Slipping trans?

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cinimod2

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Alright I have a automatic a904 trans bolted to a 318 small block. The trouble I'm having is that whenever I come to a complete stop at a stoplight or stop sign and press the gas pedal sometimes the engine will rev up then kick into gear. Now does this mean that my trans is slipping or could it be that the kickdown linkage needs to be adjusted.
Any help would be appreciated
Thanks in advanced dom
 
have you had this ride for awhile? did it just start or has it always been. and last but least have you done anything (trans service or carb swap)? usually you can blame the kickdown linkage for just that- kicking down a gear under throttle issues (too early too late ect). assuming proper fluid level and kickdown adjustment I would suggest dropping the pan for service and check (replace) filter (to confirm it's not loose) and look in the pan for excessive amounts of fluff. (there will always be some). also if there is no magnet I would put one in the pan (can't hurt).
 
ive had it for 3 or 4 months now. its always been like this. i havent done any trans service but the carb was swapped over to a edlebrock 4 barrel before i got it.
I guess ill have to drop the pan and check it out this weekend.
Thanks Dom.
 
If your car neutrals on a hard turn and then kicks back in drive, I would say it is low on fluid. If not, it is more likely to be internal' Maybe lip seals or cracked apply piston.
 
Nice call.
When they get worn and old they don't reach the sealing surface unless you give it gas and this raises the trans pump flow.
The confirmation would be that it's worse when it's cold out.

j5dart said:
Maybe lip seals QUOTE]
Click to expand...
 
If a worn band, I think it would affect both 1st and reverse. However, even then it may not be the band, but the servo piston that applies the band. One piston is known to often **** in its bore (forgot which) and there is an inexpensive after-market upgrade. I think you can get at all without removing the valve body, but you do have to drop the pan. Get at least a shop manual first and maybe a trans manual. You can easily apply air to test the pistons if you have an air compressor, if you remove the valve body.

If it is the lip seal that others mention, that requires removal and rebuild. I wonder if it could be symptoms of a worn front pump. That, and many other things can be tested by measuring pressures on the ports outside the tranny. You might do that first or have an experienced shop do so before you pull the pan.
 
Could be all of the above.
First- with the engine hot idling in neutral pull the tranny dip stick and check the level. Also look at the oil is it a nice red or dark almost brown, smell it, is it burnt.
Second- Check that the kickdown linkage is adjusted properly, kickdown lever on tranny should be all the way forward at the same time carb is wide open.
Third- if everything looks and smells good drop the pan and check for everything from bronze to steel to rubber bits fileings and drop the filter and make sure its clean.

Let us know what you find.
 
Sounds like seals to me.

Worn or mis-adjusted bands won't cause it in breakaway drive because no band is applied in breakaway drive. Only in manual low, second gear, or reverse is a band or band apply servo in use.

The throttle pressure linkage adjustment will not cause this problem either.

Sounds like it's just tired and needs rebuilt.
 
The pump would be more noticeable in lo or reverse since they run on much higher pressure. the servoes used to get cocked in the case after a rebuild. it would give you a bind up going forward because the lo reverse band would be locked on. i would say both bonds and the pump could be ruled out. more than likely forward drum issue.
 
j5dart said:
more than likely forward drum issue.
Click to expand...

Which is the REAR drum of the 2 drums ,and trans will have to come out to fix it.

As someone said check the fluid first , then make sure the throttle valve linkage , (KICKDOWN) is set up properly.
 
Or "direct drum" is the one with the input shaft on it.
The order of removal would be pump, front drum, and then the direct drum.
Pull the pump, remove the second gear band, then lift both drums out by the shaft.
There are instructional video's on the internet.

JohnRR said:
Which is the REAR drum of the 2 drums ,and trans will have to come out to fix it.

As someone said check the fluid first , then make sure the throttle valve linkage , (KICKDOWN) is set up properly.
Click to expand...
 
demon seed said:
Could be all of the above.
First- with the engine hot idling in neutral pull the tranny dip stick and check the level. Also look at the oil is it a nice red or dark almost brown, smell it, is it burnt.
Second- Check that the kickdown linkage is adjusted properly, kickdown lever on tranny should be all the way forward at the same time carb is wide open.
Third- if everything looks and smells good drop the pan and check for everything from bronze to steel to rubber bits fileings and drop the filter and make sure its clean.

Let us know what you find.
Click to expand...
The kickdown lever should be all the way REARWARD when the carb is wide open. First check the fluid level and condition as demon seed outlined. Next, I would do a full pressure test but more than likely, you're going to have to pull the tranny and pull it apart to find the problem. If you have to go that far, you may as well rebuild it.
 
Quote: The kickdown lever should be all the way REARWARD when the carb is wide open.

Ya I had it bass ackwards.:glasses7:
 
If it has done this for months- rebuild time. too much wear, and pieces of crap in it.
 
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