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Stick and slip

2K views 29 replies 3 participants last post by  ozfest 
#1 ·
Looking for a little guidance. I have a 94 Trooper with an auto trans. with appx 160K miles. I've read on here that these do not have a dipstick or fill. Mine happens to have a trans dip stick . Am I missing something?

Have been noticing the trans slightly slipping and from time to time will go into limp mode. When I do drive it lately I've been babying it taking off slow etc. And it doesn't do it. Also when in reverse it will make a whining noise. Was going to do a filter/fluid change hoping that that might resolve the issue. I've read on here of the range sensor etc.

Any thoughts or experience would be appreciated.
 
#2 ·
The 4L30e was used from 1990 to 2003, from 1990 to 1995 there was a dip stick. It was removed supposedly to prevent overfilling. The "range sensor" is correctly identified as the transmission Range Mode Switch (RMS).

The RMS is actually six switches in a single package, one is the P/N safety switch, one switch operates the Backup lamps and the remaining four switches generate a binary code that tells the Transmission Control Module (TCM) what position the transmission Manual Valve is in. The Manual Valve has seven positions. P,N,R,D,3,2,L.

Slipping is caused by low hydraulic pressure or worn clutch frictions. Low ATF or dirty filter can cause low hydraulic pressure. Limp mode is initiated by the TCM when an electrical problem is detected involving the transmission solenoids.

Fresh AFT and filter may solve the problem, also try some Lucas Transmission Fix mixed with the AFT when you refill. Btw, some early transmissions don't have a drain plug.
 
#5 ·
ozfest said:
Also since I do have the dip stick can I just do my fluid fill thru there? Or do I need to pump it in from underneath?
Fill from the dipstick hole, get the ATF level close to full mark and start the engine, let it idle for a while to get the fluid warm. Top it up to the mark with the engine still running and don't overfill it. Use a Dexron III substitute like Castrol Transmax Import Multi-Vehicle
 
#7 ·
So I didn't have time for the Trans filter change and wanted to take it for a short drive and see how she would do since I just had the Timing Belt/ Tensioner/Waterpump done :| so I cjecked the fluid and it was a bit low so warmed her up topped it off and went about 15 miles and again the Check Trans light / limp mode I pulled over and spent about an hour in a store came out got back in when I pulled out of the parking spot I felt that the reverse was odd kind of like a stall or like a worn U Joint. Went on home when I got back to park ( I live on a hill) no reverse just revs.

Pretty bummed since I spent some money on the Timing belt repair.

Please tell me I'm not completely screwed :(
 
#12 ·
The button should stay in the On (depressed) state. When D is selected and Winter Mode is engaged it configures the transmission for a 3rd gear start. Since it takes a lot more torque to get moving in 3rd gear than Reverse, no slip in Winter Mode would point to Reverse related problem. Since Reverse requires more torque than 1st gear there is a Reverse boost feature that boosts hydraulic pressure when Reverse is selected by the Range Mode Switch (RMS).
 
#14 ·
Went out cleaned the switch up now neither stays depressed. Was able to reverse up my street as it did before struggling up the street which is about a 20 degree incline. Was thinking of hitting the salvage yard and looking for a switch that works.
 
#15 ·
So I'm attempting to do the trans filter now and pulled several skid plates off and bolts on the cross member. I am having a problem pulling the cross member off. There seems to be a nut that can be reached trough a hole in the member 17mm which seems to be some rubber mount. I can not loosen it to save my life. it seems to flex. Any tips?
 
#16 ·
ozfest said:
So I'm attempting to do the trans filter now and pulled several skid plates off and bolts on the cross member. I am having a problem pulling the cross member off. There seems to be a nut that can be reached trough a hole in the member 17mm which seems to be some rubber mount. I can not loosen it to save my life. it seems to flex. Any tips?
I had the same problem on my 97. The nut was on tight and the bolt which is a part of the trans mount was spinning. I was able to move the cross member so that I could reach the bolts that hold the trans mount to the transmission using an open end wrench. It was slow, but got it off with the cross member still attached. I then cut the old mount off the cross member and installed a new mount. Such a pain. Put some anti seize on those nuts before you reinstall the cross member.
 
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#18 ·
Well got the filter change new fluid and 12oz of the lucas. Took it for a spin and seemed ok for a bit then total slip in drive and 3rd sloweddown dropped to second and hobbled back. So a bit bummed. Also went to take the key out of the ignition.......... no go
 
#19 ·
I have a 97 that started to show signs of slipping in 3rd. I changed the filter prior and 3 fluid changes due to a pesky pan leak. Put 2 bottles Lucas Trans fix and use Performance button with slight improvement. It wasn't a bad slip but it was slipping. I unplugged my TPS and shirting was super firm, like slam shifting, no slip. Ran it for a day then plugged it back in and no more slipping in 3rd, weird. I just bought a second Trooper and made an appointment with a trans shop, go figure? How it fixed itself I have no clue.
 
#20 ·
Ha funny. TPS? I have to say I'm bit disheartened since I just had the water pump/ timing belt etc. done. Thought about selling it but probably wouldn't get much for it. I really love the Trooper it's pretty clean as well as the engine at 166K miles. Wondering how much this repair is going to run. :cry:

Any how thanks to all for the replies they are appreciated.

Ozzy
 
#21 ·
What was the condition of the fluid? My trans started acting up after fixing timing belt, water pump, brakes, starter, power steering, valve cover gaskets, shocks, tie rod, lift, tires, hubs, sensors, tow hitch, etc. I was waiting for a manual trans to show up but luckily mine fixed itself.
 
#23 ·
The throttle position sensor on the throttle body. When this is faulty it can mess up shifting. My shifting was all funky, may have been the TPS but not sure how running in unplugged then plugged fixed the problem. Is your trans slipping in Winter mode from a stop? Does the slipping improve with the Performance button pressed?
 
#24 ·
So after the fluid / filter change still same slipping. Pretty much no change. Made several calls around with rebuilding being anywhere from $1300.00-$1800.00

I did have a guy that was recommended by a tire shop I do business with and was the first to offer to diagnose at no charge and said it may not need a complete rebuild. I think I may take him up on it. It's tough since I bought the Trooper for $1200.00.
 
#25 ·
If someone is willing to diagnose it at no charge, you got nothing to lose. Our local shop charges $145 to diagnose which can be applied to the bill if you choose for them to fix it. You never answered Buster's question of whether the trans slips from a stop when in "Winter" mode. When you press the Winter button, you'll see "Winter" light up on your dash which means the trans is in 3rd gear. If it does slip, chances are fluid pressure is low or 3rd clutch is gone.
 
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