Mechanic replaced [lots o'stuff] -vibration - vibrates; how bad can it get?

[Hank Roberts]

EDITED -- partly solved maybe completely solved, see #37. Bad steering knuckle at bottom of right front strut, that the prior places hadn't noticed. Way bad, worn well beyond adjustment.

 

=====

 

Original post and long chronicle of possible suggestions follows:

 

My mechanic pulled and replaced an engine (a rebuild that had failed under warranty sent back and returned). While doing that, he told me later, he 'found the clutch pressure plate worn and replaced it' -- no charge.

 

It's also had both front axles/joints/CV boots replaced, both were clicking.

 

Since then the car's had a vibration during acceleration -- felt most strongly in the floor at the gas pedal.

 

I've read the prior threads -- lots! -- on vibration/tranny/clutch.

Mechanic claims they were aware of the alignment marks and that isn't the problem, has driven it, says there's nothing wrong.

 

Nevertheless it has this shake.

 

I'm wondering:

-- could this be they messed up the alignment?

-- or could replacing just the pressure plate leave things shaky?

-- how bad can it get, can it cause a clutch failure?

-- is this why I hear you should replace a whole clutch kit, not just a worn pressure plate?

-- will I be back to read answers to this on Sunday night, assuming I really take it to the mountains this weekend as planned in a couple of hours?

[[HTi]Johnson]

Hello, it depends. If it was a pressure plate, or anything attached to the crank, like flywheel, pressure plate, or even a pulley, it would vibrate with engine RPM. THe more RPMS, the worse the vibration.

 

How's the drivability? Like: Does it drive better or as good a it use to, accelerate the same? Does the engine shake real bad at idle?

 

I'm asking these because, with the engine replacement there is a lot of variables. Like timing belts that were put on wrong, distibutor not correctly timed, or firing order is off. If your engine shakes a lot while idling, I'd first check the plug wire order and then the timing.

 

And if you could tell us the year of your 'Ru, that'll help a lot too.

 

And, last thing, how Subaru inclined is your mechanic?

 

Hope it's something simple,

Justin Johnson.

[naru]

Did the vibration start after axle replacement?

Sounds like a bad inner CV.A lot of "rebuilt" axles are of dubious quality.

 

Not likely a clutch problem.

[calebz]

 

And, last thing, how Subaru inclined is your mechanic?

 

Hope it's something simple,

Justin Johnson.

 

Good question. More accurately though, is this the same mechanic that did your transmission and the myriad other repairs you have had in the past couple years?

 

If so, run.

 

 

If not, I would probably be inclined to ask him what led him to believe the PP was bad. Was the disc replaced also?. TO bearing?

[[HTi]Johnson]

Did the vibration start after axle replacement?

Sounds like a bad inner CV.A lot of "rebuilt" axles are of dubious quality.

 

Not likely a clutch problem.

OH yeah, or does the vibration get worse with speed or the car. Thanks, Naru, I forgot about crappy rebuilt axles. He didn't say whether the axles were replaced while the engine was out or a different time.

[GeneralDisorder]

On the other hand, I've experienced some noticeable increase in vibration when installing very tight NEW axles. I get the GCK ones, and being brand new rather than rebuilt they sometimes seem to expose second order vibrations that were not there to begin with. In my case it was a combination of bad tranny mounts, and soggy engine mounts. The axles were so new they simply didn't absorb anything. It's a lot like your describe - vibration while accelerating only. Anyway - something to take a look at. Could also just be really crappy axle rebuilds.

 

GD

[baccaruda]

GD snipes baccaruda for the win!

 

bad tranny mounts, and soggy engine mounts.

GD

ya bastid.

 

 

 

 

How's the car feel when you're coasting it?

[Hank Roberts]

This is not the mechanic in Palo Alto who screwed up the prepurchcase inspection so badly.

 

This is not the mechanic in Berkeley that made me yell SOS for many reasons.

 

This is the mechanic in Berkeley that the (distant) engine/transmission rebuilder suggested for some warranty work. They are an independent, longtime local and I see quite a few Subarus and Toyotas in there, few as old as my 1988.

 

He said he noticed the clutch pressure plate was worn while he had the engine and transmission out (also replaced transmission shift bushings that the SOS Subaru place forgot to fix).

