Hey guys! I saved a 72 from the scrap yard, everything is solid! Except the body, someone tryed to make it a fj45 with caulk and sheet metal screws... But! It had a swapped out newer f engine and a 4 speed, I currently have a 72 with a three speed and wanted to do the 4 speed swap, any help? I want ti swap transfercases too Can I just swap out the transition gear from the 4speed transfer Into the 3 speed? Anything else I need?
4 speed swap help! Saved a 40 from the scrap yard
- Thread starter hi5tothaface
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- Thread starter
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Forgot to mention I rescued this jem for only 200 bucks!!
Good score! First try to find out what Tcase is behind the 4 speed. The very first four speed had the same t case as the 3 speed. Also, the 3 speed Tcase has lower gearing in lo than the 4 speed(keep the 3 speed case if you have the right gear to mate the 4 to the 3) if the 4 speed Tcase has the 4 speed case, keep them together if you don't have the transition gear(transition gear is 16 spline with 31 teeth)HTH
No clue about the gears or tcase stuff, but what an awesome deal on that one. Post us some more pics of it.
- Thread starter
- #5
Thanks man!
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Any more pics?
Got a new user name haha but here ya go! Here's a few
LAMBCRUSHER said:
I have both trannys sitting right in front of me, is there any way to tell the transfercases apart? Any clues to wether the 4 speed transfer is the newer one or the same gearing as what's on the three speed?
I popped off both pto covers and counted the teeth on the transition gear and they are both 29 teeth, does that mean there the same? The only thing that looks different with the 4 speed is that there's no pto gear
And with the 4 speed the pto spacer, there's just enough room to count the splines and it's a 16, but on the 3 speed you can't see the splines...
the 3 speed t case will have 10 splines. Now, put the trans in Neutral and put the tcase in lo 4wheel drive. turn thr rear output shaft of the tcases while watching the input gear thru the PTO cover. the 3 speed case should be 2.3 to 1 ratio in lo, so you should have to turn the output 2.3 time to get the input gear to fully go round once. Now, if the case behind the four speed has the same ratio-and not 1.9 turns of output to get one turn of input, then just run the 4 speed with the case whats on it. If the 4 speed case does only take 1.99 turns of the output to get the input to turn once, then you will need to get the proper transition gear, pto spacer, and transition bearing to mate the earlier case to the later transmission. of course, you could just run the trans and case as is, but it will net a tiny bit less gear in lo speed.....
the 29 tooth input is for the 3 speed case. If your 4 speed has 29 teeth and 16 splines on its input gear, then you have the lower geared 4 speed tcase already mated to the 4 speed.....lucky bastid
LAMBCRUSHER said:
Thanks a lot man! You're a smart guy! Haha
I replaced all the bolts in the shifter plate with tapered phillips head screws. Does not seem like much, but it was enough to keep it from hitting the transmission hump. Made it a WHOLE lot quieter.
I also kept the vacuum shift, so I had to trim a small amount from the bottom channel in the tub.
It's a tight fit! Don't put the motor mounts on the body or the bell housing until you have it in. They REALLY get in the way!
I also kept the vacuum shift, so I had to trim a small amount from the bottom channel in the tub.
It's a tight fit! Don't put the motor mounts on the body or the bell housing until you have it in. They REALLY get in the way!
The ones I've had, the four speed nose cone has some ribs, but the three speed nose cone is pretty smooth. There may be some crossover and they're compatible, so a PO could have replaced either with either.
Your rig is awesome! Keep up the good work!
Your rig is awesome! Keep up the good work!
Heres what the 4spd and 3spd transcase is going into! Its a 72' and it was my first ride, going strong ever since
