C6 won't downshift
Thread Starter
|
Posting Guru
Joined: Nov 2009
Posts: 1,219
Likes: 4
From: Norton, MA
C6 won't downshift
Pretty basic problem, my C6 won't shift down at a stop. I can drop it down to 1st, and it shifts up to 2 and 3 fine, but I'm waaay up high in 3 every time I take off from a stop.
The kickdown linkage isn't hooked up, but the vac modulator is.
What are all the possible causes of this problem?
AleX
The kickdown linkage isn't hooked up, but the vac modulator is.
What are all the possible causes of this problem?
AleX
Thread Starter
|
Posting Guru
Joined: Nov 2009
Posts: 1,219
Likes: 4
From: Norton, MA
Well, I guess I don't know that the modulator is functioning, but I can tell you that it's new, within about 6 months (when I completely overhauled the trans), and that it worked fine before i took the truck off the road at the end of summer to replace the engine. Also, the engine pulls about 21 (mm in Hg???, whatever the units on a vacuum guage are) at idle.
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 59
Trending Topics
Thread Starter
|
Posting Guru
Joined: Nov 2009
Posts: 1,219
Likes: 4
From: Norton, MA
Just back from a second test drive. Let the whole truck get nice n cold for this one, to see if that made any difference, and no, it still didn't downshift, not even the first stop sign, about a half a mile down my street.
Going to pop off the hose now and check for vac at the mod., and see if there's any fluid flowing through the mod. at the same time.
If I come to the conclusion that this is a governor problem, I can't deal with that right now timewise. Am I doing any damage whatsoever by shifting it full manual?
Going to pop off the hose now and check for vac at the mod., and see if there's any fluid flowing through the mod. at the same time.
If I come to the conclusion that this is a governor problem, I can't deal with that right now timewise. Am I doing any damage whatsoever by shifting it full manual?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 59
Be sure to check the condition and color of the transmission fluid. It can tell you a lot about what's going on, specifically if the clutches are burning up.
I would lean towards the governor, and then the valve body. I highly doubt you're problem is the modulator. However, it would nice if it is, cheap and easy to fix.
Josh
I would lean towards the governor, and then the valve body. I highly doubt you're problem is the modulator. However, it would nice if it is, cheap and easy to fix.
Josh
Posting Guru
Joined: Oct 2008
Posts: 1,038
Likes: 11
From: Southern AB
I had the same issue so what I did was pull the tail shaft(about 4 quarts in here) and take the govenor off and cleaned the piston up with some very fine emery cloth and pour some fresh transmission fluid in it and bolted it back on. What happens is all the junk you would see in your pan the fine metal gets into you govenor and then the piston won't move proper causing it to not downshift do to the piston being sticky takes about 2 hours at the most to clean up. I would also drop the pan and filer and change the fluid and put some lucas trans conditioner in it and with in about 100 miles she will be shifting nice.
Can you hurt it if you continue to drive it? Possibly but as long as you shift manually you should be fine you just don't want to be taking off in second all time as it will heat up your transmission. Also you can rent a video on youtube made by Ken Collins at bad shoe productions which will show you how to do a full rebuild on the C-6, I purchased it recently and it is a great video.
D
Can you hurt it if you continue to drive it? Possibly but as long as you shift manually you should be fine you just don't want to be taking off in second all time as it will heat up your transmission. Also you can rent a video on youtube made by Ken Collins at bad shoe productions which will show you how to do a full rebuild on the C-6, I purchased it recently and it is a great video.
D
Last edited by dman2008; Jan 12, 2011 at 08:47 AM. Reason: spelling
Thread Starter
|
Posting Guru
Joined: Nov 2009
Posts: 1,219
Likes: 4
From: Norton, MA
Ya, I have the BadShoe video, liked it very much, and I have a 4X4, but that is true, I could access the governor fairly easily actually, by popping of the T case. I'll think about that.
AleX
AleX
Mountain Pass
Joined: Dec 2018
Posts: 119
Likes: 2
From: Fayetteville, NC
I'm having the same issue. I thought it was the modulator, replaced it.. adjusted it several times,,it's not solving my issue... From what i'm reading, I think i'll have to take it to the shop.
I don't think I can handle such a job..for it to down shift while driving I gotta floor it or manually down shift it.
If i am at a dead stop it'll down shift.. At times when i let off the brake, I feel a thump like slop in the steering / front end, But i think that it's down shifting once i start to roll a tad.
whatchy'all think ??
I don't think I can handle such a job..for it to down shift while driving I gotta floor it or manually down shift it.
If i am at a dead stop it'll down shift.. At times when i let off the brake, I feel a thump like slop in the steering / front end, But i think that it's down shifting once i start to roll a tad.
whatchy'all think ??
Thread
Thread Starter
Forum
Replies
Last Post
SullyMtMan
Clutch, Transmission, Differential, Axle & Transfer Case
2
Nov 15, 2021 03:25 PM
dustyroad
Clutch, Transmission, Differential, Axle & Transfer Case
20
May 8, 2019 07:36 PM
Chris Ko
Clutch, Transmission, Differential, Axle & Transfer Case
4
May 13, 2017 10:23 PM
JoeF150
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
3
Feb 27, 2003 02:56 PM
