Manual transmission choices

[brucecooner]

The Peugot's second gear synchros have been particularly obstinate this winter.

I don't think I'd trust its internals to lug me up a mountain anyway.

 

So I'm looking for information and recommendations on what sort of manual to manual swaps are available.

I want to do some offroading, have the ability to travel some genuine 4x4 trails, but I'm not going rockcrawling.

I'd like to have some towing ability, nothing large, but that's not a hard requirement.

 

The AX15 has a good reputation, but it's a different length, and apparently you need to replace everything out to the diffs if you go that route.

The later NV3550 might still work with the 231 transfer case?

 

Can anyone speak to the pros/cons of some different choices?

Which ones might be easier to source?

Which ones will have the kits and adapters to get the job done?

 

One big wrinkle I bet is fun to deal with is that the CPS is stuck up on the bell housing.

Being manual already, I don't think the engine will care what it turns, but I'm no mechanic.

And then I'm sure there are 1000's of little details I'm not even aware of.

 

I know it can be done in a driveway but if I'm being honest, I don't have the skills to align the things to the other things.

But, I saved a LOT of money by not buying a new Gladiator, so I can probably afford having it done. 

IF there's a shop on earth that even does things like this that is.

 

[cruiser54]

If second gear shifts are all that's an issue, there might be work arounds versus changing transmissions. 

any swap done by a shop is gonna be lots of money. 

 

Since you're in Goodyear, contact Christian at Arizona Freedom 4X4 in Wickenburg to do the work and estimate it? He knows his stuff and generally has a good stash of parts. 

[87MJTIM]

I swapped from the BA10 to the AX15.  I got a proper tcase with 23 spines and shift linkage.  Other than those two parts, I did not have to change the drive shafts.  Both the front and rear fit the new trans and tcase.

 

Other parts to get: the AX15 cross member and trans mount.  If you switch to an external slave cylinder, you will need a new hydraulic system.

[pizzaman09]

I highly recommend an external slave cylinder.  I went  through the misery of a replaced internal cylinder on an AX-15, it still leaked.  The external slave conversion is completely worth it if the transmission is off.

[87MJTIM]

19 minutes ago, pizzaman09 said:

I highly recommend an external slave cylinder.  I through the misery of a replaced internal cylinder on an AX-15, to always leak.  The external slave conversion is completely worth it if the transmission is off.

+1

 

My BA10 went through 5 internal slave cylinders in the first 20 years.  I made sure it would not see a 6th.

[Htchevyii]

Wow! I only had one go bad since 1992. It was a LUK with 10,000 miles on it. That was enough for me to change to the Advance Adapters conversion kit. It's been a very long time since my AX15 swap, but I definitely did not change driveshafts. I did have to change the transfer case input hub to the correct spline. I had to fool around with the transfer case linkage as well, but the Azzy's kit is the way to go 

[brucecooner]

On 2/11/2024 at 6:07 AM, cruiser54 said:

If second gear shifts are all that's an issue, there might be work arounds versus changing transmissions. 

any swap done by a shop is gonna be lots of money. 

 

Since you're in Goodyear, contact Christian at Arizona Freedom 4X4 in Wickenburg to do the work and estimate it? He knows his stuff and generally has a good stash of parts. 

If I were just driving it around town, I wouldn't worry about replacing it.  I can live with the cranky shifts till it warms up.

But I made the mistake of having the fluid changed a while back and now it's leaking from every seal, dangit.

 

I found that company's page, but looks like they may be out of business.  I am hunting around for options.

 

 

On 2/11/2024 at 10:40 AM, 87MJTIM said:

I swapped from the BA10 to the AX15.  I got a proper tcase with 23 spines and shift linkage.  Other than those two parts, I did not have to change the drive shafts.  Both the front and rear fit the new trans and tcase.

 

Other parts to get: the AX15 cross member and trans mount.  If you switch to an external slave cylinder, you will need a new hydraulic system.

