1,001 question on tranny swap

[JOJABOY]

I know there has been a thousand questions and threads on doing an overdrive trans swap but here's one too boot. I've looked through the treads but haven't seen a definitive answer.

I'm going from Th400 to 200-4r. I have the trans, lock up, dipstick tube, trans mount, TV cable (still have to get the bracket). My question is in regards to the slip yoke.

I know that the 200-4r has the same mount position as the Th400 and is 11/16" shorter in overall length. My question is will that 11/16" make a difference? Does the slip yoke need to be all the way in? Or will I need to get a longer yoke and trim it down?

Also....Am I better off getting a 27 spline 1330 series slip yoke vice getting the 1310 to 1330 conversion U-Joint?

[brad_man_72]

I try to avoid using conversion joints when building shafts. You never know when something might fail. Most parts stores struggle to get you the right joing when everything is stock. Plus the quality of conversion joints aren't as good, usually not available in spicer life. (Sealed, solid cross, great tolerances and finish)

If your driveshaft was the right length before you had about 3" of spline lockup, using the same shaft you would have about 2" of spline lockup. Buying a longer trans yoke and trimming it down (and having to take it to a driveline shop to be reballanced anyways) is about the most bass akwards way of fixing the problem puts more strain on the tailshaft bushing and cost as much if not more than a retube and ballance.

The slip yoke should never be all the way in, at ride height it should be out about an inch. Or 2.5" from the end of the tailshaft to the center of the ujoint.

You live in LA I know we have a couple of driveline shops around there, I don't know how much custom stuff they do compared to us, they handle production work mostly. Look up powertrain industries they should be able to help you get your truck on the road.



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[JOJABOY]

There are a ton of drive line shops here. I'm just trying to figure out which way to go. I don't want to visit a shop and them try to tell me something "bass ackwards" or try to get me to pay for labor I don't need.

I'm running a stock 2-part drive shaft on a stock height 69 C-20. The slip yoke seems to be in nearly all the way (from outside visual). I was wondering if that 3/4" difference in trans lengths falls within a tolerance.

[ScottG]

Have the driveline shop put yours together correctly. I did that with mine, and couldn;t be happier. New joints, center support and yoke. They will have you take some measurements with the trans in. Measure from the rear seal of the trans to the FRONT mounting bolts of the center support. Then measure from the front edge of the yoke on the rear end to the same hole on the center support. Of course thats if you have a 2 piece shaft...