|
|
|
The 93 245 has had a knocking noise when reversing up a hill (i.e. under a load). It is directly proportional to the wheel speed. The sound seems to originate between the two front seats. I don't reverse up a hill much, so I really have not paid too much attention.
Well, I had some free time this weekend and inspected the propeller shaft area. No signs of contact or rubbing. The shifter linkage looks free and clear as well. However, the tranny mount was a bit squashed, so I replaced it with a Volvo OEM mount. I had to lift the tranny about a 1/4" to make the holes line up.
Now the car knocks/grinds in every gear, including park. It dissipates at speed (over 10-20 MPH and that's as fast as I've taken it.), but is constant when stopped in Park/R/N/D. When in neutral, if I rev the engine, there is something out of balance that causes a vibration I've heard/felt before.
I put the 245 back on jack stands with all wheels off the ground, started it up, ran it through the gears and no noises at all, including the rev in neutral. Sounds great. Damn!
I closely inspected the propeller shaft area again and there are no signs it's hitting anything at all.
I find it odd that my symptoms only got more persistent when I put a new tranny mount in which raised the rear end of the tranny a bit.
The motor mounts are Volvo OEM and brand new as well. Everything looks tight.
I plan to check the linkage adjustment in the morning. If that does not work, what other experiments can I try?
Do I have a bad torque converter? How do I inspect it?
Thanks for any pointers.
|
|
-
|
|
|
First, thanks again for all the suggestions. I was able to rule out a lot of stuff with your help.
What I discovered is that the new transmission mount raised the transmission and also raised the catalytic converter, which is now resting against the propeller shaft center bearing support bracket. This contact point is causing the noise.
I cut an old piece of rubber housing from a coil wire and wedged it between the converter and bracket. Noise gone. That's obviously a temporary fix and now I can really 'feel' the exhaust note.
The previous owner welded a new converter in place just before selling it to me last summer. Since then, I've replaced both failed motor mounts and squishy tranny mount. This was enough to move the converter against the bracket. I knew exhaust work was in the near future, but was hoping to put it off until the summer, but I guess not.
Can an exhaust shop break the welds, re-align and re-weld, or am I looking at a new cat? The front weld is very close to the flange connecting to the down pipe. I don't see enough room to cut and weld another connection. But that could be done with the rear section.
Thanks again.
|
|
-
posted by
someone claiming to be CB
on
Fri Jan 24 01:06 CST 2014 [ RELATED]
|
|
important info that you did not include in your First Post
I bought this Car from someone
I don't know what he-she did to it before.
Thanks
for spinnin the wheels here
|
|
-
|
|
|
With these cars being 20-40 years old, that's true of all of them except a rare few. No need to be insulting.
|
|
-
|
|
|
A good welding shop should be able to - a car place may be more aware of rules about "reusing" catalytic converters and try to sell you a new one. You could hack-saw it apart yourself, but the hard part would be welding it back correctly.
You might even be able to bend the exhaust pipe, but I think that's probably a bad to very bad idea. Best thing to do is call an exhaust shop, if they refuse to do it, call a welding shop or a mobile ag(ricultural) welder. They're very talented, in general, and should be able to do it.
Good luck!
|
|
-
|
|
|
Depending how much clearance you need you/the welder can probably cut nearly through the pipe from both sides front and rear of the cat and reweld them making a slight dog-leg. Would be best to drop it down for the finish welding though for the best job. Also, it's often possible to release the clamps and move the sections around a few degrees to change the alignment for extra clearance.
|
|
-
|
|
|
Hello,
I think you have to inspect underneath the car while engine is running to isolate the source and have somebody in driver's seat to rev up the engine later.
Find a ramp where you can drive the entire car up that have a space to safely inspect underneath. Alternatively you could drive into a wheel alignment centre where there is a space dug into the floor, into which you could inspect underneath the car safely.
Like you've mentioned all wheels must touch the ground in order for the noise to appear. My guesstimate is that the rubber doughnut have deteriorated at the centre propeller-shaft bearing support.
Just a suggestion.
Amarin.
|
|
-
|
|
|
A stretch - but are the heat shields still well attached? They've started to rattle on all of my cars with age at the downpipe and one underneath the driver/passenger seat area. I don't know if it's the best option, but once the rattling starts, I've cut them off with no ill effects.
|
|
-
|
|
|
I checked the heat shields early on, and rechecked yesterday. All are in place and tight.
|
|
-
|
|
|
Update from today.
Shifter linkage adjusted per the green book, no noticeable change.
Visual inspection of the torque converter show no signs of leaking, damage, warping or 'play'.
Transmission fluid is red and full.
The exhaust system feels rigid along the entire length and not contacting anything it should not be.
With the car on jack stands, it sounds great in all gears - no noise at all.
Driving around today I found:
When idling at a stop and when moving while maintaining a constant speed on a flat surface the noise is present.
If I go up a hill or accelerate, even floor it, the noise vanishes.
When I let off the gas w/o braking, the noise comes back.
When coming down hill and downshifting into 3rd gear to hold my speed, the noise is the worst.
I can feel the noise vibration in the e-brake handle, even at idle.
I cannot feel the vibration in the gear shift lever or any other part of the car.
The noise seems to come from between the front seats, near the gear shift lever. It sounds like something is out of balance and loose, causing the vibrating knocking. Could be a bearing or two, but not sure which one or how to inspect.
Not sure what to do w/o dropping the transmission.
Any further pointers are very helpful.
|
|
-
|
|
u joints
--
Patrick, '68 220 , '53 GMC 4104, '97 VW Transporter.
|
|
-
|
|
|
Yes, I was going to say that but he put in new ones.
He may have let the shaft pieces get out of phase with each other or they were that way in the beginning, if this car now has a new owner?
I was wondering about the tail shaft bearing in the rear of this automatic transmission. If the driveline was driven a long time this way, there maybe excessive wear up inside the tail piece.
Backing up a car reverses things out of their normal way of doing things.
I know this because, I get slamed in reverse sometimes without even trying!
<(:o)>
Phil
|
|
-
|
|
|
I thought it could be the propeller shaft until it started happening in startup and Park. The u-joints are not new and probably original. I did not find any play or evidence of misalignment or chaffing. The fact this happens in 'Park' makes me believe the culprit is forward of the propeller shaft.
Thanks.
|
|
-
|
|
|
"I thought it could be the propeller shaft until it started happening in startup and Park."
If it is happening in park when the car isn't moving (wheels and drive shaft locked), it may be that the transmission has been raised to hit the body and is moving about due to engine movement at idle.
How are the motor mounts?
--
1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.
|
|
-
|
|
|
If the rear suspension arm bushes are very worn, especially the short upper arm ones, the diff nose will rise and fall when you go from forward to reverse and back. This changes the drive shaft position and may allow clunking. The new mount may just have stabilised the front of the shaft so all of the slop is now at the back. Noises inside a car are very hard to pin down. As a test, come to halt on a slight slope. With the foot brake still on, in neutral, put the handbrake on fully. If the bushes are bad the car will seem to roll back noticeably when you come off the foot brake. This is caused by the axle moving round and taking up the movement of the worn bushes. If this is the case check and fix.
|
|
-
|
|
|
I tried Derek's test and the car does not move at all. I had also inspected the rear suspension prior to my original post and did not anything too sloppy, just the usual mush of rubber bushings.
Thanks.
|
|
|
|
|
