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AX-15 grinds when shifting to reverse

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MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

AX-15 grinds when shifting to reverse

Postby MasonMcK » June 6th, 2017, 6:10 pm

Hey guys. It's been a while since I was last on here but I've started to have some issues with the clutch on my Jeep. When I installed my 4.7L stroker I also installed a new throwout bearing, pilot bearing, and a new Centerforce clutch. As per the recommendation, I didn't get the flywheel resurfaced but instead I lightly sanded the contact surfaces. While I was inside the bellhousing I also cleaned everything up and greased the clutch fork pivots. After I got it put back together it drove perfectly fine for about a month when it started grinding whenever you tried to shift into reverse. Over the next 3 or 4 months it gradually got worse until I decided I would try rebleeding the clutch hydraulics to see if that would help.

I ended up breaking off the bleeder fitting so I just replaced the whole hydraulic system with new Dorman cylinders and a Russell braided SS clutch line (plus an adapter from advance adapters). I installed everything yesterday and spent the rest of the day yesterday and all day today trying to bleed the system to where it no longer grinds in reverse.

I've tried bleeding it numerous different ways and I always end up with the same result: good firm pedal, but it still grinds horribly into reverse. Driving down the road it works just fine shifting between forward gears, no grinding at all. Just going into reverse.

Does anyone have any insight on this issue? It's been driving me insane. It literally grinds so bad that there is hardly a sound difference if you try to slide it into reverse with the clutch in or not. Right now the only way I can get it into reverse is by shifting into a forward gear with the clutch in and then immediately shifting it to reverse which gets old quick.

Also, on a semi-related note, whenever I press the clutch in it makes a pretty loud groaning noise which you can also feel in the pedal. I had someone press on the pedal while I laid underneath and it's coming from the bellhousing. Any idea what could be making that noise? It's bad enough that I would like to drop the transmission just to fix it.

Sorry for the long read. I'm just desperate for help at this point.

Thanks,
-Mason

MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: AX-15 grinds when shifting to reverse

Postby MasonMcK » June 10th, 2017, 4:26 pm

Anyone?? Any help is appreciated. It's almost unbearable to drive. Sometimes when shifting gears it will sort of "clunk" into the next gear. Not full on grinding but not a nice smooth shift. Other times it's completely fine. It also still grinds in reverse and whenever I start out from a stop the clutch will shudder no matter how smoothly I let it out.

Thanks
-Mason

GreenYJ
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: October 21st, 2016, 2:02 pm
Vehicle Year: 1994
Vehicle Make: Jeep
Vehicle Model: Wrangler

Re: AX-15 grinds when shifting to reverse

Postby GreenYJ » June 13th, 2017, 4:19 am

I lived with a squeak/groan when moving the pedal slowly through full travel. Went away when I replaced clutch master. I also have difficulty at times getting in gear when stopped. I figure my pilot bearing is dragging on the input shaft. It'll go into gear fine with the engine off.
1994 Sahara YJ

jsawduste
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Stroker Displacement: 4.9
Location: Michigan

Re: AX-15 grinds when shifting to reverse

Postby jsawduste » June 13th, 2017, 8:38 am

Reverse is not synchronized. For some reason the clutch is not disengaging completely.

Multiple number of reasons that could cause this. I think you already know this.

Wish I could be of more help but for some reason the disc is not disengaging from the flywheel/pressure plate.

Pilot bearing is a possibility, flywheel surface etc etc.

MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: AX-15 grinds when shifting to reverse

Postby MasonMcK » June 17th, 2017, 10:14 am

I'm hoping that the pilot bearing is still good because I replaced it along with the throwout bearing and clutch just over 1700 miles ago. I'm not hearing any concerning bearing noises either. The only noise that I'm hearing is the annoying squeak/groan noise whenever you actuate the clutch (coming from inside the bellhousing). I've spent the past week pulling the complete hydraulic system out and bench bleeding it more times than I could begin to count so I'm pretty much ruling it out as a possiblity.

Then I was reading a similar thread last night with the same exact symptoms as me... all caused by a broken clutch pedal. But nope I'm not that lucky. Went out and checked this morning and mine is in mint condition.

So at this point I'm thinking that I have a bent clutch fork. Is there any way to tell without pulling the transmission out? Because with my luck I would waste all the time and effort only to find out that it wasn't the issue. Would someone possibly know how far the pushrod pocket of the clutch fork should be from the clutch slave cylinder mounting surface? Also does anyone know of a heavier duty clutch fork that will fit? If I do end up dropping the transmission I don't want to have to pull it again anytime soon.

Thanks for all of the help guys. I'm about at wits end trying to figure this out.

-Mason

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SkylinesSuck
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Posts: 328
Joined: February 14th, 2009, 11:11 pm
Stroker Displacement: 4.6L
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: Wrangler
Location: Northern VA

Re: AX-15 grinds when shifting to reverse

Postby SkylinesSuck » June 17th, 2017, 3:15 pm

This didn't start until way after you swapped all that, right?

MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: AX-15 grinds when shifting to reverse

Postby MasonMcK » June 17th, 2017, 9:04 pm

Yes the clutch worked perfectly right after the new clutch,TB, pilot bearing, and motor were put in. After about a month it started to clunk when trying to put it into reverse. Probably a month after that the slight clunk between gear teeth became a slow grind unless I shifted it into 4th before putting it into 5th. It also became gradually harder and harder to put into any forward gears as well. Eventually it got so bad that I couldn't even get it into a forward gear anymore unless I was already rolling. So I replaced the clutch hydraulics thinking that it was just the slave or master cylinder that was the problem. Before installing it I bled it out completely on the bench and I am certain that there is no air left in the system. I also bled it more once installed.

I am still unable to get it into any forward gear and can't even begin to get it into reverse. If I shut the engine off I can shift the transmission into all of the gears easily. And if I leave it in gear and release the E brake with it parked on a hill, the clutch will hold the Jeep in place until the pedal is about 1/4" off the floor. It's really bad.

Thanks for the help.
-Mason

MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: AX-15 grinds when shifting to reverse

Postby MasonMcK » June 20th, 2017, 8:51 pm

So I dropped my transmission down today expecting to see a bent clutch fork or a seized pilot bearing. As far as I can tell the clutch fork is NOT bent. And the pilot bearing looks fine too. I didn't remove the clutch from the flywheel yet because I lost the light so I have yet to actually feel the pilot bearing. Though the transmission input shaft has no wear or marking on it so nothing concerns me there. What I did notice is that the diaphragm spring fingers where the throwout bearing rides on have the slightest bit of wear which I would consider normal, but the fingers are not all level with each other. It's a pretty obvious difference and it's not just one or two. The fingers are bent with a sort of swash-plate motion all the way around. The difference between the highest and lowest ones is probably an 1/8". Go figure the clutch is already out of warranty. Do you guys recommend that I replace the pressure plate and the disc or should I be fine with just a new pressure plate? Only 1700 miles on the clutch. Also, is there anything that I'm missing that could have caused this problem? I don't really want to waste another $400 if I don't have to.

Thanks guys
-Mason

jsawduste
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Stroker Displacement: 4.9
Location: Michigan

Re: AX-15 grinds when shifting to reverse

Postby jsawduste » June 21st, 2017, 5:15 am

Had a similar issue happen with a BBC Camaro many years ago.

Turns out I put the disc in backwards and the over travel bent the fingers much the way you describe.

:doh: on me

MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: AX-15 grinds when shifting to reverse

Postby MasonMcK » June 21st, 2017, 11:22 am

jsawduste wrote:Had a similar issue happen with a BBC Camaro many years ago.

Turns out I put the disc in backwards and the over travel bent the fingers much the way you describe.

:doh: on me


Hmm. I got the clutch pulled off the engine this morning and the disc was installed with the solid friction facing on the pressure plate side and the slotted facing on the flywheel side. From what I've read this is correct for the Centerforce DF's. I'm still so puzzled by this.

Could the throwout bearing possibly be at fault? It wasn't making any noises and it still feels like new, but could it be machined wrong causing the actual bearing face to press more on one side of the fingers more than the others?

I think that I'm probably going to end up replacing everything inside the bellhousing again just to be sure. The flywheel is also scored now too and also has several hot spots on it so I'll be replacing that too. Any brands that people like for the flywheels? Or are they generally all just as good as the next?

Also do you guys think should I go with the Centerforce again or if I should go with a LUK clutch or another brand? While it worked I loved the Centerforce but if people don't have good luck with them then I'll start looking at other options.

I really appreciate all of the help.
Thanks

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SkylinesSuck
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Posts: 328
Joined: February 14th, 2009, 11:11 pm
Stroker Displacement: 4.6L
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: Wrangler
Location: Northern VA

Re: AX-15 grinds when shifting to reverse

Postby SkylinesSuck » June 28th, 2017, 5:20 am

I have been rocking a Luk Gold clutch for a long long time with no issues.

MasonMcK
Where's the "any" key?
Where's the "any" key?
Posts: 25
Joined: November 6th, 2016, 3:59 pm
Stroker Displacement: 4.7L
Vehicle Year: 1995
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: AX-15 grinds when shifting to reverse

Postby MasonMcK » June 29th, 2017, 9:02 pm

SkylinesSuck wrote:I have been rocking a Luk Gold clutch for a long long time with no issues.


I was really leaning towards ordering the LUK gold clutch but Centerforce ended up replacing my previous one free of charge being that it was a mechanical failure and not just worn out. So props to Centerforce on this one but next go around I'll probably go with the LUK gold.

Thanks for the input.
-Mason


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