Mx 150 power shift issues

[84 5288]

I've got a 01 mx150 with issues in 1st and 3rd power shift , when in 1st or 3rd you can hear the motor pull down maybe 10- 20 rpm, way less then dead heading a remote, and the loader gets a little jumpy and steerings got a different sound but works normal. I've got 4 gauges in the valve, 1st is 260-290 and fluttering 2nd is 290 steady 3rd is 260-290 fluttering and 4th is 290 steady , no pressure rise on any gear that's not engaged. All the gears work normally. Anyone have any ideas, before I pull the rest of my hair out. 1 solenoid was newer , ohmed out fine 1 was the old square one,  replaced that one but figured it wasn't the problem,  it wasnt.. anything in the power shift valve that can cause this?  Just seeing if anyone has a idea before tearing a bunch of stuff apart for no reason.  Thanks

[CIHTECH]

Sealing ring failure on input (top shaft) 3rd sealing ring back. The 3rd sealing ring separates 1st & 3rd gear regulated pressure. Same applies to bottom shaft....

You will not see pressure raise on gauge other than the circuit you have selected. 

Oil escaping by sealing ring pressurizes opposite clutch on said shaft, and because solenoid  / shift spool is in demanded position it will be dumping any back pressure to tank / trans for the unselected gear. 

Top / Input shaft is 1st & 3rd, while bottom shaft is 2nd & 4th. 

You have a transmission job in your very near future.........

Shop Notes...

MX, MXC MAXXUMS TO TROUBLESHOOT POWERSHIFT, USE THE FOLLOWING CHART.

                  S1                       S2

1^ST GEAR    OFF                   OFF

2^ND GEAR   ON                    OFF

3^RD GEAR   ON                    ON

4^TH GEAR   OFF                  ON

NOTE; TEST PORTS ARE 4 – 3 – 2 – 1 TOP TO BOTTOM

NOTE; S1 IS THE BOTTOM SOLENOID AND S2 IS THE TOP SOLENOID

SOLENOIDS 349295A1 SHOULD TEST 10 ohms @ ROOM TEMPATURE

RELAY 87414866 IS IN THE SIDE CONSOLE. SELECTOR SWITCH 193633A6

NOTE; TRACTOR WILL DEFAULT TO 1^ST GEAR WITH NO VOLTAGE

[84 5288]

I didn't want to hear that, but figured it was coming anyway, just figured ask about the valve if a spool could be  hanging up.. so the sealing rings is why when you go to 3rd theres about a 5-10 second pause before it starts pulling down that few rpm , it takes that time to start building pressure in 1st clutch pack. 1st I don't notice much rpm drop at all but pressure is fluctuating.  Well looks like its getting run in 2nd and 4th for a little while until I get time. Thanks for the info 

[CIHTECH]

4 hours ago, 84 5288 said:

so the sealing rings is why when you go to 3rd theres about a 5-10 second pause before it starts pulling down that few rpm

When you remove sealing rings, carefully raise them up out of groove and cut with razor. Now cut the sealing ring into 180 degrees from your original cut. Study the cross section for a wear profile of the sealing ring, this will give you an indication of your sealing ring groove wear.

You can feel the stepped wear in the upper 1/2 of the groove with a sharp instrument (razor blade works) if you have sealing ring groove wear in the shaft it will need to be addressed. 

Check I.D. of oil distribution hubs where sealing rings "set" likely need t replaced them as well. 

[HydroTek]

I have re-cut the groove shoulder in those shafts a few times 

better to have too much side to side , than a tapered shoulder 

[84 5288]

Thanks guys, I'm sure theres going to be lots of replacement parts with it having 14,xxx hours on it and no idea what's been done previously. I'll know more later when I get it tore down and I'm sure I'll be back with questions. Thanks again 

[HydroTek]

That tractor is pretty easy to get apart -- gonna roll the rear back from the front 
-- remove the front driveshaft first , if it has one 
-- you prolly need to look at the couplings anyways 

a couple of dowel bolts will help with alignment when going back together
-- and a ratchet come along , so you dont have to wrestle things 

Make some decent stands with rollers for the rear , but front can be stationary
-- just need adjustments on each leg of the stand , for tilt 

Friend of mine had a 'universal' set of stands using 6" steel wheels , extendable box tubing, and chains with turn buckles for height adjustment -- these worked pretty well in his mobile mechanic business 
Stands went at an angle in the roller wheels and used the chains to adjust -- would fit most any tractor -- and would break down to go in his van truck