Have a d6m (3wn03292) has started slipping in 1st gear in reverse or forward , 2nd and 3rd gears in forward and reverse are fine. Any guidance would be appreciated.
Drain the transmission oil and take a look in the suction screen. Post photos of what you find.
I pulled transmission today and replace a speed sensor it was coding up for , ran for a hour no issues , then started acting up again, no codes, medium throttle in first fwd or reverse it will grunt like something is dragging and every now and then just plain stop you in your tracks like you set the park brake, swapped brake solenoids still same thing . No issue in 2nd or 3rd
And what did the suction screen look like?
I’ll be honest I didn’t see your reply till just now so i haven’t pulled it , but oil looked brand new and nothing out of ordinary looking when I pulled transmission to replace speed sensor . It almost feels like something is binding up or it’s fighting it’s self , when you locks up you can go to 2nd gear and it takes off like a brand new machine
What Active Codes do you have.? I can't believe that you pulled the transmisson and never looked at the suction screen. That's Diagnostics 101.
Had complete service done including transmission less than 50 hrs ago so really didn’t think about it, considering it was only doing it in first gear and not all gears , I had to pull transmission to replace speed sensor that was bad . Only took about 45 min to a hour to get it slid out
No codes now
Pull the cab floor plate up. When the transmission acts up, put the engine at Low Idle RPM and select 1st gear. does the drive shaft between the torque converter and the transmission stop turning like someone stuck a bar in the U-joint.? Maybe also put a pressure gauge on the test point for the 1st speed clutch, run it into the cab so you can watch the needle.
I will check but here is another factor , if you use decel pedal when it’s acting up and decel all the way to idle it frees up and starts moving, like something releases . I read somewhere where it could be two speeds trying to engage , I changed #2 modulating valve because the plastic connector was broke as well , I was gunna try and check pressures tomorrow .
No 5 reads 300 cold , after warming up drops to 200 then when it stalling it goes down to 50 or so bouncing around , hit decel and it goes back up to 200
2nd and 3rd are 400psi
Is that with the transmission still in 1st speed.?
Yup
I found problem , as well as burnt clutches
I don’t know got attach photo it’s saying too big
The maximum size for a photo is 10Mb IIRC. If your file is larger than that then you'll have to compress it before it will upload.
I refer you back to my Post #2 above - "Drain the transmission oil and take a look in the suction screen. Post photos of what you find."
One friction was gone but the culprit was the two seals that on the shaft that supply oil to the 1st gear clutch pack, one was there and intact but the second one was tore up . All in all not too bad to do
I would replace the Belleville springs in clutch 5 while you are in there.They are notorious for breaking. New part numbers are improved. Have scene several fail. P/N 9G1234
9G1234 ID Good bs Bad Springs
(EDIT) Good vs Bad