English is not my first language and since I have switched separator plate one time between all tests, the results and challenges might appear contradicting.
Happy to try to clarify!
Thanks for your patience!
The first section of the thread, when I experienced slipping in all forward gears, was with the HD2 set up.
Between the first part and the second part I disassembled the VB and replaced the HD2 separator plate with some other adjustments and the second gear selector was not slipping anymore.
Here it is again, from start.
After the full rebuild of this transmission, which I did with a lot of attention to detail and reading of yours and others advice in combination with the service manual, I experienced slipping in all forward gears. Only reverse was nice and firm, all other shifter positions slipped. It gained speed but slipping bad.
This is some info on the original build,
“1992 case, complete alto and kolene steels kit, Transgo HD2 kit and internally dual feed modification, fully rollerized, steel forward hub, case saver, new electronics, bearings, seals, EZ-TCU, 3200 stall converter.
Drilled pump against seal blow out, drilled strator against convertor drag, drilled rear strator support and overrun clutch housing for better flow and finally direct drum to prevent centrifugal apply. HD2 Separator plate drilled to 2nd: 0.11inch, 3rd: and 4th: 0.125inch
Omitted 3rd clutch and reverse checkballs. HD2 relief valve installed.
Rear end play 0.1 mm, front 0.2 mm. All clutch pack plays within spec. All sprags in correct direction.
All clutches and servos air tested. Some leak in 4th clutch, possibly due to strator seal ring gaps. Some leak in the direct, possibly due to hole drilled to prevent centrifugal apply”
At this point I had a great reverse but slipping in all forward shift positions. Transmission was indicating that it started in first gear but never engaged in first gear. Only started in second gear..
I had good line pressure according to below table. I had a stable pressure during slipping shifts, no pressure drop at all.
DISASSEMBLY 1.
After this I dropped the pan and VB to make some modifications and further tests.
This is how it looked,
I air tested everything again to confirm any leaks in the clutches. Same results as above.
I replaced the HD2 separator plate with a drilled stock one, same hole sizes as above.
I plugged the HD2 pressure relief valve.
I inspected that all valves moved in the VB and that solenoids and electronics worked.
I reinstalled with all 8 checkballs in place.
Replaced oil, filter and verified oil level.
After this modification I got a firm 2nd gear in 2nd shifter position.
Still slipping in 3rd and 4th shifter positions, still no 1st gear.
At this point I could safely manually get it up to speed and it had a noticeable shift from manual 2nd to manual 3rd, 3rd to 4th and lock up.
Stable high pressures between all gears. Above my max pressure reading of 200Psi.
DISASSEMBLY 2
Removed the complete transmission and did a full disassembly. This time the oil was clean.
I can’t find anything that causes this.
Forward and direct clutch packs are about 0.012’ looser then when installed, all sprags correct..
I do not have proper vacuum testing tools for the VB. Very small leak in the AFL, last compartment, with the elongated end section of the valve. That does not seem to bad but hard to know when I can’t measure. That part of the valve looks nice but the middle part looks questionable,
Since there are no 4L80e VBs in Sweden to what I can find yet, I tried air testing the VB together with the case to see which clutches and servos get air at what point.
This testing method is questionable and made up by myself as I lack further ideas.
I assembled only the VB and servos to the case. I put compressed air supply to channel 2 in the case and blocked of all other passages leading to the pump.
If I understand it correct passage 2 should be line pressure supply. With this I tried running thru all shifting options on the gear selector together with energizing the two shift solenoids.
I used following to guide me on what combination to set for what desired state.
P/N, no clutches engaged. No difference if solenoid A is energized of not.
Reverse worked with both reverse band pin moving and direct clutch air flowing into the case. Solenoid A did not do any difference.
D, when both solenoids off, air flows thru forward and intermediate case channels.
When energizing solenoid B air flows into direct case passage as well.
When energizing solenoid A, nothing happens.
When energizing both A &B, same case as for when solenoid B energized.
Solenoid A is just clicking but nothing happens.
Same goes for manual 3rd. Solenoid A does not make a difference.
In manual low, front band and intermediate stay applied and rear band unapplied even if solenoid A is energized. That is the state for 2nd gear in 2nd shifter position.
Isn’t solenoid A supposed to adjust that for the transmission to shift to 1st gear?
Is this a valid test method and is it enough to feed air to passage 2 in case?
1-2 valve looks ok.. but it does not seem to make a difference to anything….
Hope this makes my challenge easier to follow.
Appreciate suggested next steps!
Thanks!