help diagnosing a few clunks & shudders...

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dlb
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My tercel:: '87 sr5, '83 dlx parts car
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help diagnosing a few clunks & shudders...

Post by dlb »

Hey gang. So I recently bought an '86 SR5 that is, for the most part, in great condition. There are a few sounds it makes that I'd like to diagnose and fix though, nothing serious at this point, but I really want to make this car mint so it lasts me and is reliable. So here are the sounds neither I or my mechanic have been able to figure out:

#1 - clunk when shifting, occurs when I let the clutch pedal up and the gear engages. You can feel the car pull when it happens, like the clutch just grabs really suddenly. I've learned to operate the clutch pretty smoothly now but something is definitely loose or unhappy there.

#2 - clunk when I let off the gas suddenly. Is very similar, if not the same, as the previous clunk I just mentioned so maybe they are related or even the same thing? My mechanic showed me that there is a bit of play in the CV joints (when the front end is jacked up, you can freely spin the wheels an inch or two before they stop and require force to be turned further) and that might be it, though he said they're really in good shape and not to worry about them until they start to clunk or growl when turning.

#3 - front end shudders a little bit at 100 km/h and higher. Not too bad, the steering wheel doesn't shudder at all but you can feel it in the pedals.

#4 - clunking in front end when going over bumps, like potholes. It sounds like the shocks or struts are hooped and the wheels are justing bouncing up and down but we've checked the struts and apparently they're fine.

#5 - engine surges a little bit when gearing down. If I'm driving along and then let off the gas, or gear down to brake, the engine does these really quick and light little surges. I mean, it definitely slows down, but it's not as smooth as it should be.

So far, since I bought the car my mechanic and I have replaced the front rotors and pads, spark plugs, fuel, oil, and air filters, water pump, coolant, and removed the rear sway bar (it was more or less dangling anyway) and advanced the timing a little bit. If anyone has any suggestions of what these other problems might be, I'd really appreciate their input!

Thanks,
David
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ARCHINSTL
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My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
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Re: help diagnosing a few clunks & shudders...

Post by ARCHINSTL »

Some of my clunking disappeared when I renewed the two motor mounts and the transmission mount. The latter is fairly easy and the former is more difficult, but doable even lying in a gravel driveway. Incidentally, the little shock damper on the right lower side of the block is NLA at any Toy dealer/warehouse (in North America, anyway).
More clunks vamoosed with the strut insert replacements and all new front bushings.
The swaybar-to-lower control arm and the latter's attachment to the unibody are kinda Achilles Heels on rustbelt cars.
The bolts holding the right side steering knuckle to the strut seem to self-loosen on some of our cars.
Did you do a Search using "clunks" as the criterion? Lots of info available.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
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Re: help diagnosing a few clunks & shudders...

Post by Petros »

one and two might be related (even three). Check the engine mounts, it can cause both of these behaviors. the other issue could be worn/sloppy CV joints (is there a thumping when you accelerate around turns?). Number one could also be a bad or contaminated clutch. Is there oil coming from the rear seal? Replacing the clutch is not too costly if you do it yourself, but it is a big job and very costly to pay a shop to do, so make sure it is really a bad clutch before you take it all apart.

3 and 4 might be related, check all the bolts in the suspension. Sometimes they work loose and should be re tightened. Especially check the two bolts on the bottom of the struts. Also check the lower ball joint and tie rod ends. Also check the condition of all the rubber parts on the sway bar and lateral link. I put a large pry bar at the joint and see if there any slop in the rubber bush. A shimmy that comes and goes can also be an out of balance tire, so have the balance checked on the wheels and tires. Make sure you are satisfied that if you can not find it, that all the important and safety related stuff is in good working order, if you fail a ball joint or other suspension part, you could lose control of the car at hwy speeds.

Number 5 could be a vacuum leak in the engine/emission control equipment. Do a search on vacuum leak and you will find what usually leaks, and how to locate it using a can of carb cleaner. that is usually an easy fix.

It sounds like you just have to work through a number of issues that are common to older cars, but all of these are fairly easy and inexpensive to fix yourself.

Good luck.
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tercel4wdrules
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Re: help diagnosing a few clunks & shudders...

Post by tercel4wdrules »

Welcome! Once you iron out all the kinks you will find that these cars are very reliable, but first you will have to go through everything.

For #2, I had the same problem on my '84. I replaced the control-arm to sway bar bushings. I was only able to locate these from the dealership. In addition, I also replaced the inner tie rods, you need to check these because play in these will cause sloppy steering and if worn enough, they will contribute to clunking in the front end when you back off the gas. After I replaced both of these items the car was noticeably smoother when I backed off the gas pedal, it was a nice welcome because it was quite annoying previously.

#4... For the clunking over bumps, you should check the control arm bushings and the ball joints, those are the most common culprits for clunks that are heard over bumps. A bad ball joint will also contribute to a shimmy at hwy speeds, especially during downhill deceleration. I also had a bad ball joint and that caused very bad vibration while decelerating downhill and I had it immediately replaced. It's important to check those out. Have you checked the strut mounts?

Almost every Tercel 4WD I have seen and driven for sale with high mileage has always had need for front end work.

For #5 does the car have a flat spot or anything like that? I would look for vacuum leaks around where the intake manifold and cylinder head. I have found that those bolts like to come loose and will cause problems with vacuum leaks. The other place I would check would be the carb base as well.

Good luck with it!
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dlb
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My tercel:: '87 sr5, '83 dlx parts car
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Re: help diagnosing a few clunks & shudders...

Post by dlb »

Hey guys, thanks so much for your advice! I appreciate it in a big way and will talk to my mechanic buddy about all your suggestions. I'm learning bit by bit as we work on it, I have only a little mechanical experience so far so it's a big learning curve but I hope to be able to diagnose problems and work on them myself soon. In the meantime, it's great to know there are such avid Tercel enthusiasts out there who love this wagon as much as I do and have so much knowledge to share. Thanks again!
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emmahumpfritter
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My tercel:: 1985 tercel 4wd
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Re: help diagnosing a few clunks & shudders...

Post by emmahumpfritter »

This is a vey helpfull thread, especially since I'm going through my Tercel as well. Thanks!
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