Manual Transmission - Issues shifting into 1st & Reverse (Compilation thread)

[BHank0688]

I haven’t done any research on this yet. I’m wondering if CF internal slave/ hydraulic kit would work with my act clutch. I’d assume if their pressure plate works with stock hydraulics that it will (haven’t looked into that yet to know if it’s fact or not).

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[OldGuyNewJeep]

I haven’t done any research on this yet. I’m wondering if CF internal slave/ hydraulic kit would work with my act clutch. I’d assume if their pressure plate works with stock hydraulics that it will (haven’t looked into that yet to know if it’s fact or not).

I toyed with that idea, but decided against. If it didn’t work well the labor to undo would be the same cost as just buying the whole CF kit. Might be a fun experiment for someone who does their own work.

500 or so miles on my new setup. So far so good. The pedal feel is marvelous.

 

[RubiSc0tt]

Well, I guess I'm in this fun group now. The ACT clutch groans on occasion and has been having more trouble going into gear. At first I thought it was me just being careless and hamfisted, but alas, it's gotten pretty blatant now.

I think completely custom master, slave/throw-out and beefier hydraulic line make most sense.

Maybe a stupid question, but Has anyone tried this? Any mechanics or builders who have done this?
The reason I ask is because I do really like my ACT clutch and heavier flywheel. It makes daily driving and rock crawling much easier. I don't want to have to fully replace the clutch either.

There has to be SOMETHING, right? I'm going to just Google "External Slave cylinder 44lb" and see what comes back, because that's all I have at this point and I would like to fix this before it leaves me stranded.

 

[BHank0688]

Well, I guess I'm in this fun group now. The ACT clutch groans on occasion and has been having more trouble going into gear. At first I thought it was me just being careless and hamfisted, but alas, it's gotten pretty blatant now.


Maybe a stupid question, but Has anyone tried this? Any mechanics or builders who have done this?
The reason I ask is because I do really like my ACT clutch and heavier flywheel. It makes daily driving and rock crawling much easier. I don't want to have to fully replace the clutch either.

There has to be SOMETHING, right? I'm going to just Google "External Slave cylinder 44lb" and see what comes back, because that's all I have at this point and I would like to fix this before it leaves me stranded.

I’ve searched a bit and haven’t found anyone that has done this. I did email center force this morning asking if their internal slave/ hydro kit would work with a stock clutch. My theory being if it does and since act uses the stick hydraulics, then it has to work right ?Their response:
“This hydraulic should work with the stock clutch, however my concern would
be you might experience a very high engagement clutch pedal as the stock
hydraulics and stock clutch already provide a high clutch pedal release. “
I’m not too sure what that tells me or not. I’d love to find someone to build a heavy duty version of the factory slave and master and replace them and see how it does. I’d also like a not plastic throwout bearing. Process of elimination to rule things out is about all I got anymore with this whole clutch issue.

 

[RubiSc0tt]

I’ve searched a bit and haven’t found anyone that has done this. I did email center force this morning asking if their internal slave/ hydro kit would work with a stock clutch. My theory being if it does and since act uses the stick hydraulics, then it has to work right ?Their response:
“This hydraulic should work with the stock clutch, however my concern would
be you might experience a very high engagement clutch pedal as the stock
hydraulics and stock clutch already provide a high clutch pedal release. “
I’m not too sure what that tells me or not. I’d love to find someone to build a heavy duty version of the factory slave and master and replace them and see how it does. I’d also like a not plastic throwout bearing. Process of elimination to rule things out is about all I got anymore with this whole clutch issue.

I've been doing visual comparisons while on lunch at work. I found this is picture on ebay. Circled below is the slave cylinder:

Looking at the way it mounts, I googled. "External hydraulic slave cylinder 44lb" and got a bunch of results from all the auto parts stores but also places like Jegs, Modern Driveline, etc. Doing a visual comparison, a few of them look like they MIGHT work, just based on shape and how they attach, or could be modified. Next question is will the internals work? Because each one has a kit with a hydraulic line and some have a master cylinder.

