil a bit darker with a few slivers of metal on the magnet. I have to set up parts and check with a friend to use his shop. I have two weeks before I need to use the car, that probably translate into 2 weekends to work with.

 

Thanks for sharing your 2 cents with me.

[nipper]

Sometimes it pays to go to the dealer. Let them look at it since this is an unusually early failure. Maybe subaru will work with you, or it may be something else.

 

 

It's hard to diagnose sometimes over the net.

 

Have the front end looked over, ball joints etc. Check the carrier bearing.

 

Are you getting binding on tight uturns?

 

nipper

[edrach]

I second what nipper said. Have it checked out by a dealer and/or independent Subaru shop. No point in spending money for parts that aren't needed.

 

My own VC failure was pretty obvious. Anything sharper than a 45 degree turn (in either direction) and the thump, thump, thump was there. Even worse backing out of a parking space. My car had 125K on it when the failure started; we bought it at 112K. No telling what the previous history/use had been. I also had the car checked by a Subaru mechanic with more than 25 years of Subaru work at a dealership.

 

Something that hasn't been mentioned yet, if you're not the original owner. Is there any chance that the car was towed on a hook rather than a flat bed? I'm not sure if this is as serious with a 5MT as it is with an automatic, but it might be the cause of your premature VC failure.

[CNY_Dave]

Would a CV joint failure not make much noise or bind while coasting, where a VC problem would show up coasting or under power?

 

Dave

[nipper]

VC shows up on turns for the most part, or a thud in the drive line (but not a rythemic thud).

 

 

Without the binding on the turns showing up, your VC is fine.

 

nipper

[idosubaru]

I replaced the front right half axle today and the symptoms are still there. I can add now that the further I drive it, the worse it gets. This is not a noise, it is a periodic impulse. After 5 miles it feels like a flat spot going around with the tire, another 5 miles and the flat spot gets bigger.

 

this doesn't sound like typical VC, but at such low mileage and a young car nothing is adding up to this point. i third the vote for a dealer inspection since this doesn't sound normal.

 

are you saying it's exhibiting issues while driving straight?

 

If you can do it yourself you might consider swapping the other axle (with the used one you just removed, since you know it wasn't the cause), just to see if the other axle has issues.

[wagnerku]

I am going to take Grossgary's suggestion and swap the axels and do the check below from an earlier thread on the board. This makes sense to me, do you see any flaws in this test?

"If the viscous coupling unit went out you would have either no drive (unit is not coupling) or vary notisable binding (unit is locked up). A quick way to tell if the unit is locked up is to jack up one tire and try to turn it . If it turns with some resistance your OK if not The unit is locked up. Good luck" http://www.ultimatesubaru.org/forum/showthread.php?t=14992

[wagnerku]

The VC is locked up. I ran the above test. I jacked up the FR tire following a 10 mile freeway drive and could not budge it. 3 hours later it started to move and after setting overnight it is loosened back up.

[edrach]

The VC definitely has a heat component to it when it starts to fail. I found mine showed no symptoms for the first 5 minutes of driving (after sitting overnight) and and then slowly started to bind. After a 2nd 5 minutes binding on all turns in either direction was quite evident.

 

As to a CV axle failure: unless two axles fail at the same time and in the same manner, an axle failure produces symptoms generally when turning in one direction (a loud clicking under full lock for an outer joint (CVJ) failure) or a significant thumping or vibration IN A STRAIGHT LINE during acceleration which goes away instantly when you let off on the gas indicates an inner joint (DOJ) failure.

[wagnerku]

No more torque bind. The car is running fine with a new VC. I installed it last weekend. Many thanks for the tips I picked up here that allowed me to do it myself.

 

I was priced out if any other options. The service manager at the nearest Subaru dealer gave me an estimate of 1 hr. for diagnostic, 10 hrs. labor, labor at $90/hr and $550.00 for the part which was not in stock. It would have arrived today at the earliest. Fortunately, I had a choice of 3 other dealers within 45 min. and they had the part on the shelf.

[edrach]

Would a CV joint failure not make much noise or bind while coasting, where a VC problem would show up coasting or under power?

 

Dave

Let's differentiate joints: CVJ (outer joint), common failure symptom is clicking under full lock turns in one direction. DOJ (inner joint), common failure symptom is mild vibration up to severe vibration (feeling like the transmission will fall out of the car) while on positive throttle which goes away instantly as soon as you let off the gas.

 

VC bind never shows up while travelling straight; thumps while turning in either direction. The sharper the turning the more severe the thumping.

[edrach]

No more torque bind. The car is running fine with a new VC. I installed it last weekend. Many thanks for the tips I picked up here that allowed me to do it myself.

 

I was priced out if any other options. The service manager at the nearest Subaru dealer gave me an estimate of 1 hr. for diagnostic, 10 hrs. labor, labor at $90/hr and $550.00 for the part which was not in stock. It would have arrived today at the earliest. Fortunately, I had a choice of 3 other dealers within 45 min. and they had the part on the shelf.

Since you did the job yourself, I guess you realize that 10 hours labor was a rip-off. $550 for the VC is the list price; when I had mine changed, the shop only charged 3 hours for labor. Knowing what's involved, I thought that was fair. It only took my mechanic 10 minutes to diagnose the problem; five minutes of driving to suspect it and 5 minutes on the lift to confirm it.

[edrach]

No more torque bind. The car is running fine with a new VC.

Doesn't if feel great now that it's running right again. I no longer fear making a u-turn or parking.

:banana::banana:

[wagnerku]

Since you did the job yourself, I guess you realize that 10 hours labor was a rip-off. $550 for the VC is the list price; when I had mine changed, the shop only charged 3 hours for labor. Knowing what's involved, I thought that was fair. It only took my mechanic 10 minutes to diagnose the problem; five minutes of driving to suspect it and 5 minutes on the lift to confirm it.

 

It was a phone estimate so maybe the the labor estimate would have dropped to 4-5 hrs. if I took the car in. I wasn't willing to take a chance. I knew my independent mechanic was busy and I couldn't wait for him to get to it.

I had about 10 hours involved; taking my time to make sure it didn't break something else while doing the repair, I have been known to do that on more than one occasion.

Besides the satisfaction of doing it myself, I now have some extra car money for the next items. At 65k I have covered all the recommended maintenance for the 60k checkup except for brake fluid and coolant change.

 

The sticky point was pulling off the rear cover, I tapped and pulled to get it moving off the dowels, once I had a gap, I worked my way around with a thin paint scraper to avoid gouging the sealing surfaces.