Transmission Fluid for 1967 Cadillac Seville

[BKW]

I apologize in advance because this is probably a very dumb question but I promise you I,ve been looking. Where do you add transmission fluid to a 676 DeVille? I can locate the dipstick, but the the cap where I add transmission fluid.

Thanks in advance for the help.

[Eric DeVirgilis CLC# 8621]

Transmission fluid is added at the actual dipstick tube itself.

[BKW]

Thank you for that, very very, very helpful. Oh and I'm serious, not being snarky in the least. I was literally trying to figure out what would happen if I poured transmission fluid down that spout lol.

[bcroe]

Thank you for that, very very, very helpful. Oh and I'm serious, not being snarky in the least. I was literally trying to figure out what would happen if I poured transmission fluid down that spout lol.

That is a 50 year old switch pitch transmission.  If its never been apart, getting
a new set of rubber clutch piston seals installed might avoid a serious breakdown
later.  And changing the filter sometimes is good.  Bruce Roe

[BKW]

That is a 50 year old switch pitch transmission.  If its never been apart, getting
a new set of rubber clutch piston seals installed might avoid a serious breakdown
later.  And changing the filter sometimes is good.  Bruce Roe

Actually right now I'm just doing some patch work. I'm planning, within the next 60 days to rebuild or replace the transmission. I'm not a stickler for keeping the car original (hope that doesn't offend anyone). I want a safe drivable car for weekends and goofing off.

This is certainly a scope of work beyond my abilities. How hard will it be to find a suitable mechanic (there is a Cadillac dealer near me and there are a couple of guys there who know older cars). If I can't find a mechanic how hard is it to get a suitable replacement transmission?

[The Tassie Devil(le)]

These transmissions are virtually plain old TH400's, the same used by All GM Brands, and therefore any Transmission Shop should be able to do it blindfolded.

You will probably get a better deal at a shop that specialises in Transmissions, as they will have all the special tools for it, and will be already set up to tackle such tasks.   A basic Mechanic will have to take time to clear up a place to work on it, and won't necessarily have the area to fully clean and assemble the item.

Bruce.

[savemy67]

Hello Bryan,

I think it will be easier to have your transmission rebuilt than it will be to find an already rebuilt replacement.  As mentioned, a transmission shop is probably a better choice than the dealer, as the TH400 in your '67 has not been manufactured for decades (although the Automatic Transmission Service Group - ATSG - still publishes a rebuild manual for the TH400, also known as a 3L80) and a dealer is unlikely to be staffed and equipped for a transmission that old.

As you indicated that you will not be rebuilding the transmission yourself, a local shop will probably have the means to remove and replace the transmission.  This is a chore in and of itself, and one that you might have to arrange separately if you purchased a rebuilt unit.

Where do you live?  If possible, try to find a local shop that can demonstrate that it has experience rebuilding older transmissions.  Unfortunately, in order for a shop to provide some sort of warranty, the shop may want to replace parts that may in fact not need replacing, like the torque converter.  For '65, '66, and '67, the TH400 used a variable pitch torque converter, and you would not want a shop to replace this part, so be sure to have that discussion with any shop you are considering.  And bring your checkbook.

To read about the rebuilding of my '67's TH400, go here and scroll down to reply #88:

http://forums.cadillaclasalleclub.org/index.php?topic=133691.80

Good luck with your undertaking.

Respectfully submitted,
Christopher Winter

[bcroe]

My first attempt at rebuilding a TH400 32 years ago, was very much as described by
SAVEMY67.  The new place has a lift and a trans jack, even at my leisurely pace
removal takes less than an hour. 

If your trans isn't much worn, hard parts in good shape, a simple sealing ring kit
might be all it needs to reliable for a long time.  I have used TRANSTAR 34002A   
K34900D   $38.  And new set of 3 Torrington roller thrust bearings. 

I have had plenty of trouble with trans shops; that's part of why I learned to
rebuild my own TH400/TH425 trans.  Other reasons are to build something
better than you can buy, and to save a fortune. 

A shop will want to spend the max $ on a full rebuild, change everything in
sight, which you don't necessarily need.  Clutches may be OK; steels and
bands almost always are.  Check bushings, most may be just fine.  The shop
won't have a SWitch Pitch torque converter, so they will just throw it away
and put in a later fixed pitch.  DON'T LET THAT HAPPEN.  Your SWP converter
will creep less idling, give better performance, shift smoother, and help gas
mileage.  Some of this depends on the special control switch working correctly. 
Do some internet research: to get a real improvement, replace the switch with
a SWP controller.  Bruce Roe

[BKW]

Thanks guys, really appreciate the advice. Once she's got fluid in her she runs right as rain tho shoe starts a little rough on her first start of the day. I'll run that down a little later. I've got appointments tomorrow to check with trans' shops and see what gives. I'll keep you all informed here, tho I suspect it will be about 60 days before I try getting this done just due to the cost.