Transmission repair 4L60E

jackass

I just purchased this van. I was told the transmission is shot. It runs perfect and drives fine for short distances, a quarter mile, but then loses momentum and transmission fails to go forward anymore. If I shut the van off for an hour and go back it will start and drive again. The transmission fluid is full but smells like horseshit. It is likely burnt. Otherwise this looks to be a well kept van, not abused at all.

I am well aware of the problems these transmissions have. Has anyone had this particular issue as my symptoms are somewhat unique. I would love to try to recover this transmission in hopes to avoid an immediate rebuild.

My question is, would it behoov me to change the filter and transmission fluid a couple times and "perhaps" put in an additive like "lubeguard" or "lucas" to see if that helps.

Any suggestions are appreciated.

jackass

I will mention that that the transmission does shift into 2nd gear just fine without any harshness but I did not drive it far enough to see if it would shift into 3rd.

jackass

I should mention that there are no check engine lights lit on the dashboard.

One thing I read was to first check the fuses and the BTSI solenoid (although I believe the BTSI is only for locking the steering column shifter) ... I have not done that yet as I JUST purchased this van. Could it be "that" simple?

jackass

My van is 2001 GMC 1500 Savana ... passenger van with 220,000 miles ...

jackass

FYI ... Reverse works fine also

jackass

I want to mention that my symptoms are different than the usual 3 that affect most of these transmissions. My symptom is that it will drive fine in all gears, include overdrive, for about 3 miles until it just loses power. The engine continues to run normally, but the engine races as if it is in neutral. I have shut the engine off and restarted it and sometimes it will move slightly, but for the most part it needs to be shut off for several minutes up to an hour before it will drive again...at which point it will go forward or reverse briefly until losing power. I did check my exhaust and it appears to be flowing normally when this occurs. I do not believe this issue is related to a clogged catalytic converter.

imidazol97

You could try a filter and fluid but how does the current fluid look? Is it red, clear, or brown/black? Those are the stages of transmission fluid life from overheating. The smell is usually not relevant: the fluids often smell sharp.

I would assume the previous own tried changing the fluid and filter... before deciding to dump the van. He likely conferred with a transmission repair shop who decided that whatever pressure control is not working right the transmission needs replacement or a full overhaul.

It sounds like you're trying to diagnose the transmission without contacting an expert. A quality repairman knows what likely has gone bad. Opening up the box for repairs would likely have something else failing after repair of only part, so overhaul is the best solution, IMHO.

thecardoc3

The most common thing we find when you are suffering a complete loss of engagement is a pump failure.

These two pics that I took are a good representation. BTW to fix "this" requires a complete overhaul, new pump and convertor.

Mr_Shiftright

I would agree. There is a severe pressure loss in the trans. There's nothing in a can gonna fix that. You could get yours rebuilt or spring for a bit more and get a remanufactured unit with a longer warranty. Used units are risky unless you buy one from a vehicle that you could actually drive and test beforehand.

jackass

I think I fixed it. I tried dropping the transmission fluid pan and the exhaust pipe is in the way. There was no way I am attempting getting the exhaust bolts off the manifold, so I drove the van a mile to my mechanic who changed the fluid. What was in there was likely the original fluid and filter (220k miles). It was covered in thick mud and pudding like substance. This was obviously the problem. The pump would only work for so long until the muck clogged it. The van is driving fine now, but time will tell if there was any long-term damage. It does not seem to pull from an dead stop very hard after driving it for a long run. I am afraid to give it much throttle in this condition ... hoping that driving it conservatively will allow it to self-clean and begin working 100%. For now, it runs fine. Thank you all for your help. If things change I'll come back on here, but if it does I'll probably be rebuilding it or buying a new one.