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Discussion Starter · #1 ·
Hi HI all, I have an 01 Trooper that gave me various problems so about 2 months ago I pulled the 4L30E and rebuild it with a TRANStec full/master rebuild kit (what ever kit the cam with the clutches steels and seals/everything), and a Superior #K078 low band servo piston, a Transgo center support bushing and both Superior STL-4L30 and K4L30-E shift kits/pump kits.

I did leave out the big black spring that goes into the pump.
I used Castor Oil Import Multi-Vehicle ATF like many others have said.

Got it put back in the Trooper and it drove great, a little harsher but I don’t mind. Now, as hindsight is 20-20 I didn’t realize they gave me an extra steel and clutch for 2nd and 2 extra clutches and an extra steel, so I put them all in, and I live in the mountains in VA, so when up shifting and down shifting it would slam hard into 3rd, that was a mistake.

It drove it fine for 400 miles about a week, then I stopped to make a right turn at a light, and It wouldn’t move, got it to go into WINER mode (3rd) and had to drive 30 miles home. Now it wouldn’t move in L (1st) so I guessed the low band, dropped the pan and adjusted it, helped but really delayed engagement, like 5 seconds from N to D or L, so something was wrong for sure with the band.

3 pan bolts had also stripped the case when I torqued the pan to 9ft lbs, so it had to sit for 2 months while I put a oil fired heated in the family’s old house and some other stuff had to be done first.

I pulled it again last week and sure enough, the band was off of the 2 dowels that it rests on in the case. And also, the servo piston sealing ring that applying the band was broke in one place (photo included). I also pulled the extra steel and clutch out of 2nd and one extra clutch and the extra steel out of 3rd.

I left one extra clutch in 3rd next to the spray assy. according to and old article I found by a guy in New Zealand that I would help in the trooper, and since mine down shifts to 3rd often in hills, I left the extra one. I didn’t take everything apart, only took out the assemblies then separated second and third, just to get the band.

Replaced The band and servo piston ring, swapped another case that I had and it went all back together last night, filled with new fluid and tried it, when I pulled it down to L (1st) it was almost instant engagement and load on the engine, so I took that as a good sign.

I filled with new fluid and got it to 110 and checked to level, it waHere’s where my problem is and need help

Went for a drive in D and went into and thru 1st strong and fine, the into 2nd felt like it slipped a little going in and while in gear, then it tried to go into 3rd and just started to rev up like N, got stopped and put it into D and WINTER mode and slipped a lot, started to move, and kicked itself out of WINTER, but if I go to 3 it will start out in 1st and the go into 2nd just fine. Couldn’t get fast enough in 2nd to see if I had 4th.

I read on about this in another thread where someone else was having trouble and Buster28 told them to do this to see if they had 2nd gear manually. I did this to try to so if I had 3rd manually.

I unplugged the 7 (or 9) pin main case connector from trooper wiring harness, and when for a drive and in L I had 1st and then went to 2 and it tried to shift into 3rd but was still slipping very bad if it was engaged at all, didn’t pull, just reved up.

I have checked the fluid while warm (115) Does any one have any advise that might help? Thanks
 

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To produce the 3rd gear ratio (1:1), the 2nd and 3rd clutches are applied and the reaction drum brake band is released. The 3rd clutch drives the planetary gear set input sun gear which in turn drives the planetary gear set short pinions. The 2nd clutch ring gear drives the planetary gear set long pinion gears.

The 2nd clutch frictions mate with the 3rd clutch drum so the planetary gear set input sun gear and the 2nd clutch ring gear are rotating at the same speed. Since the long and short pinions are in constant mesh and rotating at the same speed the planetary gear set is locked and the planetary gear set carrier and tail shaft rotate at the same speed as the input sun gear (1:1).

If either the 2nd or 3rd clutch slips all the torque "leaks out" of the slipping clutch and the planetary gear set carrier and tail shaft cannot drive the rear wheels. Based on your reported symptoms it appears the 3rd clutch is slipping.

