Need help on 4L60E. Jerks at 25mph.

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September 30th, 2009
ocmdiaz714

Need help on 4L60E. Jerks at 25mph.

I have a '94 Cadillac Fleetwood with the 5.7L LT1 V8 engine and 4L60E automatic transmission. The car has 150k miles and I just purchased the vehicle a couple of months back. I was told by the previous owner that the transmission had recently been rebuilt. I took the car to two smog checks where it failed twice. I suspect a bad EGR valve, cat. converter or O2 sensors might be the cause so I'm going to have those replaced soon. Well the day before the transmission problems started occurring I had been driving without a gas cap, which I lost at a gas station and since been replaced and I also degrease the engine. I let the engine cool down and later sprayed down the engine with the degrease and let it sit for 15 minutes. Then I sprayed it down with cool water, I saw some smoke coming out from what it seems to be engine or transmission but didn't think much of it as it later went away.

Well the next day I felt the engine jerk whenever I hit 25mph, after the 25mph mark the car ran smootly but whenever I decelerated and again hit 25mph the engine jerked. I also got the service engine soon and traction control lights on. I checked the transmission fluid and the level was fine so I read the codes which gave me a throttle position sensor error which I later had replaced. That didn't help as the car won't go over 25mph on @ (Automatic Overdrive) or D or 3 (Third Gear) anymore. The transmission fluid has also turned brown with a mix of black (which may mean the dipstick is just dirty?) I was told by the owner this might have been caused at the smog check as the mechanic might had forgotten to turn off the traction control causing the transmission to burn fluid.

The thing is that I can drive fine and smooth when driving on 2 (Second Gear.) What should I do? Thank you.
September 30th, 2009
joecar

Can you post a scanner log file...?

150K miles like the transmission might be worn out... the dipstick is not just dirty, that "dirt" is your clutch/band friction material.

Quote:

I was told by the owner this might have been caused at the smog check as the mechanic might had forgotten to turn off the traction control causing the transmission to burn fluid.

This is just plain false.

Limp mode defaults to 2nd gear.
September 30th, 2009
ocmdiaz714

Quote:

Originally Posted by joecar

Can you post a scanner log file...?

150K miles like the transmission might be worn out... the dipstick is not just dirty, that "dirt" is your clutch/band friction material.

This is just plain false.

Limp mode defaults to 2nd gear.

How can I get the scanner log file?
So would a drain just be a waste of money at this point?
Thanks.

I also got this advice from Yahoo Answers but it would be unfortunate if the drain would be a waste at this point.

Quote:

The tranny has gone into limp mode, probably because it lost electrical power or because the PCM detected a fault. In limp mode you will not have 1st and 4th gears and torque converter lockup will not work. Reverse will still work but in drive (D) it will only operate in 3rd gear. 2nd gear will work but only if you put the shifter in 2nd gear and it will also operate in 2nd gear if you put the shifter in 1st gear. Your tranny is powered on the same circuit as the O2 sensors and if an O2 sensor shorts out it will blow the tranny fuse. I suspect that washing the engine may have shorted an O2 sensor and blew the tranny fuse. I suggest you check your fuses. If you don't find the problem there then check the harness connectors at the tranny. Also if your tranny fluid is brown with a mix of black like you said, once you restore electrical power to the tranny I suggest you waste no time flushing that fluid and changing the tranny filter. But before you do the flush I strongly recommend you add a good quality transmission cleaner to the transmission and let it circulated thru the tranny for about 15 minutes before flushing. That will clean up the transmission and break down the sludge and varnish build up so that it will be removed during the flush. Many people make a great mistake by not adding a high quality cleaner to the tranny before flushing and then the sludge and varnish build up is dislodged soon after flushing and clogs the valve body. GUNK TransMedic Transmission Flush or something of equal quality will do a good transmission clean up and break down the sludge and varnish build up so that it will be removed during the flush. If you experience harsh upshifts after the flush then I suggest you add a bottle of GUNK TransMedic Automatic Transmission Treatment. That will coat and better lubricate the pump, gears, and valve body internals which will help to smooth shifts.

But before you do anything I suggest you check the tranny fuse or do whatever troubleshooting is necessary to restore elecrical power to the tranny and if you must drive it in the meantime I suggest you manually shift it into 2nd gear to get it moving and then shift to drive (D) so that it shifts into 3rd gear because starting out in drive (D) will be 3rd gear while in limp mode and the increased torque converter slippage by starting out in 3rd gear will generate a lot more heat than normal and the excessive heat generated can do serious internal damage.

