Clutch questions

[69-72]

On my 72 Blazer. This is my first M/T vehicle so I don't know much about all this.

It seems when the truck is cold there are no problems with shifting it, but after driving a while the gears start to grind, especially going into reverse. Any ideas what the problem is there?


Also is there a way to adjust the clutch pedal travel, I have to step on it till it touches the floor for it to work, and its wearing out my new carpet.

[JimKshortstep4x4]

There is an adjustment rod from the "Z" bar to the clutch release arm that can be lengthened to help your situation. Make sure there is some free travel in the clutch pedal,
(3/4" approximately) after adjusting.

Jim

[Sport/Truck]

I'm thinking a good synthetic oil my help also. Too heavy of an oil will cause some problems, but it usually gets better once it warms up, in your case it's getting worse.

One thing that helps with reverse is put in first gear, then go into reverse. Low gear to low gear = no grinding.
s/t

[68gmsee]

After you check all of the mentioned possibilities.

Make sure that the rubber grommets in the linkage ends are intact- both on top column and on the transmission itself. In other words the ends should be firm and not all loose and wobbly.

Insure that the link adjustments are correct on the column. Do a search on this. There were some real good pics and procedures that guys have posted in the past.

If all of the above are correct, you could have a transmisson problem or the pressure plate is not disengaging the clutch plate from the flywheel properly. The clutch link adjustment should help there. I've also had new defective pressure plates in the past. Another potential problem is defective or worn clutch disc or even throw out bearing.

My clutch pedal has about 1 1/2 to 2" of travel. before engaging the pressure plate.

Good luck!

[68gmsee]

Forgot to mention, make sure that you are using the correct weight gear oil.

For the most trucks sae 80 or 90 should be okay. I use 90 on mine.

[69-72]

Thanks for all the help. I guess a better way to describe the problem is that when I put it in reverse I kinda have to wait for the gears to stop spinning for it to go in to gear, even though I am already at a full stop. I should also mention this is a four speed.

[vectorit]

If its a granny gear trans, meaning that you start out in second gear all the time. Since first gear is too low for the street, as in my case I had the same issue before I rebuilt the trans. Back then I would through it into second gear, then to reaverse to prevent the grind or block to get into reverse. Funny thing to is, that I have to do this in my Toyota Tacoma 4x4 manual trans.!
On my 68 there is a couple V notches on the through out bearing actuating arm, you can try to move the Z bar rod to a different notch to get a better throw angle.
If you are sure that the clutch is good, and you have made all the linkage adjustments you can with no change. Then there could be a possibility that someone has monkeyed with the clutch pedal linkage in the dash? If so, then that will require taking the gauge panel out. Then take all tension off of the linkage, and then adjust the clutch pedal arm a couple teeth back to give a better throw. (But that is on the extreme side of adjustment, meaning you should be able to take care of your issue with the outside linkage).

Good luck!

[Brad]

Originally Posted by 69-72

Thanks for all the help. I guess a better way to describe the problem is that when I put it in reverse I kinda have to wait for the gears to stop spinning for it to go in to gear, even though I am already at a full stop. I should also mention this is a four speed.

That sounds normal to me. If you have non-syncro gears then this is what will happen. On older transmissions, 1st and reverse don't have syncros.

[68gmsee]

Originally Posted by 69-72

Thanks for all the help. I guess a better way to describe the problem is that when I put it in reverse I kinda have to wait for the gears to stop spinning for it to go in to gear, even though I am already at a full stop. I should also mention this is a four speed.

You might want to check the transmission type. Check the model number on the side and post it if you have trouble trying to figure out what you have.

I don't believe your problem is a non sync unit unless you have some older model 4 speed.

If you have to wait for it to stop spinning even after you are no longer moving, it could be the flywheel pilot shaft bushing, throw out bearing, pressure plate or clutch adjustments.

Take the flywheel inspection cover off and have someone step on the clutch to see if it releases the clutch disc. If you take it to a shop, they can do this for you and tell you what the problem is for probably not too much money. They can even check it with the engine running in neutral. Stepping on the clutch and releasing it to see if it disengages the disc.


This is an excerpt from the "clutch wizard" site.

Internal clutch Release Problems:

Not all release problems are caused by the release mechanism. Things can go wrong inside the clutch as well. A loose damper spring in the clutch disc, bent disc, frozen pilot bearing, collapsed release bearing, or metal shrapnel from a broken cover can cause the clutch to bind and not fully release when the pedal is depressed. The release fork might bend. The pivot ball can wear or break. There are many reasons for a clutch to hang up.