FAST99Z

Wow, 6000 miles since my heads cam install and mostly easy driving. I don't race the car. Transmission has been clunking on the 1-2 and 2-3 shift. Had it in for service and fluid change three months ago and was told "everything is fine"

Since then, the clunking has stayed about the same and now I am getting the ATAP code for a slipping transmission. I also noticed it slipping when I punched it and it hit the rev limiter before shifting.

Does this mean a tranny rebuild?

FAST99Z

I talked with a good mechanic at the dealership I work for and he said this might not take a full rebuild. It seems this could could just mean the torque converter is slipping by about 200 or more rpm and the tranny might just need a new valve body.

Does this sound right to anyone. We are going to pull the transmission next Tuesday

Smitty

The P1870( Transmission Component Slipping) code your car is tripping is usually due to the converter clutch shuttle/signal vavle sticking in the vavle body.The vavle wears the bore in the casting and gets prone to stick when the transmission warms up.Most of the time this starts to happen in the 60-70,000 mile range,sometimes sooner depending on driving conditions.If driving condition are where the converter clutch is locking and unlocking alot(areas with alot of hills) the code might popup
sooner.
The vavle sticking is only one of many possible causes for a P1870 code to set.This code has kick more than just one good transmission mans ***.
The vavle in yours could be the possible cause.There is a way to fix the vavle problem WITHOUT replacing the vavle body assembly.BUT...usually waiting to long after the syptoms show up,the torque converter will need to be replaced too,and you've already said it's been doing it for a few months.When the code sets the PCM increases line pressure to "protect" the transmission and one of the side effects is rough shifts.It does this on each ignition cycle,so it might not do it when you first start driving for ,but starts before you get to where your headed.
Another thing is you said,the transmission IS slipping?If it has started slipping while in gear,the clutches are wearing due to excessive heat being generated.The best thing due do is going ahead and plan for a rebuild with a torque converter.

FAST99Z

Thanks for the replies:

1. My SY3500 only has 6000 miles on it, how could it have gone bad? Maybe, I can just send it back to Yank for inspection while the tranny is being rebuilt.

2. I did notice my torque converter would cycle between lock and unlock under moderate throttle pressure if I climb a hill at the lockup speed of 35 mph. That had happened for a few months and seemed to be a programming issue.

3. Yes, the transmission did slip when I punched it at 60 mph and the rpms bounced off the rev limiter.

4. Please educate me more on these problems

Thank You

FAST99Z

ttt, more replies

Larry

iTrader: (4)

I switched to Ford F type fluid and eliminated my slipping problem. Don't know how this will affect the tranny long term but it has to last longer than were it still slipping.

1BADTA382

I had the same problem in my car for a couple of years, it would always be hitting the rev-limiter, i rebuilt my transmission about 4 times with performance upgrades and would still hit the rev-limiter,i added a deep pan, i retunned my shifting points several times, and it would still hit the rev. Two weeks ago my tranny went out again along with my 3600vig torque converter, so i rebuilt my tranny again and put my stock converter again, it hasnt hit the revlimiter since.
So my point is, i really think you should check that converter out, my 3600vig was cuasing me to hit the revlimiter for almost 2 1/2 years, I was never able to find the problem untill the converter gave out. I guess precision didnt leave it right after i had restalled it from a 2800 to a 3600.

FAST99Z

I am going to have the yank converter pulled and sent back to have it checked out ($150 to look it over)

Most likely getting a full transmission rebuild and a new rear end

FAST99Z

ttt, the car is at FLP and I will know more in a couple days. Chuck used to work at my chevy dealership and he is looking over the transmission for me. Probably a rebuild and an Eaton rear end.