 

On 2/11/2024 at 7:18 PM, Htchevyii said:

Wow! I only had one go bad since 1992. It was a LUK with 10,000 miles on it. That was enough for me to change to the Advance Adapters conversion kit. It's been a very long time since my AX15 swap, but I definitely did not change driveshafts. I did have to change the transfer case input hub to the correct spline. I had to fool around with the transfer case linkage as well, but the Azzy's kit is the way to go 

 

Yeah I was mistaken on the transfer case.

It looks like I can get the transmission and parts for a swap that comes with the new 231 input from advance:

https://www.advanceadapters.com/4407

That plus the crossmember, mount, and I'll do the external cylinder swap, oh and rebuild the 231 since it's gotta be opened anyway.

I'm sure there are lots of other bits I don't even know I need...

 

I need to watch a video and see exactly how far beyond my abilities this job is.

My main fears are being able to get to all the bell housing bolts, not gimping up the CPS, and I understand there's some tweaky alignment stuff somewhere in the whole deal.

I think it'll require running new hydraulics for the clutch too. 

The current clutch was replaced not that long ago but when I check the reservoir, it looks like there's rust in the fluid so the old line should probably get replaced.

But after bending twisting and installing almost every foot of brake line on the thing last year, I have PTSD from the thought of running more solid lines.

 

 

 

 

[cruiser54]

 

Bruce, PM me if you want their contact info. 

[Htchevyii]

@brucecooner

I uses the AA kit, the only difference being that mine had already been ax15 swapped. if it helps, here's my video:

 

 

[Eagle_SX4]

I recently found out that when the previous owner swapped the Peugeot for an AX15 that he didn't change the cross member. There is still enough room to use the original cross member it will just push the back of the transmission up about 1 inch. If you decide not to change the cross member just double check your output shaft and pinion angles to make sure they are acceptable.

[brucecooner]

11 hours ago, Htchevyii said:

@brucecooner

I uses the AA kit, the only difference being that mine had already been ax15 swapped. if it helps, here's my video:

 

 

So an external slave cylinder swap turned into a new transmission.  Dang.
But I think the real hero of the video is the patio heater, I hate the cold too.

I liked and subscribed though, good stuff.  I wonder if I'll get an AX drilled for a Wrangler too...

 

18 hours ago, cruiser54 said:

 

Bruce, PM me if you want their contact info. 

I tried the freedom email and he actually got back to me.

Unfortunately he closed up shop start of this year, so I just missed him.

He gave me a couple of leads though, and said he still has parts for sale, so I might be hitting him up for stuff.

 

 

6 hours ago, Eagle_SX4 said:

I recently found out that when the previous owner swapped the Peugeot for an AX15 that he didn't change the cross member. There is still enough room to use the original cross member it will just push the back of the transmission up about 1 inch. If you decide not to change the cross member just double check your output shaft and pinion angles to make sure they are acceptable.

I watched a video earlier today by a shop selling an adapter that bolts to the AX15 and to the original crossmember, which intrigues me.

 

Some more questions I've found...

 

I've heard the AX is about an eighth of an inch longer than the BA.  

Supposedly a slip yoke will take this up, and supposedly all Jeeps had a slip yoke at the rear.

I'm too much of a noob to have known to check for this, but I could swear I haven't seen a slip yoke on mine (will check tomorrow).

DID all Jeeps have slip yokes?

 

So apparently I'll have to get a bell housing that accepts an external slave cylinder.

And I've read that all models after '94(?) had an external slave cylinder?

But would those all have the spot for the CPS?

So, what's the process for choosing a bell housing? I assume the bolt patterns are the same front and back regardless (4.0 to AX15).

Is someone making brand new bell housings for this application? (I guess Advanced Adapter would be the goto for that)

 

 

Is the bolt pattern at the back, to the TC, going to be the same regardless of the transmission?

