64 Electra 401 nailhead

Thorenm

New member
5
0
1
Buick Ownership
64 electra 401
Hi everyone, 1st post here! I have a 64 Electra with a 401 4bbl and a th400. I’m working on it for a customer. When I got the car it was previously rebuilt only 2 years prior. Car had a bad shake 2 cylinders had low compression thought ok that will solve the shake. Valve seals were trashed bottom end looked great .030 over pistons, cross hatching looked good. Now she runs again and does run better especially at idle but at I’d say 1200-1500rpm it has a bad shake. All cylinders have good equal compression but after reading on the forums I’m thinking the flexplate was installed incorrectly. Can anyone verify this by letting me know if those seem like the right symptoms for the flex plate being installed wrong? Before I drop the transmission or is there a way to see if it’s placed right without dropping the trans.

Thanks you,
Thoren M
 

MelsRegal

Full Member
8,206
1,501
113
Buick Ownership
Regal GS 2017
Are you sure it's a TH400 because it wasn't used in 64?
How are you going to install a flex plate incorrectly, it uses a dowel and hole for alignment?
Did you check for a bad plug wire or bad cap, rotor, points or condenser?
 

Thorenm

New member
5
0
1
Buick Ownership
64 electra 401
Are you sure it's a TH400 because it wasn't used in 64?
How are you going to install a flex plate incorrectly, it uses a dowel and hole for alignment?
Did you check for a bad plug wire or bad cap, rotor, points or condenser?
From what I’ve read there is no dowel for the flex plate just a hole your suppose to line up but is easily missed. I did not remove the flex plate so I don’t know. Yes it’s getting plenty of spark and the wires are oriented correctly etc.
 

MelsRegal

Full Member
8,206
1,501
113
Buick Ownership
Regal GS 2017
From what I’ve read there is no dowel for the flex plate just a hole your suppose to line up but is easily missed. I did not remove the flex plate so I don’t know. Yes it’s getting plenty of spark and the wires are oriented correctly etc.
Dowel on crankshaft, watch the video.
I meant wire resistance not sequence.
How about cap, rotor, points, condenser?
______________________________
 

Thorenm

New member
5
0
1
Buick Ownership
64 electra 401
Dowel on crankshaft, watch the video.
I meant wire resistance not sequence.
How about cap, rotor, points, condenser?
I understand that’s how they usually go on but I read in some forum that Buick did not have a dowel on the crankshaft on the 401. If that was miss information than I don’t need to pull the trans. Once the car revs past 1500rpm it does smooth out to so I don’t believe it’s necessarily out of balance I just can’t figure it out. It has an updated pertronix ignitor so no points or condenser i checked spark with a spark plug checker and it seems strong I did not check resistance with a meter.
 

Thorenm

New member
5
0
1
Buick Ownership
64 electra 401
Are you sure it's a TH400 because it wasn't used in 64?
How are you going to install a flex plate incorrectly, it uses a dowel and hole for alignment?
Did you check for a bad plug wire or bad cap, rotor, points or condenser?
I’m not sure that’s what the owner told me although I did not check and it does look like the original trans.
 
Looking to update and upgrade your Buick luxury automobile? Look no further than right here in our own forum store - where orders are shipped immediately!

MelsRegal

Full Member
8,206
1,501
113
Buick Ownership
Regal GS 2017

Thorenm

New member
5
0
1
Buick Ownership
64 electra 401
Last edited:
Get your turbo buick badge right here!
Protect your vehicle from code scanners
Top