This is what I'm thinking may be the way to work. It will require more research and an experienced shop willing to work with you, but there HAS to be something out there; In drag racing alone, people do all sorts of crazy driveline stuff (including big forced induction V8 swaps with stick shifts) in all sorts of platforms: There has to be something aftermarket that works. Hell, a new clutch kit is like $2-3k installed, that's a big range to play with if you can find a heavy duty slave/master cylinder and hydraulic line kit for $300 on Jegs/ Summit/ or something.

If I'm off base with this thinking, someone please @ me and tell me why before I go down another rabbit hole. I realize doing it over, I should probably just go with CFII with the Hydraulics, but if I can find a good solution for less than the cost of a do-over replacement clutch kit, that would save money and down time for me and others.

 

[BHank0688]

I've been doing visual comparisons while on lunch at work. I found this is picture on ebay. Circled below is the slave cylinder:

Looking at the way it mounts, I googled. "External hydraulic slave cylinder 44lb" and got a bunch of results from all the auto parts stores but also places like Jegs, Modern Driveline, etc. Doing a visual comparison, a few of them look like they MIGHT work, just based on shape and how they attach, or could be modified. Next question is will the internals work? Because each one has a kit with a hydraulic line and some have a master cylinder.

This is what I'm thinking may be the way to work. It will require more research and an experienced shop willing to work with you, but there HAS to be something out there; In drag racing alone, people do all sorts of crazy driveline stuff (including big forced induction V8 swaps with stick shifts) in all sorts of platforms: There has to be something aftermarket that works. Hell, a new clutch kit is like $2-3k installed, that's a big range to play with if you can find a heavy duty slave/master cylinder and hydraulic line kit for $300 on Jegs/ Summit/ or something.

If I'm off base with this thinking, someone please @ me and tell me why before I go down another rabbit hole. I realize doing it over, I should probably just go with CFII with the Hydraulics, but if I can find a good solution for less than the cost of a do-over replacement clutch kit, that would save money and down time for me and others.

That’s all above my pay grade , I can unbolt and bolt stuff on that’s about it lol. I’m on the fence with ordering the CF internal slave / hydro kit only and installing that with my current ACT. No matter what I don’t see a solution that doesn’t involve dropping the transmission. The sound mine makes after it warms up is coming from inside the bellhousing for sure. I suspect the plastic throwout getting warmed up and the extra pressure on it from the stronger springs in the ACT setup, but who knows. Then even if that was the noise issue no one makes a non plastic version of it I do not believe, and even if they did I’m still stuck with a hydro system that’s letting air in. So the CF internal slave setup would get rid of all those potential issues. However, is it worth all that work to find out it is somehow in fact the act clutch components themselves creating issues?

 

[AVGeek99]

One thing I just thought of as potential cause for all the issues people with aftermarket clutches end up having is tire size and gear ratio.

Disclaimer... I've always loved driving manual transmissions, but I'm not a mechanic and I know very little about the inner workings of a clutch assembly.

Could the tire size and or gear ratio (diff) potentially be a factor in what causes all of these shifting issues. Increasing the tire size and lowering the diff gear ratio is going to put more torque and stress on the clutch. Overtime could this be a contributing factor into what is causing them to not engage/disengage fully resulting in all these issues?

Has anyone ever asked the question of what tire size and gear ratio people have that have or are experiencing the issues?

Personally, when I had 35s and 4.10s I very rarely had some notchyness shifting to 1st gear at a stop light. Shortly (4-5 months, about 10 to 12k miles) after upgrading to 4.88s, then 37s a few months later is when the issues became more prevelant, and then they continued to just get worse over time.

Thoughts?

 

[BHank0688]

One thing I just thought of as potential cause for all the issues people with aftermarket clutches end up having is tire size and gear ratio.

