tds

When I do a hard acceleration (mash the gas pedal to the floor) my transmission will not down shift. Any ideas other than taking it to a transmission shop?

Thanks,

Tom Severski
832-594-9541

Professur

but it shifts normally through all the gears when you're gentle? No bogging or sputtering?

tds

It shifts normally through all the gears when I'm gentle. All upshifts are good under normal acceleration. Upshift from 1-2 is harsh when I'm under moderate acceleration.

Professur

http://www.bdub.net/manuals/TH425_tr...oting_1969.pdf

waterzap

There is something on the carb that downshifts. Not necessarily on the transmission.
Could just be the linkage thats broken

waterzap

Love that manual..thanks

tds

Just had the carb rebuilt - they told me transmission was not downshifting (I already knew that) and offered to diagnose the probem for $500. Since they just rebuilt the carb, I hope that is not the problem!

waterzap

$500 is steep. Could be something as simple as a vacuum leak. Or could be the transmission and everything in between. Friend has a 75 Eldorado that did not downshift. He was missing a part next to the carb. Dont know what it was, but cost him $20 in the end

waterzap

They also explain it all here

http://forums.cadillaclasalleclub.or...=125550.5;wap2

tds

Thanks for the information. I thought $500 was way high to just diagnose the problem, espically after I just paid them $600 to rebuild the carb! Think it might be time to find a new mechanic!

joe_padavano

Well, just off the top of my head, how about testing the kickdown solenoid and switch? The solenoid is internal to the trans and opens a valve to activate the kickdown function when 12V is applied to it. Simply applying 12V to the terminal on the side of the trans case will cause the solenoid to click, which you can hear without taking the trans apart. If it clicks, the solenoid is good and the external wiring and switch need to be tested. If it doesn't click, drop the pan and replace the solenoid.

By the way, this is about a 30 minute diagnostic job, so your oh-so-helpful carb shop is making $1,000 an hour. Find a new mechanic...

waterzap

Carb rebuilding serivice is around $300 - $400
Can get it all over the web

http://www.thecarburetorstore.com/servlet/Detail?no=28

http://www.quadrajetcarburetors.com/...g-service.html

joe_padavano

I'm not sure how this relates to fixing the trans, but if you are referring to my $1,000 an hour comment, that's based on the quote of $500 to diagnose the downshift problem, which should take 30 minutes. Do the math. It's unrelated to carb rebuilding.

tds

Joe,

Thanks for the advise.

Concerning the carb work, the guy has a good reputation, and he did the removal, replacement, and adjustments. No real complaints about the carb! Just trying to get the tranny to down shift!


Thanks,

Tom

joe_padavano

I'm sure he's a great carb rebuilder, but I wouldn't hire a plumber to rewire my house. Just sayin'...