 

I wondered, because I thought normally a whole kit of clutch parts get replaced at the same time; he said that's all that was needed.

 

I have a 1988 GL 5-speed 4wd wagon.

 

Vibration is not noticeable coasting or idling.

 

Vibration doesn't show up in the steering wheel (rearview mirror, seats) -- it's specifically in the area of the gas pedal.

 

Vibration is most noticeable (in city driving, all I've done so far) in first gear specifically, accelerating uphill from a stopsign. Less noticeable on the flat, in first gear starting out from a stop.

 

The throttle position sensor has just been replaced, which fixed 'bogging down' at various places; the old one tested bad, the replacement from a junkyard they say tested good.

 

So, yeah, it could be one of the replaced front axles.

 

In full steering wheel lock in a turn, the right one sounds funny, louder now than when they fixed it. Hmmmm. Kind of a groan.

 

I'm about an hour from taking it on the road -- unless anyone wants to warn me about anything really nasty that this could lead to on the highway or on mountain 4wd forest roads, where I need to take it.

 

I'll check back one more time, and if it's not smart to drive it like this, I won't.

[Qman]

It may be a bearing, a motor/trans mount, a driveline(U-joints are staked), could be an axle even. Is the dog bone(engine stabilizer) connected and tight? Are you feeling it in the gas pedal itself or the floor beneath your foot?

 

Must be very frustrating!

[Hank Roberts]

It's in the gas pedal or the floor right at the pedal.

 

I asked them to look at the motor and transmission mounts and replace them if there was any doubt; they said they were OK, and I was emphatic about wanting them checked.

 

I don't know what to look for (don't have a lift or garage at home) re engine stabilizer, wouldn't recognize it. I'll try to look.

 

Disappointed to find several of the insulating boots were off of various wires that would've had to be handled reinstalling the engine, just hanging down on the wire instead of covering the connector. And the battery terminal plastic covers, positive was hanging loose, negative was sitting loose on top of the battery.

 

Someone there (Autometrics is the shop) is just not paying attention or doesn't give a damn about the work being finished, that tells me.

 

Bad sign when the little stuff isn't finished right.

 

I guess I'll try driving it -- I'LL BE on the highway for a few hours and if that seems ok, take it up into the forest roads and hope to get back tomorrow or Monday.

[Hank Roberts]

350 miles later ....

 

I got to the first long uphill -- a series of switchbacks (paved road) up from the north end of Potter Valley. That's the end of the pavement. I'd driven about 120 miles of freeway and 20 miles of paved road, with about the same shaky-in-first as before, figured I'd chance it.

 

On those paved switchbacks, a long steep climb in first gear --2wd-- the front end shook badly the whole way up.

 

Well, OK, I was committed to back roads at that point. I drove on in on the dirt road in 2wd, about the same; bit of pavement near Lake Pillsbury; then onto the mountain road climbing, gravel and dirt and steep.

 

Much less shaking while in 4wd in first gear -- both high and low range, I drive the last 9 miles climbing about 3000' in low first.

 

But there's a whole lot more noise than before in the right front wheel -- groans at full lock left and right, creaks on bumps. Same noise I complained about before the mechanic replaced both front axles/joints, and that was before the shudder started.

 

I decided I didn't trust the car to poke around more in the back country, slept over -- stars!! -- cold but worth the trip to see the stars. Got up, packed and drove home this morning.

 

After the long drop down to Lake Pillsbury (engine braking mostly) the middle part of the trip home was by a different route -- long stretch of dirt road to Elk mountain, not steep, curvy; little noise from the right front again, usual shaking in first --and now in second gear - while accelerating. Getting worse.

 

Pavement starts with a long series of S-curves and switchbacks off Elk Mountain. Creaks from right front. That was all engine braking, no hint of any vibration ever while going downhill or coasting or sustained speed.

 

Back onto the freeway for the last 2 hours.

 

And dang.

 

In the last 60 miles I picked up a new noise, from the rear end.

 

Did I mention the mechanic replaced the rear differential (junkyard part) and rear wheel bearings a while back? One of the four bearings was a ball of orange grease and rust particles, that was a correct diagnosis.