Disclaimer... I've always loved driving manual transmissions, but I'm not a mechanic and I know very little about the inner workings of a clutch assembly.

Could the tire size and or gear ratio (diff) potentially be a factor in what causes all of these shifting issues. Increasing the tire size and lowering the diff gear ratio is going to put more torque and stress on the clutch. Overtime could this be a contributing factor into what is causing them to not engage/disengage fully resulting in all these issues?

Has anyone ever asked the question of what tire size and gear ratio people have that have or are experiencing the issues?

Personally, when I had 35s and 4.10s I very rarely had some notchyness shifting to 1st gear at a stop light. Shortly (4-5 months, about 10 to 12k miles) after upgrading to 4.88s, then 37s a few months later is when the issues became more prevelant, and then they continued to just get worse over time.

Thoughts?

How many miles did you have on the he clutch before going to 37s and 4.88s? My jeep has 35s and 4.10s . I would assume this doesn’t matter just because I haven’t seen/ heard enough with people on stock clutches with lifts / regear with problems (pre latest software).

 

[Duece McCracken]

One thing I just thought of as potential cause for all the issues people with aftermarket clutches end up having is tire size and gear ratio.

Disclaimer... I've always loved driving manual transmissions, but I'm not a mechanic and I know very little about the inner workings of a clutch assembly.

Could the tire size and or gear ratio (diff) potentially be a factor in what causes all of these shifting issues. Increasing the tire size and lowering the diff gear ratio is going to put more torque and stress on the clutch. Overtime could this be a contributing factor into what is causing them to not engage/disengage fully resulting in all these issues?

Has anyone ever asked the question of what tire size and gear ratio people have that have or are experiencing the issues?

Personally, when I had 35s and 4.10s I very rarely had some notchyness shifting to 1st gear at a stop light. Shortly (4-5 months, about 10 to 12k miles) after upgrading to 4.88s, then 37s a few months later is when the issues became more prevelant, and then they continued to just get worse over time.

Thoughts?

Im a stock tire/gear rubicon. Having the issues with my ACT on Centerforce JK adapted hydraulics, B&M shifters, for like 20k miles at this point. It hit a point of annoyance/lockout and has not progressed any further. One of these days once I clear my other projects out of the garage I will be installing the nickle plated hub clutch disc that ACT has sent me.

It really is just grease contamination on the input splines causing binding of the clutch disc. The Aisen trans and oem twin disk were poor choices from Jeep. The trans is over complicated, poorly geared, and extremely sensitive to input shaft torque. The OEM twindisk was vague and terrible feeling, not to mention the fire/failure of it.

Jeep screwed up making a manual.

 

[bllprk]

It really is just grease contamination on the input splines causing binding of the clutch disc. The Aisen trans and oem twin disk were poor choices from Jeep. The trans is over complicated, poorly geared, and extremely sensitive to input shaft torque. The OEM twindisk was vague and terrible feeling, not to mention the fire/failure of it.

I totally agree. I took a CF clutch that was struggling with 1/R with 10,000 miles on it, removed it, cleaned it, and re-installed it and it worked amazing. I had blamed hydraulics the entire time, but cleaning the spline fix was amazing.

I will be removing my CF clutch with 30,000 miles on it it the next two weeks, and I will try to look at the spline.

Will you lube the nickel plated plate spline?

 

[Duece McCracken]

I’ve searched a bit and haven’t found anyone that has done this. I did email center force this morning asking if their internal slave/ hydro kit would work with a stock clutch. My theory being if it does and since act uses the stick hydraulics, then it has to work right ?Their response:
“This hydraulic should work with the stock clutch, however my concern would
be you might experience a very high engagement clutch pedal as the stock
hydraulics and stock clutch already provide a high clutch pedal release. “
I’m not too sure what that tells me or not. I’d love to find someone to build a heavy duty version of the factory slave and master and replace them and see how it does. I’d also like a not plastic throwout bearing. Process of elimination to rule things out is about all I got anymore with this whole clutch issue.

