Transmission Won't Shift Up in D
Thread Starter
|
Cross-Country
Joined: Apr 2026
Posts: 54
Likes: 10
Transmission Won't Shift Up in D
'88 E350 with C6 with 87k miles.
My transmission had a bad leak at the speedometer cable bullet was leaking a lot of fluid. I replaced the bullet. During the job, a significant amount of ATF flowed out of the hole where the bullet went into. I only had one quart to refill so I did that thinking that's all I needed. Stupid me. After putting in that one quart, I then drove the van about 1/2 a block to a level parking lot and bring the transmission up to temp before I checked the fluid again as I didn't want to overfill. It was short another two quarts! After topping up the fluid, I drove it around and the transmission refused to shift up from 1st while in D. It will shift to 2nd if I put the shifter in "2" from D. It will shift down to 1st if I put it back in D. I checked and re-checked the fluid when at idle when all is at operating temp and confirmed it is full. I checked the Vacuum Modulator by pulling the vacuum hose and it's dry so no leaky Modulator.
Is it possible the transmission running so low on fluid introduced sediments into the governor and now that won't let my transmission shift up automatically? Would appreciate any wisdom or advice. Am I doomed to rebuild this C6? It only has 87k miles and it's never towed anything and it was shifting perfectly right up this point.
My transmission had a bad leak at the speedometer cable bullet was leaking a lot of fluid. I replaced the bullet. During the job, a significant amount of ATF flowed out of the hole where the bullet went into. I only had one quart to refill so I did that thinking that's all I needed. Stupid me. After putting in that one quart, I then drove the van about 1/2 a block to a level parking lot and bring the transmission up to temp before I checked the fluid again as I didn't want to overfill. It was short another two quarts! After topping up the fluid, I drove it around and the transmission refused to shift up from 1st while in D. It will shift to 2nd if I put the shifter in "2" from D. It will shift down to 1st if I put it back in D. I checked and re-checked the fluid when at idle when all is at operating temp and confirmed it is full. I checked the Vacuum Modulator by pulling the vacuum hose and it's dry so no leaky Modulator.
Is it possible the transmission running so low on fluid introduced sediments into the governor and now that won't let my transmission shift up automatically? Would appreciate any wisdom or advice. Am I doomed to rebuild this C6? It only has 87k miles and it's never towed anything and it was shifting perfectly right up this point.
Lead Driver
Joined: May 2004
Posts: 5,050
Likes: 138
From: Maryville
'88 E350 with C6 with 87k miles.
My transmission had a bad leak at the speedometer cable bullet was leaking a lot of fluid. I replaced the bullet. During the job, a significant amount of ATF flowed out of the hole where the bullet went into. I only had one quart to refill so I did that thinking that's all I needed. Stupid me. After putting in that one quart, I then drove the van about 1/2 a block to a level parking lot and bring the transmission up to temp before I checked the fluid again as I didn't want to overfill. It was short another two quarts! After topping up the fluid, I drove it around and the transmission refused to shift up from 1st while in D. It will shift to 2nd if I put the shifter in "2" from D. It will shift down to 1st if I put it back in D. I checked and re-checked the fluid when at idle when all is at operating temp and confirmed it is full. I checked the Vacuum Modulator by pulling the vacuum hose and it's dry so no leaky Modulator.
Is it possible the transmission running so low on fluid introduced sediments into the governor and now that won't let my transmission shift up automatically? Would appreciate any wisdom or advice. Am I doomed to rebuild this C6? It only has 87k miles and it's never towed anything and it was shifting perfectly right up this point.
My transmission had a bad leak at the speedometer cable bullet was leaking a lot of fluid. I replaced the bullet. During the job, a significant amount of ATF flowed out of the hole where the bullet went into. I only had one quart to refill so I did that thinking that's all I needed. Stupid me. After putting in that one quart, I then drove the van about 1/2 a block to a level parking lot and bring the transmission up to temp before I checked the fluid again as I didn't want to overfill. It was short another two quarts! After topping up the fluid, I drove it around and the transmission refused to shift up from 1st while in D. It will shift to 2nd if I put the shifter in "2" from D. It will shift down to 1st if I put it back in D. I checked and re-checked the fluid when at idle when all is at operating temp and confirmed it is full. I checked the Vacuum Modulator by pulling the vacuum hose and it's dry so no leaky Modulator.
Is it possible the transmission running so low on fluid introduced sediments into the governor and now that won't let my transmission shift up automatically? Would appreciate any wisdom or advice. Am I doomed to rebuild this C6? It only has 87k miles and it's never towed anything and it was shifting perfectly right up this point.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,740
Likes: 2,669
From: SE Florida
That and the governor are what controls the shifts. Since it shifts manually, I suspect the governor over the valve body, but it could be either.
Thread
Thread Starter
Forum
Replies
Last Post
truckinup
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
8
May 24, 2012 11:35 PM
TheKirbyMan
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
18
Jan 10, 2012 01:04 AM
Sycostang67
Clutch, Transmission, Differential, Axle & Transfer Case
6
Nov 4, 2009 10:17 AM
79 E350 rescue
Clutch, Transmission, Differential, Axle & Transfer Case
1
Dec 4, 2003 09:24 PM
