LS to AX15

[Ron84cj]

I will be adding here another Master/slave setup here in a few months that will be even easier to deal with. My friend finished his Rx7 project and used an internal slave. It is smoother and just feels nicer overall. Some people are against this but honestly it is a lot less exposed to mud and everything else (I like this idea). So I am going to try it and report back.

Sorry, I used to have a lot more pics for this thread but they were lost when the site crashed years ago and I don't have them anymore either. But if anyone wants me to snap a pic of something I would be happy to do so. Or if you have any questions.

 

[ag4ever]

Are you referring to the annular internal clutch slave?

My NV4500 that was out of a 2003 GM 2500 had that type of slave.



I plan to use that, but I have not seen specs on what bore master they used on those trucks.

 

[Ron84cj]

Are you referring to the annular internal clutch slave?

My NV4500 that was out of a 2003 GM 2500 had that type of slave.

View attachment 91533

I plan to use that, but I have not seen specs on what bore master they used on those trucks.

Yes, something similar. Once I figure it out I'll post up. I don't want to give miss information.

 

[Oakley]

I simply bolted my LS up too a 6 speed automatic out of a Denali. Too old and lazy for all that shifting these days anyhow
But very nice post and detailed

 

[Ron84cj]

I forgot to add in my list the flywheel which was the Novak conversion flywheel. Whether you drill holes in a factory LS flywheel like I did at first or use the conversion flywheel from Novak like I did later, the factory starter does work with both. I think I got everything else.

 

[Randyzzz]

Great thread and info!

 

[Ron84cj]

Ok, so for those of you wanting to do the external slave like my first setup, here it is. 1989 Mazda RX7 slave (3/4" bore) to Ford Escape brake hose (I think 2006) to typical 3/16" brake line to the Wilwood 3/4" clutch master cylinder (not pictured here).

The bracket dimensions...
You can use a 2" X 2" X 1/4" thick angle iron 7 1/2" long. Just trim it as needed to fit your bell.

The small threaded holes you can drill and tap for either an M8X1.25 or a 5/16-18 bolt. For the large holes the SBC gen 1 uses 3/8" bolts. If you are making this for a SBC gen I drill the large holes to 25/64. The LS used a 10MM-1.5 pitch bolt. So for the LS drill them to 13/32.

I measured everything from the end of the bracket. The center of the first big hole is at 1/2", the second is 4 1/4".

4 15/16" to the first small threaded hole and 6 31/32 to the second one.

 

[Ron84cj]

1" from outer edge to center of hole

7/8" from outer edge to center of hole

 

[Chamba]

Where were you when I did my ax15 swap?! This is brilliant.

 

[Ron84cj]

Notice I have a couple of spacers between the bracket and the slave. I have noticed a slight variation of clutch fork lengths. Shim it according to how long your fork is. You want that rod to push on the piston as straight as possible so you don't have premature wear.

 

[Ron84cj]

Where were you when I did my ax15 swap?! This is brilliant.

Sorry bud. I should have done this sooner. Hopefully this helps others out.

 

[Ron84cj]

LIST NUMBER 2. I NOW VERY MUCH CONSIDER THIS THE PREFERRED ROUTE!!! THERE ARE LESS MOVING PARTS.

I modified my first list to try and keep it complete.

-Early YJ clutch pedal along with the support bracket for the firewall. Mine was from an 89.
-Wilwood 3/4" bore Clutch Master to basic off the shelf brake 3/16" brake line
-The brake line then connects to an adapter (Allstar performance ALL 50101)
-From that adapter to the line that goes down to the slave. Just get the kit (Howe Racing 8287)
-Then to the internal slave (Howe Racing 82876)
-Chevy Bell for 11" clutch NOT the bell for 10.5" clutch (VERY IMPORTANT)
-Chevy 11" clutch from 77 Chevy 305 C10 Pickup. (The spacer plate I mentioned earlier between the Novak adaptor and the snout is not needed).
-Novak flywheel (LS400-35X)
-Pilot bearing/bushing from Novak. There are two available. I needed the inner one even though Novak told me the outer one is what I needed. So measure what you actually have to make sure you get the right one. DO NOT just go by what they tell you.
-Exhaust manifolds from C6 Corvette. (The truck manifolds won't work because they hit the firewall)
-Shifter from a YJ. I added a little to the top to make it taller just for comfort.
-AX15 to DANA 300 clocking ring (I bought mine on ebay for like $40)
-AX15 tailshaft seal from a 94 V6 Dodge Dakota 4x4. The Wrangler version will NOT work and no, you don't need that expensive double lip seal. The Dakota seal works perfect.
-I mounted the trans using a factory cj mount and bracket. I just simply drilled new holes to match the AX15 mounting holes. I also drilled new holes in the factory skid plate since it is now further back than the T176 that it replaced.
-Obviously you will need your driveshaft lengths changed. I actually used a rear drive shaft for the front and rear. The fatter drive shaft does comfortably clear everything INCLUDING the factory truck oil pan. No need for an F body oil pan.
-There is an oil level sensor on the side of the pan directly in the way of the driveshaft. Simply plug it off.
-Speed sensor, Dakota Digital makes one to go inline with your cable driven speedo. I don't remember the signal it sends but make sure when you send out your computer they change it to match. Believe it or not, I have yet to hook mine up and have had absolutely zero issues.
-Send out your factory computer to turn off the antitheft crap and anything else you delete out of the harness. Any dyno shop can do this for you.
-I used the factory clutch fan, works great. Even with no shroud I have had zero overheating problems in 100+ degree stop and go traffic. I would still highly recommend a shroud though. I have just been lazy and haven't gotten to it yet.

