Novak Conversions Jeep Wrangler YJ radiators

What transmission should I put in my YJ?

Pamp

New Member
Joined
Nov 8, 2024
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7
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IN, Lowell
Hi All , I need to put a automatic transmission in my 88 yj and get rid of the Peugeot five speed , what should I put in my jeep?

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why are you going from a standard shift to auto? it going to take alot of work as well as money. i think your yj looks real good.
 
why are you going from a standard shift to auto? it going to take alot of work as well as money. i think your yj looks real good.

Hi I’m 60 yrs old I’ve just had knee replacement and my 42nd surgery it will be to hard to shift a manual all the time
 
i truly understand your situation and certainly do hope everything works out for you. i am 84 and still drive my jeep daily and enjoy ever minute of it. please keep us posted of your progress.
 
Dang, do you have a hot stroker or modern swap under the hood? The gen 3 LS in my Grand Wag is rated about that.

Hi it’s a 4.2 bored out 30 over big cam Weber carb and header with 2 1/2 exhaust. Before I change the gears I did a burn out tor the gears out in the rear end and F up the trans
 
Well, there is a reason many hate the Dana 35 and swap it out. From what I've read the early 5 speeds weren't that great either.

I'd have to see dyno numbers on a rebuilt 4.2 with just a cam and exhaust given that it takes a pretty hot stroker to make that kind of power and stock they were about 120hp. A cam and exhaust just isn't going to increase the power that much without a bunch of other work. The 4.0s were only 190hp. Even the 4.0 head swap will only yield about 40hp.

I will say the 727 in my Wag handles the LS with ease. It is just a bit stronger than the 32RH/999 series transmissions, but also is more parasitic. The 32RH/999 stll was used behind small v-8s, so I'd wager it will hand what that motor will put out just fine. Line pressure control is important to get correct. I run a Loakar cable on my LS/727 setup and it allows me to dial in perfect RPM shift settings for the 2.72s.
 
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The early 5 speeds were weak. Not surprised at all that you smoked one of those. They were just a poor design all around.

The stock autos and the AX15 are stout. I would also be extremely shocked if you were actually achieving 275HP. The boring of the motor will help things some, the exhaust won’t do hardly anything at all and the carb will make it run more reliably but it isn’t gonna boost power like that.

For what it’s worth, you could have smoked the 5 speed with a stock motor, your new motor is not why that happened.

Also, consider a Regear. I can’t tell what size tires you have but they are clearly larger than stock. A Regear will lessen the stress and heat buildup in the transmission so that once you do swap, it will live longer. If you have 3.07 gears and large tires, that’s a good recipe to kill an auto due to heat from the tall gearing.
 
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The early 5 speeds were weak. Not surprised at all that you smoked one of those. They were just a poor design all around.

The stock autos and the AX15 are stout. I would also be extremely shocked if you were actually achieving 275HP. The boring of the motor will help things some, the exhaust won’t do hardly anything at all and the carb will make it run more reliably but it isn’t gonna boost power like that.

For what it’s worth, you could have smoked the 5 speed with a stock motor, your new motor is not why that happened.

Also, consider a Regear. I can’t tell what size tires you have but they are clearly larger than stock. A Regear will lessen the stress and heat buildup in the transmission so that once you do swap, it will live longer. If you have 3.07 gears and large tires, that’s a good recipe to kill an auto due to heat from the tall gearing.

Hi I have had both axles rebuilt with 4:11 gears and 33” ,12.5 wide tires . How can I make more power with the engine I have
 
Novak Conversions Jeep Wrangler YJ radiators