rough ride

June 30, 2010 1:46 AM

'97 Corolla rumble: I think the transmission or clutch is suspect. What should this cost to fix, and are there more durable components that could be installed for future driving?

There isn't much more to it. I just noticed a strange rumble that shakes the whole little car gently. It is especially present when in neutral and approaching a stop, or when in reverse. The car has 125,000 miles on it, but is in fine shape and was driving smooth as silk last week.

It's a 5 speed manual. I have also noticed difficulty getting into reverse, and have caught the transmission grinding in reverse with the clutch pedal to the floor. This seems wrong.

The most basic way to describe the feel is 'rougher' than it was, like something came loose. I know that a full mechanic check-up is next. What should I expect to pay if things are due for replacement? Are there better-than-other replacement parts? And has anyone experienced similar strangeness? I love this little car and have a big stomach knot on these problems.

Thanks hive mind!

posted by roygbv to technology (9 answers total)

At a decent independent gearbox specialist my 2000 Corolla cost £500 to replace the gearbox bearings, which was the problem I had when the transmission started to rattle.

That's parts and labour, London prices.
posted by MuffinMan at 2:21 AM on June 30, 2010

When you say it happens when you are in neutral coming to a stop, do you mean that the clutch is engaged but you're still in gear, or that you've shifted out of gear and the clutch is disengaged? If the former then it sounds like the clutch is dragging, i.e. failing to engage completely. It could just need adjustment -- if it's the cable operated type then cables stretch. If it's hydraulic then the seals in the cylinders can start to leak. If the latter then it doesn't sound like a clutch or transmission issue at all but rather something like worn motor mounts.
posted by Rhomboid at 2:41 AM on June 30, 2010

Might be both, actually. I get the rumble with the stick in neutral, clutch pedal to the floor. When I stop or hit a bumpy bit like this, it seems to get louder. When the car is in gear and I put the clutch down it does a similar thing, and it 'drags' on reverse now and then - gears grind. I have to press the clutch to the absolute floor to ensure smooth shifting. Lastly, the shifting is a bit chunky, there is resistance when going into some gears.

Thanks for the help. Any more experience is appreciated!
posted by roygbv at 3:40 AM on June 30, 2010

It does in fact sound like it could be both. If the clutch cable just needs adjustment then that should be pretty cheap, maybe as little as a half hour of labor. Motor mounts are also pretty straightforward to replace. I hesitate to estimate a cost (so take this with a huge grain of salt) because I know nothing about the specifics of this car but I'd say in the general ballpark of maybe $250-$300 if just one is worn. There's usually two or three of them in total and they are like big rubber grommets on steroids that hold the engine in place and allow it to flex a little bit under torque.
posted by Rhomboid at 3:55 AM on June 30, 2010

It is especially present when in neutral and approaching a stop, or when in reverse

Generally speaking, if your concern occurs primarily when the car is in neutral, you're effectively ruling out the transmission. In fact, my test for whether or not something is caused by a transmission malfunction is to put the car in neutral while in motion. However, the difficulty shifting combined with the mileage of the car makes me think it might be time for a clutch.

An alternative likely scenario, like Rhomboid says, is that you have one or more failing motor mounts. In addition to holding the engine and transmission in the car, the mounts other primary functions are to insulate you from the drivetrain vibrations and to limit the amount that the drivetrain can shift and move when torque is applied.

It's starting to sound like you have a number of problems that are ganging up on you. Grinding into gear with the clutch to the floor is usually going to indicate a worn out clutch. The vibration, rumble, and noise could even be some steering or suspension component showing wear.
Toyotas, especially of that vintage, go through struts and shocks like crazy. I'm going to bet that the struts are worn out and the tire tread has become choppy as a result. When you're coasting down the road, the choppy tires will give the car a full-bodied vibration as well as make a low whurmawhurmawhurma noise. It'll be especially pronounced in neutral, when the engine is at its quietest. And when you go over a bump, the bad struts will make sort of hollow clatter dokdoka as they reciprocate over the uneven road.