 

By the last few miles today coming home what had been just a 'noise' has become a chatter/clunk rotational noise in the rear end -- unrelated to the shake in first gear that still happens near as I can tell. Something's very broken. I'll go under it with a flashlight once I settle myself down and unpack -- but it's going back to the mechanic Tuesday Am. It might make 10 blocks downhill from here to there, or might not. Scary noise.

 

Brake part loose? (Braking is very noisy in the rear but perfectly even, no jerk or pull or shudder, just sounds like normal drum brakes very magnified.) Axle or differential or wheel bearings?

 

12 days from now, we take the niece and nephew camping for two weeks.

That's the two weeks per year I need a vehicle capable of ten percent grades in 4wd low. And the road's a mess this year, up there.

 

What do you all think of the new Toyota Land Cruiser they just came out with? I may have to buy something.

 

Remember I'm coming up on age 57, and the failed carpal tunnel surgery left me pretty unreliable handling tools without dropping them. So if I buy a vehicle, it's the last one I'll probably ever buy. I'd been hoping the Subaru would fix up well enough to last me, but without a mechanic locally who really knows these cars, it was a fool thing to hope.

[GeneralDisorder]

I think I would have a look at the driveshaft u-joints. Have to unload the rear wheels (get them in the air) and then check for play in the shaft. I had a similar shaking with a bad u-joint in one of my shafts.

 

If you can, jack each wheel up, and check carefully for play. Try to shake the wheel up and down and in/out as well. Also check the axle nuts to make sure they are tight, and that nothing is working loose. If something is wearing out the nut's can work loose and make even more noise as well as more damage.

 

Your front end "creaking" sounds like possibly a strut top bearing. I've had one or two that would do that under full lock turns. Might be dry in there. I'm not sure these can be repaired (ie - bearing replaced) - may need to replace the whole strut top.

 

As for a new vehicle - if you are seriously at the point where you cannot work on the Subaru yourself, it may be wise to find something else that can work for you. Especially if the mechnics in your area are just not up to working on it. Thing is - few cars are as simple as an EA series subaru, so I just can't understand why this mechnic cannot seem to get things right for you.

 

GD

[Hank Roberts]

[oops, duplicate post removed]

[Hank Roberts]

I seriously can't work on a vehicle myself (well, I'm fixing the inside of the 1969 Dodge camper van, but have a competent Dodge mechanic for anything else). The Subaru, I am afraid, was just worn out by neglect when I bought it.

 

Clarify for me -- the shaking problem is most noticeable (going uphill in first) in front wheel drive. Are there U-joints involved at all in front wheel drive system?

 

The noise in the rear is in 2wd (haven't been in 4wd since it started earlier this afternoon).

 

When the 5-speed dual range is in front wheel setting, how much of the drive train to the rear is even turning?

[GeneralDisorder]

Well - actually the entire rear drive assembly is "along for the ride" at all times. Since the rear wheels are connected to the diff, and that to the driveshaft it's all spinning at all times. The disconnect is inside the transmission - all it does is disconnect the rear drive shaft from the engine. Make no mistake tho - everything that spins when the vehicle is in 4WD is also spinning in 2WD - it's just not "driven"

 

When you put it in 4WD it actually places constant tension on the (potentially) loose u-joints or other problem area. This will tend to quiet the problem as the area in question will be in tension from both ends - from the wheels, and from being driven by the engine. So when in 4WD often I've seen bad u-joint quiet down a bit, and not vibrate nearly as much.

 

GD

[Hank Roberts]

Very helpful, thank you.

 

Well, front struts and the section between the differential and the transmission) are all I hadn't so far replaced or rebuilt.

 

Figures!

[blownbimer]

My mechanic pulled and replaced an engine (a rebuild that had failed under warranty sent back and returned). While doing that, he told me later, he 'found the clutch pressure plate worn and replaced it' -- no charge.

 

 

Anyone else find this odd? never seen a mechanic give free parts...maybe not charging labor for parts when hes already in there....but never just free parts because they were worn...

 

I'd also say its something in the driveline.... have you tried pulling the park brake and "loading" the driveline? listen for thumps and such? maybe that will help you pinpoint where about its comming from.

 

Good luck!

 

Erik

[Hank Roberts]

To clarify --- he put in the clutch plate no charge; charged about $80 for the part. He had everything out of the engine compartment at the time anyhow, paid by the rebuilder, under their warranty. All I can say is, thank God for companies that honor their warranties..... but I wish one rebuild was all it needed.

