BIGBOS

I got about 5000 miles on my TH400 now...since day one I've had a vibration...it doesn't happen while accelerating with the foot to the floor, but sometimes if I do it under 1/2 throttle and take it up high in a gear, slowly but surely accelerating it will vibrate....

Then while cruising when I get up to like 50-55 it starts to vibrate in a steady pace, sometimes it sounds like the car wants to come apart...but its built strong, so I assume it wont...

The worst of it is when I got all out full 1/4 mile blast....and get up to like 115-120, then let my foot off, it shakes the whole car pretty bad....

Any ideas on what this is?

MacGyver

iTrader: (5)

Brian,

My car does EXACTLY the same thing. I'm thinking it's one of two thing or a combination of both. I know my driveshaft is out of balance. So I'm hoping a dennys driveshaft will cure that part of it. The other part is I think that when I drilled the holes in the flexplate for the JW converter that I didn't get the converter exactly centered on the flexplate. This would definately cause a vibration. I know that this is also the case with my car because when I put the car in neutral and rev the engine slowly to around 3000 rpm I get the vibration. So I would have both of those things checked out.

Will

BIGBOS

Hmmmm, my driveshaft was speed balanced...

I've made a converter change since the JW....I kind of miss the hit of that old converter... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Any other way to figure out exactly what it is....

I will address the issue of the flexplate with my installer and see if they centered the converter right on the flexplate....I wonder if drilling holes where they weren't originally would throw it off balance?

BIGBOS

Thats a possibility, but I'm not sure if that would solve it...

steve

are you using a stock driveshaft?
if not, who made it?

the flexplate (or flywheel to some of you) might be warped also, try rotating it like 90-180 degrees...

steve frank

BIGBOS

My driveshaft isn't stock, its built by a local company, I forgot the name, but its speed balanced and built for nitrous, so a lot of power can go through it...

The flexplate might be warped, thats what I think it would be...is there any way to prove that theory wrong, wouldn't mind having someone look under the car while I'm driving and looking to see what the hell is shaking so hard...

<small>[ December 10, 2002, 09:52 PM: Message edited by: BIGBOS ]</small>

Billy the Great

iTrader: (2)

i wonder though...
why did changing converters eliminate alot of this vibration? i remember the first time i rode in it with the jw and i thought the mount was busted thats how bad it was shaking. remeber when we raced the guy on the EOX comin home from fratos? could it just be an inherent part of having a race converter?

BIGBOS

Yea, I remember that as well....I thought it got better when I had the converter changed...I didn't feel the vibration at first, but then it came up...

I have a tach on my dash, and the vibration causes it go go blurry...thats how bad it shakes....thats after I let off of like a 120 mph run...

Reckless

iTrader: (9)

My TH350 has been doing this for a while now. I tried a different DS and it helped a bit. Most of the vibes are on decel and/or above 3000 rpm. It is not engine related or in the rear end, because it doesn't happen in neutral at any speed or rpm. So it has to be between the flexplate and the rear end.

When my tranny was first installed, it never had any issues with this. When I pulled everything out to rebuild my motor last year, the vibration began after installing everything.

What was changed? Had a friend go through the tranny and rebuild it. Sent the converter back to Yank for a refresh. No change to flexplate. No change to DS. So I figured it was just a slopppy tranny rebuild.

A friend is getting the tranny/converter setup from me, but we are having the tranny redone by Carl Rossler and gonna send the converter back to Yank again for refreshing. Hopefully, his car will be vibration free.

I want to know of the change in DS helps you guys out! Good Luck!

Hawkn01

iTrader: (1)

Did you check your pinion angle compaired to your tranny output angle? Might be something you should check.

BIGBOS

So a few things I could try would be rotating the driveshaft 180 degrees and checking the pinion angle relationship between the tranny and rearend...

I might have access to a lift this friday, if not I will wait till my car goes into the shop in spring and have my installer fix it..

BIGBOS

TTT, on any other ideas...

Tim98TA

iTrader: (7)

Rotate the driveshaft 180 degrees. LOTS of time this does it.

Tim

dug

iTrader: (10)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by hawkn01:
<strong>Did you check your pinion angle compaired to your tranny output angle? Might be something you should check.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You should really check this. The pinion angle and the trans output angle need to be paralell or else there will be vibration problems. The pinion angle might be changing as it goes through the suspension travel.

Reckless

iTrader: (9)

Check this link BOS for pinion angle:

http://www.rosslertrans.com/Tips/Pinon.htm

BIGBOS

Thanks... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

CONFUZED

iTrader: (3)

i put the yank hub adapter and flywheel in mine,before i didnt have any adapter(converter didnt have anything to center it)it had vibration before,now it does not.just an idea.

<small>[ December 12, 2002, 10:42 PM: Message edited by: CONFUZED ]</small>

MADSCI

The nose of the convertor has to go into the crank or you will get a vibration...you cannot rely on the convertor bolts to center the convertor.. most companies will machine the nose so it`s correct! for my TH400 swap, we did it in house, no big deal really...we have done several of these swaps with no issues.. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

BIGBOS

my old JW converter had an 1/4" crank pilot extension welded in....and it still vibrated... <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Reckless

iTrader: (9)

My converter is a Yank and it came with my Yank TH350, so I'm guessing that's not what is causing my vibration. I think my issues are internal to the tranny or alignment issues.

Todd