!@#$ - Thinking of selling - please help
 

On top of the nagging starting problem the my SVX has had for months, a new issue popped up last week that, so far, has left everyone scratching their head and me saddly pondering the new car market. Here goes . . .

When does it happen? Driving at highway speeds for 15+ minutes. Has occured consistently under these conditions for the last week+.

What happens? Gradually, a deep rumbling starts in the mid-rear part of the car. Vibration, felt in steering wheel, shifter (5-speed, been working fine for 9 months), as well as entire car. Feels somewhat like driving over a continuous line of very small speed bumps at first. Rumble and vibration get worse with continued driving (and presumably continued heat). Eventually gets so bad (with continued driving) that it can be felt as a very slow-frequency vibration/motion even at <10mph - almost like something is unbalanced or rotating unevely, tied to vehicle speed. Once it starts, it occurs in N and drive gears, clutch in or out. No change in symptoms while turning or braking. So far, once the car cools down, back to normal.

What's been suggested by the local shops? Nobody can figure out anything. Suggested that there's a possible issue with the front/rear viscous coupling, but no solid theory. Suggested that I just drive it until it totally breaks. (Not a viable option.)

My thoughts: Probably related to something with fluid lubrication since it can't even be recreated until driven (heated) for 15+ minutes. Definitely not a rear wheel bearing (been down that road several times).

I really don't know what to do. I still need this car for daily driving, and I can't just drive something until it breaks in the middle of January in Kansas City. I'd consider selling it if it comes to that, but I've put so much $$$ into it over the last couple of years, and probably couldn't get beans out of a sale with a stipulation like this.

Please help. Any ideas are appreciated.

What does the diff gear oil look like?

I would also check to see if the parking brake shoe is sticking - not likely but you never know.

Sounds alot like an out of balance driveshaft or bad joint in the driveshaft but that wouldn't support it happening only when warmed up.

I agree, checking the parking brake shoes might be the ticket. Since you've put in the manual you're probably using the pkg brake more than ever and in cold weather you're asking for a freeze-up of the cables. All it takes is a slight drag to heat up the drum portion of the rotors to cause a vibration. Even at slow speeds the vibration is probably fairly busy, isn't it?

Several rears ago I had a 83 gl 4x4 wagon with the same symptoms you are describing. wouldn't act up untill several minutes of highway miles. the whole car would shake like it was about to come all apart. cv joints were tight and quiet so I change the u-joints in the shaft to rear diff . no change. A week later after driving for an long period of time when I got home I checked the inner DOJ joints by grabbing them with my hands as soon as I could after I stop in the driveway. What I found was one was much hotter than the other. replaced that one and never had the problem Again. Drove me nuts trying to figure it out though.

The DOJ [ double offset joint] can be changed without replacing the whole axle. If your car has high milage though you would probably be better putting in a complete rebuilt or new axle. I have never had much luck with rebuilt axles on my subarus. It could of been the supplier rebuilting poor axels though. with the lifetime warrenty they just were changed alot for free.

i would think main carrier bearings holding the drive shaft in,, not shure if svxes have them..

that is in the the middle and rear portions of the car and the bearings can go bad causing a vibration or woble sound.. it has to be something in the drive line.. rear axles.. difrentials who knows...

does this do why the car is nutruel?? like free reving, probably not.

iwould chek the whole driveline system. could be also transmsion issues.

does the cluch grab hard?? any slipage there.??

I also agree that the inner cv joints can cause similar problems, but it's not been my experience to have them require a warm-up period. Not to say that it never happens that way, but I will keep that in mind if I ever run across a similar problem.

Hey Dorian
 

What's up with your car? Do any of these things make sense based on how the car is acting?

Todd

.......pssst, if you sell your car, I want it!

Update
 

Well, no good news yet, but thanks for all of the ideas - keep 'em coming. She's now at a shop that I've never tried before, and I'm supposed to hear something from them later this week. I just don't have time to do the troubleshooting myself right now, and I saw an SVX at this guy's shop a couple of months ago, so I thought it was worth one last shot. IMHO, the rear DOJ theory sounds most promising, but I went over several of your suggestions with the shop owner. I reluctantly gave him free reign to experiment at my expense, so, whether it gets fixed or not, I'm sure to take another major hit. Thanks again - I'll keep you posted.

I was talking about the front inner axel joints. those were the ones that I had the trouble with. They are [ DOJ ] joints the same as on the back. I would drive the car and than see which is hotter to the touch and start there. you can unbolt the rear section of the drive shaft to elimanate the reardrive. this will tell you if it is a front problem or rear problem. when my car acted this way the whole car would shake while driving and coasting also in neutral.

How many miles have you put on that new 5spd box? Do you think it could be related to the 5spd?

Update
 

Thanks for the correction Pilot. That actually makes even more sense based on what I was told today. The second shop that I took it to said they were "95%" certain the vibration was originating from the front, somewhere around the center diff. They said the lower front portion of the tranny housing (center diff area) seemed excessively hot. Their first thought was that a bearing inside the 5sp housing, possibly for the center diff ring gear carrier, was going out. Second thought was that an incorrect tolerance between the center diff pinion and ring gears was causing the problem. This is remotely possible since I did have the tranny rebuilt with those heavy-duty gears. But, in both of these cases, it still seems odd that that car would drive perfectly until fully warmed up. I mentioned the front DOJs to the mechanic, and he said it was definitely still a possibility, though he didn't detect a drastic difference in temp between the left and right.

So, following the cheapest-fix-first approach, here's the plan of action. Replace the right (or left) front axle with a remanned axle and see if that fixes it. If not, swap the original back in and replace the other side axle with the reman. If that doesn't work, I guess my next step has to be swapping out the entire 5-speed. (I've put about 12K miles on mine, btw.) I really hope it doesn't come to this last step - $600-1000 just for a decent salvage 5-speed, not to mention labor and the wasted cost of those h.d. gears. Guess I could always try to find someone to re-rebuild a tranny with those gears, but it probably wouldn't be worth it.

Fingers crossed for a bad axle joint.

Have you eliminated SolarSVXs suggestion that it may be a drive shaft bearing?

Matt

That should be your best approach. you will only have to buy one axle that way. If the first side doesn't change anything you should be able to put the axle they removed on the other side. If it was a drivshaft center bearing it would vibrate all the time and get worse under accellerating. My bet would be a front DOJ after what I went through to find that was my problem.

A tentative woohoo!
 

Just got off the phone with the shop. They found a remanned front axle in Kansas City and picked it up this afternoon. The mechanic said that, when he compared the seating of each current front axle into the center diff, there seemed to be a little more play in the right one. So, based solely on this hunch, he replaced the right axle first. He just got back from a 45 mile drive, and the problem is gone! He seemed a little amazed by the whole thing, and still a bit skeptical that it's really fixed, so I'm going to drive it for a while before he gives back the core. But, based on a 45 mi drive, things are looking pretty good. If that wasn't the root cause, it was certainly a key component.

Thank you all so much, and especially SVXPilot. Without you, there's absolutely no way my SVX would have been fixed so soon, if ever.

In the unfortunate case that the problem resurfaces, I'll keep you posted, but I'm hopeful that I'm out of the woods for now.