Major tranny problems!!

[720_KID]

I own an 86 720 4x4 KC TBI, the problem is all on the tranny. I wad driving when all of a sudden I pressed on my clutch and I heard the ugliest screech and grinding ever. I pulled up to my friends house and I noticed that I couldn't shift into gear with out it grinding first. My clutch pedal had pressure but I also realized the clutch would engage when I would BARLEY lift my TOE off the pedal. I took the truck home very slow and it grinded through the gears all the way, also the transmission made some noise on the way. I had already changed both the master and slave cylinder maybe about 9 months ago. I took the tranny fluid out today and I found metal shavings in there. I already know that ain't good. So would I be a good Idea to rebuild the transmission even thought it has all those shavings in there?

[ggzilla]

It is not a good Idea to rebuild the transmission until you've troubleshooted what's wrong. Which involves coming up with potential causes then testing to see if that's really the cause. I'm sure others here will have some ideas.

[720_KID]

What should I do to troubleshoot it?

[ggzilla]

First we need an idea as to what's wrong. I'm sure others will have ideas.

 

Alternatively you could disassemble the transmission and hope there is some obvious problem visible. But generally its better to come up with ideas first. For example maybe it needs a fix that doesn't require disassembling the gearbox.

 

My first thought is that the cluster gear has chipped first gear. If that's what happened then replacing parts is needed, rather than simply rebuilding it.

[bottomwatcher]

Sounds like the classic bad countershaft bearing, I have had 4 go out over the years. Does everything sound fine in fourth? That would be because 4th goes straight through without loading the countershaft. Look for a C series trans from a hardbody.

[datzenmike]

From the description it sounds like the release bearing has failed. The drain plug on the transmission has a magnet on it that collects any metal particles. Have you ever changed the oil? It should be changed every 3-5 years. Later owners tend to not keep up maintenance and have no idea what the last owner did or didn't do. A black paste with some metal particles on it is normal.    

[Nuclear Water Boy]

You said you found metal shavings in the trans fluid,,,describe "Metal Shaving" large pieces/chunks or typical micro floaters in the oil? I gota agree with King Rat in that it sounds like your throw out bearing. Either way you're going to have to pull the trans. If the clutch and T/O are still good then seperating the trans and having a look is your next order.

[datzenmike]

Normal. Certainly normal if hasn't been changed in "I don't know how long."

 

 

Not normal.to have bearing race parts stick to it.

[Nuclear Water Boy]

Oh man!!! now that's a description if I've ever seen one..

 

Lou "How does your drain plug look?

[720_KID]

When I took off the drain plug it has thick long metal shavings, like in the second picture kingrat put up. The release bearing is practically new since I changed it this past October.

[720_KID]

Fourth gear and reverse where hard to get too since it grinded.

[720_KID]

Also I forgot to mention, that loud noise I heard came from the front if the tranny.

[Robert]

Pull the tranny off the engine....see if the disc is in good shape. As the disc wears out, the springs can fall out and jam the clutch so it will not disengage and cause exactly what your talking about.

 

 

Either way, everyone is only guessing without more input. Pull the tranny and see if its external or internal.

[wayno]

Sounds like the lower cluster gear bearing failed, it usually makes some noise as a warning, like rattling when in neutral while idling, or making noise in every gear except 4th.

You need to pull the transmission, it's going to be a pain, but you are going to have to do it.

Was there any fluid coming out of the bottom center of the bellhousing?

[datzenmike]

This.

[720_KID]

I'm gonna pull the tranny this Saturday. It wasn't leaking any type of fluid from the bell housing. When I drained the oil it was just black paste with those large shavings I mentioned earlier.