*Michael, I would recommend a full tranny flush rather than just a pan drain. But even just a pan drain will be beneficial. But if you do just a pan drain then I suggest you don't use a tranny cleaner before the drain because the cleaner must be completely removed from the tranny. And as for the GUNK TransMedic Transmission Flush, I have only found the synthetic at the Advance Auto Parts store I use but if it is available in non-synthetic then either will probably be fine. But I would still choose the synthetic because I'm sure that would lube better while it cleans. But I do know that the GUNK TransMedic Automatic Transmission Treatment is available in both synthetic and non-synthetic. I have seen both of those at the parts store. The non-synthetic GUNK TransMedic Automatic Transmission Treatment will be fine if you do a DEXRON-III fill, which was the GM factory fill ATF on your 1994 tranny. But if you do a fill with the new DEXRON-VI synthetic ATF then you might consider the synthetic GUNK TransMedic Automatic Transmission Treatment after the flush and fill. The synthetic DEXRON-VI ATF replaced all previous DEXRON fluids in 2006 and GM says the synthetic DEXRON-VI is compatible with all previous non-synthetic DEXRON fluids. It does not hurt to mix them. But if it was me, I would opt for the DEXRON-III fill. It's much cheaper than DEXRON-VI and it was the original factory fill on your tranny. But if you experience harsh upshifts after the flush and fill I do think it would be best to use the synthetic GUNK TransMedic Automatic Transmission Treatment even if you do a DEXRON-III fill. It will blend perfectly with non-synthetic DEXRON-III and I'm sure it will help to improve lubrication. Keep in mind though that the DEXRON-III license was not renewed after 2006 and it is getting hard to find labeled as DEXRON-III so if you have trouble finding it then look for the DEX/MERC ATF label. Since the license expired that is how DEXRON-III is labeled now (DEX/MERC).
October 1st, 2009
joecar

What scantool do you have...?

Get a wiring diagram for your year/model, and check fuses; engine degreasing is generally a bad idea.

If the trans is acting up, a fluid change/flush will not repair it.

The trans cleaner may cause sludge to be "relocated" to the valve bores and solenoid orifices... also, it has been found that sludge may be "supporting" aged/baked seals so they don't leak; once the sludge is removed there is no support for the seals so they break/leak.

Quote:

I was told by the previous owner that the transmission had recently been rebuilt.

Look at the trans case, is it dirty/greasy...? If so then the trans wasn't rebuilt; otherwise maybe it had been... if it had and the fluid is brown/black, then there is a slipping problem.
October 1st, 2009
joecar

The jerk at 25mph is probably due to the PCM detecting an electrical problem and so increasing the line pressure causing the car to jerk during the 2-3 shift... the PCM would be setting a DTC for any problem it sees... with your scantool you should see which DTC's are present.

Check for wet connectors (all engine sensors, and trans subharness connector)...

If the PCS solenoid gets no current (shorted by wet connector) then line pressure is at max (jerk during shift).

Maybe your trans is ok, but the fluid should look dark red (pretty much like new fluid), and discoloration is an indication of slipping and/or overheating (they are related).
October 29th, 2009
ocmdiaz714

Quote:

Originally Posted by joecar

The jerk at 25mph is probably due to the PCM detecting an electrical problem and so increasing the line pressure causing the car to jerk during the 2-3 shift... the PCM would be setting a DTC for any problem it sees... with your scantool you should see which DTC's are present.

Check for wet connectors (all engine sensors, and trans subharness connector)...

If the PCS solenoid gets no current (shorted by wet connector) then line pressure is at max (jerk during shift).

Maybe your trans is ok, but the fluid should look dark red (pretty much like new fluid), and discoloration is an indication of slipping and/or overheating (they are related).

The fluid is more like a light brown/red, but not the bright red I see in my truck's transmission. I don't have a scan tool and the reason I came here is because "N0DIH" sent me to speak to you. I'm taking the car in for an inspection and scan next week at Randy's Automotive and Transmission, in Orange, CA. Also, as an alternative to replacing or rebuilding the transmission I was looking at buying a rebuild kit from AutoZone and taking it to a shop. The kit itself costs $70.99 and the cost on having it rebuilt with the kit would be $500 at Atlas Transmission Plus in Los Angeles, CA. I might have made a mistake of putting in "Lucas Transmission Fix" fluid into the transmission this past weekend. I haven't noticed a difference yet I'm afraid I shouldn't have done that.

