No reverse on 4l80e after dual feed
09-18-2018, 10:39 AM
#1
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No reverse on 4l80e after dual feed Alright, I redid my 4l80e again. I decided to dual feed the direct because this is a towing/hauling truck so I want to play it safe. Well, I get everything reinstalled and now I have no reverse. I put in a reman VB from global transmission parts, as well as a new reverse band. The truck will eagerly creep forward in drive and 1st, so I know the band it applying or else I wouldn't have 1st, and therefore this creeping action.
I used this video to the letter. I did not remove any checkball s because the video didn't mention anything about that. Not sure if I have 3rd or 4th because I haven't been able to back out of the shop.
Any thoughts?
I used this video to the letter. I did not remove any checkball s because the video didn't mention anything about that. Not sure if I have 3rd or 4th because I haven't been able to back out of the shop.
Any thoughts?
09-18-2018, 11:07 AM
#2
TECH Junkie
Alright, I redid my 4l80e again. I decided to dual feed the direct because this is a towing/hauling truck so I want to play it safe. Well, I get everything reinstalled and now I have no reverse. I put in a reman VB from global transmission parts, as well as a new reverse band. The truck will eagerly creep forward in drive and 1st, so I know the band it applying or else I wouldn't have 1st, and therefore this creeping action.
I used this video to the letter. I did not remove any checkball s because the video didn't mention anything about that. Not sure if I have 3rd or 4th because I haven't been able to back out of the shop.
https://www.youtube.com/watch?v=WuVj4xzDzz0
Any thoughts?
I used this video to the letter. I did not remove any checkball s because the video didn't mention anything about that. Not sure if I have 3rd or 4th because I haven't been able to back out of the shop.
https://www.youtube.com/watch?v=WuVj4xzDzz0
Any thoughts?
You don't need the band for 1st gear. Only the forward clutches and the low roller. The band only applies in manual 1st so that you can have engine braking. It doesn't allow the roller to overrun.
Do you have 3rd gear? If you have a strong 3rd gear, then the problem is more than likely with the band.
09-18-2018, 01:33 PM
#4
TECH Junkie
You could leave the band out and it would creep in manual first. You don't need the band to move forward in 1st gear
09-18-2018, 05:03 PM
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Alright, I have good and bad news.
the good news is that reverse works-mostly. It takes a little bit of throttle to get it to engage-most likely because of the extra volume of the direct piston from the dual feed? Thoughts?
thr bad news- I haven’t hit the road yet. First, the abs light is on and I have no speedometer. It has a u1041 code and a p052 code. The p code is for speed sensor A
Low circuit input or something. The U code is something about the EBCM loss of contact (the abs module won’t show up on my scan tool either btw). Very strange. It has 2 new speed sensors, by the way, and it is a 4wd truck.
also, in the driveway earlier, it did upshift out of first, but the wheels locked/skidded. Of course I let off the gas immediately. It was in 2nd, and coasting. I manually shifted to 1st, just to test, and it had engine braking. This is when I discovered my reverse works.
thoughts? Thanks!
the good news is that reverse works-mostly. It takes a little bit of throttle to get it to engage-most likely because of the extra volume of the direct piston from the dual feed? Thoughts?
thr bad news- I haven’t hit the road yet. First, the abs light is on and I have no speedometer. It has a u1041 code and a p052 code. The p code is for speed sensor A
Low circuit input or something. The U code is something about the EBCM loss of contact (the abs module won’t show up on my scan tool either btw). Very strange. It has 2 new speed sensors, by the way, and it is a 4wd truck.
also, in the driveway earlier, it did upshift out of first, but the wheels locked/skidded. Of course I let off the gas immediately. It was in 2nd, and coasting. I manually shifted to 1st, just to test, and it had engine braking. This is when I discovered my reverse works.
thoughts? Thanks!
09-26-2018, 03:23 PM
#7
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I fixed it. The intermediate sprag was backwards. I also removed the reverse checkball. If you dual feed your '80e, make SURE to remove that reverse checkball or it WILL NOT WORK!
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09-27-2018, 08:37 AM
#9
TECH Junkie
Thanks for posting results. P.s. you don't have to remove reverse checkball. That often makes reverse engagement too rough...especially in vehicles with raised line pressure. Best thing to do is just drill the reverse feed orifice slightly larger. It will give a smooth apply that's not too aggressive but not sluggish