Transmission Slipping?

[-Alero-]

mine also does this herky jerky heartbeat skip thing in the higher RPMs and i took it to a shop my dad takes his vette, and they kept my car for 2 weeks and then ended up saying this "your hitting your rev eliminator in your ECM and thats something we dont touch"

my car is under warrenty and they just dont feel like hooking up thier 9,000$ master OBD reader to my car because the warrenty company i have wont pay nearly enough to meet what they would normally qoute.

it took them 2 weeks to basically shoo me off to tell me they dont want to work on it............i argued with them for 30 minutes and said i dont have a ecm i have a pcm and there is no rev eliminator the redline on the car is 6,250! not 4,500 and they just tried to effing tell me my gauge needles are reading incorrectly.........god damn it! what a waste of time...so still no answer

[Midgear]

126k on my car with original fluid was a bad idea.. the crap looked like someone grinded down a block of aluminum and dumped it into chocolate milk.

or brown metallic paint.. either one- tranny was slipping alot, so 25 quarts of tranny fluid later- the tranny still slips a bit when I give it hell, but not near as much.

[zzyzzx]

Originally Posted by mitchell72

okay this may sound dumb but i have never had a car without a tranny dipstick

Automatic transmission = dipstick
Manual transmission = may or may not have a dipstick. You pull the speed sensor to get to the fluid.

The no dipstick method does not make any sense to me.

[Cliff8928]

Originally Posted by zzyzzx

Automatic transmission = dipstick
Manual transmission = may or may not have a dipstick. You pull the speed sensor to get to the fluid.

The no dipstick method does not make any sense to me.

On the manual, there is a fill plug and a drain plug.

the automatic has a fill and and a plug to check the level.

[Midgear]

Originally Posted by Cliff8928

On the manual, there is a fill plug and a drain plug.

the automatic has a fill and and a plug to check the level.

yar.. the alero doesn't have a dipstick-

[mitchell72]

i was having this problem also. took it to the shop and it ended up being a pressure control silinoyd (im sure thats not spelled right, but you get the idea) it lets enough pressure build up to change gears. driving with this bad for too long will cause the transmission to fail. ended up being around 600

[Justin081]

mine was taking kinda long to shift from 1st to 2nd like it wouldnt shift when it should it would take a few seconds then kick in. i got my fluid and filter changed and it was fine for a couple days and now it does it again. it seems like it does it more in the morning when its cold ... not as bad when warmed up. could this be because its low?

[undecided02]

just change em and see if that cures it. either way it couldnt make things worse

[zzyzzx]

If this car is anything like my Escort, slippage can be caused by:

1. Old fluid. It can get thicker with age and particularly on a cold start it can slip at first startup of the day and maybe while it's warming up

2. Clogged (or partially colgged) filter. Has the same effect as #1, since it prevents fluid from getting where it is supposed to.

3. Weak transmission oil pump. Also has the same effect as #1, since it prevents fluid from getting where it is supposed to. This can be tested via a gauge connected to a port on the transmission on my Escort, and presumably on most or all cars.

mitchell72's circumatances should be considered quite unique in that he was actually able to take his car someplace for a transmission repair as opposed to the usual complete rebuild that is the only thing that most places will do. I'll have to reasearch the whole pressure control solenoid thing, since it's probably worthwhile.

And any of you who have read enough of my posts should know that my Alero is a "new" car (~22,200 miles) and the bulk of my automotive experience is with Ford Escorts that I use as my commuter car, but most of the advice here is generic anyway. One important difference might be that the Escort has a TSB for a weak transmission oil pump (complete with parts kit ro upgrade an existing oil pump) and that IMO people are more willing to try things like rebuilding an Escort transmission by themselves (for obvious reasons).

[zzyzzx]

http://en.wikipedia.org/wiki/Transmission_control_unit

Pressure control solenoids
Modern electronic automatic transmissions are still fundamentally hydraulic. This requires precise pressure control. Older automatic transmission designs only use a single line pressure control solenoid which modifies pressure across the entire transmission. Newer automatic transmission designs often use many pressure control solenoids, and sometimes allow the shift solenoids themselves to provide precise pressure control during shifts by ramping the solenoid on and off. The shift pressure affects the shift quality (too high a pressure will result in rough shifting; too low a pressure will cause the clutches to overheat) and shift speed.

[zzyzzx]

YouTube video of someone changing their solenoid:
http://www.youtube.com/watch?v=JUSSj_2eHUY

Interesting but I'd like to see more on how to diagnose said solenoid.

In my Escort Factory service manual, it recommends the stall test then the pressure test that I mentioned before.

It would also be interesting to see how many of these solenoids that the ATX has.

[zzyzzx]

Also interesting reading:
http://autorepair.about.com/library/faqs/bl024g.htm

Interesting in that I had no idea that the transmission used the MAF sensor.