I did see a video where someone pointed out the BA only used 5 bolts, so they put a plastic plug in the sixth hole in the TC, and that hole had to be tapped before use.

 

 

 

 

 

[Htchevyii]

@brucecooner

They all came with the slip yoke where the driveshaft just slips into the transfer case. Unless something has been changed or your truck is lowered, I wouldn't expect a problem there. 

 

the later ax15 or NV3550 external slave bell housing will work and had the same crank sensor mount. I got frustrated trying to piece everything together and just ordered the kit from AA. if we had a Pick N Pull type yard, I would have probably watched for something there. I used this kit: https://www.summitracing.com/parts/add-712590-ir?seid=srese1&ppckw=pmax-jeep&gclid=Cj0KCQiA5rGuBhCnARIsAN11vgS1kJ8YocRAeCo5JikgXRB_9w5Bs9JZukgjbSO3-oGUd5D4u1-jqYgaAjMwEALw_wcB

 

I did not have to drill or tap  any holes in my transfer case. Maybe there was an extra hole that was unused with the Peugeot that was used with the AX15, I really can't remember. 

 

 

 

 

[89 MJ]

14 hours ago, brucecooner said:

But would those all have the spot for the CPS?

Yes, 94+ bellhousing still have the CPS location. 

[pizzaman09]

5 hours ago, Htchevyii said:

@brucecooner

They all came with the slip yoke where the driveshaft just slips into the transfer case. Unless something has been changed or your truck is lowered, I wouldn't expect a problem there. 

 

the later ax15 or NV3550 external slave bell housing will work and had the same crank sensor mount. I got frustrated trying to piece everything together and just ordered the kit from AA. if we had a Pick N Pull type yard, I would have probably watched for something there. I used this kit: https://www.summitracing.com/parts/add-712590-ir?seid=srese1&ppckw=pmax-jeep&gclid=Cj0KCQiA5rGuBhCnARIsAN11vgS1kJ8YocRAeCo5JikgXRB_9w5Bs9JZukgjbSO3-oGUd5D4u1-jqYgaAjMwEALw_wcB

 

I did not have to drill or tap  any holes in my transfer case. Maybe there was an extra hole that was unused with the Peugeot that was used with the AX15, I really can't remember. 

The adapter linked here is what I used to convert my AX-15 to external slave.  It was an awesome kit.  I learned two important lessons, 1st the throw out bearing will look uncentered when you receive it.  The thrust bearing is spherical mounted and will center itself when used. 2nd do not cut the plastic things holding the pin in the slave cylinder!  The plastic things center the pin for aligning with the clutch fork cup.  I cut mine and it didn't align with the cup, launching the pin past the fork and resulting in a lot of fluid sent out of the slave cylinder front.  To solve this I replace the really cheap plastic slave with a brand new metal one from O'Reilly's, and didn't cut the plastic things, they will automatically break on the first pedal push.

 

This is the slave cylinder, it was surprisingly inexpensive and very high quality, made of metal rather than plastic. https://www.oreillyauto.com/detail/c/power-torque/power-torque-slave-cylinder/ptq5/cs2326?q=CS2326&pos=0

[Eagle_SX4]

 

13 hours ago, pizzaman09 said:

This is the slave cylinder, it was surprisingly inexpensive and very high quality, made of metal rather than plastic. https://www.oreillyauto.com/detail/c/power-torque/power-torque-slave-cylinder/ptq5/cs2326?q=CS2326&pos=0

That is awesome you found and aluminum slave cylinder. I was forced to use a plastic one when I did the external swap. 

 

I used a 91-96 master cylinder. They can be found in aluminum. The reason I swapped to a later one was because I had replaced 3 brand new renix ones in a year before I thought there must be a better design. I haven't had any issues with the newer style since.

 

There are 2 things you need to do in order for it to work. First enlarge the hole where the clutch pedal mounts. Second elongate the lower hole because the the bolt spacing is slightly narrowed compared renix years.

