Atmos

ok I have a hypothetical about an xj clutch. good luck making any sense of this. but any feedback is greatly appreciated
I had this idea about how to make crawling easier and I've never seen this mod before (probably because it destroys the clutch)
I know there are performance clutches that do this. I dont want to buy or install one
the question is, will making this mod destroy my clutch? I dont know all the mechanics of a clutch

here is your crudely drawn side view of a clutch in a cherokee.
the triangle is the pedal. the red is the "sweet spot"



I want to weld a "stopper" of sorts. if that makes sense. right at the end of the "sweet spot"


so when I apply pressure to the clutch to shift gears, it will stop right at the end of the sweet spot.
that way theres less room for error in a quick shift situation
in theory, I would be able to shift much quicker right? less chance of stalling..


see where the clutch pedal would be stopped by the welded piece?
the only thing that worries me is that the pedal will never be pressed all the way down. I dont know if that's detrimental

Atmos

I hope someone can understand what I'm trying to say

Atmos

very curious about this. bump

mr white

You need to press the clutch all the way down to trip that switch so you can start it. Either remove the switch (which is a dumb idea) or rig it somehow.
It's going to be a pain in the ***. Not to mention, it probably won't work right and it doesn't seem like it would be worthwhile.
You probably won't be able to shift any quicker anyway.

Atmos

I'm thinking about doing a removable one eventually and testing it out. and I've owned two xj's that didnt require being in 1st gear or putting the clutch down in order to start it so that didnt even cross my mind haha.
it was just a thought

kjc

You're crazy! OK, now that we've established that you are indeed quite insane.. When you depress the clutch pedal, force is applied to the 'release bearing' or throw-out bearing as it is often called, by way of a lever that is bolted to and pivots on your bell housing. The bearing sits on the trannys output shaft adjacent to 'fingers' on the pressure plate which is bolted to the engine(flywheel). w/o going into too much tekkieness, the force on the pressure plate fingers allows the clutch to slip. The 'sweet spot' you refered to (nice drawing by the way) is where the clutch slips enough to effectively disengage the tranny from the engines applied power. That said, I don't see any real problem with doing what you described, but i'd make dam sure to go past the 'sweet spot' at least an inch or so, because you want to be certain you can fully disengage the clutch (like for actually stopping) Now.. Since I too am certifiably wacko, I'd suggest you look down under the dash where the clutch pedal mounts, and see if you could wedge a hard piece of rubber, or a small block of wood to make the pedal 'bottom out' just below your 'sweet spot'. Just duct tape it in place, or wire it, then if it doesn't work as you'd hoped, you won't have an unsightly steel bar welded to your floorboard. (I can hardly wait for the flamers!) I have to go now, it's lights out here at the sanitarium. Good Luck!

freegdr

bolt thru floor boad touching bottom of clutch pedal will limit travel done

Atmos

ok that was thorough. not sure why I'm certifiably crazy. It was an honest question and Im pretty sure it would help me with the way I personally handle a clutch (while crawling). they design short clutches like this for nascar and stuff (I think). but I am going to try to put a removable one in some day and see how it works. a removable one didnt occur to me at first so this thread is kind of unneccesary in the first place. thanks for the feedback though

buckshot500

Just wondering if the reason for this is so you can have the clutch "just barely disengaged" and still have your weight on the pedal, in other words to brace yourself over bouncy terrain for a few seconds & then re-engage the clutch just a little quicker?

I kinda see where you're going with this, but is the reason being that your clutch is engaging really high up on the pedal stroke?

Also is your clutch hydraulic? If so, have you tried bleeding it?

kjc

no offense intended, i was just playin'

"I know there are performance clutches that do this. I dont want to buy or install one the question is, will making this mod destroy my clutch? I dont know all the mechanics of a clutch

^^That was the only reason I tried to go into a little detail.^^

1990cherokee4x4

A clutch bump stop .. Sounds like a good idea but I'm not convinced you will really shift faster just save a millisecond not pushing the clutch in all the way

I think the only way to make the clutch disengage faster would be to make the rod coming out of the master cylinder longer and the pedal shorter



Box = master cylinder
Black oval = plunger
Stick thing = plunger rod connected to pedal
Dotted line = location for plunger to be for "sweet spot"
( picture not even close to scale)

It's pretty simple longer pedal more leverage but more movement to get it all the way down
Shorter pedal quicker ..
The shaft shouldn't make much Much difference because you still have to push the plunger in the same distance but with the longer one would make your pedal closer to you
But the shorter one would let you make the bumps stop part shorter and keep the pedals all in one line more or less
( someone pease correct me If I'm wrong)
But I believe that the best way is to have a shorter pedal and shorter shaft
To keep from having to push the pedal really far down

Atmos

great feedback guys. Im not sure now if I would really benefit and shift faster. but instead I could just hold down the gas at 2000-2500rpm maybe and feather the clutch. that way the clutch is basically my gas pedal, get what I'm sayin? I think thats what I was going for instead of faster shifting. but I could ride the clutch like that without a bump stop... Im still interested in trying.

and @buckshot500. I dont even have a jeep at the moment. but I will accept nothing other than a 91-95 with the ax15. so it will just be the stock trans and clutch in the future
this idea just occured to me and I posted it and was just wondering what everyone thought. just for the record I have no technical knowledge so it sounded possible to me

1990cherokee4x4

'Feathering' the clutch at 2000+ rpms will probly make it jerk really bad
Just saying cuz mine has a brand new clutch and I shift at 1500 ish and I can feel it when ever it engages

Atmos

I'm talking about strictly for crawling. but then again, I dont know 33's with 4.10 gears handle.

1990cherokee4x4

Ah I'm saying 1500 on the street I actually just finished my ax15 swap and haven't got to test it out on the rocks but I'll be running a 4.88 or 4.56 with 39s and reduction box so my will be much different feel than yours ..