Need some help chasing down a grinding noise. I have done a lot of research but nothing quit matches up with what I am hearing.

First things first. I have a 1979 F250 4x4. A few days ago I put the truck in reverse and as I was backing up it was like the drivetrain locked up. After that I put the truck in gear and started on my way. As I got up in speed a pretty loud grinding noise was coming from the tranny. 2nd and 3rd gear aren't bad but when I get up to 40+mph it sounds like ****. If I push in the clutch the grinding is still there. While driving I also put the transfer case in neutral, kept the tranny in gear, pushed in the clutch and the grinding stopped. Any ideas?

I also took the lid off, inspected the forks and thoroughly cleaned the inside but noise still continues. Any help would be appreciated.

Jeff

 

What did you find inside to clean out? Sounds like a bearing. Once you stopped the trans from turning, the noise went away even though you were still rolling. Any grindings on the drain plug?

 

I didn't find any significant metal particles in the fluid but it was a murky brown color.

Yes, I was going approximately 40-45 mph, put the transfer case in neutral, kept tranny in gear, pushed in the clutch, turned off the truck and the noise stopped.

I am leaning towards a bearing as well, but not sure where to start.

 

Gotta pull the trans to know for sure. Real fun job in a 4x4....I feel your pain. Do you have:

--place to work

--solid supports if needed, depending on how high your truck is.

--floor jack with store bought or home built trans adapter

--tools

--beer

--several friends who have done this before who will do it for you....

 

--place to work. Yup, next to the curb.

--solid supports if needed, depending on how high your truck is. No luck there.

--floor jack with store bought or home built trans adapter. Floor jack yes, but no trans adapter.

--tools. Yes

--beer. PLENTY.

--several friends who have done this before who will do it for you.... None have done it but they will learn with me. I live in NJ and the people here think a tool box consists of a credit card and telephone book. At least where I live.

Where do I start?

Where is the best place to buy a rebuild kit if it comes to that?

 

Working on the street laying in the gutter makes that credit card thing look mighty good.

To start, take a look under your truck. Your transfer case is probably married to the trans. That means the transfer case comes out first, or, if you are really, really strong, you can pull the trans/tc together. (don't)

Secure the vehicle, pull the drive shafts, pull the TC, pull the trans.

Replace your clutch while you are at it.

Parts, note they want you to have a press to swap those bearings:

Parts for the New Process 435 Transmission


drivetrain.com is another site with parts, but they are down at the moment.

 

I appreciate all of the information and assistance. We shall see how this goes. If anyone has any more advice or tricks of the trade it would be greatly appreciated.