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

[Jeremynolan94]

flywheel can be resurfaced

I just asked the shop and they said they could outsource it to a machine shop they work with. That may be what I do. Just waiting to hear back from Dirk to see what he thinks is the beset step moving forward.

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[roaniecowpony]

Alright, the shop has the clutch out and they confirmed the incorrect grease was definitely causing the shifting issues. The clutch dust bound up with it and made it very gritty.

The shop also sent over photos of the flywheel with this odd heat scorching pattern on it. I have an email into ACT but am assuming I'll need a new flywheel overnighted to Boise. The clutch never felt like it was slipping or overheating, so I was very surprised to see this. I know I'm a decent manual driver too as I've never burned a clutch before. Thoughts?

Jeremy,
Unless there's a big step in the flywheel, I don't see anything to worry about. That's a pretty common thing to see.

The fact that it's primarily on one side makes me think the pressure plate has some bias contact/pressure on that side. But again, nothing really terrible. The wear is also toward the outsid and not much inboard. That could be a flatness issue, if this flywheel had been resurfaced incorrectly. But if this is a low mile clutch/flywheel, it takes some time to wear in all the components. Frankly, I'd put it back together unless it was vibrating/chattering upon normal engagement from taking off.

 

[Jeremynolan94]

Jeremy,
Unless there's a big step in the flywheel, I don't see anything to worry about. That's a pretty common thing to see.

The fact that it's primarily on one side makes me think the pressure plate has some bias contact/pressure on that side. But again, nothing really terrible. The wear is also toward the outsid and not much inboard. That could be a flatness issue, if this flywheel had been resurfaced incorrectly. But if this is a low mile clutch/flywheel, it takes some time to wear in all the components. Frankly, I'd put it back together unless it was vibrating/chattering upon normal engagement from taking off.

I just spoke with Dirk at ACT and he confirmed that it would be okay to reinstall as-is. He wasn't concerned about the heat marks and said that it appeared to be pretty normal. So hopefully I'll have the car back by the end of today.

 

[SadRobot]

I just spoke with Dirk at ACT and he confirmed that it would be okay to reinstall as-is. He wasn't concerned about the heat marks and said that it appeared to be pretty normal. So hopefully I'll have the car back by the end of today.

It's going to be driving so much better now. I'm sure it's a huge relief to get that red gunk outta there.

 

[sherpaJL]

curious if a 'Skip Shift Eliminator' would help with any of these issues.

 

[CorvZ061]

curious if a 'Skip Shift Eliminator' would help with any of these issues.

These don’t require skip shifting, so no. Those are used on GM vehicles that required a 1-4 shift for economy reasons.

 

[Jeremynolan94]

Just got the Jeep back from the shop and it is a night and day difference. Shifting is much smoother, the clutch does not creak or have any more weird sounds, and the pedal pressure required to engage and disengage it is much, much lighter than before. I'm very happy with how things feel and will certainly report back if anything changes. I can't thank the people at Boise 4x4 enough for getting me in and sorting out everything on such short notice. Dirk at ACT was also a big help and very happy to chat through everything with me.

 

[BHank0688]

I'm 1,500 miles into a road trip, of which approximately 500 has been off road in central Idaho. Unfortunately I am now getting nearly every issue mentioned in this thread: lockout from 1st and reverse, an occasional slight "whirring" sound when engaging first, and "creeping" forward when clutch is pushed in and I go into first gear. Luckily I have an appointment today at a 4x4 shop in Boise to get things sorted out. I brought along a new throwout bearing and ceramic grease which Dirk at ACT kindly sent me.

Shifting overall feels terrible, very "sticky" between gears, like something is not sliding correctly. Given that I had my clutch installed at the same shop that originally messed up @SadRobot's, I'm hopeful that removing the clutch, cleaning the Red n' Tacky grease that the shop (presumably) used, installing a new throwout bearing, and using the proper grease will fix my issue. I'll ask them to do an extra bleed of the slave cylinder while they're at it. While I'd rather not fork out my own money to do this, the dealer said the recalled clutch is on backorder so I wouldn't be able to get that done in the necessary timeframe on my trip.

I'll report back when I get my Jeep back!

Any chance you looked at the new throwout bearing before it was put in? Was just wondering if it had any part numbers on it. Wish I didn’t just now think it that lol. It’s good to see your jeeps back up and going.

 

[Jeremynolan94]

Any chance you looked at the new throwout bearing before it was put in? Was just wondering if it had any part numbers on it. Wish I didn’t just now think it that lol. It’s good to see your jeeps back up and going.

I did not look at it that closely. I have the old one and can check for a part number if you want.

 

[sherpaJL]

These don’t require skip shifting, so no. Those are used on GM vehicles that required a 1-4 shift for economy reasons.

mopar uses them also. and yes I know what they are for and how they function.
I was thinking the same tech could be used to trick the controller to allow shifting.
The more I read, the more I think these M6 shifting issues are electronic in nature.

just food for thought

skip shift eliminates the annoying computer controlled 1st to 4th shift in the 6-speed manual transmission

 

[CorvZ061]

mopar uses them also. and yes I know what they are for and how they function.
I was thinking the same tech could be used to trick the controller to allow shifting.
The more I read, the more I think these M6 shifting issues are electronic in nature.

just food for thought

skip shift eliminates the annoying computer controlled 1st to 4th shift in the 6-speed manual transmission

The issues aren’t electronic, it’s caused by the clutch not fully releasing, whether from air in the hydraulics or the clutch sticking. These don’t have any solenoids to prevent shifts afaik. I haven’t experienced any issues yet, but I’m betting if they cut off the jeep it drops right into 1st.