 

I crawled under and looked last night. The U-joint (between drive shaft and rear differential) is powder-white shading to blue metal. Looks like it got hot. That's different. Nothing else obviously changed from the day before. I suspect I better put some oil on it before trying the 10 blocks to the mechanic, if it turns at all Tuesday AM.

 

Well, the last freeway miles I drove, it's either bridge or traffic lanes between barrier dividers, couldn't have stopped without being rear-ended in holiday traffic.

 

Just as I got off I passed a mother goose followed by two tiny babies, hiking along the exit lane, they had only about 150 feet to go to where there was a grassy shoulder and some space to escape into the median. Must've tried to cross the freeway from the Bay side a mile or two back and hit the barriers in the middle. Hope they made it.

[Hank Roberts]

Ok this is different.

 

Under the car, looking at the differential from the right hand side.

 

The front end of the differential, before the U-joint, hangs down from the body.

 

There's a big round metal ring it hangs from, by a bolt through the ring.

 

I can see daylight all 'round the bolt and washer -- nothing around it to hold it from bouncing around.

 

Looks like there used to be rubber in there and it's all gone.

 

I wonder if the shaking in first gear, and now the grinding noise, was just the metal pieces rattling around loose? There's a good half inch of air around the bolt that looks like it should have been rubber.

 

Guess I'll find out tomorrow.

[GeneralDisorder]

Yeah - those front diff supports do go bad like that sometimes - the rubber gets old and just falls apart. The excess vibration from the bad u-joint may have been the final straw for it. Definately going to be part of your strange noises that you developed. Probably be able to locate a decent one from a junk yard. I know I could get one up here anyway - if your mechanic can't locate one, PM me.

 

GD

[Hank Roberts]

I'm not even sure the U-joint is bad, it looks fine close up once I cleaned off road dust.

 

I think the front end of the differential was just bouncing an inch or so up and down and front and back, and the clanking is the crossbolt that's now floating in the opening where the rubber used to be as the U-joint rotates, it'd thrash up and over and down with each rotation.

 

They replaced the differential about 400 miles ago.

[gryphon]

I have this EXACT same problem with my '85 Brat. I describe it as a "wobble" ... only when accelerating in first gear, not as bad when in 4WD, under my feet or under my butt... I've searched this forum from one end to the other and tried anything that even seemed remotely similar...this place is great!

 

Mine started when I had the clutch and front axles replaced. The shop also replaced the transmission mounts. I took it back to them several times and they acted like they could not feel it. But, I have driven this car for many years and the wobble is most certainly there.

 

I've recently replaced ALL of the axles on the Brat...the front ones twice thinking the problem must have been with one of the new ones.

 

In my quest to figure this out I have replaced both U-joints and the differential mount, but the wobble remains. Replacing the diff mount has helped with a little road noise, but not the wobble. I don't believe the rubber being gone out of your old diff mount would allow the thing to "thrash around". You still have the weight of the car on it...only it's metal on metal...I drove my Brat for many miles without that bushing...

 

I've tried adjusting the stablizer (dog bone) and it seems to have made a slight difference. I have purchased new motor mounts and a new bushing for the stablizer but I have not installed them yet... I really believe/hope it is the motor mounts.

 

As for the cause...I feel like wobble has been there for a while but not very apparent since motor and trans mounts were bad, it was floating...when the shop replaced the transmission mounts it tightened up the drive line and caused this wobble to be more apparent.

 

I'll be installing the new mounts soon...I still drive the Brat every day with the wobble. I will make another post after installing the mounts.

[Hank Roberts]

Well I have had a lot of repair done this past year, or not done, based on what the mechanics believed could and couldn't be possible and didn't look at -- sounds like you have too.

 

I'm still suspicious on mine, I'd bet that after all this I've got other bad rubber mounts -- even though I asked the shop to check each of them while the motor and transmission were out. I have a steep street for them to test it on next time that requires first gear to get up. And will insist. I'm slow to get pissed and I'm getting there.

 

The motor has been out twice -- the first rebuild engine I got came bad, got sent back, came back leaking coolant, got sent back, and I've got about 450 miles on the second rebuild. So it's not like there wasn't time to check all these mounts.

