NEED HELP : Length of drive shafts on J-10

[Tigger4X]

What are the lengths for the drive shafts for a long bed with a TH400 and Dana20?

[threepiece]

There is a difference between 3spd and 4speed trans. And I think V-8 and I6 engine as well. Let me know what combination you have as I might have a sample leaning against the wall.

[Tigger4X]

My truck has a TH400 and not a stick ...

I knew I was leaving something out, but the brain was on bingo and fading.

Hopefully you'll still have some info with it being an auto and not stick.

[jsinajeep]

You still didn't tell him what engine it has.

[Tigger4X]

You still didn't tell him what engine it has.

Thanks Dad!


Its got the 401 baybee!

[threepiece]

I saw the "Dana 20" but missed the "TH400" In the first post.

I have a rear shaft shaft from a 73 J4000 with a V-8 however it happens to be the only shaft that got mixed up in my stock. I ended up with two shafts that were not taged and one of them was from that truck. I have two shafts in my stock that are taged "May Be For 1973 J-4000 Auto, V-8".

If you give me an approximate measurement we may be able to help each other out.

[Tigger4X]

You didn't miss the TH400 part ... I "edited" that in after you asked about it. That way anyone else who read the first post, but not through the whole thread wouldnt ask again. Happens more than one would think. LOL


I guess I should have also further clarified that I need the 401/TH400/Dana20 shaft lengths because I want to swap out the TH400/QT with Low Range thats in it now. I already have access to a TH400/Dana20 combo but dont have access to a set of drove shafts. I also dont have the ability to install them only to find out my current drive shafts need to be altered or replaced. IF I had another set of wheels it wouldnt be an issue.


Sorry for the added confusion. And thanks for trying to help!

[J20 project]

Your rear shaft will work.

Front will need to be a bit longer.

J20

[Tigger4X]

Good to know! At least IF needs be I can run without a front shaft.


Does anyone know if there is another shaft that will bolt up or do I need to take it to a shop and have it lengthened?

[jsinajeep]

When I did my QT to D20 change on the Cherokee the front
drive shaft worked and the rear needed to be lengthen about 2".

[J20 project]

Does anyone know if there is another shaft that will bolt up or do I need to take it to a shop and have it lengthened?

One thing people discount, is that we are talking about a 1310 series driveshaft.....Extremely common ujoint system among many brands of vehicle.

An hour spent in a junkyard w/ center to center measurements and a base knowledge of what a 1310 series ujoint is,,,can reveal lots of options on driveshafts.
Even a 1330 shaft can be run due to conversion joints...right?
Loose driveshafts in a junkyard tend to be cheap in my experience.

Now, the front shafts have to be pretty specific due to their small size, re:th400,,,,but the rear shafts are out there in large numbers......

Tigger, don't misunderstand me, there is an optimum length that you should measure and verify w/ this changeover, then go find that perfect number...got it?

J20

[Tigger4X]

When I did my QT to D20 change on the Cherokee the front
drive shaft worked and the rear needed to be lengthen about 2".

I dont know enough about the differences in the frames to say why, but I thought the truck was different from the Cherokee/Wagoneer.

Maybe the wheelbase difference too?

[Tigger4X]

One thing people discount, is that we are talking about a 1310 series driveshaft.....Extremely common ujoint system among many brands of vehicle.

An hour spent in a junkyard w/ center to center measurements and a base knowledge of what a 1310 series ujoint is,,,can reveal lots of options on driveshafts.
Even a 1330 shaft can be run due to conversion joints...right?
Loose driveshafts in a junkyard tend to be cheap in my experience.

Now, the front shafts have to be pretty specific due to their small size, re:th400,,,,but the rear shafts are out there in large numbers......

Tigger, don't misunderstand me, there is an optimum length that you should measure and verify w/ this changeover, then go find that perfect number...got it?

J20

This is definitely one of those things that I want to learn so doing a conversion or finding other optional parts isnt such a PITA. Unfortunately I have never measured a drive shaft before much less been able to measure the distance between the case and axle to figure out what length of drive shaft to go hunt for.

I havent had much experience at all in swapping out u-joints other than a direct swap. I did change out the yoke to upgrade to a larger u-joint but that was something that had already been done by others and all I had to do was find "X" vehicle in the junk yard to wrench the part off of. No real mental knowledge going on. Not knowing the difference between 1310 and 1330 can quickly lead me to buying a part that will end up on my shelf with a plethora of other stuff. Or the need to buy other stuff to make it work with cash I dont really have to spend.

To spend a month of saturdays in a junk yard with someone who knows what they are doing, even if just to watch and learn, would be a HUGE boon to the knowledge pool. I dont always do so well with reading and such so hands and eyes on is my best way to learn.


Attempting to comprehend all of this and type this out probably wasnt the best idea after a half night of sleep and a migraine like a freight train.