2002 4r70w issues
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Junior Member
Joined: Oct 2022
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2002 4r70w issues
Hey all, having some tranny issues on my 2002 f150 4x4 xlt, 4.6L.
I acquired the truck for pretty much nothing knowing it had tranny problems, thinking it could be fun to try and fix myself without the pressure of needing it. The previous owner was an elderly man that had been driving the truck for the last 5 years with this issue he told me. The issue is it has a delayed forward engagement, and slipping into overdrive. If you turn overdrive off, there is no slipping. If you rev the engine, the forward engagement kicks in, if it's cold, you need to rev the engine at higher rpm for it to engage. So once you're in drive and turn the overdrive off, it shifts fine and drives great. When i actually acquired the truck, i drove it like this on a 13 hour road trip home without any issues. It slipped a couple times when i forgot to turn the overdrive off. When the fluid is hot, it engages faster with little revving but still delayed.
Fast forward a year, the truck has been pretty much sitting with very little driving. I decide to tackle the repair after extensive hours on youtube. What I ended up doing was dropping the valve body expecting to find a broken snap ring on the OD servo, but it wasn't. Everything actually looked ok to me. But not really knowing, first time into an automatic tranny. I ended up replacing all 3 solenoids, the 1-2 accumalator with a sonnax bullet aluminum one using the OEM springs, I also put in a bullet aluminum OD servo, and a new piston in the 2-3 accumalator, new wiring harness bracket as well.
So after 100s of dollars , a bunch of new parts, it still does the exact same things as before. So now I am at a crossroads, should i continue to keep buying parts ? Is it possible that it could be the neutral safety switch(Transmission position sensor ) ? I'm kinda thinking no as it does not have any issues starting.
The only parts I didn't change in the valve body were the valves, they all seemed to be functioning fine, springing back. I did not do the Jmod, but thinking maybe i should have. To me it seems like there is not enough fluid pressure to engage it into drive, once it is in drive it seems fine. The slipping into OD I am not sure if its related or a separate problem, Any tips appreciated, I was avoiding taking it right out to open it up as its my first, but at this point, its either that or just get rid of it. I don't want to put too much more money into it as its just not worth it. Unless i know it will be fixed.
I acquired the truck for pretty much nothing knowing it had tranny problems, thinking it could be fun to try and fix myself without the pressure of needing it. The previous owner was an elderly man that had been driving the truck for the last 5 years with this issue he told me. The issue is it has a delayed forward engagement, and slipping into overdrive. If you turn overdrive off, there is no slipping. If you rev the engine, the forward engagement kicks in, if it's cold, you need to rev the engine at higher rpm for it to engage. So once you're in drive and turn the overdrive off, it shifts fine and drives great. When i actually acquired the truck, i drove it like this on a 13 hour road trip home without any issues. It slipped a couple times when i forgot to turn the overdrive off. When the fluid is hot, it engages faster with little revving but still delayed.
Fast forward a year, the truck has been pretty much sitting with very little driving. I decide to tackle the repair after extensive hours on youtube. What I ended up doing was dropping the valve body expecting to find a broken snap ring on the OD servo, but it wasn't. Everything actually looked ok to me. But not really knowing, first time into an automatic tranny. I ended up replacing all 3 solenoids, the 1-2 accumalator with a sonnax bullet aluminum one using the OEM springs, I also put in a bullet aluminum OD servo, and a new piston in the 2-3 accumalator, new wiring harness bracket as well.
So after 100s of dollars , a bunch of new parts, it still does the exact same things as before. So now I am at a crossroads, should i continue to keep buying parts ? Is it possible that it could be the neutral safety switch(Transmission position sensor ) ? I'm kinda thinking no as it does not have any issues starting.
The only parts I didn't change in the valve body were the valves, they all seemed to be functioning fine, springing back. I did not do the Jmod, but thinking maybe i should have. To me it seems like there is not enough fluid pressure to engage it into drive, once it is in drive it seems fine. The slipping into OD I am not sure if its related or a separate problem, Any tips appreciated, I was avoiding taking it right out to open it up as its my first, but at this point, its either that or just get rid of it. I don't want to put too much more money into it as its just not worth it. Unless i know it will be fixed.
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Junior Member
Joined: Oct 2022
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After thoroughly watching even more Youtube, I have come to the conclusion that the forward clutches are likely burned out and i will need to pull the tranny out and do a rebuild. Its a new adventure, the vehicle isn't really needed or being used at the moment, so no hurry. Winter and cold temps have arrived where i live, so this will be a spring project.
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Joined: Dec 2006
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From: Joplin MO
