Swapping A T-15 For The T90

Off topic...
I drove up to a flatty (and early CJ) trailride in MA back in 2001(?) from PA in my 3B that I saw listed in the events section on WillysTech. I often wonder if I wheeled with any of the guys on here. I bring it up now because that picture of your yellow 2A looks awfully familiar. Were you there?

 

Well, the 47 has a little history. It was in the western Mass. area for a long time. Then it moved out west for a while and then returned home. I bought it back aprox. 4 years ago, from a guy out eastern Mass. and brought it back to western Mass. The prior owner probably did have it wheeling in the area for a long time. I actually have some pictures of it during that time frame and the guys at Endangered Species Jeep knew it well. That was during my YJ days. When I bought it, I brought it by Endangered and they recognized it right away, the day I bought it. I used it here on the farm for a year, working its little butt off. Then one day, after coming out of the woods, I hit the pasture and it was going sideways. It only had one body mount left. My plan was to get it a little straighter, and low and behold, three years later and its in its present state. 4.3 fuel injected Vortec, T-15, Dana 20 with Terra Low and Saturn overdrive, Placing power to the ground is a Dana 30 with disc's, offset dana 44 flanged with an Eaton and a lunch box up front. 4 1/2 inch lift with 35 Mud Terrains, PS, PB with drop pedals off a XJ, new tub, with old firewall and top cowl. Its almost done, minus the throw out bearing and exhaust. Its getting there and I'mnot too upset about not being original anymore, but I have tried my hardest to keep it something new and something old. I have a vintage white soft top to and I plan on a heater, I know sissiy right. I boxed the frame as well.

 

And now this little guy.

 

Lets not forget the Scrambler. But that a project after the 47. I expect the CJ5 to be in between the two. It should be a quick ( compared to the 47) restoration. Maybe 2 months

 

Masscj2a thinks the ability to rock the Jeep between 1st and reverse is important. Growing up and learning to drive on the soft sand of the Outer Banks, rocking has a lot of merit. When getting underway from a stop in deep sand, you really do need to back up about 2 feet in your track, and quickly grab 1st to use the momentum to get going. Otherwise, you just churn a hole.
This being said, I have a question to this group. Does anyone know how to properly double-clutch? Its a skill that takes a little practice, but it becomes just part of driving after a while. I learned to drive in my old Tux with a column shift. Rocking between 1st and reverse was just a natural with the shift lever just below the rim of the steering wheel. It took a while longer to master double-clutching to be able to grab 1st at 10 mph or more without catching a tooth. When I converted the Tux to a cane shift, downshifting into 1st while underway was a breeze.
Later, when I was about 19, I got a CDL and hauled sand with our old B-Model Mack dumptrucks (2 of them). There wasn't a single syncro in those transmissions, and upshifting was pretty easy, but slowing down without coming to a stop required accurate double-clutching for the downshifts. It was very satisfying to downshift several gears in a row without catching any teeth. Is double-clutching a lost art?
-Donny

 

Deciding on a Jeep model is really the paramount decision.
That's because the chosen model yeilds the greatest influence on the completed system.

Model selection is followed by drivetrain selection:
Engine then; Transmission then; Transfer case then; Axles.

You have already stipulated the model as an early CJ-5.
You also stipulated the engine as F134.
To me the only practical transmissions for 134 Willys powered Jeeps are the T90A, T90C, or T98A.

I did a good bit of experimenting with T15 vs T18 via mock up fitting.
But those transmission were mated to a Dauntless and mock up fitment was specific to the flat fender jeeps.
The 134 engine requires much different fitment concerns than a Dauntless and the flatties have a somewhat different engine compartment than a 5.

 

You ain't kidding!

 

My first vehicle was a 1951 Fargo (Canadian Dodge) truck. 4speed non synchro so the only way to shift was double clutching. It definitely kept my friends from borrowing my truck.

 

double clutching is just natural for me. I learned to drive with a non synchro. my Dad would not let it rest until I learned. can get my 3B into 1st gear without any trouble

 

During my high school vacations (in Oregon) I drove a KB11 (Kenworth) log truck. If you couldn't double-clutch you didn't get into the cab. This was during the mid 50's and I would venture to say at least 40-50% of the guys in my high school could do it.

 

Try that in any high school today.
"What's a clutch?"

 

Happy Thanksgiving everyone. OK, so now its a double clutch thread ? You guys are no fun anymore. So back to the subject. No best replacement for the T-90 suggestions ?? Or are you all inlove with the T-15 like me, you want to see me attempt it ?

 

Happy Thanksgiving to all out here!
Sorry about derailing your thread regarding the T15, but it would sure be easier and cheaper to keep the T90 and just learn to drive it as it was designed. The T90 really isn't a bad transmission at all.
You seem bent on installing the T15, and I'm sure it can be done. It is a really nice transmission, but for all the adapting and fitting, we are questioning how practical the swap is, especially putting it behind a F134.
You seem to be looking for encouragement to move forward with your proposed swap. Please, go ahead with it and keep us in the loop as to how you make it work. We here on this forum don't always do things the easy way, but we seem proud when we make things work anyway.
Good Luck -Donny

 

Why thank you gentleman and I hope you had a great day. Glenn, I will take those words as , at least slightly encouraging. Keys5a, its not so much that I don't know how to double clutch or drive a standard transmission, I have been a commercial operator for over 40 years and still carry my license to drive and learn to drive on a Willys pickup. The transmission was not a big deal then and is not now. I still to this day, double clutch every standard I drive, no matter how high tech it is. It was the fact that 1) I have never seen or heard it done and 2) YES I do like the T-15. 3) Its the challenge and the comradery of the Jeep nuts in the world to see if we could pull together to come up with a way. That's all and if you have any ideas about how, I am all ears. I have not pulled the T-90 out yet and it will probably stay in the cj, at least until spring. Its getting cold in the north east right now and I still have the 47 nagging at me. But at least I hope you have enjoyed the thread and made you think. No not about how nuts I am, but getting those creative juices flowing.

 

Seems that we all expect a Borg Warner T15 behind a Willy 134 to be impractical.
That said I do believe we are all interested in concrete evidence to either prove or disprove our expectations.
So please do proceed.
Custum boring of a pilot bushing should prove to be a breeze.
I think we are mostly concerned with how you overcome the non existent bellhousing adapter dilema.