700R4 whine

[BigOrange90Jimmy]

The bane of my existence...automatic transmissions!

The trans in the truck I purchased whines when placed in gear. From my research, it seems to be pointing to the torque convertor. The trans shifts fine, but when placing it in reverse or drive, it does bang into gear pretty harsh.

Thoughts or confirmation of my research? 86 K10 with unknown miles on transmission...or anything else for that matter. Haha!

 

[Big Ray]

check fluid level...?

 

[63chevyll]

Planetarys are known for whining when they get loose...bad.

 

[kennyw]

Pull the pan and inspect. Any metallic debris and it is time for a rebuild.

 

[BigOrange90Jimmy]

Fluid level is good. I can hear the whine with zero movement of the truck in gear. I just got the truck Friday, so pulling the pan will come Thursday or Friday.

 

[bubba blazer]

Had the same issue with my '86 K5. It started whining at about 220k miles and it sprang a leak requiring 1-2 qts a month. It shifted fine and only whined in D or R (seemed louder in R). I changed the fluid but it didn't change the noise (no debris or pieces were found on the pan & fluid didn't smell burnt). I finally pulled it to get rebuilt and told the trans shop to inspect it closely due to the whine noise but he said nothing looked out of the ordinary and it was just plain tired. He did say the filter looked clogged (which I stupidly didn't change when I did the fluid change)

 

[Blue85]

The whine is probably from the pump. They all whine some - the question is whether or not you hear it over everything else. Sometimes shift kits up the pressure and makes them whine more. How loud is it? How does the tranny shift otherwise?

The clunk is probably just from slop in the rear end. It's normal to hear more clunk with one of these transmissions than something like a later model 4L60E. In later 700s there was an auxiliary valve body to soften the engagement - I want to say 86+.

 

[Greg Ducato]

If it only whines in gear it will be the filter or the converter thrust bearing on the stator most likely. The clogged filter causes a pump whine, but since you say it runs and drives OK then my money is on the converter. The bang into gear can be a lot of things but I would first check idle rpm or a bad vacuum line. Easy stuff first....

 

[BigOrange90Jimmy]

The whine is probably from the pump. They all whine some - the question is whether or not you hear it over everything else. Sometimes shift kits up the pressure and makes them whine more. How loud is it? How does the tranny shift otherwise?

The clunk is probably just from slop in the rear end. It's normal to hear more clunk with one of these transmissions than something like a later model 4L60E. In later 700s there was an auxiliary valve body to soften the engagement - I want to say 86+.

It's highly audible. The truck has headers and 40 series Flowmasters on it, and I can hear it above all of that, even with the windows up. I figured it had quite a bit of slop in the drivetrain as most older 10 bolts do. I will pull the pan and all tomorrow to check it out, along with checking the idle speed and vacuum.

 

[BigOrange90Jimmy]

Here's an update/conclusion for this:

That transmission is shot. The torque converter is bad, the pump needs to be turned to true it up and remove the scoring, clutch band and 2nd, 3rd, and 4th gear clutches are smoked.

My days of automatics are over. 465/241 combo is going in.