Be aware that 3rd clutch apply fluid is also the same fluid fed into the release side of the brake band servo so a fluid leak could cause the 3rd clutch to slip and the brake band to drag.
 

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Discussion Starter · #4 ·
Thanks for the input Buster, as you said that the 3rd gear apply fluid also moves the servo to release the band, is there a possibility that I did something wrong with the servo sealing ring?

In the shift kit(s) (I don’t remember which one) there was a second little piston that they said to put around the base of the spring, that sealed around the apply pin, and sealed to the case with 2 O-rings. And there was also a little cap that I put into the number 22 hydraulic circuit hole, for the servo that reduced the port hole size down to 1/8”, could either of those be the possible problem?If not, what else could I do from the pan/valve body side of things?

Could the “B” solenoid (2-3shift) be bad and causing my symptoms? I do appreciate the knowledge and advice you’ve given me several times,
 

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If the Shift B solenoid is inoperative, L (Manual 1st) will produce the 1st gear ratio but D 1st produces the 4th gear ratio. Getting the truck moving from a stationary position in 4th gear is difficult so you know something is wrong right away.
There are several ways to screw things up when modifying the transmission so there could be a problem with the servo release pressure.
 

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Discussion Starter · #6 ·
Ok, if I understand correctly, I do not need solenoids, put I need to pull the valve body and remove the orfice plug in #22 hydraulic port, and need to look at the servo sealing ring, and the shift kit piston with the O-rings that seals around the apply pin and pin bore? Is that correct?

Is there and chance that I would need to replace the superior servo piston and put the OEM cast aluminum back in? Do you have any idea what the superior servo piston does, or improves, because I can’t figure that out anywhere
 

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My guess is the steel used to make the piston does not wear as quickly as the OE piston so there is less likely for a fluid leak to develop in the pin bore.
Are you sure you have valve body check balls in the correct location?
 

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Discussion Starter · #8 ·
I’m am 98% sure per the ATSG manual, I could have it wrong though, it sounds like I’m going to be pulling the valve body anyway to look. If one or both of them are wrong could that be the problem? Or would it happen if the check ball locations in the case are very worn?
 

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If the check ball does not seal the orifice 100% it is probably not significant but leaving one out is a big deal. The problem with the design of this transmission is the servo apply pressure is not released when the servo release pressure is applied. The area on the release side of the piston is greater than the apply side so there is more force applied to the release side. But any leaks the release fluid circuit can cause the servo to move toward to apply position resulting in brake band drag which wears out the friction material prematurely.
 

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Discussion Starter · #10 ·
A couple of days ago I dropped the main pan and valve body, nothing looked wrong/out of place, the 2 check balls where in there correct places, and I also pulled the servo piston assy. out, and removed the the #22 port office plug from a shift kit, put it all back together and torqued it, and if felt so exactly the same.

Friday evening I pulled the transmission again, and today I opened it back up, after 3 hours of looking, I can see nothing out of the ordinary, and put it all back together and ready to put back in the car tomorrow.

Is there something I shout pull it back apart and check for? 2nd and 3rd clutches/steeles looked fine, all the lip seals on the pistons were fine, and air check both drums to make sure that the pistons were compressing the clutch packs and they did.
 

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A couple of days ago I dropped the main pan and valve body, nothing looked wrong/out of place, the 2 check balls where in there correct places, and I also pulled the servo piston assy. out, and removed the the #22 port office plug from a shift kit, put it all back together and torqued it, and if felt so exactly the same.
What happened when you drove the truck?
Did you replace the brake band?
 

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Discussion Starter · #12 ·
Yes I did, at the same time I replaced the servo piston sealing ring, 1st in D or L is as fine as it could be. Almost immediate engagement and loading the engine down. Also when I dropped the valve body, I replaced the filter, it didn’t look dirty at all, but I dont think it hurt it.

When I had finished the valve body job I tried it while on my jack stands, and it shifted thru all 4 gears up to 70 mph without a problem and when I thought it should with no load, I forgot to mention that, should that mean anything?
 
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