4L80E shift problems
12-14-2003, 08:07 PM
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4L80E shift problems All, I posted this in the conversion forum, but thought I might get some good response in here as well!
Well, the engine ('00 6.0/4L80E into a '87 land cruiser BTW) cranked right up with the new and rehabed injectors. I checked the transmission fluid before running it and it was off the scale on (high) the dipstick, probably because the engine has to be running and in neutral. Well after starting,it ran for about 10 min, then I checked the transmission fluid in nuetral and it was understandibly low after filling the cooler and lines. 3 qts later, it was in range. After that I took it out for a spin (in D and OD) and shifting is problematic. It struggles to shift from one to two and refues to stay in two once there. It seems to stay in 2 if shift it there manually.
So my questions are could it be one of the following?
1. Running 10 min in park with the fluid low. Could this have done damage?
2. Transmission sat for 2.5+ years like the engine so could its fluid passages also be gummed up like my injectors were
3. VSS - I had to install the VSS with an adapter into the toyota transfer case. Could it be that the sensor is too far away from, or not aligned properly with the reluctor ring used in the adapter. What is the correct gap between the sensor and the tip of the ring? Does it have to be perfectly aligned?
4. Brake signal to Torque converter lockup solenoid. Per the recomendation of the shop that did my harness, I wired up the brake signal for this solenoid to be 12V+ with the brake applied and 0v with the brake off (same as brake light). But now in looking at the factory manual seems that chevy has the opposite --> a 12V+ to this signal with the brake off and 0V with the brake applied. I thought this would only affect it in 3rd or 4th gear.
I have considered getting Autotap to debug, but budgets are tight this time of year, so I would like to postpone this if possible. Does anyone know of a place in houston (SW) that I can have the codes scanned cheap?
Thanks in advance... This board is great! After the wonderful advice last time, I have high hopes.
Colin
Well, the engine ('00 6.0/4L80E into a '87 land cruiser BTW) cranked right up with the new and rehabed injectors. I checked the transmission fluid before running it and it was off the scale on (high) the dipstick, probably because the engine has to be running and in neutral. Well after starting,it ran for about 10 min, then I checked the transmission fluid in nuetral and it was understandibly low after filling the cooler and lines. 3 qts later, it was in range. After that I took it out for a spin (in D and OD) and shifting is problematic. It struggles to shift from one to two and refues to stay in two once there. It seems to stay in 2 if shift it there manually.
So my questions are could it be one of the following?
1. Running 10 min in park with the fluid low. Could this have done damage?
2. Transmission sat for 2.5+ years like the engine so could its fluid passages also be gummed up like my injectors were
3. VSS - I had to install the VSS with an adapter into the toyota transfer case. Could it be that the sensor is too far away from, or not aligned properly with the reluctor ring used in the adapter. What is the correct gap between the sensor and the tip of the ring? Does it have to be perfectly aligned?
4. Brake signal to Torque converter lockup solenoid. Per the recomendation of the shop that did my harness, I wired up the brake signal for this solenoid to be 12V+ with the brake applied and 0v with the brake off (same as brake light). But now in looking at the factory manual seems that chevy has the opposite --> a 12V+ to this signal with the brake off and 0V with the brake applied. I thought this would only affect it in 3rd or 4th gear.
I have considered getting Autotap to debug, but budgets are tight this time of year, so I would like to postpone this if possible. Does anyone know of a place in houston (SW) that I can have the codes scanned cheap?
Thanks in advance... This board is great! After the wonderful advice last time, I have high hopes.
Colin
12-14-2003, 11:43 PM
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Hrmm .. I'm no tranny expert by any means. I do remember some guys in the truck forums swapping in the 80e though. Parish8 is one of them. He commented about real sluggish 1-2 shift, kinda like it was hesitant to drop into 2nd real good. You might try dropping a copy of this in there too, since it is a truck tranny more so than a car tranny.
A good cleaning couldn't hurt it at all. I would think though, the 200+psi would help unclog some of the gunk. There are some screens on the seperator plate that might be a little stopped up though, but I don't know if that would do this.
A good cleaning couldn't hurt it at all. I would think though, the 200+psi would help unclog some of the gunk. There are some screens on the seperator plate that might be a little stopped up though, but I don't know if that would do this.
12-15-2003, 09:02 AM
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Most likely is that sitting 2.5 yrs all the seals are dry and hard. They may or may not be cracked. That, along with gummed up fluid could cause all the shifting problems.
However, yes, the spacing of the vss adapter could be the problem as well.
BTW, if you don't have all of the computers from the original truck, the thing will never work right.
Best advise is, find a transmission shop with an "ATSG" 4L80E certified tech and have him try to dig you out of your mess. Costly? yes. Worth your life?
However, yes, the spacing of the vss adapter could be the problem as well.
BTW, if you don't have all of the computers from the original truck, the thing will never work right.
Best advise is, find a transmission shop with an "ATSG" 4L80E certified tech and have him try to dig you out of your mess. Costly? yes. Worth your life?
