|
Register or Log In To remove these advertisements. |
|
|
|
|||||||
 |
|
|
Thread Tools | Display Modes |
02-28-2015, 09:22 AM
|
#1 |
|
Registered User
Join Date: Nov 2009
Location: Lake Jackson,Texas
Posts: 126
|
What is the other relay for?
Does anyone know why some 87's have two relays on the firewall. I know one is for the fuel pump, but what is the other one for?
Thanks
__________________
Tommy 1 Pt. 3:21 '72 C10 LWB 402 |
|
|
|
02-28-2015, 11:13 PM
|
#2 |
|
Registered User
Join Date: Dec 2013
Location: Humble, Texas
Posts: 185
|
Re: What is the other relay for?
If it has an M40 trans it's a downshift relay.
__________________
I know the "VOICES" aren't real but they have some great ideas. 1978 GMC Sierra Classic C25 1983 Datsun 280ZX Turbo 1997 Chevy Cheyenne K2500 1999 Polaris Sport 400 |
|
|
|
|
03-01-2015, 08:25 AM
|
#3 |
|
Registered User
Join Date: Nov 2009
Location: Lake Jackson,Texas
Posts: 126
|
Re: What is the other relay for?
Thanks. I've be a chevy guy for a long time and had never heard of M40. Learn something new everyday.
__________________
Tommy 1 Pt. 3:21 '72 C10 LWB 402 |
|
|
|
|
03-01-2015, 11:31 AM
|
#4 |
|
Registered User
Join Date: Jan 2009
Location: Southern Md
Posts: 228
|
Re: What is the other relay for?
M40 is the RPO code for the TH400 transmission.
__________________
04 Yukon XL 2500 w/ Quadrasteer  61 Chevy C60, 261 inline six 86 Chevy C20 2wd, Banks 6.2 05 GMC Sierra 2500hd Duramax |
|
|
|
|
03-01-2015, 12:54 PM
|
#5 |
|
Registered User
Join Date: Nov 2009
Location: Lake Jackson,Texas
Posts: 126
|
Re: What is the other relay for?
I'm surprised to see a TH400 in a shortbed 1/2 ton. Seems overkill.
__________________
Tommy 1 Pt. 3:21 '72 C10 LWB 402 |
|
|
|
|
03-01-2015, 07:29 PM
|
#6 |
|
Registered User
Join Date: Nov 2009
Location: Sherman, ME
Posts: 2,366
|
Re: What is the other relay for?
Yeah, I've seen a few 87 1/2 tons with a TH400 behind a 305. Definitely overkill, but I think TH350's had been phased out by 1987, leaving the TH400 as the only non-overdrive automatic available.
|
|
|
|
|
| Bookmarks |
|
|
Linear Mode
