What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

SM465 mech. linkage vs. hydro

Hasn't the linkage fallen out on Cleveland Rock on 2 different occasions? That right there would convince me to switch. I'm not saying that in your shoes I would make it a priority, but if I came across a good deal or something I would jump on it.

Sure lines leak, but that's easy to take care of. I wouldn't worry about failures considering the few miles you put on your rig in a year.

My 2¢. :thumb:
 
4X4HIGH said:
I guess you could compare it with power steering versus manual steering the best. Both systems use the same steering components but one system uses a manual steering box with only operator assistance (yourself) while the other system uses a hydraulic steering box with operator assistance AND hydraulic assistance. Obviously the system that uses two different types of assistance will be easier. The same thought can be said manual brakes versus power brakes.

You can always argue that the leverage of a mechanical system could be greater than the hydraulic therefor being the same effort but no amount of mechanical leverage will ever be greater than hydraulic pressure.

I know someone is going to argue this point and i'd love to read about it. :D
Click to expand...

As Rene said without some kind of power assist (i.e. PS pump in the steering or vacuum booster for the brakes), the hydraulic clutch setup is just another way to gain "leverage".

The only way that one setup could have lower pedal pressure than the other is if the pedal travel were different, and its not.
 
mrk5 said:
Hasn't the linkage fallen out on Cleveland Rock on 2 different occasions? That right there would convince me to switch. I'm not saying that in your shoes I would make it a priority, but if I came across a good deal or something I would jump on it.
Click to expand...

Yep, and on other obstacles too. That was a body movement and adjustment issue which has long been fixed.

mrk5 said:
Sure lines leak, but that's easy to take care of. I wouldn't worry about failures considering the few miles you put on your rig in a year.

My 2¢. :thumb:
Click to expand...

Yeah but if my mechanical system works, doesn't leak and doesn't cost a couple hundred dollars why should I switch? Most people consider hydro a high priority upgrade with a 465 and I don't really get it.


Really, I'm just kinda stirring the pot and promoting argument and the spread of information ;)
 
Last edited by a moderator:
well, I have an automatic, if i were to switch to manual tranny, id get hydro because i have to go on the hunt for a tranny, linkage, bell, petals, etc. so id just get the hydro right away from a donar late 80's vehicle because of availability in the local yards, the mechanical linkage is found on older vehicles anyhow so i would think its harder to find and more beat to hell. Im pretty sure the factory switched from mech to hydro for reliability and cost, not leverage.
 
Here's my experience with it:

My friend let me drive his rig around on a rock garden... he has a mech. setup, and I went with Hydro in my crew cab when I swapped it this past summer.

The difference between the 2 was not pressure pedal feel when driving normally. I mean, if you took a force gauge and compared the feel I would be surprised if it was even slightly different. But the the real kicker is, when I was driving my friend's rig and got it twisted up in the rocks, I had to put ALL of my weight onto the pedal to get the clutch to disengage all of the way.After experiencing that in his truck, I decided to go hydro in mine when I did the swap, and am glad I did. With my hydro setup, the pedal feel doesn't change when the frame/cab is flexing and twisting off road.
 
Bore diameter difference between the clutch master and the clutch slave is what makes it easier to disengage the clutch on a hydraulic system . Changing the bore diameter in either piece will change the amount of force that is applied at the clutch fork given the same pressure from your foot on the clutch pedal.
 
4X4HIGH said:
Bore diameter difference between the clutch master and the clutch slave is what makes it easier to disengage the clutch on a hydraulic system . Changing the bore diameter in either piece will change the amount of force that is applied at the clutch fork given the same pressure from your foot on the clutch pedal.
Click to expand...

You aren't understanding hydraulics correctly: Hydraulics are just another way of trading travel for force, just like a lever arm. There's no magical extra force added just because you're using hydraulics.
 
38377k5 said:
You aren't understanding hydraulics correctly: Hydraulics are just another way of trading travel for force, just like a lever arm. There's no magical extra force added just because you're using hydraulics.
Click to expand...

I think you better read this then YOU will understand that the bore difference between the master and slave will definately change the force applied. http://www.tpub.com/content/engine/14037/css/14037_67.htm
 
38377k5 said:
Yeah but if my mechanical system works, doesn't leak and doesn't cost a couple hundred dollars why should I switch?
Click to expand...
I was assuming you'd be going the pick 'n pull route. But then I guess you would have to be concerned about premature failure.
 
