jmd88iroc-z

I have an '86 700r4 w/overdrive combo to a '70 350 4 bolt.

My question is, why does the tranny skip when in overdrive? When I manually shift from 1st to drive, everythings fine, but when I go to overdrive, its like there's teeth missing or something. Could anyone tell me what could be the problem?

jmd88iroc-z

I see alot of views, but no replies.

my3rdgen

This may not be the problem you are having, but when I read the post the first time I immediately was reminded of a time I was at a friend's tranny shop and on the bench he had a rear planet from a 700R4 that had NO TEETH left on any of the planet gears, they were completely worn down. He said it came out of a 4X4.

chris718

if you are referring to gear noise/grinding in fourth i can understand that.on a 700r4 the rear planet is overdriven in 4th to generate the .70 ratio.if there is noise it can be that the rear planetarary is mechanically damaged ,ie there are teeth missing or broken.to obtain reduction we must understand the held divided by the driven principles of simple planetary gear operation..this means that in order to obtain 1st 2nd and fourth and also reverse in a 700r4 you must operate in reduction thru both gearsets.this means you should have noise in these ranges as well as fourth if the planet assembly is damaged.

jmd88iroc-z

There's no noise from the tranny, it just shudders under load. It's not a constant shudder, but when it goes from drive to overdrive, it jerks. I don't know what the problem is. I've had several causes from others as to what it might be, but I haven't had a chance to check it out. I was just wondering if someone might recognize the problem just by the explanation. Thanks anyway.

chris718

it may be that the torque convertor is recieving a signal to lock up.try unplugging the electrical connector on the transmission right behind the shift lever.it is a square plastic plug,see if it changes

Buisson91B4C93Z

TRY UNPLUGGING THE TCC. It's not a fix but it may tell you the problem. If that has no results, then it sounds like the overrun clutch isn't releasing or is slow to release, It souldn't be applied in 4th. Does the shutter or skip go away after a second or two or is it a constant in OD. How many mi.. on the tranny, what year is it, what color is the fluid?