You can do a basic check for these things before you bring the car in. With all of your weight, jounce the vehicle. That is, press down on, say, the front drivers side corner on the fender or bumper to fully compress the suspension and allow it to rebound. If it compresses really easily and then flops back to its resting position after a couple reciprocations, then you need new struts. Repeat this test at ever corner of the vehicle. Struts in good condition should resist jouncing and have a crisp, limited reciprocation.
Check your tires by running your hand lengthwise along the direction of the tread. The tread should be uniform. With bad struts, you will detect choppy or cupped undulating tread wear.

This could be shaping up to be a big repair. A new clutch is going to be a couple hundred bucks, installed. And new struts and tires may wind up totaling the same. Prioritize your repairs and spread them out. The advice of your mechanic will help you do this, too.
posted by Jon-o at 4:27 AM on June 30, 2010

It is especially present when in neutral and approaching a stop, or when in reverse

Generally speaking, if your concern occurs primarily when the car is in neutral, you're effectively ruling out the transmission.

Just going to chime in to clarify this - the transmission is only ruled out if the engine is in neutral and the car is stationary. Most of the gearbox rotates constantly if the wheels are turning, so you'll only be ruling out whether the gearbox is worse under load or not if you take Jon-o's sentence literally without further clarification.

Engine mounts are a definite possibility, but unless you have shaken your engine in position before, it'd be hard to make a value judgement on whether it is worse or not. With the engine unloaded the drivetrain will be free to move with its internal oscillations and bang against its faulty engine mount which would transfer larger 'thumps' but smaller, more constant 'deep rattle' kind of vibration when the engine is loaded in one direction. Something that may make it more pronounced would be to apply power on and off a few times and see if you can get a clunk to be repeatable. That'll add weight to the engine mount evidence, but again, it's hard to isolate this unless you grab the engine in the bay (not running) and shake it back and forth to see if it moves. Unless you know if it is more than it should or not, this may not help you. If you can get it to bang (or clunk) like this, though (even gently) then it is certainly mounts.

An engine mount should be a relatively cheap fix, however. In addition, just to respond to your extra question there will really be no 'upgraded' parts that would be worth installing. Original equipment parts (even if fitted by an independent mechanic) will most likely be the better quality parts. After market parts are, by definition of the economies of scale) almost guaranteed to be lower quality in some regard.
posted by Brockles at 7:27 AM on June 30, 2010

it 'drags' on reverse now and then - gears grind. I have to press the clutch to the absolute floor to ensure smooth shifting. Lastly, the shifting is a bit chunky, there is resistance when going into some gears.

Google says this is a hydraulic clutch. Have you checked the fluid? Does the pedal feel squishy? If you quickly pump it up and down a few times does it get stiffer and then make it easier to get into those gears?
posted by fritley at 11:08 AM on June 30, 2010

Wow, awesome information! Thanks everyone. I hope this doesn't get crazy expensive.

A few people checked the car out when I bought it, and one of the recommendations I received was to have the struts replaced. They withstand the jounce test and the tread seems even, further my trusted mechanic said "they're fine." Might take it somewhere else to just be sure, but. I can see some big rubber engine mounts getting weird at this age. I also just brought the car from Boise, ID to Portland, OR and the environment is much different, plus it's city driving. Poor car is getting a workout.

I'm new to mechanics in the Portland, Oregon area, so let me know if you have someone you love. Again, thanks for the help everyone! Always impressed by Mefi answers.
posted by roygbv at 11:21 AM on June 30, 2010

Fritley: dunno about this. Doesn't seem to stiffen up at all. I'm not sure what the difference feels like, though, so I have no idea if the clutch is hydraulic or not. I will check the fluid next.
posted by roygbv at 11:24 AM on June 30, 2010