It may be entirely possible to generate more force at the clutch through the hydraulic system than is capable in the mechanical linkage.

At some point you can no longer make levers longer before they are just too big, where as a hydraulic system can probably be kept more compact and still generate significantly higher forces.

That being said, I haven't studied the diameters of the bores in either the master or slave nor have I measured and calculated the forces created by the mechanical linkage.
 
cybrfire said:
It may be entirely possible to generate more force at the clutch through the hydraulic system than is capable in the mechanical linkage.

At some point you can no longer make levers longer before they are just too big, where as a hydraulic system can probably be kept more compact and still generate significantly higher forces.

That being said, I haven't studied the diameters of the bores in either the master or slave nor have I measured and calculated the forces created by the mechanical linkage.
Click to expand...

Its not like they have to make clutch pedals as long as possible to attain sufficient pedal force.

No doubt that hydraulics are a more compact and maneuverable way to multiply force, that's where most of their benefit comes from. No doubt that hydraulics are VERY useful in many, many cases. They are great for things like brake and clutch linkages too for this very reason (I'm not contradicting myself here ;))

I have no idea what the bore is on the K series clutch master cylinder or the slave cylinder and it doesn't matter in this case.

Its pretty simple, work in equals work out. Both setups have very similar pedal travel and pivot points, both have the same travel at the clutch fork. This implies that both generate the same resistant force at the clutch pedal. Period. There's no magic here, no power assist from the motor, just different ways of manipulating force.

The mechanical linkages are stout and very reliable WHEN BODY/FRAME MOVEMENT IS KEPT UNDER CONTROL. Poly body mounts usually solve this problem and are probably a good upgrade regardless.
 
For reference, the clutch master and slave bore diameter is vitually identical for the 96 chevy 4x4 1-ton system I bought to run on a nv4500. I don't have the exact dimension, but the amount of piston travel at the master is the same as the piston travel at the slave (on my system).
 
38377k5 said:
Poly body mounts usually solve this problem and are probably a good upgrade regardless.
Click to expand...

Poly mounts will not help much because the body is going to twist. You’re going to need a full cage mounted to the frame to prevent the severe frame twist which Chevy’s are infamous.
As for the "feel" between the mechanical and hydraulic clutches, I think the mechanical clutch has a huge return spring inside the cab. The lever aspect between the mechanical and hydro will be the same but the large spring will definitely add more force to the pedal.
 
The only problems I have ever had with my mechanical setup is when I tried to install a body lift. The linkage bound up and the pedal was stuck 1/2 way down. So I had to cut down my 3" body lift blocks to about 1 7/8". But if i really wanted all 3" of body lift i could have easily cut the linkage rod and extended it 3". Besides that, just make sure your z-bar stays greased since there is a grease zerk on it.

I had the original clutch in my truck up until the to-brearing quit on me last spring. In its place I installed a centerforce dual friction clutch which actually made the clutch feel lighter than the original. Also my 95 S10's clutch pedal is much heavier than my centerforce and that one is hydrolic, so go figure... :doah:
 
If you've got the twisting of your rig under control, I don't think it's necessary if you've never had a problem. You know my situation, and why I went with hydro. ;)
 
Only comparisons I've got are between my hydraulic setup (isn't "hydro" water folks? Anyone know the proper abbreviation? At one time I had seen hyde) and my dads mechanical setup.

One of the problems you will run into is the variations in the setups...vehicle, engine, drivetrain, condition, maintenance, type of clutch and so on. No fair comparison unless both setups have been in the same truck, and you know both are working correctly.

Doesn't the mechanical setup use a spring on the pedal? Hydraulic does not as far as I remember. How about the forks and pivot? Aren't those different/different locations?

What about the angle of the pushrod on the two...no engineer, but doesn't the mechanical pushrod travel from the pedal downward at a 45* angle (roughly) compared to pedal travel, while the hydraulic pushrod is directly inline with pedal travel? Obviously pedal travel is more of an arc, just seems like the mechanical pushrod runs at a weird angle compared to the direction of the pedal travel.

In any case, the mechanical setup on my dads is terrible compared to my hydraulic. As I laid out before, it's probably not a fair comparison. He's running a carbed big block with a lopey cam in a 6000lb truck with 4.10 gears and a clutch setup that's roughly 34 years old, and I'm not.
 
You must log in or register to reply here.

Latest Posts

Top Bottom