Clutch Hydraulics

[AH64ID]

I had a CON-OFE put in last spring and ever since the install I have a really hard time getting the trans into 1st or 2nd, unless I go 3-2 or 4-1. If I come to a stop and leave the clutch in I can shift no problem, but as soon as I release the clutch and then engage it to shift I can't get into 2nd. It's worst when warm, when cold it shifts fine.



I talked to SBC and they think my OEM hydraulics are shot, but I don't want to test that theory with the $315 SBC hydraulics to find it didn't fix it.



Fluid is Amsoil MTF, replaced since the clutch install with no change.



Any thoughts?

 

[Prairie Dog]

Mine has always been that way at least if I'm in neutral and then try for first or second to start off ~ yours is worse since the new clutch?
If I'm shifting between 1st and 2nd it goes ok. It's just getting it into either of those from N that's hard. Sometimes I get in a hurry and just about bend the shifter! #@$%!
From all I've read, it seams to be the nature of the beast.

I'm starting to kinda wonder about my Hyd's - seems like the clutch engages awfully close to the floor. .
I wonder if part of our problem is that the brake fluid in the hyd's just gets old.

 

[blacksheepdiesel]

Could be the hydraulics. You can buy the slave cylinder from Napa and try that. Since it is not a dual disc clutch I really don't see any need for the HD hydraulics.

Did you put a new flywheel with pilot bearing in it with the clutch? If not the pilot bushing could also be the problem.


Godspeed,
Trent

 

[Prairie Dog]

Change the slave? I didn't think you could bleed the system.

 

[NIsaacs]

Usually the hydraulics work or they don't. Does it feel like the peddle looses some of its tension if you hold in down for a few seconds, like something is bleeding off?



The systems come from Dodge as a unit, master and slave pre bled, with a quick connect on the line. Most after market also, however they are also available separately.



Sometimes different pressure plates require a slightly longer stroke system than original equipment and can cause a slight drag on the disk. Possibly this can be fixed by the heavy duty SBC unit. Maybe that is one of the reasons for it?



Also sometimes a new disk on an old main shaft will bind due to slightly mismatched splines. If it does, it can cause the disk to drag on one side or the other.



If the pilot bearing is dry and dragging, it can cause the complaint also. I prefer the bushing for this reason, they seem to last forever and almost never cause enough friction to cause hard shifting.



Nick

 

[AH64ID]

Mine never did it with the OE clutch, was butter smooth.

The pedal feels fine, in fact if I hold the pedal in and never let it out there isn't an issue, even if I hold it for a minute.

I have the OEM flywheel, and it's been resurfaced. I am not sure on the pilot bearing, I didn't do the work.

The thing that gets me is it's only hard to shift when the clutch has been engaged in N with a warm trans, and once I'm in gear it's fine, and if I am moving (even . 002 mph) it's fine.

 

[NIsaacs]

Your hydraulics sound fine, if the stroke is long enough for the new pressure plate. Any drag is usually worse when warm. There is less drag in the transmission to help slow/stop the clutch disk. From a stopped, idling in neutral (800 rpm), clutch engaged, to a clutch release to shift into gear (0 rpm) is a big difference compared to shifting once you are rolling. That is probably why all is well once you get started. It doesn't take much of a clutch release/drag issue to cause hard gear selection from a stop.



Nick

 

[p-Bar]

Sounds like the engineer that designed the ford setup went to work for Chrysler and carbon copied the same design. The slave on the Ford had a allen screw so the only way to bleed it was gravity bleed (remove the allen and let it drip). Glad I'm done with manuals.

 

[AH64ID]

Glad I'm done with manuals.

Haha. . you couldn't pay me enough to run an auto, especially a 48RE :-laf

 

[Prairie Dog]

Haha. . you couldn't pay me enough to run an auto, especially a 48RE :-laf

I don't know, if you gave me an extra $8 or $ 10K I might consider it.







Nah.

 

[mwilson]

Try a quick blip of the clutch pedal in neutral after you try to put it in gear the first time, then slide it into gear as the mainshaft slows back down.



Works on wore out, balky truck trannys.



Nick, you know what I am talking about... .



Mike.

 

[blacksheepdiesel]

Prairie Dog,

Yes, the clutch can be bled. GCroyle posted the following video on YouTube about the process.

Bleeding External Clutch Hydraulic Release Systems Without Bleed Screws - YouTube

Godspeed,
Trent

 

[Prairie Dog]

Thanks Trent, that's a great vid. I know brakes can get spongy with old fluid that has absorbed water. This makes brakes spongy and that's kind of how the clutch feels.
It certainly wont hurt to change it out.

 

[seafish]

Don't know if this helps or not, but when I put in my Con-OFE I also put in the SBC upgraded hydraulics. Don't have ANY problems downshifting or upshifting and I am still using ATF+4 until the warranty runs out.

Of course, I am also running the SBC billet shift knob... maybe that is what makes it shift so smoothly. :-laf

 

[BDaugherty]

I installed a street dual disc with the 3250lb pressure plate last friday and I now have similar symptoms to what the OP describes except mine is a little worse. I ordered the SBC hydraulic upgrade and plan to install it this evening. I will report back wifh the results. One thing that i want to mention is that the stock prssure plate is around 2800lbs when new and decreases over time so most any new clutch will require more travel/pressure to fully release. Also, I ran new factory hydraulics ($175) on my '01 with a CON OFE with no problems. But remember, clutch hydraulics are cheaper than new syncros...

 

[AH64ID]

I talked to SBC again and they really don't think its hydraulics, the symptoms just don't match weak hydraulics. They referred me to Monty and Blumenthals, he too is stumped and wants me to put some friction modifier, and more fluid in (I run 7qts, and he wants me at 10).

 

[blacksheepdiesel]

I can't see the 10 quarts helping anything over having 7 already. I could see changing to a different fluid helping more than adding 3 more quarts. Royal Purple has always worked well for me.

Do you know how much was taken off the flywheel? If too much is taken then a flat washer needs to be inserted behind the ball stud the throwout lever rides on to help the clutch work correctly.

Godspeed,
Trent

 

[NIsaacs]

Ten quarts is ridiculous if that is to help with the complaint and a dang poor fix of the "real" problem.



I don't think there is an issue with too much material removed from the flywheel or a need to space out the ball stud. The self adjusting slave cylinder will overcome any lost geometry of the clutch system dimensions. However, the master cylinder sometimes can not. It does not have enough volume per release, to move the slave enough if the pressure plate requires more.



Just as an example; if the new pressure plate requires . 600" to release and the oem system only produces . 550" stroke, it is too short. Yet, the original plate might only need . 500", so the system works fine.



Nick

 

[blacksheepdiesel]

The trick for putting the washer behind the ball stud came directly from Peter at SBC.

Anything above 7 quarts in the transmission is simply going to come out of the rear seal at a quick pace, especially when driving in hills or mountains. '

Godspeed,
Trent

 

[NIsaacs]

The trick for putting the washer behind the ball stud came directly from Peter at SBC



Godspeed,

Trent

The washer thing is okay if you keep in mind how much is machined off the flywheel, usually measured in thousands of an inch and use a washer thickness to match. It is also to help keep the shift fork square with the original angles of it's stroke. This is a good thing, however it will not increase the stroke of the slave cylinder, if that is the reason for the disk drag. That my not be the reason for the complaint at all. It still might be the disk binding/dragging on the main shaft. Also, unless you know the total thickness of the before and after complete clutch thickness, you can be just shooting in the dark, and assuming you need the ball spaced out.



Nick