Getting Into Gear vs Clutch Slipping

[Corey'sgotachev]

I have been trying to figure out the right spot for my clutch to be adjusted to. I have 350 mated to SM465 and out through the NP205.

It's been hard to get into R unless it's turned off. Today I adjusted the clutch to where it will go into gear. When I test drove it and hit the gas, the clutch slips like crazy! I doubt I could go up any sort of incline.

What is the next step? I was thinking clutch but it's been fine until recently. It hasn't been slipping and I haven't burnt it up.

Could it be the first gear/reverse syncros?

Any advice on my next step would be great!!!

Thank you!

[franken]

If it won't go into whatever the clutch isn't releasing.

[Corey'sgotachev]

Originally Posted by franken

If it won't go into whatever the clutch isn't releasing.

So you're saying clutch work?

[El Dorado Jim]

reverse gear has no synchros, i know 1st gear doesn't either...you need to adjust your clutch so you have just a little free play in your pedal before it starts to disengage the clutch...google clutch adjustment....I have a sm465 in my trucks also, sometimes you have to double clutch to get it into reverse

['68OrangeSunshine]

Did you replace the clutch, pressure plate, resurface the flywheel. R+R the throw-out bearing? Sometimes the wrong new T/O bearing will interfere.

[Corey'sgotachev]

Originally Posted by '68OrangeSunshine

Did you replace the clutch, pressure plate, resurface the flywheel. R+R the throw-out bearing? Sometimes the wrong new T/O bearing will interfere.

I have not done any work to it. It's been slowly getting harder to put into gear. I attributed it to the slave cylinder becoming loosened.
In the past it was easy to get into R. I've never really used 1st(granny low) so don't know if it goes easy or not.

[Corey'sgotachev]

Originally Posted by El Dorado Jim

reverse gear has no synchros, i know 1st gear doesn't either...you need to adjust your clutch so you have just a little free play in your pedal before it starts to disengage the clutch...google clutch adjustment....I have a sm465 in my trucks also, sometimes you have to double clutch to get it into reverse

So if I adjust clutch to go into 2nd (or 1st if you consider L, 1, 2, 3) gear easy then go to R?

I haven't had to do that previously, 6 months ago. It's like something is slowly getting worse. -?-

[Corey'sgotachev]

I'm making a list of "could be's". Could be:
-warped clutch
-Leaking input shaft seal
-throw out bearing
-power shaft bearing
-syncros (from neighbor transmission guy: First and reverse are the same gear. It slides either direction depending on which direction you want to go. If you have to adjust the clutch to tight that it slips just so the tranny doesn't grind you either need a new power shaft bearing or first gear syncros. I don't think it's the bearing because they get noisy when they go bad. Either way when you tear it down both get changed.)

The dumb 'ol truck has a hydraulic clutch conversion installed. I've put only a few 100 miles on it in less than year and when I got it, it worked fine.

There are no new noises, just the grinding try-to-get-in-gear noise until I adjusted clutch slave until it stopped...

[B. W.]

Originally Posted by El Dorado Jim

reverse gear has no synchros, i know 1st gear doesn't either...you need to adjust your clutch so you have just a little free play in your pedal before it starts to disengage the clutch...google clutch adjustment....I have a sm465 in my trucks also, sometimes you have to double clutch to get it into reverse

X2 - sounds like a simple clutch adjustment is all you need. You said it was converted to hydraulic, have you had to add any fluid? If so, you have a leak (you need to fix the leak) and you have air in the system, you need to bleed it just like a brake system (except clutch systems are almost always more difficult to get the air out of!)

on you list:
1. forget the warped clutch, not an issue here
2. input shaft seal - not your problem. It is easy to check - pull the dust cover off of the bottom of the flywheel & look for oil. This will cause a clutch to slip but will NOT keep it from disengaging when you push in the pedal.
3. throw out bearing - will be very noisy when bad. With the original manual adjustment you can still get enough adjustment for the clutch to work properly even with a bad throw out bearing. With your hydraulic system - don't know. I have seen bearings come completely apart & the inner race slips inside the pressure plate. You can visually check this also with the dust cover off.
4. I have no idea what a power shaft bearing is but is is not part of this transmission
5. synchros - not your issue. No synchros for 1st or reverse, chances of all the others going bad at the same time are slim

[Corey'sgotachev]

Originally Posted by B. W.

