Full Size Jeep Network

Hi guys I would like to eventually 4spd swap my 73 j2000, (360 th400 QT). I have seen a couple of cj t18s on marketplace but if I'm correct they won't work. Do I need to look for a j series 4 SPD trans, and does it need to be from a V8 or will the 4.2 version work? Also I'll need a manual pedal assembly, will it just bolt in? Also what type of clutch do fsj's have, z bar style?
Thanks for your input.

Sent from my moto e5 cruise using Tapatalk

In FSJs, Jeep makes up the difference between the length of the 258 and the V8s with a spacer/adapter between the engine and transmission. This makes the manual transmission input shaft very long in these V8 FSJs. This topic has been covered ad nauseam in the forums if you search.

Wagoneer and J-trucks are the same in this respect. Baby Jeeps 1971-1976 got the close ratio T-18, which is probably not what you want. The 258 FSJ T-18s are short input, like the close ratio CJ transmission, but wide ratio. With a short input and V8, your shifter will come up under the dash.

Find a V8 J-truck or Wagoneer donor and take everything you need. Yes it will all bolt in. Or just buy that Jeep and sell your '73.

What's a z-bar? It's just a clutch, 11" Borg&Beck type for the 360 and 401.

tgreese wrote:In FSJs, Jeep makes up the difference between the length of the 258 and the V8s with a spacer/adapter between the engine and transmission. This makes the manual transmission input shaft very long in these V8 FSJs. This topic has been covered ad nauseam in the forums if you search.

Wagoneer and J-trucks are the same in this respect. Baby Jeeps 1971-1976 got the close ratio T-18, which is probably not what you want. The 258 FSJ T-18s are short input, like the close ratio CJ transmission, but wide ratio. With a short input and V8, your shifter will come up under the dash.

Find a V8 J-truck or Wagoneer donor and take everything you need. Yes it will all bolt in. Or just buy that Jeep and sell your '73.

What's a z-bar? It's just a clutch, 11" Borg&Beck type for the 360 and 401.

I meant is the clutch linkage mechanical or hydraulic, thanks for the reply, I'll start looking for a donor.

Sent from my moto e5 cruise using Tapatalk

Ah, mechanical. Possible it was cable for a year, but I don't think so.

tgreese wrote:Ah, mechanical. Possible it was cable for a year, but I don't think so.

Does the clutch bellcrank mount in the same location as the auto trans linkage, if so would you think a cj bellcrank and linkage kit would work? I'm starting to put a list together, got a lead on a trans, waiting for reply from seller.

Sent from my moto e5 cruise using Tapatalk

My reaction - sorry if I seem impertinent, but why would you think the CJ parts would fit? All different, AFAIK. Principle is the same, but the measurements are all significantly different.

If you can get a complete FSJ donor, you can pick from the donor what you need at your leisure. Then sell off what's left over. Unlikely anyone will have a complete list of all the parts you'll need from the donor.

Much simpler to pay a premium price for the Jeep you want (a 4-speed J-truck) and sell the automatic truck to someone that wants it. JMO.

tgreese wrote:My reaction - sorry if I seem impertinent, but why would you think the CJ parts would fit? All different, AFAIK. Principle is the same, but the measurements are all significantly different.

If you can get a complete FSJ donor, you can pick from the donor what you need at your leisure. Then sell off what's left over. Unlikely anyone will have a complete list of all the parts you'll need from the donor.

Much simpler to pay a premium price for the Jeep you want (a 4-speed J-truck) and sell the automatic truck to someone that wants it. JMO.

I'm not saying they will be a direct fit, as long as I can get them to work with some modification. I don't expect to find all the parts I need from the same person the cj stuff is cheap and available is what I mean. Yes a donor truck would be nice but J series are few and far between in FL I'm not paying for a nice one. I want to keep this one.

Sent from my moto e5 cruise using Tapatalk

I expect the place where you need a donor the most will be the pedals. I expect dimensions of the CJ parts will be way off here, though the design and components are similar. Possible you could go the hot rod route and adapt an aftermarket pedal set to the truck. Without the factory linkage, I'd expect a hydraulic clutch would be easier since you would not have to figure out the proper linkage and bellcrank geometry without a factory example. I have not measured the linkage, but the rods are definitely different, and I'd expect the bellcrank to be longer in the J-truck due to the wider chassis. You can use a short input T-18 (or one of several other truck 4-speeds) if you can accept the shifter placement. Some have let the stalk come up under the dash, then heated and bent the stalk into a dog leg so that it's reachable. Not how Jeep did it, but workable.

