70 series retard adj tool

rod - i may also be interested in one. please send some info. thank you

Those blinkey boxes were just that; B!*%^ Boxes. They only were accurate if you had trans temp up to a specific temp. The best way to adjust the RPS34 tranny was to take the tractor out in the field and work it, plowing or pulling a disc, until temp gauge was in work range, and then remove the floor plate. If there was a hesitation between the up shifts start turning the retard screws in a 1/4 of a turn at a time until hesitation is gone. Then do the same with the other retard for down shift. If engine draws down between shifts the retards are screwed in to far. You will notice a bit of engine drag with a cold tranny, and may have to readjust (back off) for winter use, such as being used on a mixer wagon or snow blower in the winter, to prevent engine drag between shifts.
Loren

Like Loren mentioned the fancy Blinky Box as it has been so named really is not necessary for the retard adjustment. I will describe that to the other fellow also. I see them as only being a tool of CASE's history for value, not as a needed tool to help a tractor operate better. Rod.

thanks for responses. is there a pic of top of control valve body on rps 34 showing location of c1 thru c4 retard valve screws ? turning to right increases pressure ? I looked at manual and did not see. thanks

The retards do Not regulate pressure. They regulate how fast the oil leaves a clutch pack as a shift is made, thusly holding a pack semi engaged until different clutch pack takes on the load.
Loren

Thanks for the information on not needing the bbox.
My problem is kinda how you describe it...but...
First gear powershift and reverse work very well as do the hydraulics with the new pump. But when I shift from 1st to second or 3rd the motor "drags down" like the brakes are on and the hydraulics work really slowly.

(quoted from post at 11:51:17 04/11/18) Thanks for the information on not needing the bbox.
My problem is kinda how you describe it...but...
First gear powershift and reverse work very well as do the hydraulics with the new pump. But when I shift from 1st to second or 3rd the motor "drags down" like the brakes are on and the hydraulics work really slowly.

Click to expand...

I do not like the sounds of your symptoms, if the bogs and you lose hydraulc flow it sounds like you have deeper issues than adjustments, first, there are only two retard adjustments c2 and c3, as previously explained, the retard adjustments set the rate of clutch disengagement so the outgoing clutch and the incoming one are syncronized to keep from having a "power lapse" if that makes sense. If you had a retard problem it would be momentary, not continuously dragging the engine down. I as most other quit using the blinky box completely, as Loren saidit takes a long time to get the tranny oil up to a temp that will work for the blinky. The main problem is that the blinky setting that the lights say is correct with hot oil will keep C3 in on a downshift long enough to throw you through the windshield some morning when you take off and downshift as both C2 and C3 are in at the same time due to the slow decay of C3 because of cold oil trying to get through the tight retard screw set for hot oil If anything it is better to have c3 a little soft to avoid the above scenerio. Hope this makes sense as some things are easier to do than translate to someone else.

So from that I'm guessing that two of my clutch packs running 2nd and 3rd powershift mode are in need of repair internally...

Thanks for the info...with all the reading
and the great response on this site I'm
guessing it's time to rip her in half...any
idea what could be wrong inside??
There seems to be lots of problems that can
occur with this transmission but not a lot
of commonality of problems...
Thanks for any help...where we live up
north there is little to no one who knows
much at all about these things.

What does the tractor do when you start it up and depress the clutch pedal, do you have to grind it into gear , does it try to move with the clutch depressed, can you shift from neutral to a gear without grinding? There are some missing pieces here I think but at any rate, slow hydraulics when the problem is happening means a major internal oil leak. When you push the clutch do you get an engine surge momentarily? C4 must be working to give reverse and serves as a transmission brake otherwise for shifting purposes. In some respects it soinds like a C2 but if clutching and starting out is normal in ps1 that throws a question mark in there.

I do want to tell you that that rps34 transmission is a great transmission and will last most time as well as it is taken care of, do not let anyone disparage that transmission based on hearsay, I have seen older 970s turbocharger with 7700 hrs without splits. Lack of oil and filter changes will cause sticky pilot spools and destruction of clutch pacs. People who change filters and throw the bypasses away with the old filters is more common than many realize, the filters might as well be left out completely as to being installed without the bypass cartridges. If you are not mechanically inclined and familiar with proper cleaning and loc tiing procedures I would recommend you find an old school 70 series specialist to assist you on a rebuild, if done properly they are good for thousands of hours. Certain parts are mandatory replace items and if it an older unit update the ps clutch pistons to the late style clutch pistons.

Shifting into gear takes a while for the
gears to stop before you can slip it into
gear. Sometimes you just can't get it to go
into gear it will just grind which I
feather the shifter to see if it's going to
stop at all or just grind in which case I
just shut down engine and try again with
clutch pushed in. But if you start it with
the key in one hand trans lever in other
with foot on the clutch pedal.... just as
it starts...you can slip it into gear and
the motor won't load up or bog. Then you
can shift from say 4gear 1st powershift to
2nd gear 1st power shift or back into
reverse no problem...until you fully stop
and let your foot off the clutch. Sometimes
if you rev up to 1200rpm or so foot the
clutch and immediately back off the
throttle it will slid into gear. I have
worked on many units....just not a power
shift case.

If the C4 pressure is correct with the clutch down and you hear a engine surge and usually you can hear the planetaries sing with the clutch down you can assume the hydraulic portion is ok. From the added info you have given C2 seems to be the area i would zero in on, You could check the clutch spool travel, it must travel into the valve and out till it is completely out, on the early models I completely removed the pedal stop screw that stopped the pedal from allowing the spool to completely seat in the body. If C2 is going to zero with the clutch depressed In my opinion you are looking at a problem at C2, the additional info all points to that in my opinion,

Loren, Rod, what think you, give some input on this!!

Another quick question, does it load the engine in 3rd powershift? In practice C2 and C3 are both activated in 3rd and you should not be seeing a bog down in that range even with C2 warped, if you are then C1 is suspect as it should be released in that range. Maybe you have a combination of issues to deal with.

Yep...3rd sounds like the brakes are on and
the hydraulics are slow just like 2nd
If this friggin winter of ours would ever
let up....(still have 3 feet of snow in the
fields and snowing again today)...I guess
I'll just start tearing it down. Can't plow
snow with it any more anyway. Gotta use the
Cat..
Problem up here is all the guys that
actually worked on these tractors are dead
and the shops are charging 165 dollars an
hour's for guessing....so they just replace
everything. My neighbor got his
fixed...6000 dollars...got it home ...still
won't work. Nearest shop 200 miles away...
So this is why I gotta fix my own.

Keep us posted, you really have my curiosity built up, c1 should be out of the circuit in 3rd ps and c2 should not bind it up even if warped as it and c3 are engaged together, a split looks inevitable.