problems with kickdown shift RPM

[str12-340]

I have run into a problem that I've never seen on a torqueflite in 40 years. I installed a freshly rebuild 904 behind my small block with an A&A standard pattern valve body (which I have in 2 other cars). Car works fine in drive and delivers crisp "drive around" shifts, but when I floor it at 10-20 mph it kicks down, but only holds 1st gear to about 3500 rpms. I have tried adjusting the linkage , but with no improvements. Does anybody have any suggestions as to what is up? My other transmissions are set to hold 1st until 4500 rpms and I never had a problem like this before...

 

[Paul P&B Performance]

my guess since the vb works fine in other trans, it is the weights in the the tailshaft gov.paul

 

[pishta]

I agree, Mopar action did an article on this years ago. Like a rebuild with a 'hemi' 5.0 band lever and higher shifting governor weights in the tailshaft. Paul could probably tell you the correct part number.

 

[fishy68]

The governor weight and spring determines the maximum shift rpm. No matter how you adjust the throttle pressure linkage the governor over rides it when it reaches it's determined rpm. You just need a higher RPM governor shift package. Here's a link to the governor package page on A&A. You'll see they come in several different RPM packages. You'll see it's listed under a 727 trans. but their the same until you get into the late 80's-90's diesel stuff

http://www.aandatrans.com/Departments/Chrysler-727-Trans/Governor-Kits.aspx

 

[str12-340]

Thanks so much for the replys and all the good technical information. I'll get a new governor from A&A and give it a whirl!!!

Can anybody suggest where I can get some good instructions on replacing the governor? Other than changing converters or installing a valve body, I've always left internal trans stuff to a shop.

 

[fishy68]

Jack the car up and secure on jack stands making sure it's a few inches higher in the back than the front so the atf runs into the main case.

Remove the driveshaft.

Unbolt and remove the cross member. You will need to support the trans from the pan (use a large flat board to support the whole area of the pan) so it doesn't drop down. It doesn't take much to support it.

Unscrew the speedometer cable

Directly under where the trans mount bolts onto on the bottom of the extension housing you'll see 2 large Phillips head screws holding a piece of metal about 1/2" wide by 3" long. Remove it. There's be a cork gasket underneath so be careful not to damage it removing it or you'll be replacing it.

Remove the bolts holding the extension housing onto the main case.

Under that piece of metal you removed you'll see the ends of a very large snap ring. You need to get that snap ring to let go of the rear bearing. I use a set of very large inside flat bill type snap ring pliers to spread the snap ring and then you pull the extension housing off. NOTE: sometimes that snap ring can be a bugger to get spread far enough if you don't have snap ring pliers big enough.

Once you have the ext housing off you'll see the governor riding on the output shaft. On each side there's a snap ring. You only need to take one off to pull the pin that holds the governor assy in place. I prefer to take the snap ring off the side the governor comes out of cause the snap ring is small and the opening on the other side is so small it's not easy to get the snap ring back on. Swap the governor and assemble in reverse order. I apply thread sealant to the extension housing bolts and torque them to 30 ft. lbs.

Here are some pics of a 904 I'm currently rebuilding.

1st picture is a pile of parts and the output shaft that has the governor and bearing on it.

2nd picture you can see the metal plate you need to remove

3rd pic is looking down into the black hole at the snap ring. Not easy to see the ends of it but that where it's at.

BTW: it might not be a bad idea to purchase a new extension housing to main case gasket cause sometimes they stick and tear when you take them apart.

 

[str12-340]

WOW, I can't thank you enough!!! I'll print this out and work off of it when the parts arrive!

 

[fishy68]

Glad to help. Let us know how it turns out

 

[oldkimmer]

........to start off is this the same car and same kd linkage u have always used with the other trannys? is this the 3 piece rod system with the pivots?.......actually the gov weights may not at all be the problem[but very well may be] as I've run into this problem a few times..........if u do not have the right [matched] kd linkage pieces u will not be able to adjust the kd for later shifts no matter where u have it adjusted because it works on a ratio ...........post some pics of the linkage please...........kim........

 

[oldkimmer]

..............OK , I re read ur post so it seems ur talking that u have 2 other cars with this vb..........this is the 3rd....r u using 2bbl linkage on a 4bbl.........post some pics and i'll try help u understand what I'm saying.............kim.........

 

[AJ/FormS]

Id recommend a quick check of the throttle pressure valve, to make sure the dang thing is engaged inside the trans.This can be done under the hood but I recommend to do it at the trans. Just remove the KD rod at the lever. Then push the lever all the way to the back as far as it will go.You should feel spring resistance and the spring should return the lever to the front.Total travel, Im guessing should be about 2 plus inches as measured at the rod-hole. Then reinstall the KD rod and make sure the carb is pushing that lever all the way back,as well.
Its also possible that a wrong spring was installed there. Some of those springs in the kit are very similar in sizing.I know they are color coded, but still its possible. I wish there was a detailed spring description including; wire size,number of coils, left or right wound,length and diameter, and color,included in the kits.But,Alas,Ive never come accross one. I suppose its also possible that someone forgot to crank up the line pressure during the kit install.
Governor weights/springs also need to be related to the rear gear ratios.