vibrating 401 darnnit!!!!!!!!!!

[maccj5]

i recently put a 401 in my 73 cj5 --- it had an automatic behind it so i bought one of those 401 flywheels off ebay to put behind my t18 the harmonic balancer is original to it i fired it up for the first time today it runs good and sounds awsome it took it for a trip up the road and get a bad vibration bad enough that i wont run it again till i find the problem has anyone used these cheap china? flywheels and had this happen? or do yall have an idea where the problem might be?

[mdill]

First guess is the flywheel is not balanced for a 401 (maybe 360 or 304)
Does the viberation happen when sitting still out of gear and you bring the RPM's up ?

Mike D.

[joe]

I too suspect it's not a function of it being a "cheap Chinese" flywheel but rather "the wrong" flywheel. As Mike said 360/401 flywheels are not balanced the same.

[maccj5]

it was bought as 401 flywheel and was marked on the box as a 401 flywheel

[Gambler68]

sure it wasn't like a 'racing only' application that's not externally balanced? (they do with with harmonic balancers).

Stick with our vendors, real AMC car ones, and MadDog Racing and Bulltear and you won't go wrong usually.


I hope you didn't buy that from those ProComp guys in CA, they have nothing to do with the ProComp you think of (shocks). I verified this after ordering an ignition part, getting jerked around, and finally checking out the company.

[maccj5]

i havent got it back together but i had the balance checked against a 401 flex plate and it was 2 oz.s off!!! all i can think of is right box wrong flywheel in box!!

[FSJ Guy]

Heck, I wish I had a 401 to vibrate. :(

Seriously, I bet the wrong flywheel was put in the box.

[swampedge]

China what do you xpect? Those pre-schoolers making those fly wheels can't read yet..................just kidding. Could'nt resist.