[pizzaman09]

5 hours ago, Eagle_SX4 said:

 

That is awesome you found and aluminum slave cylinder. I was forced to use a plastic one when I did the external swap. 

 

I used a 91-96 master cylinder. They can be found in aluminum. The reason I swapped to a later one was because I had replaced 3 brand new renix ones in a year before I thought there must be a better design. I haven't had any issues with the newer style since.

 

There are 2 things you need to do in order for it to work. First enlarge the hole where the clutch pedal mounts. Second elongate the lower hole because the the bolt spacing is slightly narrowed compared renix years.

I was surprised, I was expecting plastic but when I opened the box I found it to be metal.

 

My only complaint or at least observation on the slave cylinder swap is that the clutch weight is about double compared to when it was with the internal cylinder.  Your comment makes me wonder, could the later 91-96 slave cylinder be a different diameter (smaller) which would allow for a lighter external slave setup?  

[Eagle_SX4]

I also noticed an increase in pedal pressures when I swapped to an external slave cylinder.

 

As far as I understand it is because of the location slave cylinder. With the external cylinder the pivot of the clutch fork is farther away increasing the pressure needed to disengage the clutch. With a hydraulic throw out bearing (internal slave) there is no arm for it to pivot on, resulting in a lighter pedal.

 

 

[brucecooner]

On 2/14/2024 at 1:18 PM, 89 MJ said:

Yes, 94+ bellhousing still have the CPS location. 

Good to know.  I see Novak sells a bellhousing that's been cleaned and inspected.

 

It's a later one so it meets the two main criteria:

-CPS placement

-accepts external cylinder

 

https://www.novak-adapt.com/catalog/adapters/engine-to-transmission/amc/ax15-to-nv3550-amc/

 

Pricey though!

I'm not too worried about cost here, I've bought very few large things I want in life (family always came first), but I saved some money that way, and this Jeep is really the first truly big purchase I've ever made specifically for ME.

 

That said, why spend hundreds you don't have to?  I plan to hit up the local-ish guy cruiser recommended.  His shop is closed but he said he's got some parts lying around.

 

 

1 hour ago, Eagle_SX4 said:

I also noticed an increase in pedal pressures when I swapped to an external slave cylinder.

 

As far as I understand it is because of the location slave cylinder. With the external cylinder the pivot of the clutch fork is farther away increasing the pressure needed to disengage the clutch. With a hydraulic throw out bearing (internal slave) there is no arm for it to pivot on, resulting in a lighter pedal.

 

 

The slave cylinder is another major area of inquiry for me.  I definitely want to go external (hence the bellhousing requirement).

Personally I would call increased pedal force an improvement. 

 

The master cylinder on my Jeep is fairly new, maybe a couple of years old. I think the internal cylinder is leaking, again, as I type this.

But as I said previously, it looks like there's rust in the old line that got reused, and I wasn't very impressed with the master cylinder that was installed, it's got rust spots all over it already.

 

I've been intrigued by those pre-built clutch line kits, where the cylinders are already attached with a braided stainless line and no bleeding is necessary, you just have to run the line down to the transmission (using curse words and magic, I presume).

 

I was thinking last night about acquiring the parts, assembling what I can, and seeing if an area shop can just install what I take them.

Then the job is more of a straightforward install, which more shops might be willing to do.

A risky plan, but if I were risk averse I wouldn't own a 40 year old truck (that said, it seems some four year old trucks are a bigger risk than this one).

And if a shop won't do it, I'll just have to go with what I got.

 

I also plan to get another NP231, rebuild it if needed, and install the new input hub, so I don't have to take my Jeep out of service while I work.

Then I'll just have a spare tc on the parts pile.

