If you had a 1984 model and heard a clunking coming from the back seat area everytime you came off or went back on the throttle, where would you look first?

I have very little know history on this car, including the true mileage.

I have been reading posts about rear-end clunking for over an hour. Of all the things it could be, I say transmission mount or mounts. If I shift very carefully, it does not make the sound.

Is there a cheaper alternative to the $100 OEM type mounts? Will encasing a bad mount in urethane work on an early car? See thread:

https://rennlist.com/forums/944-turb...ion-mount.html

 

if it does it when you take off- say you hit the gas then it pauses and smacks, then you let off and it pauses and smacks again, you may need a new clutch. The rubber center comes apart and lets the center move back and forth off the safety.

 

Sounds exactly like a failed rubber center clutch to me and you are banging on the limp home tabs. It will sound like it's coming from the rear in the form of drivetrain backlash. Very common on original NA clutches after 100K+ miles. Jack up the rear of the car, out of gear, reach into the bellhousing at the transaxle. If you can turn the driveshaft by hand more than 1/8"-1/4" your disc is shot. If it's solid but you can turn the wheels in gear without the shaft moving it might be your ring and pinion. Don't rule out a bad CV but it sounds more like the clutch from what you describe. These are the limp home tabs that bang against the disc when the rubber fails. See where it's mushroomed from forward/backward contact?

 

+1

Check inside the clutch inspection port for rubber dust/fragments.

 

I believe you guys are right. The clutch has to be replaced anyway. The throwout bearing is really noisy. I'll do those checks this morning as the car is already up on stands. I'm curious that no one said transmission mounts though. Do they have a distinct sound, or do they rarely go bad?

 

your 84 has two mounts, and ive never seen them go bad enough to make noise. Usually there will just be excess play but thats usually in the later, single mount style.

 

Things to look for at the rear of the car:

Make sure the CV joint bolts are torqued to spec.

The CV joints may have bearing wear groves. Mark both axel shafts L&R-In&Out. Repack the 4 CV joints and "flip" the shafts from L to R. This will put the bearings on a new part of the joint.

When you drain and refill the transaxle, put a rag over the pail and check for metal slivers.

Mounts have been covered----tighten the rear shock bolts to spec.

The torque tube/drive shaft has 4 bearings. Do you get any vibration from the center tunnel area ?

Back to the front----
Check for disc thickness:
http://www.clarks-garage.com/shop-manual/clutch-03.htm

Stick a deep well socket in the gap that fits real snug and measure the socket.

Pull the starter and poke your finger in to feel for 1/8" to larger chunks of rubber center disc. (disconnect battery first)

GL
John

 

I had the exact same problem that you describe, and it turned out to be the CV joints.

 

you could always take off the large inspection cover on the front of the trans-underneath- and grab the trans coupler with a pair of channel locks and see if it moves back and fourth- it shouldnt if the clutch is disengaged.

 

That is odd. When my CV joints started to go they clicked. The only clunk sound I ever got from the rear end was an incorrectly torqued M030 sway bar. The clunking was intermitent and happened turning right or backing up with the wheel turned right. It took a while til someone from here guided me in the right direction or I would have needlessly done the rear bearings.

 

The clutch thickness is quite good. There was nothing more than about a tablespoon of dust that came out of the bellhousing. No rubber chunks. However the throwout bearing whines like hell when I push the clutch in so I've got to go in there anyway. The trans mounts look good and I'm glad xsBoost90 said something good about them. I used a prybar all around them and can't get any discernable movement out of the entire assembly. Seems solid. I changed the trans fluid and used a filter. Nothing but pretty pink Redline MTL. Almost wished I hadn't changed it!

I'll torque the shock mounts. That actually happened to another vehicle this year, but I had forgotten. I'll also do the CV joints and swap axle shafts this week.

So far I've done:
Repaired 95% of the electrical systems
Replaced and/or rebuilt the entire brake system
Repaired most of the interior and cleaned the carpet.
Repaired and cleaned the fuel system.
Replaced the hatch latches.

This week will be engine mounts, tie rods, CV shafts, rebuild clutch slave cylinder, alignment and balance.

Then the timing belt and clutch "projects"!

So far so good I guess. Even in it's poor state, I was impressed with its handling and smooth, strong pull from the engine the two times I took it out on the road. I can't tell you how excited I am to get it right and safe enough to thrash it a bit! Thanks for the help!

 

If it is the CV joints, it's fairly easy to check.

My O/S CV joint 'clunked' when changing gear or pulling away, coming on and off the throttle, but I wouldn't have described it as coming from the back seat area. It sounded just like it was coming from the wheel... but I guess it might depend on if it's the outboard or inboard CV joint.

I jacked up one side of the car at the back, put the car in gear and tried to turn the wheel - no play. I then tried the other side and there was a certain amount of play letting me turn the wheel back and forth a bit. Looking at the driveshaft while turning the wheel, I could see the outside CV joint was turning while the inside one wasn't, so I knew which joint was causing the problem.

Switching the driveshafts around isn't too difficult unless the bolt heads have been rounded off, but it's still easier to just check for play before getting too carried away. If your CV joints are actually clunking, there's going to be a lot of play in them.

Chris.

 

Yeah, keyword is "started," I let mine go for a while, haha. It was definitely a big clunking noise by the end, and directly related to torque -- every time I touched the accelerator. And it did sound like it was coming from the back seat, I thought torque tube initially (which is why I waited so long to actually address it, because I didn't want to deal with that). But new CV joints and all was good again.

 

Was your bad CV joint an inboard or outboard one? I only recently changed my CV joint due to this clunking noise - it was very bad, but only one CV joint actually had any play - the outer offside one.

To me, it sounded like the noise was coming from behind me, over to the edge of the car and it sounded immediately recognisable as coming from the wheel.

That said, sound always seems to travel weirdly through cars, maybe I just assumed it was the wheel and was imagining that was where the noise was coming from

Chris.

 

To answer John_AZ's question about torque tube bearings... I wouldn't know. The engine mounts were bad. Combine that with a couple broken exhaust donuts, one bad tie rod, a hatch that wouldn't stay tight and a squealing throwout bearing, it is amazing that I heard the "clunking" at all! I've taken care of the front repairs and today I'm doing the rear stuff. I'll let you know....