X2 - sounds like a simple clutch adjustment is all you need. You said it was converted to hydraulic, have you had to add any fluid? If so, you have a leak (you need to fix the leak) and you have air in the system, you need to bleed it just like a brake system (except clutch systems are almost always more difficult to get the air out of!)

on you list:
1. forget the warped clutch, not an issue here
2. input shaft seal - not your problem. It is easy to check - pull the dust cover off of the bottom of the flywheel & look for oil. This will cause a clutch to slip but will NOT keep it from disengaging when you push in the pedal.
3. throw out bearing - will be very noisy when bad. With the original manual adjustment you can still get enough adjustment for the clutch to work properly even with a bad throw out bearing. With your hydraulic system - don't know. I have seen bearings come completely apart & the inner race slips inside the pressure plate. You can visually check this also with the dust cover off.
4. I have no idea what a power shaft bearing is but is is not part of this transmission
5. synchros - not your issue. No synchros for 1st or reverse, chances of all the others going bad at the same time are slim

A few weeks ago I was trying to adjust and pressed on pedal too hard-bent the pushrod for master cylinder. I have taken MC apart 3 (4? it's all a blur)times to get air out and replace bleeder valve in slave. Pedal not squishy at all.
Today I adjusted it out so it would go into 3 and 4-hard to get into R but with lots of pressure it would go. Test drove, STILL slips.
Here's a pic of pressure plate. Not sure but I think it looks ok?

[B. W.]

You should only have a little play at the top of the pedal before you feel the pedal begin to depress the clutch. (3/4 to 1" according to service manual) I think you have the clutch adjusted too tight so that it is already pressing against the pressure plate. If it's pushing against the pressure plate with your foot off of the pedal then the clutch will always slip because it is not engaging completely.

You are having to adjust it this tight because you cannot get enough "throw" to depress the fingers on the pressure plate to fully release the clutch & allow for easy shifts ("throw" is how much the release bearing moves against the pressure plate). You don't have enough throw because there is air in the system.

You can have someone press & release the clutch pedal while you look at the release bearing. It should release completely off of the pressure plate fingers. You don't need a lot of clearance, just a very little but you do need clearance for the clutch to engage completely. It can be very difficult to remove all of the air from hydraulic clutch systems. I have fought them for years, I've even made up a few new curse words along the way!

[Corey'sgotachev]

Originally Posted by B. W.

You should only have a little play at the top of the pedal before you feel the pedal begin to depress the clutch. (3/4 to 1" according to service manual) I think you have the clutch adjusted too tight so that it is already pressing against the pressure plate. If it's pushing against the pressure plate with your foot off of the pedal then the clutch will always slip because it is not engaging completely.

You are having to adjust it this tight because you cannot get enough "throw" to depress the fingers on the pressure plate to fully release the clutch & allow for easy shifts ("throw" is how much the release bearing moves against the pressure plate). You don't have enough throw because there is air in the system.

You can have someone press & release the clutch pedal while you look at the release bearing. It should release completely off of the pressure plate fingers. You don't need a lot of clearance, just a very little but you do need clearance for the clutch to engage completely. It can be very difficult to remove all of the air from hydraulic clutch systems. I have fought them for years, I've even made up a few new curse words along the way!

That makes sense. I'm getting good at taking the MC off the firewall. I did bleed the system-no more air bubbles came out of slave. The MC does sit with the wrong end up, the hydraulic fitting side so there could be a sneaky bubble in there.
It does seem like I'm not getting the full throw of the piston.

[Corey'sgotachev]

How do you know if master cylinder needs a rebuild kit or just needs to be replaced?

I'm wondering if I'm not getting the full throw of the pedal because the master cylinder needs to be replaced? It's not leaking but could the fluid not get forced into hyd line to pull the slave cylinder the proper distance?

I'm 90% sure there isn't air in the system. The pedal is hard the full stroke, not squishy like typical air in the line.

[garyd1961]

Have you checked the oil level in your trans? Low gear oil will make it hard to go in reverse. Not sure exactly why but the oil slows the gear down or something like that.

[Corey'sgotachev]

Originally Posted by garyd1961

Have you checked the oil level in your trans? Low gear oil will make it hard to go in reverse. Not sure exactly why but the oil slows the gear down or something like that.

I have not! ...but I will! It is oily down there! Gear oil, yes?

Thank you Garyd1961