1961 center support bearing / carrier

[ken smith]

My 1961 Impala with 348 engine and 700R4 trans started a very loud chatter /shudder " under the floorboards" on medium to hard acceleration from a dead stop. Also started the same noise on hard 1-2 shift....
Can't find anything wrong , put new L/S motor mount in...could the driveshaft support be going bad after 1500 miles? What are symptoms of this support being bad? Normal easy driving is no problem....
Thanks!

 

[1958 delivery]

Was the support replaced 1500 miles ago?

 

[ken smith]

Put a new support in when I installed the 700R4 and modified driveshaft.....had no problem until a couple weeks ago.
At first I thought the engine was "lifting up" because of soft mounts and the exhaust pipe was hitting the floorboards....

 

[1958 delivery]

Did you balance the new driveshaft, both pieces?

 

[ken smith]

Yes....No vibration while driving ( up to 90-95 mph ) only "heavy" shudder or vibration under hard acceleration for a couple seconds...
heavy "metal to metal" contact noise under the floor.........

 

[61BUBBLE348]

Ken,

have you checked the clearance between the trans and the firewall seam, the 700R's can get a bit tight in that area.

is your trans mount still together? I have seen these tear.

to check your centre bearing support get under the car and see if the tail shaft has any movement up and down if this feels sloppy that will be one of your issues.

good luck with your fault finding

cheers

 

[Jim Sullivan]

Have you check the drive line angles? How about the rear control arm bushings? They could be moving under load throwing off the pinion angle.

 

[63 dream'n]

Drive shaft phasing.....possible shimming of bearing.....was there an exsisting shim under or between carrier brng. and frame that moved under removal of drive shaft?.Does the L/S motor mount = the height of the original

 

[models916]

Check the Banana bar mount at the crossmember. That's the spot they crack and change the alignment.

 

[ken smith]

I have driven this car for about 1-1/2 years with no problems......whatever is wrong happened in the last couple weeks.....starting to pull out my hair! Even checked to see if
plastic fan blade was touching a nut/bolt in the shroud.....also just rotated the left muffler , was only about 3/8" from the floor brace. Will try again. Looked in tunnel at center support
looks good / intact no play. Next step is pull the driveshaft....

 

[61BUBBLE348]

Ken, check your engine mounts first.

If your fan is now touching and your muffler has moved, I think you might have a broken engine mount.

 

[ken smith]

I think I had a poor choice of words regarding the noise in my '61 Impala......I'm getting a "severe" metal to metal hammering / knocking noise for a few seconds
on medium to hard acceleration and 1-2 shift under power...normal easy driving and shifting has no problem. Definite noise from under floor...no play or looseness at tailshaft
Center support looks good from looking inside tunnel , but could center support be torqueing to the side of tunnel under acceleration?

 

[DonSSDD]

Pull the drive shaft, its pretty easy to do and your center support bearing could have failed, even after 1500 miles. The stock ones are poorly made by many suppliers, spot welds let go, or the alignment of the base plate is crooked when made. I had to order 3 to get a good one with the last one I bought.

It also could be bad if you have a driveline issue with angles/alignment causing added stress on the center bearing.

Don

 

[chevymusclecars]

I had a noise in one of my cars that sounded serious and after looking for the cause found that the prior owner had put longer than necessary bolts to hold the seat mount. As it turned out when the car was driven very hard the bolt would hit the exhaust pipe and make more noise than you would believe?

Bill

 

[ken smith]

May have found the source of the noise.....while looking thru the driveshaft tunnel from the rear , I noticed the front of the driveshaft was not in the center of the tunnel...
it was very close to the left side of the tunnel wall. Loosened all the mounts and the trans crossmember , was able to shift the driveshaft to the center of the tunnel....
will test drive later today....hope this does it! Thanks for all the thoughts and ideas!

 

[4speedman]

I would recommend taking the driveshaft out for a look, it is a small job.I had a problem with the support being to close to the left side frame and for whatever reason on a left turn it would tap the frame on the inside and the noise would travel through the frame and it would sound like it was near the left front wheel??It was a poorly made center support that was leaned over to the left side.This is a part that needs to be checked often then again they can go long periods with no problem.

 

[ken smith]

Just made a " short " test drive....NO NOISE !!! I think the problem is solved! Thanks to all of you for the suggestions and experiences! Thanks a lot!

 

[61belairbubbletop]

So..............
What was the issue ?

If you are leaving the OEM type center support in, some people have drilled thru the side walls of the frame and installed long bolts. The idea is to run the bolts up against the center support on each side to hold it in place.
Don't know your intentions are for driving the car. Just thought I'd throw that out there.

 

[tripower]

May have found the source of the noise.....while looking thru the driveshaft tunnel from the rear , I noticed the front of the driveshaft was not in the center of the tunnel...
it was very close to the left side of the tunnel wall. Loosened all the mounts and the trans crossmember , was able to shift the driveshaft to the center of the tunnel....
will test drive later today....hope this does it! Thanks for all the thoughts and ideas!

Just made a " short " test drive....NO NOISE !!! I think the problem is solved! Thanks to all of you for the suggestions and experiences! Thanks a lot!

I would still pull the drive shaft and check the carrier bearing. If it is the stock type bearing as Don said the spot welds will break on the torque side and will hing on the other side until it finally breaks.

 

[yellow wagon]

If the driveshaft wasn't exactly centered in the tunnel, you may have done damage to the shaft and/or the carrier bearing. The replacement bearings won't last long. Couple years at best. Need to go with the Inland Empire unit. Inspect and make sure all is good, and reinstall.