 

What is everyone's opinion on the "adapter" mounts, that supposedly let the AX15 use the existing crossmember?

https://www.novak-adapt.com/catalog/rear-mounts/rmax15-rear-mount

 

 

 

 

 

[89 MJ]

35 minutes ago, brucecooner said:

Good to know.  I see Novak sells a bellhousing that's been cleaned and inspected.

 

It's a later one so it meets the two main criteria:

-CPS placement

-accepts external cylinder

 

https://www.novak-adapt.com/catalog/adapters/engine-to-transmission/amc/ax15-to-nv3550-amc/

 

Pricey though!

I'm not too worried about cost here, I've bought very few large things I want in life (family always came first), but I saved some money that way, and this Jeep is really the first truly big purchase I've ever made specifically for ME.

 

That said, why spend hundreds you don't have to?  I plan to hit up the local-ish guy cruiser recommended.  His shop is closed but he said he's got some parts lying around.

If that local guy doesn’t have one, I’d probably buy the new one. Lots of used ones go for a few hundred

[pizzaman09]

55 minutes ago, brucecooner said:

The master cylinder on my Jeep is fairly new, maybe a couple of years old. I think the internal cylinder is leaking, again, as I type this.

But as I said previously, it looks like there's rust in the old line that got reused, and I wasn't very impressed with the master cylinder that was installed, it's got rust spots all over it already.

 

I've been intrigued by those pre-built clutch line kits, where the cylinders are already attached with a braided stainless line and no bleeding is necessary, you just have to run the line down to the transmission (using curse words and magic, I presume).

The new parts like your master cylinder rust easily.  I always paint mine prior to installing new ones to prevent rust.  Sometimes I paint them black, other times with clear coat, both do a good job at preventing the flash rust.

 

This is a super easy clutch to bleed, don't bother spending the extra money on a preassembled pre-bled system.  I just gravity bled mine then had my brother help by pumping it once or twice while I manned the bleed screw.  

 

When I had the internal slave cylinder, mine would pull in air from the slave side past a bad seal.  When the pedal would go soft, I could pull off the side of the road, crawl under, gravity bleed for about 10 seconds to get the air out then top off the master.  Took all of five minutes.

[Eagle_SX4]

Advance adapters sells a brand new bellhousing for the AX15. It comes with lots of parts.

 

https://www.advanceadapters.com/4894

 

They also offer a conversion kit for internal to external as well.

 

https://www.advanceadapters.com/4993

 

I got my braided clutch line from them and it works great. Don't get the braided line from Rock Auto it is not long enough.

 

Here is a list of parts I used to connect the 91-95 master cylinder to the external slave.

 

HOSE-60 STAINLESS -3 FITTING
SKU: 716130-60

https://www.advanceadapters.com/hose-60-stainless-3-fitting

 

It is a 60 inch -3 AN line and they sell adapters separately to connect to what ever master/slave combo you have.

 

These are the adapters I used.

 

FITTING JEEP TJ MASTER CYL.
SKU: 716130TJ

https://www.advanceadapters.com/4560

Used on the slave cylinder 
 

FITTING- JEEP YJ MASTER CYL
SKU: 716130

https://www.advanceadapters.com/5046

Used on the 91-95 master cylinder.

[brucecooner]

On 2/15/2024 at 3:36 PM, pizzaman09 said:

The new parts like your master cylinder rust easily.  I always paint mine prior to installing new ones to prevent rust.  Sometimes I paint them black, other times with clear coat, both do a good job at preventing the flash rust.

 

This is a super easy clutch to bleed, don't bother spending the extra money on a preassembled pre-bled system.  I just gravity bled mine then had my brother help by pumping it once or twice while I manned the bleed screw.  

 

When I had the internal slave cylinder, mine would pull in air from the slave side past a bad seal.  When the pedal would go soft, I could pull off the side of the road, crawl under, gravity bleed for about 10 seconds to get the air out then top off the master.  Took all of five minutes.

 

On 2/15/2024 at 4:37 PM, Eagle_SX4 said:

Advance adapters sells a brand new bellhousing for the AX15. It comes with lots of parts.