 

[K1Paddler]

I ended up here a few days ago after experiencing same as everyone else here seems to be - low pedal engagement and increasingly hard to get in gear. I've also got a third, seemingly unrelated issue, where the Jeep won't start unless clutch is pressed insanely HARD to the floor (and a P083F code) which I'm looking at resolving separately with one of two switches in the mix there (pedal sensor and interlock). Anyhow, all of this comes at 78k miles and 1 year/18k miles on the ACT clutch. I believe the hard shifting began roughly 5-8k-ish ago. It has has progressively gotten worse. Not sure about timing of the the extremely low pedal engagement, but somewhere along the way.

On the two primary issues of clutch engagement and shifting, I found this thread and have been reading up here the last few days. Decided to try the dry bleed procedure discussed around the 50-51 page. Did it last night, overnight roughly 8 hours it sat. It lost 2lb of the 15lb of vacuum. Promising. Test driving this morning the engagement point moved from where it was (nearly immediately off the floor) back up to close to middle. A very noticeable change. The shifting was much smoother as well and not getting blocked going into gear. I'm guarded on this though because I only drove for about 30 minutes so not exactly under the typical heated temps where that issue seems to really present. I'll know more on that over the next day or two after I get some time on it. Whatever the case, that dry bleed process requires minimal effort, is clean and simple. Definitely worth a shot IMO. I used the Mightyvac and a homemade stopper for the reservoir. Got the stopper at HD, drilled small hole and inserted one of the Mightyvac hose adapters.

 

[OldGuyNewJeep]

I ended up here a few days ago after experiencing same as everyone else here seems to be - low pedal engagement and increasingly hard to get in gear. I've also got a third, seemingly unrelated issue, where the Jeep won't start unless clutch is pressed insanely HARD to the floor (and a P083F code) which I'm looking at resolving separately with one of two switches in the mix there (pedal sensor and interlock). Anyhow, all of this comes at 78k miles and 1 year/18k miles on the ACT clutch. I believe the hard shifting began roughly 5-8k-ish ago. It has has progressively gotten worse. Not sure about timing of the the extremely low pedal engagement, but somewhere along the way.

On the two primary issues of clutch engagement and shifting, I found this thread and have been reading up here the last few days. Decided to try the dry bleed procedure discussed around the 50-51 page. Did it last night, overnight roughly 8 hours it sat. It lost 2lb of the 15lb of vacuum. Promising. Test driving this morning the engagement point moved from where it was (nearly immediately off the floor) back up to close to middle. A very noticeable change. The shifting was much smoother as well and not getting blocked going into gear. I'm guarded on this though because I only drove for about 30 minutes so not exactly under the typical heated temps where that issue seems to really present. I'll know more on that over the next day or two after I get some time on it. Whatever the case, that dry bleed process requires minimal effort, is clean and simple. Definitely worth a shot IMO. I used the Mightyvac and a homemade stopper for the reservoir. Got the stopper at HD, drilled small hole and inserted one of the Mightyvac hose adapters.

Hey, I think we “met” in the FB group for this issue. Thanks for posting here, too!

I’m encouraged by your dry bleed success, even with the 30 mile caveat. I’m going to try it this weekend. Since having my fluid changed and system bled at a [new to me] shop my pedal engagement is drifting closer and closer to the floor.

GPT tells me to start the bleed after getting the system nice and hot with symptoms present. I’ll report back the result.

(Separately, I have a years old issue with “service axle locker system” popping up at low speed, usually while turning, and only when the system is hot. I potted my sensors a good year before this ever started so I don’t think it’s those. I suspect ABS sensors or something grounding out when things get hot, maybe due to increased vibration or something. Past two winters it’s gone away and then returned in summer. It’s always something with these damn things!)

 

[K1Paddler]

Yep that was me. Please do report back I'm definitely interested to hear the results on your end.

In my case my wife (the Jeep's her daily) even noticed the difference. It definitely made a difference in the pedal. Jury still out on shifting, but after some more intensive driving over the next few days I'll see if shifting remains smooth and know for certain.

I think the advice of the other poster over there on FB is very sound re: doing a preventive full system bleed every 15-20k. It makes good sense and is going to be my next step here (I'm currently at 18k on my ACT and fluid). Plan to follow that bleed process he so generously laid out. Hoping to get to that today or tomorrow, after I replace the clutch interlock switch that came in the mail yesterday, for that other unrelated issue

 

[roaniecowpony]

I'm an outside observer to this issue, but I did help replace cylinders and bleed them 6 ways to Sunday and my background is engineering. I've also installed an ACT clutch on the OP's latest engine when we installed it, as well as having driven her Jeep with and without the issue. So, I guess I've been around the issue quite a bit and I'm familiar with the hardware.

I think we all can agree the pedal pressure of the ACT clutch is heavier than the OEM. I think this is the root of the issues that eventually develop. The initial installation with the proper lube on the throwout bearing works fine until the grease is depleted/dispersed/contaminated with dust. Then, I believe, the friction, on the sliding portion of the throwout bearing, goes up and the problem begins. The creaking noise is friction, which I believe is the plastic of the throwout bearing sliding and sticking on the shift clutch fork and the snout of the transmission. The master and slave cylinders have plastic pushrods, IIRC. I think these pushrods deflect under the added pressure that occurs when the grease on the throwout bearing gives up.

Some potential solutions might be:
- a throwout bearing with lower friction material where it contacts the shift fork and snout of the transmission.
- replacing the master and slave pushrods with metal pushrods.

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