 Donolie
"2nd Year" Gold Supporting Member
Posts: 150
Loc: Detroit
Reg: 03-17-08
|
05-15-12 02:27 AM - Post#2226030
Is this a TH400?
Is the tube next to the dipstick the vaccume that should go to the carb?
Also, while driving, the spedo is bouncing, say at 15 mph, between 10-20... Is this what I've heard graphite fixes?
Thanks,
Don
|
|
Allan In NE
Contributor
Posts: 903
Reg: 12-27-11
|
05-15-12 03:38 AM - Post#2226037
In response to Donolie
The metal part of the vacuum line should slip inside the modulator neck. Then, the rubber hose would be sealing the "connection" by being over the top. The way it is now, it is kinking that hose.
If you're gonna hook it to to carb, make darned sure it's not 'ported' vacuum.
Allan
| Lifelong GM automatic transmission specialist |
|
 Vaughn
"11th Year" Gold Supporting Member
Posts: 13554
Loc: Colorado Springs, CO
Reg: 08-08-04
|
05-15-12 12:06 PM - Post#2226207
In response to Allan In NE
On the speedo question - it depends on what you are hearing. If you hear a ringing noise coming from the speedo, this is a problem with the gauge - and the gauge needs to be rebuilt/repaired by a speedometer shop.
If you are hearing a "thwack" type of noise, this is the speedometer cable.
Graphite will never "fix" a speedometer cable - it might stop or slow down the problem for a while, but it isn't a permanent repair. Once you start hearing a speedometer cable, it means that strands of the cable have broken and are rubbing against the inner cable housing - that is why graphite will never fix the problem. The only real way to fix the problem is to replace the speedometer cable. Speedometer cables aren't very expensive, so it pays to fix it the right way.
|
Donolie
"2nd Year" Gold Supporting Member
Posts: 150
Loc: Detroit
Reg: 03-17-08
|
05-16-12 02:05 AM - Post#2226401
In response to Vaughn
Allan,
does that vacuum need to be connected? I read there is also a switch, that gets it's power from the radio or something? As it stands, the only thing connected to the carburetor is the EGR, fuel, and throttle cable. The brake booster is being powered from the Driver side breather (PCV valve). The Carburetor is a 4160 holly (600cfm, vacuum secondary 4barrel)
The radio is not hooked up, and the heater does not work. Not sure about the windshield wipers yet- not sure if this would affect the operation of the switch/modulator being connected...
If it's not in a ported line, what will this cause? On this carburator, I only see (Fuel inlet, Full manifold vacuum source, timed spark vacuum source, and PCV hose)
Thanks again,
Don
Edited by Donolie on 05-16-12 02:18 AM. Reason for edit: No reason given.
|
Allan In NE
Contributor
Posts: 903
Reg: 12-27-11
|
05-16-12 04:29 AM - Post#2226423
In response to Donolie
Yes,
It has to be hooked up to full manifold vacuum to allow the transmission to upshift.
The electrical connector activates a solenoid to force a downshift. Power source is not important, but it must be routed thru a throttle controlled switch.
Allan
| Lifelong GM automatic transmission specialist |
|
56sedandelivery
Valued Contributor
Posts: 2558
Age: 61
Loc: Everett, Wa.
Reg: 02-26-08
|
05-27-12 05:02 PM - Post#2230481
In response to Donolie
"Technically speaking", due to the deep pan, it's probably a TH475 (just the factory's heady duty version of a TH400. They also had straight cut planetary gears, so they tend to make more noise. Bigger trucks and motor home used them. Most of them would have "HD" cast on the top part of the bellhousing. Cases were also thicker in some places, and they used 6 lug torque converters. You can upgrade a TH400 with the internal parts of a TH475. Butch/56sedandelivery.
|
brendon13
Forum Newbie
Posts: 7
Age: 19
Reg: 12-20-11
|
06-08-12 08:14 AM - Post#2234714
In response to Allan In NE
allan, i need some help understanding whats wrong with my trans too
|
Allan In NE
Contributor
Posts: 903
Reg: 12-27-11
|
06-09-12 06:26 AM - Post#2235060
In response to brendon13
allan, i need some help understanding whats wrong with my trans too
Tell me what transmission and what your symptoms are and I'll see if I can head ya down the right path. 
Allan
| Lifelong GM automatic transmission specialist |
|
cloudmaster
Senior Member
Posts: 974
Loc: Arrowsmith, IL
Reg: 01-30-02
|
06-15-12 02:06 PM - Post#2237505
In response to Donolie
There's an electrical switch which is activated at full throttle (it's on the firewall and pushed by the gas pedal) on original TH400 trucks. The switch, when activated by full throttle, activates the kickdown (electrically doing what a TH350's kickdown cable does). It connects to a terminal on the driver's side of the transmission.
The transmission generally doesn't need connected to the radio.  But you would get power for the kickdown switch from the accessory lead, which would also power the radio.
'71 Malibu: 350/200-4R/3.73 Eaton posi
'75 Elky: 350HO/TH350/3.42 peg leg
'85 C20: 454/TH400/3.73 locker
'95 Caprice Wagon: LT1/4L60E/3.42 posi
'95 BMW 740i: untouched, but a V8
'04 Grand Marquis: 2V4.6/3" pipes/SCT flash |
Edited by cloudmaster on 06-15-12 02:07 PM. Reason for edit: No reason given.
|
|
Gain extra benefits by becoming a Supporting Member 
drtyler (4)