Im running the ACT promass, with the Centerforce External Hydraulics, a SS braided clutch line and B&M shifters. The Centerforce externals are adapted JK hydraulics, which are made for a single disc clutch. They are stiffer(which I like) than the OEM JL/JT hydraulics.

Its not a clutch hydraulic issue. The gear lockout/shifter binding is unaffected, still occuring everyday for me. Vehicle is a daily driver for me through winter, and I'd have to check, but I have like 20k miles of this issue. It reached a point of suck/annoyance, and has just maintained it. Has not gotten any worse. My B&M shifter may be helping me get into gears, its definitely not hurting or the cause of the situation.

I've been all up, in, and around the clutch assembly. I did my clutch install, all the hydraulics, borescoped the bellhousing, really been all over this for quite a few years at this point.

 

[Duece McCracken]

I totally agree. I took a CF clutch that was struggling with 1/R with 10,000 miles on it, removed it, cleaned it, and re-installed it and it worked amazing. I had blamed hydraulics the entire time, but cleaning the spline fix was amazing.

I will be removing my CF clutch with 30,000 miles on it it the next two weeks, and I will try to look at the spline.

Will you lube the nickel plated plate spline?

I will use the supplied grease, EXTREMELY sparingly though. I'm not going to cowboy it.

Running it dry would be a mistake in my opinion. It'll bind, or form a burr. Then jam it up past the point of driving.

I'll probably polish the input splines though!! Then do a "La Croix" flavor. "Input shaft splines stored in a warehouse that also stores grease" worth of lube.

I'll document it of course.

 

[BHank0688]

Im running the ACT promass, with the Centerforce External Hydraulics, a SS braided clutch line and B&M shifters. The Centerforce externals are adapted JK hydraulics, which are made for a single disc clutch. They are stiffer(which I like) than the OEM JL/JT hydraulics.

Its not a clutch hydraulic issue. The gear lockout/shifter binding is unaffected, still occuring everyday for me. Vehicle is a daily driver for me through winter, and I'd have to check, but I have like 20k miles of this issue. It reached a point of suck/annoyance, and has just maintained it. Has not gotten any worse. My B&M shifter may be helping me get into gears, its definitely not hurting or the cause of the situation.

I've been all up, in, and around the clutch assembly. I did my clutch install, all the hydraulics, borescoped the bellhousing, really been all over this for quite a few years at this point.

I’d be curious what the force of springs on the act pressure plate are vs stock jl vs stock jl. My biggest annoyance so far is the creaking / ratcheting feel and sound the pedal makes when pressing and releasing the pedal only when vehicle has been driving for 10-15 mins. Sound seem to be coming from bellhousing to me. Putting the scope in there multiple times hasnt showed me anything. I’m really wondering if my issue is plastic throwout bearing with heat and extra force of act pressure plate springs cause it to deflect and make it collapse around the transmission shaft some. Had anyone heard of issues with a centerforce clutch with their internal hydro/ throwout ?

 

[BHank0688]

I also did the install myself and used supplied grease sparingly .

 

[Duece McCracken]

I’d be curious what the force of springs on the act pressure plate are vs stock jl vs stock jl. My biggest annoyance so far is the creaking / ratcheting feel and sound the pedal makes when pressing and releasing the pedal only when vehicle has been driving for 10-15 mins. Sound seem to be coming from bellhousing to me. Putting the scope in there multiple times hasnt showed me anything. I’m really wondering if my issue is plastic throwout bearing with heat and extra force of act pressure plate springs cause it to deflect and make it collapse around the transmission shaft some. Had anyone heard of issues with a centerforce clutch with their internal hydro/ throwout ?

I still get a rub groan, its a byproduct of a singlemass flywheel. As far as a creak goes, I'll have to pay attention on my way home.

The throwout bearing is most likely fine, but maybe the clutch fork is deflecting a bit under the pressure. Which may contribute to a poor feeling, but not sound.

Sound is sound for me, lol

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