 

Heck, I asked the current mechanic to check the mounts and shocks at the back while the differential was just recently out. Three mechanics I've had this car to in the past year didn't check -- or don't know how to recognize a good mount. After 230k plus miles I new the rubber would likely be bad if it was still original.

 

...I don't believe the rubber being gone out of your old diff mount would allow the thing to "thrash around". You still have the weight of the car on it...only it's metal on metal...I drove my Brat for many miles without that bushing...

/quote]

 

It sounded like a clothes dryer tumbling with a chunk of metal in it, driving slowly in first gear down to the mechanic's this morning. There's no arguing with actual observation -- and I can tell you for sure on mine, with the rubber gone, the differential and the attached U-bolt and axle have been thrashing around, the metal's visibly shiny where it's been moving and banging.

 

The rotation of the drive shaft has plenty of torque to cause the end that's not well attached to bang around. Like twirling a jump rope.

 

To quote a doctor friend, "Theory and practice are the same, in theory, but in practice, they're different."

 

Looking at the place where my differential hung from the car body, there's a tiny little bolt that was used -- looks like 1/4" diameter, with a big washer on either side that should have held it against the rubber when there was rubber. I wonder if that bolt was the right size for the opening in the shock mount rubber. Seems way too small to spread the force out on the rubber properly all around.

 

Much further and the bolt would have been eaten up completely and the U-bolt and axle dropped. I wonder what they'd have pulled down if they fell at that end, hadn't looked for things like brake hoses between the drive shaft and the road. Betcha it'd take some other parts with it.

 

How big is the center hole in the standard rubber bushing? I wonder if the bolt used was too small and it wore out the bushing by moving around?

[gryphon]

It sounded like a clothes dryer tumbling with a chunk of metal in it, driving slowly in first gear down to the mechanic's this morning. There's no arguing with actual observation -- and I can tell you for sure on mine, with the rubber gone, the differential and the attached U-bolt and axle have been thrashing around, the metal's visibly shiny where it's been moving and banging.

 

The rotation of the drive shaft has plenty of torque to cause the end that's not well attached to bang around. Like twirling a jump rope.

 

Looking at the place where my differential hung from the car body, there's a tiny little bolt that was used -- looks like 1/4" diameter, with a big washer on either side that should have held it against the rubber when there was rubber. I wonder if that bolt was the right size for the opening in the shock mount rubber. Seems way too small to spread the force out on the rubber properly all around.

 

Much further and the bolt would have been eaten up completely and the U-bolt and axle dropped. I wonder what they'd have pulled down if they fell at that end, hadn't looked for things like brake hoses between the drive shaft and the road. Betcha it'd take some other parts with it.

 

How big is the center hole in the standard rubber bushing? I wonder if the bolt used was too small and it wore out the bushing by moving around?

 

When I replaced the diff mount I re-used the bolt. It was not eaten up, threads were still good...as I recall it was a bit heavier than 1/4". Sorry I don't know the size but it fit snuggly through the new bushing. I never had any clunking or banging. I agree there is no arguing with actual observation, but I still can't imaging driving slowly in first gear, the play in that mount would be enough to cause a sound like a dryer with a chunk of metal in it. Perhaps the bolt or the mount broke...or some other component broke.

 

Most 20 year old rubber (motor mounts, transmission mounts) should probably be replaced.

 

Good Luck!

 

Steve

[Hank Roberts]

Okay, I'm an idiot.

 

Differential mounting rubber explained here:

http://www.ultimatesubaru.org/forum/showthread.php?p=469763

 

Mechanic called and said the same thing you all said, that rubber mount looks OK, and it's normal to be able to see right through the holes.

 

That clunking noise I developed in the last 50 miles on the way home was the left rear brake falling apart -- backing plate banging on the wheel, I think he said? It didn't affect the braking performance, no pull, fooled me completely --- it just clanked with every rotation. Good thing I crawled the last few miles, I guess.

 

Brakes just do that? (shudder!)

 

Still no answer for sure on the vibration in first gear uphill in 2wd -- but he'll drive up the big hill and test for that, after the brake parts come in tomorrow.

 

And he'll look into the creaking/groaning right front strut on big bumps and when the steering's fully left or right.