I noticed you're in Southern California, I'm from Garden Grove, CA. Also, I've never worked on the transmission and don't exactly know half of what I'm being told by other forums or shops; also, just to let you know, the OBDI isn't showing any trouble codes. Thanks for the help! Here's the kit from AutoZone:

http://i37.tinypic.com/117usl3.png
October 30th, 2009
joecar

If you degreased the engine you may have gotten the PCM connector wet (where is your PCM located...?) or the trans connector wet... did you disconnect/inspect/clean these (use MAF cleaner, let air dry)...? Do that first.

Are you sure the fluid level correct...?

Is the fluid brown as in "clear brown" or "opaque brown" (water mixed in)...?

Does it look dirty...? Does it have flecks of material in it...?

If pull the pan you can get a better idea (mininal sludge = ok; much sludge = worn out; clutch material or metal = damaged).

If you don't work on it, take it to several shops, get quotes, compare prices..., let them buy the parts as they know which parts are better (I don't trust the quality of the parts in that kit)... keep in mind that the 4L60E is fairly common, so it should be easy for them to diagnose and fix for a reasonable cost...

see if the shop test drives and looks at the fluid before giving you a quote...

150K miles means the trans is most likely worn out...

I'm in GG... I'm a DIY, I work on my own cars (currently: 2001 TA, 2002 GA, 1976 Datsun).
October 31st, 2009
ocmdiaz714

Quote:

Originally Posted by joecar

If you degreased the engine you may have gotten the PCM connector wet (where is your PCM located...?) or the trans connector wet... did you disconnect/inspect/clean these (use MAF cleaner, let air dry)...? Do that first.

Are you sure the fluid level correct...?

Is the fluid brown as in "clear brown" or "opaque brown" (water mixed in)...?

Does it look dirty...? Does it have flecks of material in it...?

If pull the pan you can get a better idea (mininal sludge = ok; much sludge = worn out; clutch material or metal = damaged).

If you don't work on it, take it to several shops, get quotes, compare prices..., let them buy the parts as they know which parts are better (I don't trust the quality of the parts in that kit)... keep in mind that the 4L60E is fairly common, so it should be easy for them to diagnose and fix for a reasonable cost...

see if the shop test drives and looks at the fluid before giving you a quote...

150K miles means the trans is most likely worn out...

I'm in GG... I'm a DIY, I work on my own cars (currently: 2001 TA, 2002 GA, 1976 Datsun).

Before replacing the throttle position sensor, the on-board diagnostics where showing an error code notifying me that the TCC was stuck "on." The code went away when I replaced the sensor so I thought nothing of it afterward. The TCC might still be stuck or it was stuck as I kept driving, burning up the transmission fluid? I don't have the tools required to check it out myself and I'll be taking it a shop for a free diagnostics and test drive next week.
November 1st, 2009
joecar

The code for TCC stuck on is probably a wiring problem (a short)...

If the TCC was stuck on it would stall the engine at idle...

If the PCM threw a TCC code (it does not necessarily turn on the MIL on the dash) then the presence of that code would prevent the PCM from commanding the TCC to lock...

If the PCM is not able to lock the TCC, the torque converter continues to slip as you drive and this generates a great deal of heat... this heat is spread to the soft parts via fluid circulation... this heat kills the clutches/band and rubber parts, which results in clutch/band slippage... the fluid will look discolored and smell burnt.

Let us know what the shop says... a good shop will keep the old parts to show you so you can see what happened.
November 2nd, 2009
ocmdiaz714

Quote:

Originally Posted by joecar

The code for TCC stuck on is probably a wiring problem (a short)...

If the TCC was stuck on it would stall the engine at idle...

If the PCM threw a TCC code (it does not necessarily turn on the MIL on the dash) then the presence of that code would prevent the PCM from commanding the TCC to lock...

If the PCM is not able to lock the TCC, the torque converter continues to slip as you drive and this generates a great deal of heat... this heat is spread to the soft parts via fluid circulation... this heat kills the clutches/band and rubber parts, which results in clutch/band slippage... the fluid will look discolored and smell burnt.

Let us know what the shop says... a good shop will keep the old parts to show you so you can see what happened.

Thanks a lot, I'll let you guys know.