'83 Chevy Van Tranny Trouble - help pleeeease

[rudder-rudy]

Hello All,

I am a first time poster, new to this forum, came from this site: http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html .
Any help would be greatly appreciated ...:

I have a 1983 Chevy Beauville Sport Van ( see original brochure below) with a 350 (8 cilinder) engine and the transmission started to behave very strange. When it originally switched between 1-2 (or maybe 2-3), the actual switching took place at around 15 miles/hour. However the transmission started to make that switching from one day to the next at around 45 to 50 miles an hour which was a bit hard on the motor, but after switching up it always operated fine (until I had to brake that is ...).
So anyway I started to look into finding out what kind of a transmission I have and that  turned out to be a bit of a challenge. On the body of the transmission these are the #s stamped: 4YK202HT
After consulting several websites, junkyards, and parts stores it seems that it might be a 700R4 also referred to as 4L60 or sometimes TH-700R4.
(1-2-3-D-N-R-P) However my does not have a "vacuum modulator" as almost everybody describes, mine has a set of wires running into a 4 prong connector instead. (So maybe it is a 700R4E or a 4L60E )
At any rate someone suggested to check the governor or the throttle valve cable. This week-end I have pulled the governor and the valve inside the governor was moving freely, the plastic gear at the end was a little bit worn, but beeing a week-end I was unable to get a new one. I have found however a similar one in an old junk I have in my yard, this had a good plastic gear and slightly different weights. I made the swap nevertheless to see what happens, and I am sad to report that  it did not shift up at all to higher gears. Discouraged from the swapping, I have changed back to the old governor but it seems like now it will not shift up to higher gears at all ( I did not rev up the motor to more than 50 miles for fear of damage.) Otherwise the van is running fine in reverse and lower gear, and I know that it is usually the reverse that goes out on this transmission first when it is going bad.
The oil and the filter was changed about a year ago, and it did not look too bad at all.
I did not touch the TV cable yet as it is not quite clear to me how to check or make any kind of an adjustment on it.

If anybody could help to determine the exact type of transmission this is it would be some help ..
Also does this sound like a candidate for a rebuild ? Is rebuilding too complicated or can be done with average experience? I have changed motors before, and did 99% of repairs on my own cars ..never had any experience with transmissions before though(hm .. actually I took apart a manual one for a Ford Pinto about 13 years ago and it is still running today)
Thanks for any reply in advance ..

Rudy

[rudder-rudy]

I'll post 2 more pics for what the tranny look like - I have found these on ebay ..
it has an almost square oil pan if that helps indentifying it ...

thanks again

[rudder-rudy]

..

[Crosley.In.AZ]

It is a 700r4 tranny.

No such thing  as a 700R4E.

The 4L60E was introduced in 1993.

Check the TV cable for proper adjustment.  It must be hooked up.

If you cannot check the TV cable I doubt you can rebuild the tranny.  It is not DIY friendly

[enjenjo]

On a van that old, there is a good chance the TV cable is stretched or about to break. I have had them do this in the past. If you drove it very long in this condition, it more than likely cooked the trans, and as Crosley says, it is not newby friendly. Depending on the value of the van, you might want to have it professionaly rebuilt, or find a good used trans.

[rudder-rudy]

Thanks for the replies !
No, I have not driven it too far in its present condition. Only to experiment with it, to see what it is doing. And so a new cable might be the solution, if I can figure out how to adjust it properly.
Also when I call around asking for a "good used" one and mention that it is a 700R4 they always come back with the vacuum modulated one ... they are at a complete loss when I tell them that I have the wires with the plug and socket instead of the vacuum modulator valve.
Would it be possible to install one of those and just route the vacuum lines to it ?

thx

[rudder-rudy]

oh and I have checked the TV cable on both ends : it is hooked up, but like you said might be streched and needs adjustment

[enjenjo]

There was never ever any 700R4 trans with a vacuum modulator, ever, ever. Never. If it has a modulator, it is a T350 or T400.

All 700R4 have the plug on the side. All of them.

You can replace a 700R4 with a T350 or T400, but there are differences. Mounting, and vacuume lines for two