Check out the link to see it.




I've got a lot of up and down play in my trans tail shaft. How bad is this and how do I fix it?

 

That that would be considered normal

 

Well thats good to hear, but leaves me in the dark on a bad vibration i'm getting.
I get a vibration that gets worse the faster I'm going. I would say from about 45 and up it is pretty bad. Just like a bad u joint.

I've checked the u joints and they seem fine. I'm gonna have them replaced and the driveshaft balanced anyway hoping that does it.

Any ideas for me?

 

There is a tail shaft bushing in the rear of the transmission that can cause some weird harmonics when it's bad, but it's usually not a real bad vibe. If it still does it after the work you are having done, you will need to lean towards a bad tire or a tire balancing issue.

 

The back end of the output shaft is supported by the yoke on the drive shaft and the bushing that is in the tail housing. With the drive shaft removed the output shaft is just hanging there with no support on that end. If you want to check for up and down play you need to do it with the yoke installed. If the bushing is worn out then you need to replace it.

 

It's a disassembled assembly at that point. That measurement isn't valid to show anything.

The 700-R4 tailhousing is pretty easy to put a new bushing in, since it's solid around the bushing. Grooved T56 tailhousings are a pain.

 

Thanks for the responses guys. So, I did some more driving and what I found was that the vibration is based on engine RPM not driveshaft speed.

Basically if I'm going 50 I have a vibration, if I put it in neutral and the RPMs drop it goes away. If I rev the engine its back. So I'm now thinking its something out of whack in the trans. The only part I know of that spins at engine speed is the converter.

What else is there that could cause it? (If my assumptions sound correct)

I'm not a total newb on trannys. I've only gone through a few of them with help so i'm not scared to dig in, i just don't have the XP to know what I am looking for.

 

If this happened all at once, then check the flex plate to see if a weight has come off. Check the front crank harmonic balancer to see if the outer part of the balancer has not moved from its original location (the timing marks will have moved). I am assuming it has the same type of balancer like big block Chevys. And I have seen this present a problem like the one described here.

 

Have you checked the harmonic balancer? The rubber could have separated and let the outer ring move around.

 

Good Idea! I'll Check