Clunking noise shifting into reverse.

[39mm]

I have a 63 Riviera with Dynaflow trans. It shifts into drive quietly but shifts into reverse with a rather loud clunk. Anybody know why this could be? Thanks.

[Guest clamshells]

Motor mount, trans mount, center support. Check them all. I learn towards motor mount.

[RivNut]

Motor mounts are easy to check. Open the hood so you can see the engine from the driver's seat. With the transmission in D, set the brake hard with your left foot. Maybe even set the parking brake (or was it called an emergency brake in '63.) Give the engine some gas and watch the engine. If it raises up on the right, the right motor mount is toast. Do the same thing with the transmission in R. But this time as you watch, look for the left side of the engine to raise up. If so, the left mount is toast. Replacements are available through your local jobber. The mount might not be listed on their computers, but they're in the books. Anchor makes them.

I don't know of any quick look for a transmission mount. But unless they've been changed, 50 years of dirt and grease will almost guarantee it needs to be replaced. Search the forum for an alternate to the Dynaflow transmission mount. It will cost you big bucks to have your mount re-vulcanized plus you'll be without it for a while, so look for the alternative.

[39mm]

Motor mount, trans mount, center support. Check them all. I learn towards motor mount.

Thank you.

[39mm]

Motor mounts are easy to check. Open the hood so you can see the engine from the driver's seat. With the transmission in D, set the brake hard with your left foot. Maybe even set the parking brake (or was it called an emergency brake in '63.) Give the engine some gas and watch the engine. If it raises up on the right, the right motor mount is toast. Do the same thing with the transmission in R. But this time as you watch, look for the left side of the engine to raise up. If so, the left mount is toast. Replacements are available through your local jobber. The mount might not be listed on their computers, but they're in the books. Anchor makes them.

I don't know of any quick look for a transmission mount. But unless they've been changed, 50 years of dirt and grease will almost guarantee it needs to be replaced. Search the forum for an alternate to the Dynaflow transmission mount. It will cost you big bucks to have your mount re-vulcanized plus you'll be without it for a while, so look for the alternative.

Thank you.

[Bill Stoneberg]

Wouldn't you get the same type of noise if any of the U-joints / CV joints are bad too ?

[JanZverina]

Hi 39mm,'

Please check out the following thread on trans mounts, in which Ed Raner suggested to me an alternative, which worked fine as far as the mount replacement was concerned. http://forums.aaca.org/f177/1963-riv-trans-mount-365404.html

When I bought my '63 late last year it was clunking loudly in reverse, not only when being engaged in gear but loudly clunking as I backed up very slowly. I immediately offered $2500 less for the car, which was readily accepted. Turns out that the trans mount was shot (original and flattened), but upon closer inspection the three U-joints in the driveshaft were in pretty bad shape, as was reverse gear in the Dynaflow, which from what I read is probably the first gear to go. So it can be either one, a combo, and hopefully not all three. In my case, we disassembled the entire trans and also found that the fins in the torque converter were badly chewed up so an entire rebuild was in order.

Edited May 16, 2014 by Jan_Zverina (see edit history)

[60FlatTop]

Here's the easy way to check for a bad motor mount. Put your foot firmly on the brake pedal, put the shifter into drive, them press the accelerator pedal "power braking" the car. If the mount is bad the torque will raise the car almost vertically about 4" (really neat at stoplights when a lower car is beside you), as the torque lays the engine over, it will reach a spot where the accelerator linkage w will be suddenly pulled to full throttle. Then you know the left mount is bad and once the torque is released your wild ride and panic are over.

Bernie

[39mm]

Hi 39mm,'

Please check out the following thread on trans mounts, in which Ed Raner suggested to me an alternative, which worked fine as far as the mount replacement was concerned. http://forums.aaca.org/f177/1963-riv-trans-mount-365404.html

When I bought my '63 late last year it was clunking loudly in reverse, not only when being engaged in gear but loudly clunking as I backed up very slowly. I immediately offered $2500 less for the car, which was readily accepted. Turns out that the trans mount was shot (original and flattened), but upon closer inspection the three U-joints in the driveshaft were in pretty bad shape, as was reverse gear in the Dynaflow, which from what I read is probably the first gear to go. So it can be either one, a combo, and hopefully not all three. In my case, we disassembled the entire trans and also found that the fins in the torque converter were badly chewed up so an entire rebuild was in order.

Thanks. It doesn't make any noise after the initial clunk of shifting into reverse. No more clunking/noise when backing up. Does that tell you anything? IOW, would no noise when backing up eliminate the possibility of a bad reverse gear?

Edited May 16, 2014 by 39mm
more info (see edit history)

[39mm]

Here's the easy way to check for a bad motor mount. Put your foot firmly on the brake pedal, put the shifter into drive, them press the accelerator pedal "power braking" the car. If the mount is bad the torque will raise the car almost vertically about 4" (really neat at stoplights when a lower car is beside you), as the torque lays the engine over, it will reach a spot where the accelerator linkage w will be suddenly pulled to full throttle. Then you know the left mount is bad and once the torque is released your wild ride and panic are over.

Bernie

Thanks.

Edited May 16, 2014 by 39mm
more info (see edit history)

[JanZverina]

I would think so, but I'll defer to the more knowledgeable folks on this forum.

[Lapham3]

I recall in the 60's taking out a couple of fan shrouds as the mount broke and fan ate it. Sometimes, A loose driveline component will give a bit of a driveshaft clang rather than thunk. Another possibility is too much backlash in with the ring/pinion-also a shot/loose control arm bushing-good luck

[39mm]

I recall in the 60's taking out a couple of fan shrouds as the mount broke and fan ate it. Sometimes, A loose driveline component will give a bit of a driveshaft clang rather than thunk. Another possibility is too much backlash in with the ring/pinion-also a shot/loose control arm bushing-good luck

Thank you.

[Guest clamshells]

Motor mount: pop hood, car running look between hood and cowl and place car in drive, then in reverse watch air cleaner to see if motor "jumps".

Trans mount: lift and support car take a block of wood on a jack (not to dent trans pan) and see if the trans "jacks up".

Center support: typically if the support is bad the propeller shaft causes vibrations (to say the least) at various speeds. Check it by hand while up on stands when you check trans mounts (if you get that far).

L3's ideas can both be checked while you have the car up on stands but IME: motor mount.