 

https://www.advanceadapters.com/4894

 

They also offer a conversion kit for internal to external as well.

 

https://www.advanceadapters.com/4993

 

I got my braided clutch line from them and it works great. Don't get the braided line from Rock Auto it is not long enough.

 

Here is a list of parts I used to connect the 91-95 master cylinder to the external slave.

 

HOSE-60 STAINLESS -3 FITTING
SKU: 716130-60

https://www.advanceadapters.com/hose-60-stainless-3-fitting

 

It is a 60 inch -3 AN line and they sell adapters separately to connect to what ever master/slave combo you have.

 

These are the adapters I used.

 

FITTING JEEP TJ MASTER CYL.
SKU: 716130TJ

https://www.advanceadapters.com/4560

Used on the slave cylinder 
 

FITTING- JEEP YJ MASTER CYL
SKU: 716130

https://www.advanceadapters.com/5046

Used on the 91-95 master cylinder.

Mostly, I'm just happy I can use braided line with whatever kit I get.

 

More questions though...

I've got a lead on a Rubicon transfer case.

This sounds appealing because it looks like AX-15's are by default drilled for Wrangler applications, also the tc would already have a 23-spline input.

From what I gather a Rubicon case should be a straightforward installation onto the transmission.

I certainly wouldn't mind the lower ratio, AZ mountains can get pretty steep, and having what is apparently a stronger case would be a bonus.

I don't care if it's overkill, if it's easy.

I wouldn't mind if this requires a linkage change, I already plan on getting rid of the old stock linkage anyway, apparently there are some much better aftermarket designs.

 

 

BUT apparently the Rubicon cases are larger than the 231.

Would this mount and fit under an MJ/XJ, or would it require mount and/or body adjustment?

Also, I'd have to wonder about effects on the output side.  Would a Rubicon TC require driveshaft modification?

 

[89 MJ]

A Rubicon case may also have an electronic speedometer sensor. I'm not sure if you can put a conventional speedometer gear in or not. Many people run stock 231Js offroad. The biggest difference in capability will be gears and a limited slip in the rear. That said, if the Rubi t-case is a good price, it may be worth buying anyways. 

[ghetdjc320]

2 hours ago, brucecooner said:

 

Mostly, I'm just happy I can use braided line with whatever kit I get.

 

More questions though...

I've got a lead on a Rubicon transfer case.

This sounds appealing because it looks like AX-15's are by default drilled for Wrangler applications, also the tc would already have a 23-spline input.

From what I gather a Rubicon case should be a straightforward installation onto the transmission.

I certainly wouldn't mind the lower ratio, AZ mountains can get pretty steep, and having what is apparently a stronger case would be a bonus.

I don't care if it's overkill, if it's easy.

I wouldn't mind if this requires a linkage change, I already plan on getting rid of the old stock linkage anyway, apparently there are some much better aftermarket designs.

 

 

BUT apparently the Rubicon cases are larger than the 231.

Would this mount and fit under an MJ/XJ, or would it require mount and/or body adjustment?

Also, I'd have to wonder about effects on the output side.  Would a Rubicon TC require driveshaft modification?

 

Are you talking TJ rubicon or JK rubicon? 

[Eagle_SX4]

If you do get an AX15 drilled for a wrangler you will need to redrill for the Cherokee/Comanche transfer case clocking. The transfer case will not bolt up to it unless you cut or severely bash the floor. The problem then becomes you might need to make new seat brackets or find different seats.

 

My truck had an AX15 in it when I bought it. But someone put the wrong fluid in and it ate the synchros. I managed to buy a second one for cheap and rebuilt it. Only after I swapped the freshly rebuilt one in did I realize it had come out of a wrangler. The transfer case would not line up with the holes drilled in the output flange. I ended up drilling the new holes in the transmission with it under the truck. It was not fun.