What's up guys, I just finished my swap from t56 to 4l80e but now have an issue with my drive shaft.. I ordered a slip yoke from strange & put it on. Problem is that it only slides in a 1 1/2'' in the tail shaft after installing the bolts on the other end of the shaft. the slip yoke is about 4'' long but only goes in 1 1/2 cause the shaft is to short.. Anyone had this drive shaft issue?

 

Sounds like you'll need one that is cut or you dont have the yoke in all the way. It should go in further than 1.5" into the tail shaft. Maybe its not snapped over the O-Ring on the shaft?

 

It'll slide all the way in but then it has to slide out to reach the rear end yoke.. goes in all 4'' then slides out 2 1/2'' to be able to tighten up at the rearend

 

sub'd..

 

Sorry but what does sub'd mean?

 

he means subscribed so every time a post gets made he gets a email about it. I was under the impression it didn't go in all the way

 

^ this

im about to install an 80e coming from a T56, and if i run into the same issue, i can come look at my subscriptions under UserCP, and find this thread.

 

Ohh.. lol

 

You need a 1 1/2" longer driveshaft.. did you measure for your ds or just have the yolk put on the factory one?

 

^^^ I was under the impression that you can reuse the stock driveshaft...

 

^ same. I was actually told I may need to shorten mine cuz the tail shaft is actually a little long on an 80e vs a t56.

 

Sometimes, tolerances stack up and are not always in our favor

 

You will need a shorter driveshaft. I went from a T56 to a 4L80 with a 9" in my car. The 4L80 will require 3/4" - 1" shorter driveshaft than the T56.

My specs from ordering driveshafts (straight from PST invoices):
T56 Driveshaft: 45 1/4" seal to center
4L80 Driveshaft: 44 1/2" seal to center

I thought about having my original driveshaft shortened but ended up just buying a new one. I don't think it was worth the hassle of shipping it back to PST and having them shorten it. Ordered directly through PST. I worked with Cliff on the phone and he had great customer support. Spent plenty of time answering all of my questions.

I would suggest taking your own measurements though.

 

When I swapped to a 9" with the 60e I reused the stock ds, then when I swapped to an 80e I needed a shorter one so I had a 3.5" steel one made.. swapped to powerglide and needed a longer one so I had to get another one made, if it doesn't fit right then it doesn't fit, need to have one made. when measuring you need to slip the yolk all the way in the tranny then measure from the centerline of the u-joint to the centerline of the rear of the rear u-joint then get one made

 

Also a proper length ds should be pulled out 3/4-1" once its pulled back and bolted to rear end

 

Wouldn't that depend upon how the car is supported for the measurement?
That amount sounds likely if the car is lifted by a hoist with the wheels hanging, but if the car is on rear jackstands under the differential tubes, the suspension is compresses and that amount could be much less.
Obviously you never want it to bottom out in the trans during suspension travel.

 

With suspension compressed 3/4-1".. so if you ever bottom the car out you don't ram the yolk into the trans. Better safe than sorry, 1" isn't a lot and still have plenty of spline in the tailhousing

 

well this 1 slides out 2 1/2".. No good then.. Is it even worth taking my shaft to a shop to lengthen it or is it not worth it? shop around here charges me $150.. I have a Spohn Extreme-Duty Driveshaft that I bought from someone here

 

how much is it to get a driveshaft shortened?

 

I didn't ask to shorten it cause I need it longer