 

[Ron84cj]

List number 2 step by step...

Early YJ clutch pedal. Cut in the middle and rewelded to match the height of the brake pedal.


Then comes the 3/4" bore Wilwood connected to 3/16" brake line.


After the 3/16" brake line then the adapter (All star Performance ALL 50101)

Onward to the hose down to the slave itself.

 

[Ron84cj]

The Throw out bearing comes with shims and a couple of studs. The stud (you only need one) is only there to prevent the slave from trying to spin. Bolt your bell to your adapter, then to your engine and keep adding shims until you have approximately 1/16" gap between the throw out bearing and the clutch. You can move the throw out bearing forward and backward easily through the hole where the fork used to go. There is nothing fussy here, you just want a small gap so the bearing isn't constantly spinning.

The little stud I drilled and tapped the adapter. I was careful not to drill all the way through. If you do, don't worry about it. Just make sure you use thread sealant or you will have yourself a leak. The top line in the pic is the bleeder. As per instructions it should be pointing at roughly the 2:00 position.

 

[Ron84cj]

My buddy 3D printed out a flexible plastic boot for the bell. Of course he made it in a ridiculous color. Lol. This isn't really needed. A regular clutch fork boot with a hose clamp on it would probably work just fine too.

 

[Ron84cj]

So, the reason I decided to change things up a little. My setup that I had with the RX7 slave cylinder did work well. However, I replaced the slave and the throw out bearing 3 times each. The slave would trap water in the boot and cause the piston to rust and eventually leak. As far as the throw out bearing goes...The clutch fork was basically maxed to one side of the hole in the bell housing causing the fork boot to regularly pop off and/or tear. So it would become very exposed. Every time I drove in the rain I noticed a huge difference in pedal feel. The water basically would run down the fork straight to the throw out bearing and wash out the grease from within the bearing. I knew every time it would start go bad. It started as a squeak and would eventually start a grinding sound. I've been dropping the trans to replace this darn thing every year to every other year. It's getting VERY old. And every time I pull it out the grease is totally gone and sounds like sand paper when I rotate it. I feel I absolutely should have done this in the first place!!!! That internal slave so soooo smooth! There are less moving parts. The clutch pedal is extremely comfortable now. I cannot put into words how happy I am about this. The pedal feel in my Jeep has never been this nice! I very highly recommend the Howe kit. It's very nice quality and very easy to install. The only "mods" were drilling and tapping ONE hole for the stud by the slave and cutting/rewelding the clutch pedal. That's it!

My first setup was just like Novak but without the big price tag. I somewhat copied that setup. Novaks slave is a 3/4" bore which is exactly the same as the RX7 slave that I used. Advance Adapters uses a slave from a Toyota Land Cruiser which is also a 3/4" bore. I just liked the idea that the RX7 slave was only $17 at AutoZone and usually either in stock or I could get it within a day. Once I put a hose clamp on the boot I didn't have anymore issues with the slave. But constantly killing throw out bearings sucked hence the switch. This setup does work. But definitely doesn't feel as smooth. Here is a pic of my first setup vs Novaks. Basically the same thing.





And Novaks...

 

[hefavitzen]

For my wiring needs I worked on my own harness. I followed the write up on LT1swap.com. Most of the info is on there. I did get the rest on here but honestly I don't remember anymore. I know Randyzzz helped but beyond that sorry guys

Now that I have it running and driving, I can definitely tell you what works and what doesn't with clutch master and slaves. When the master is bigger than the slave the pedal is stiffer with a short travel distance to disengage. When the master is smaller you have an easier pedal, but the travel distance is longer. First I tried a factory cj clutch master cylinder which is a 13/16 bore. The pedal is way too stiff. This doesn't work at all unless you are Hercules. Then I tried using Novaks recommendation to use a master from an 87-90 yj which is a 11/16 bore. The pedal went to the floor and wouldn't even disengage the clutch. The factory cj clutch pedal is lower than the brake pedal. So I cut and rewelded the pedal so they are both the same height. I did not want it higher than the brake pedal.
Before

After

The pedal was much easier to push, but it would disengage the clutch JUST off the floor. I had to take out my floor mat to drive it. I didn't like this at all so I bought a universal Wilwood master that was a 3/4 bore.

This worked really well but the pedal got stiffer again. A bit too much for my liking. So the clutch was to blame. This is what Novak and Advance Adapters told me. They told me it wouldn't work and damn near laughed at me for even trying it. So I took the kick in the nuts and bought the $350 custom flywheel they told me I just had to have. Got a Gen 1 11inch clutch again and changed everything over. Only to find out..........it barely made a difference!!! I was so pissed. If I knew that I would've just left it. I was done dealing with it and decided I just needed to get used to it. Now after driving it all summer, it's really not that bad. I like the travel distance and the stiffer feel doesn't bother me as much anymore.

So is your left leg just a bit larger than the right now? Never skip leg day!

 

[Ron84cj]

Even though I'm old and fat I still skateboard with my kids and push off with my right foot. So now it's equal. Left leg gets a work out from the jeep and right leg gets a work out from skateboarding. 😂

 

[Ron84cj]

Since it has been almost exactly 2 years and several thousands of miles later since I did setup #2 I thought I would provide an update. It feels exactly like the day I put it in. Absolutely smooth as butter, way better than the external slave setup in my opinion. Very highly recommend.