The factory parts manual might help you to see the pieces you'll need. The '74-80 parts book is available on CD-ROM for less than $25 from RockAuto. The '62-73 parts bool is on the Tom Collins site, but this book seems pretty sparse wrt illustrations, and your possible donors more directly overlap the '74-80 book.

tgreese wrote:I expect the place where you need a donor the most will be the pedals. I expect dimensions of the CJ parts will be way off here, though the design and components are similar. Possible you could go the hot rod route and adapt an aftermarket pedal set to the truck. Without the factory linkage, I'd expect a hydraulic clutch would be easier since you would not have to figure out the proper linkage and bellcrank geometry without a factory example. I have not measured the linkage, but the rods are definitely different, and I'd expect the bellcrank to be longer in the J-truck due to the wider chassis. You can use a short input T-18 (or one of several other truck 4-speeds) if you can accept the shifter placement. Some have let the stalk come up under the dash, then heated and bent the stalk into a dog leg so that it's reachable. Not how Jeep did it, but workable.

The factory parts manual might help you to see the pieces you'll need. The '74-80 parts book is available on CD-ROM for less than $25 from RockAuto. The '62-73 parts bool is on the Tom Collins site, but this book seems pretty sparse wrt illustrations, and your possible donors more directly overlap the '74-80 book.

Well I found a j20 t18 complete with d20. Ya I figure the linkage is going to be a nightmare, I found a few used pedal assemblies on line, I think I could remove my brake pedal and swap in the clutch/brake combo while leaving the bracket alone. I'm still waiting on a response from the seller of the trans, you know how that goes...

Sent from my moto e5 cruise using Tapatalk

Manual transmission Jeeps from this era all use the same bell, typically called the T-14/T-15 bell. Get that and everything else you can from that J20 donor. This has to be a '74-79 donor, since they switched to the NP transfer cases and driver-drop in 1980. Only the J20 got the T-18 from 1980 on, and that transmission has a really long output shaft and adapter with a round NP-pattern (same as Ford of that era, I think).

Don't know about your pedal assembly. The brake pedal is different (narrower) with MT and the parts book shows something like 10 different parts for the FSJs '74-80. I would not expect too much bolt-up compatibility unless the parts were all from the same donor. Again, the parts book may help you here.

If I remember correctly the bellcrank for the truck is different than the Cherokee. This I believe because the truck body is set higher from the frame than the Wagoneer and Cherokee.


Also a pedal assembly from a non power brake FSJ will have a different geometry than one with power brakes.

I may have a pedal assembly that you are looking for on the shelf which is NOT for sale. I certainly have auto pedal assemblies on the shelf. I would however be willing to send a picture of both so you can consider your options.

I have the pedals in my for-sale stuff but I had planned to do a 5 speed swap (avoid the T5 though. It’s too weak for V8s. My 6 killed a stick one in the driveway!)
I was almost done an AX-15 swap for the first Ouray invasion but UPS lost my steering knuckles.

carnuck wrote:I have the pedals in my for-sale stuff but I had planned to do a 5 speed swap (avoid the T5 though. It’s too weak for V8s. My 6 killed a stick one in the driveway!)
I was almost done an AX-15 swap for the first Ouray invasion but UPS lost my steering knuckles.

Ok, I'll take a look, so did you give up on the manual swap?

Sent from my moto e5 cruise using Tapatalk

On my '84 I made a new longer shaft and used a modded '65ish clutch pedal. The '84 auto brake pedal just had a wide plate on it that I removed.

Moded the '65 z-bar to work with the NV4500 and Nissan motor.

Then I changed it to hydraulic using master and slave for a CJ.

Seems to work but haven't started the motor.

mjdriver wrote: ↑Wed Aug 05, 2020 4:38 pm

carnuck wrote:I have the pedals in my for-sale stuff but I had planned to do a 5 speed swap (avoid the T5 though. It’s too weak for V8s. My 6 killed a stick one in the driveway!)
I was almost done an AX-15 swap for the first Ouray invasion but UPS lost my steering knuckles.

Ok, I'll take a look, so did you give up on the manual swap?

Sent from my moto e5 cruise using Tapatalk

My back gave up on manual transmissions after the rollover 2 years ago in my Comanche when I was run off the road.

carnuck wrote:

mjdriver wrote: ↑Wed Aug 05, 2020 4:38 pm

carnuck wrote:I have the pedals in my for-sale stuff but I had planned to do a 5 speed swap (avoid the T5 though. It’s too weak for V8s. My 6 killed a stick one in the driveway!)
I was almost done an AX-15 swap for the first Ouray invasion but UPS lost my steering knuckles.

Ok, I'll take a look, so did you give up on the manual swap?

Sent from my moto e5 cruise using Tapatalk

My back gave up on manual transmissions after the rollover 2 years ago in my Comanche when I was run off the road.

Ohh I see, that sucks man

Sent from my moto e5 cruise using Tapatalk

Just wanted to give a little update, truck is running and driving, still need to finish up few things.

Sent from my moto e5 cruise using Tapatalk

Awesome!