Drive Line 3sp vs 4sp

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Nov 6, 2008
Threads
11
Messages
47
Location
Boise, ID
Any idea what the difference between a 3 speed and 4 speed drive line is?

I was just informed by my mechanic that my drive line is bent. I also found someone selling a used one. Problem is, I have a 4 speed in my rig, and the guy selling has one for a 3 speed.
BUT, here's the deal. Original equipment on my 73 FJ40 was a 3 speed. The guy I bought it off of put the 4 speed in, so I'm not sure what drive line is on the rig now as it is.

Can I swop one for the other without any headaches? :)

Thanks
 
Rear drive shaft.

Funny... I said the same thing to my mechanic.
He said "drive line" I asked if that's the same thing as a "drive shaft"
He confirmed the bent thing as the "drive shaft" :)
The guy selling calls it a "drive line" too.
 
4 spd trannys are a couple inches longer than 3 spds, consequently shafts are not the same length. Also, there are 3 different bolt patterns---who knows what you've ended up with?
 
you might have a cut down 3 speed shaft. This is what i have in my Rig. If this is the case you should just get the one you have re-tubed.
 
you might have a cut down 3 speed shaft. This is what i have in my Rig. If this is the case you should just get the one you have re-tubed.

Nothing like opening up a can of worms :)

I was hoping to get away cheap, and not fork over the cash for a re-build.

I'm guessing the difference would be in the tube, so I should compare measurements from there.

Thanks
 
Tube and bolt pattern are different.

Post up in classified want ads.
 
DS

for my 3 to 4 speed conversion I had mine done for 140 each

at the xfer case the ujoints bolt to the 4 speed pattern and at the diffs they bolt to the 3 speed pattern. You may have the same unless someone changed it at the diff. if you cant swap the driveshaft end for end and bolt it up that is probably the config you have

so the long end is 3 speed and the short end is 4 speed driveshaft

of course the diff coupling can be changed to either but just so you know---check the bolt pattern width
 
Nothing like opening up a can of worms :)

I was hoping to get away cheap, and not fork over the cash for a re-build.

I'm guessing the difference would be in the tube, so I should compare measurements from there.

Thanks


A re-tube is not that much, about 4 years ago when i did my 4 speed swap it was 150 to shorten the rear and re-tube the front.
 
A 3-speed driveshaft will be longer than a 4-speed driveshaft...it's cheaper to shorten one than to lengthen one.
 
The 4 speed tranny is 4 5/8"(+-) longer than the 3 speed. So the front driveshaft is that much longer and the rear is that much shorter. X3 on the retube......had mine done for $35@:eek:

Ed
 
Hi All:

Like has been mentioned by others, there are lots of variables involved (length, yoke patterns, etc.)

The easiest would be for you to have the existing rear drive shaft re-tubed; look for a commercial truck outfit like Fleetpride to do the job.

Good luck!

Alan




------------------------------------------------------------------
Any idea what the difference between a 3 speed and 4 speed drive line is?

I was just informed by my mechanic that my drive line is bent. I also found someone selling a used one. Problem is, I have a 4 speed in my rig, and the guy selling has one for a 3 speed.
BUT, here's the deal. Original equipment on my 73 FJ40 was a 3 speed. The guy I bought it off of put the 4 speed in, so I'm not sure what drive line is on the rig now as it is.

Can I swop one for the other without any headaches? :)

Thanks
 
metric tube

.....had mine done for $35@:eek:

Ed

who did it? ---was it a friend? If not I bet he is now!


By the way, My machinist had to order the metric tube special for the job but he said if that was not avail he could machine the ends to take standard ---if you run into that
 
who did it? ---was it a friend? If not I bet he is now!


By the way, My machinist had to order the metric tube special for the job but he said if that was not avail he could machine the ends to take standard ---if you run into that

Just a local country-boy genius who builds and runs mud buggies and is currently driving Monster Trucks. Jim Powers. Everyone recommended him so I just went with it. I paid him cash and he gave me a receipt, which I did not want or need. He has a steel fab shop out in the country and makes parts for other folks. I'm nothin' special to him, that's just how he rolls.;)
He works them up on a lathe and the ol' boy knows something about power transfer.


Ed
 
pure gold

Pure Gold ---think he'd help out our friend here? and I could use some spares at that price or actually at twice that!
 
Pure Gold ---think he'd help out our friend here? and I could use some spares at that price or actually at twice that!


I imagine he would. For that price, you can ship and still be under what the "normal price" is. I checked with several driveline shops and the closest was $200@
Had mine done about 2 years ago and I am sure steel prices may affect his price, but....................;)

There was a lot more tube used in the front than the rear and the price was the same for both.
Dunno where Kablam is located, but if Kablam PMs me, I'll get on it. I need to post some pics of Jim's mudbuggy anyway.

Ed
 

Users who are viewing this thread

Back
Top Bottom